Diabetic Nephropathy (Diabetic Kidney Disease)

1. Topic Overview (Clinical Overview)

Summary

Diabetic Nephropathy (DN), now comprehensively termed Diabetic Kidney Disease (DKD), represents the leading cause of Chronic Kidney Disease (CKD) and End-Stage Renal Disease (ESRD) globally, accounting for approximately 40-50% of incident ESRD cases. [1,2] It is a progressive microvascular complication of diabetes mellitus characterised by albuminuria (initially microalbuminuria, progressing to macroalbuminuria), declining glomerular filtration rate (GFR), and characteristic histopathological changes including mesangial expansion, glomerular basement membrane (GBM) thickening, and the pathognomonic Kimmelstiel-Wilson nodules (nodular glomerulosclerosis). [3]

The contemporary management paradigm has been revolutionised by landmark clinical trials demonstrating that SGLT-2 inhibitors (Dapagliflozin, Empagliflozin, Canagliflozin) provide substantial renoprotection independent of glycaemic control, with the DAPA-CKD trial showing a 39% relative risk reduction in the composite outcome of sustained eGFR decline, ESRD, or renal/cardiovascular death. [4] This complements the established renoprotective effects of ACE inhibitors (ACEi) or Angiotensin Receptor Blockers (ARB), which reduce intraglomerular pressure and proteinuria. [5,6]

Early detection via annual Albumin:Creatinine Ratio (ACR) screening and serum creatinine-based eGFR calculation is essential, as interventions at the microalbuminuria stage can slow or potentially reverse progression. [7] DKD almost invariably co-exists with diabetic retinopathy in Type 1 Diabetes – the absence of retinopathy in the presence of significant proteinuria should prompt consideration of alternative renal pathologies and possible renal biopsy. [8]

Key Facts

• Epidemiology: Affects ~40% of T1DM and 20-40% of T2DM patients; leading cause of ESRD worldwide requiring dialysis or transplantation. [1,2]
• Natural History: Hyperfiltration → Microalbuminuria (ACR 3-30 mg/mmol) → Macroalbuminuria (ACR > 30 mg/mmol) → Progressive GFR decline → ESRD (eGFR less than 15 mL/min/1.73m²). [9]
• Pathognomonic Histology: Kimmelstiel-Wilson nodules (nodular glomerulosclerosis), mesangial expansion, GBM thickening, arteriolar hyalinosis. [3]
• Screening Strategy: Annual ACR (urine albumin:creatinine ratio) + serum creatinine for eGFR in all diabetic patients from diagnosis (T2DM) or 5 years post-diagnosis (T1DM). [10]
• Therapeutic Pillars: (1) Glycaemic control (HbA1c less than 53 mmol/mol), (2) BP control (less than 130/80 mmHg) with ACEi/ARB, (3) SGLT-2 inhibitors, (4) Cardiovascular risk management, (5) Emerging: Finerenone (non-steroidal MRA). [4,11,12]
• Retinopathy Association: > 90% of T1DM patients with DKD have concurrent diabetic retinopathy; absence warrants investigation for non-diabetic kidney disease. [8]

Clinical Pearls

"Retinopathy is the Sentinel of Nephropathy": In Type 1 Diabetes, the absence of retinopathy in patients with proteinuria should raise suspicion for alternative renal diagnoses (IgA nephropathy, FSGS, membranous nephropathy). Consider renal biopsy.

"SGLT-2 Inhibitors are First-Line Renoprotection": Dapagliflozin and Empagliflozin reduce CKD progression by ~40% independent of glucose control. Initiate early (eGFR > 20-25) and continue despite declining eGFR for renoprotection. [4,13]

"ACEi/ARB for ALL Diabetics with Albuminuria": Even in normotensive patients, ACEi/ARB provide renoprotection through reduction of intraglomerular pressure and antiproteinuric effects. Target dose maximisation rather than BP alone. [5,6]

"Microalbuminuria is Reversible": Early detection and intensive multi-factorial intervention (glycaemic control, BP control, ACEi/ARB) can reverse microalbuminuria and prevent progression. [7]

"Monitor eGFR Slope": Annual decline > 5 mL/min/1.73m²/year indicates rapid progression requiring urgent nephrology input and escalation of therapy. [14]

"Avoid Nephrotoxins Meticulously": NSAIDs, aminoglycosides, and iodinated contrast (if possible) accelerate DKD progression. Pre-hydration and acetylcysteine for essential contrast studies.

Why This Matters Clinically

DKD is preventable, detectable early, and amenable to intervention. The advent of SGLT-2 inhibitors represents a paradigm shift – we now have robust evidence that progression to ESRD can be substantially slowed. However, this requires systematic annual screening, prompt initiation of renoprotective therapies, and aggressive cardiovascular risk management. Every diabetic patient needs kidney screening; every patient with DKD deserves comprehensive, evidence-based care.

---

2. Epidemiology

Global Burden

Diabetic Kidney Disease is the leading cause of ESRD globally, accounting for:

• 40-50% of incident ESRD in developed nations (USA, UK, Europe). [1,2]
• 25-45% of prevalent dialysis patients worldwide. [2]
• Diabetic ESRD incidence has increased 3-fold over the past 30 years, paralleling the global diabetes epidemic.

Incidence and Prevalence

Risk Factors

Non-Modifiable Risk Factors

Modifiable Risk Factors

Cardiovascular Comorbidity

• 80% of DKD patients die from cardiovascular events (MI, stroke, heart failure) before reaching ESRD. [19]
• DKD is an independent cardiovascular risk factor beyond diabetes alone.
• CKD amplifies cardiovascular risk: eGFR less than 60 mL/min/1.73m² and/or ACR > 3 mg/mmol increase CV events 2-4 fold. [19]

---

3. Pathophysiology

Overview: From Hyperfiltration to Fibrosis

Diabetic nephropathy progresses through distinct pathophysiological stages, driven by:

1. Haemodynamic injury: Glomerular hyperfiltration and hypertension. [27]
2. Metabolic injury: Advanced glycation end-products (AGEs), oxidative stress, protein kinase C (PKC) activation. [21]
3. Inflammatory and fibrotic pathways: TGF-β, VEGF, podocyte loss, mesangial expansion. [21]
4. Structural remodeling: GBM thickening, nodular sclerosis (Kimmelstiel-Wilson), tubulointerstitial fibrosis. [3]

Mogensen Classification (Type 1 Diabetes Model)

Note: Type 2 Diabetes often presents later in the disease course (Stages 3-4) due to delayed diagnosis and heterogeneous pathology.

Molecular Mechanisms

1. Haemodynamic Pathways

2. Metabolic Pathways

3. Inflammatory and Fibrotic Pathways

Histopathological Changes

Classic Lesions (Light Microscopy)

1. Kimmelstiel-Wilson Nodules (Nodular Glomerulosclerosis): Pathognomonic of diabetic nephropathy. Acellular, eosinophilic nodules in mesangium, composed of type IV collagen and laminin. Present in ~30-50% of diabetic biopsies. [3]
2. Diffuse Mesangial Expansion: More common than nodular sclerosis. Increased mesangial matrix and cellularity.
3. Glomerular Basement Membrane (GBM) Thickening: Earliest change. Normal GBM ~300-350 nm; DKD GBM > 400-600 nm. [3]
4. Arteriolar Hyalinosis: Hyaline deposits in afferent and efferent arterioles (efferent involvement more specific for DKD).
5. Tubulointerstitial Fibrosis: Correlates more closely with GFR decline than glomerular lesions. Tubular atrophy, interstitial fibrosis, inflammatory infiltrate. [3]

Immunofluorescence and Electron Microscopy

• Immunofluorescence: Typically negative (linear IgG may be seen in advanced disease).
• Electron Microscopy: GBM thickening, podocyte foot process effacement, mesangial matrix expansion.

Podocyte Injury: A Central Pathogenic Event

Podocytes (glomerular epithelial cells) are terminally differentiated and cannot regenerate. Podocyte loss is a key driver of proteinuria and glomerulosclerosis. [22]

GFR Decline Trajectory

• Natural History (Untreated Macroalbuminuria): GFR decline ~10-12 mL/min/1.73m²/year. [9]
• With ACEi/ARB: GFR decline reduced to ~4-6 mL/min/1.73m²/year. [5,6]
• With ACEi/ARB + SGLT-2 Inhibitor: GFR decline further reduced by ~40% (to ~2-3 mL/min/1.73m²/year). [4]
• Rapid Progressors (> 5 mL/min/year): Require urgent nephrology review; consider biopsy to exclude superimposed pathology.

Clinical Implications of GFR Trajectory: The rate of eGFR decline predicts time to ESRD and guides intervention intensity. The KDIGO 2022 guidelines recommend calculating eGFR slope using at least three measurements over 1-2 years to identify rapid progressors. [10] Patients with > 5 mL/min/1.73m²/year decline constitute ~20% of DKD population but account for majority of ESRD cases, often progressing within 3-5 years without aggressive intervention. [14]

---

4. Albuminuria Staging and Clinical Significance

KDIGO Albuminuria Categories (2022 Update)

Albuminuria staging represents the cornerstone of DKD diagnosis and risk stratification. [10]

ACR Measurement: Technical Considerations

Specimen Collection:

• Preferred: First morning void (minimises postural and diurnal variation)
• Acceptable: Random spot urine (if morning sample not feasible)
• Avoid: Post-exercise samples, during menstruation, UTI, acute illness, severe hyperglycaemia

Confirmation of Abnormal Results: The KDIGO 2022 guidelines recommend confirming elevated ACR with 2 out of 3 samples within 3 months due to significant intra-individual variability (coefficient of variation ~30-40%). [10] Transient albuminuria can occur with:

• Exercise (resolves within 24-48 hours)
• Urinary Tract Infection (pyuria, nitrites on dipstick)
• Heart Failure (volume overload, venous congestion)
• Fever/Acute Illness (inflammatory state)
• Severe Hyperglycaemia (glucose > 15 mmol/L)

Albuminuria Progression and Regression

Microalbuminuria Regression: Approximately 30-40% of patients with microalbuminuria can achieve regression to normoalbuminuria with intensive multi-factorial intervention. [7] Key predictors of regression include:

• Intensive glycaemic control (HbA1c less than 48 mmol/mol)
• Early ACEi/ARB initiation with uptitration to maximum tolerated dose
• Strict BP control (less than 120/80 mmHg in selected patients)
• Short duration of microalbuminuria (less than 5 years)
• Absence of retinopathy

Macroalbuminuria Trajectory: Once macroalbuminuria develops, regression to microalbuminuria occurs in only ~10-15% of patients. However, stabilisation of albuminuria (preventing further increase) is achievable with ACEi/ARB + SGLT-2i therapy, and associates with slowed GFR decline. [4,6]

Combined Risk Stratification: Heat Map Approach

The KDIGO Heat Map combines CKD stage (G1-G5) with albuminuria category (A1-A3) to provide precise risk assessment for progression to ESRD and cardiovascular events:

Clinical Application: A patient with G3b A3 (eGFR 38, ACR 220) has very high risk for both ESRD and CV events, warranting:

• ACEi/ARB + SGLT-2i + consider Finerenone
• High-intensity statin
• BP target less than 130/80 mmHg
• Nephrology referral (routine, 4-6 weeks)
• 3-6 monthly monitoring of ACR and eGFR

---

5. Clinical Presentation

Early Stages (Stages 1-3): Often Asymptomatic

Advanced Stages (Stages 4-5): Symptomatic Disease

Overt Nephropathy (Stage 4)

Nephrotic Syndrome (Severe Stage 4)

Nephrotic Syndrome occurs in ~20-30% of diabetic patients with overt nephropathy.

Diagnostic Criteria:

1. Heavy Proteinuria: ACR > 300 mg/mmol (or urine protein > 3.5 g/24h).
2. Hypoalbuminaemia: Serum albumin less than 30 g/L.
3. Oedema: Peripheral, periorbital, ascites, pleural effusions in severe cases.
4. Hyperlipidaemia: Elevated total cholesterol, LDL-C, triglycerides (compensatory hepatic synthesis).

Complications of Nephrotic Syndrome in DKD:

• Thromboembolism: Urinary loss of anticoagulant proteins (antithrombin III, protein S) → Hypercoagulable state → DVT, PE, renal vein thrombosis. Consider prophylactic anticoagulation if albumin less than 20 g/L.
• Infections: Urinary loss of immunoglobulins → Increased risk of pneumococcal sepsis, peritonitis (if on peritoneal dialysis).
• Acute Kidney Injury: Volume depletion (over-diuresis), sepsis, contrast exposure.

End-Stage Renal Disease (Stage 5)

eGFR less than 15 mL/min/1.73m². Uraemic symptoms dominate:

• Metabolic: Anorexia, nausea, vomiting, metallic taste, weight loss.
• Neurological: Fatigue, confusion, peripheral neuropathy (uraemic neuropathy superimposed on diabetic neuropathy), restless legs, seizures (severe uraemia).
• Cardiovascular: Fluid overload (pulmonary oedema), uraemic pericarditis, accelerated atherosclerosis.
• Haematological: Anaemia (reduced EPO), bleeding tendency (uraemic platelet dysfunction).
• Metabolic Bone Disease: Secondary hyperparathyroidism, renal osteodystrophy.
• Electrolyte Disturbances: Hyperkalaemia, metabolic acidosis, hyperphosphataemia.

Atypical Presentations: Consider Non-Diabetic Kidney Disease

Renal biopsy indicated if:

---

6. Investigations

Screening Strategy (Annual in All Diabetic Patients)

KDIGO and ADA guidelines recommend:

• Type 1 Diabetes: Annual screening from 5 years post-diagnosis. [10,28]
• Type 2 Diabetes: Annual screening from diagnosis (as duration of pre-clinical hyperglycaemia unknown). [10,28]

Core Screening Tests

ACR (Albumin:Creatinine Ratio)

Why ACR over 24-hour Urine Collection?

• Convenience: Single spot urine sample (no timed collection).
• Accuracy: Corrects for urine concentration (creatinine excretion).
• Reproducibility: Less variability than 24-hour collection.

ACR Categories (KDIGO Classification):

Confirm Abnormal ACR: Repeat on 2 out of 3 samples within 3 months (transient elevations with: UTI, exercise, menstruation, heart failure, acute illness). [10]

eGFR (Estimated Glomerular Filtration Rate)

Calculation: CKD-EPI equation (age, sex, race, serum creatinine). Do not use Cockcroft-Gault (less accurate).

CKD Staging (KDIGO):

Combined Risk Stratification: Combine CKD stage (G1-G5) with Albuminuria category (A1-A3) for precise risk assessment (e.g., G3bA3 = very high risk of progression and CV events). [10]

Comprehensive Baseline Assessment

Advanced/Specialist Investigations

Renal Biopsy

Indications (as discussed in Section 5):

1. Absence of diabetic retinopathy in T1DM with significant proteinuria.
2. Rapid GFR decline (> 5 mL/min/1.73m²/year).
3. Active urinary sediment (haematuria, RBC casts).
4. Short diabetes duration (less than 5 years in T1DM) with proteinuria.
5. Nephrotic syndrome in T2DM without retinopathy.
6. Atypical features (e.g., systemic symptoms suggesting vasculitis, myeloma).

Contraindications: Uncorrected bleeding diathesis, uncontrolled hypertension (BP > 160/100), solitary kidney (relative), small kidneys (less than 9 cm).

DKD Histological Findings:

• Glomeruli: Kimmelstiel-Wilson nodules, diffuse mesangial expansion, GBM thickening, glomerulosclerosis (segmental or global).
• Tubules/Interstitium: Tubular atrophy, interstitial fibrosis, Armanni-Ebstein lesion (glycogen accumulation in tubular epithelium – rare).
• Vessels: Arteriolar hyalinosis (afferent and efferent).

Imaging (Renal Ultrasound)

Indications: Baseline assessment in CKD G3b-5; exclude obstruction if acute rise in creatinine.

Findings in DKD:

• Kidney Size: Typically normal or enlarged in early DKD (hyperfiltration). Reduced size (less than 9 cm) in ESRD or suggests chronic process.
• Echogenicity: Increased cortical echogenicity (non-specific; seen in CKD).
• Exclude: Hydronephrosis, stones, polycystic kidneys.

Renal Artery Doppler Ultrasound / CT Angiography

Consider if: Refractory hypertension, acute rise in creatinine after ACEi/ARB initiation (suggests bilateral renal artery stenosis), abdominal bruit.

---

7. Management

Therapeutic Paradigm: Multi-Factorial Risk Reduction

DKD management is NOT solely about glucose control. It requires:

1. Glycaemic Optimisation (HbA1c less than 53 mmol/mol individualised).
2. Blood Pressure Control (less than 130/80 mmHg with ACEi/ARB).
3. SGLT-2 Inhibitor Initiation (Dapagliflozin, Empagliflozin, Canagliflozin).
4. Cardiovascular Risk Reduction (Statin, antiplatelet if indicated).
5. Lifestyle Modification (Smoking cessation, weight management, dietary protein restriction in CKD G4-5).
6. Nephrotoxin Avoidance (NSAIDs, aminoglycosides, contrast agents).
7. Monitoring and Timely Nephrology Referral.

---

1. Glycaemic Control

Target: HbA1c less than 53 mmol/mol (7%), individualised based on:

• Hypoglycaemia risk
• Life expectancy
• Comorbidities
• Patient preference

Evidence:

• DCCT/EDIC (T1DM): Intensive glucose control (HbA1c ~53 mmol/mol vs 75 mmol/mol) reduced microalbuminuria by 39%, macroalbuminuria by 54%, and long-term renal outcomes. [17]
• UKPDS (T2DM): Intensive control reduced microvascular complications (including nephropathy) by 25%.

Challenges in Advanced CKD:

• Reduced renal clearance of insulin and oral agents → Hypoglycaemia risk.
• Reduced renal gluconeogenesis → Prolonged hypoglycaemia.
• Reduced appetite (uraemia) → Nutritional challenges.

Glucose-Lowering Agents in CKD

---

2. Blood Pressure Control and ACEi/ARB Protocols

Target: less than 130/80 mmHg in all DKD patients (KDIGO 2022). [10]

First-Line Agent: ACE Inhibitor (ACEi) or Angiotensin Receptor Blocker (ARB) – even in normotensive patients with albuminuria.

Mechanism of Renoprotection

Key Trials

Practical ACEi/ARB Prescribing Protocol

ACEi Options:

• Ramipril: Start 2.5 mg OD → Titrate to 10 mg OD over 4-8 weeks
• Enalapril: Start 5 mg OD → Titrate to 20 mg OD
• Perindopril: Start 2 mg OD → Titrate to 8 mg OD

ARB Options (if ACEi not tolerated due to cough):

• Losartan: Start 50 mg OD → Titrate to 100 mg OD
• Irbesartan: Start 150 mg OD → Titrate to 300 mg OD
• Candesartan: Start 8 mg OD → Titrate to 32 mg OD

Initiation and Monitoring Protocol:

Week 0 (Baseline):

1. Check U&E, eGFR, K+, BP
2. Start ACEi/ARB at low dose (especially if eGFR less than 45 or elderly)
3. Counsel patient on:
   • Expected initial eGFR dip (10-20% acceptable)
   • Avoid NSAIDs, salt substitutes (high potassium)
   • "Sick day rules" (stop during acute illness with vomiting/diarrhoea)

Week 1-2 (Safety Check):

1. Recheck U&E, eGFR, K+
2. Assess response:

Acceptable Response (Continue and Uptitrate):

• eGFR drop less than 25% from baseline
• K+ less than 5.5 mmol/L
• BP responding (trending towards less than 130/80)
• Action: Increase dose towards maximum tolerated dose

Concerning Response (Recheck in 1 Week):

• eGFR drop 25-30% from baseline
• K+ 5.5-6.0 mmol/L
• Action: Hold current dose; recheck U&E in 1 week; dietary K+ restriction; consider holding thiazide diuretics

Unacceptable Response (STOP Drug):

• eGFR drop > 30% from baseline
• K+ > 6.0 mmol/L
• Action: Stop ACEi/ARB; urgent medical review; exclude bilateral renal artery stenosis (especially if solitary kidney or severe peripheral vascular disease)

Weeks 4-8 (Titration Phase):

1. If Week 1-2 check acceptable, uptitrate dose every 2-4 weeks
2. Recheck U&E 1-2 weeks after each dose increase
3. Target maximum tolerated dose (not just BP target)
   • Renoprotection is dose-dependent; higher doses confer greater proteinuria reduction even if BP well controlled

Long-term Monitoring:

• U&E every 3-6 months (every 3 months if CKD G4-5)
• ACR every 6-12 months to assess antiproteinuric response
• Expect ACR reduction of 30-50% over 3-6 months [6]

DO NOT Combine ACEi + ARB: Increased risk of hyperkalaemia, acute kidney injury, hypotension without additional renoprotective benefit (ONTARGET trial). [23]

Additional Antihypertensives

If BP not controlled on ACEi/ARB alone:

---

3. SGLT-2 Inhibitors: Renoprotection Mechanisms and Protocols

Sodium-Glucose Co-Transporter-2 (SGLT-2) Inhibitors are now first-line therapy for DKD alongside ACEi/ARB, representing one of the most significant therapeutic advances in nephrology in the past decade.

Mechanism of Renoprotection

Landmark Trials: SGLT-2 Inhibitors in DKD

Key Insights from Trials:

• DAPA-CKD: First to demonstrate renoprotection in non-diabetic CKD (43% of participants did not have diabetes). Dapagliflozin now licensed for CKD irrespective of diabetes status.
• CREDENCE: Established SGLT-2i as renoprotective in T2DM with high albuminuria (nephrotic range).
• EMPA-KIDNEY: Extended evidence to lower eGFR thresholds (down to 20 mL/min/1.73m²).

Approved SGLT-2 Inhibitors for DKD

SGLT-2 Inhibitor Initiation Protocol

Patient Selection:

• Indications: DKD with eGFR ≥20-30 (drug-dependent) and ACR > 30 mg/mmol (or eGFR less than 60 with ACR > 3 mg/mmol per KDIGO 2022)
• Can be used in: Type 1 Diabetes (off-label; emerging evidence), non-diabetic CKD (dapagliflozin licensed), heart failure (separate indication)

Pre-Initiation Checklist:

1. eGFR: Confirm ≥25 mL/min/1.73m² (dapagliflozin) or ≥20 (empagliflozin)
2. Euvolaemia: Ensure adequate hydration; avoid initiating during acute illness/volume depletion
3. Review medications: Consider temporary discontinuation of loop diuretics if volume replete (to prevent volume depletion)
4. Counsel patient on:
   • Expected initial eGFR dip (3-5 mL/min; benign and reversible)
   • Genital mycotic infections (~10% incidence; more common in women; treat with topical antifungals)
   • Euglycaemic DKA (rare less than 0.1%; higher risk in T1DM, perioperative, low-carb diets)
   • Sick day rules (stop during acute illness with vomiting/diarrhoea/reduced oral intake)
   • Increased urination (osmotic diuresis from glycosuria)

Initiation:

• Start Dapagliflozin 10 mg OD or Empagliflozin 10 mg OD (single fixed dose; no titration needed)
• Take in morning (to avoid nocturia)
• Can be taken with or without food

Week 2-4 (Safety Check):

1. Recheck U&E, eGFR
2. Expected findings:
   • eGFR dip of 3-5 mL/min (10-15% reduction) – this is NORMAL and protective [20]
   • K+ stable or slight decrease
   • Weight loss 0.5-1 kg (fluid loss from diuresis)
3. Action: Reassure patient; explain eGFR dip is haemodynamic (reduced hyperfiltration) and beneficial long-term

Unacceptable Response (Reassess):

• eGFR drop > 25% or absolute drop > 10 mL/min → Check for:
  • Volume depletion (excessive diuresis, poor oral intake, concurrent loop diuretic)
  • Concurrent nephrotoxin (NSAIDs, contrast)
  • Acute illness
• Action: Consider temporary hold; recheck in 1 week; resume once stable

Long-term Management:

• Continue SGLT-2i even as eGFR declines – renoprotective benefits persist despite loss of glycaemic efficacy below eGFR 45
• Stop only when:
  • Dialysis initiated (no further renal protection)
  • Patient intolerance (recurrent genital infections, euglycaemic DKA)
  • Severe acute illness (temporary hold; resume when stable)

Adverse Effects and Management:

Perioperative Management:

• Stop SGLT-2i 3 days before major surgery (especially cardiac, vascular, abdominal procedures requiring general anaesthesia)
• Risk: Euglycaemic DKA in perioperative fasting state
• Resume 48-72 hours post-surgery once eating/drinking normally

---

4. Finerenone (Non-Steroidal MRA): Emerging Triple Therapy

Finerenone (Kerendia) is a novel non-steroidal mineralocorticoid receptor antagonist (MRA) with proven renal and CV benefits in DKD, and lower hyperkalaemia risk than spironolactone/eplerenone. [11,12]

Mechanism

• Selective MR Blockade: Blocks mineralocorticoid receptor in kidney, heart, vasculature → Reduces inflammation, fibrosis (independent of BP/RAAS effects)
• Superior Selectivity: ~500-fold selectivity for MR vs glucocorticoid receptor (compared to ~10-fold for spironolactone) → Fewer off-target effects (gynaecomastia, erectile dysfunction)
• Anti-fibrotic: Reduces TGF-β signaling, collagen deposition, tubulointerstitial fibrosis
• Anti-inflammatory: Reduces macrophage infiltration, inflammatory cytokines

Key Trials

Dosing

Dose Selection Based on eGFR:

Monitoring Protocol:

1. Baseline: K+ (must be ≤5.0 mmol/L to initiate), eGFR
2. Week 4: K+, eGFR
   • If K+ ≤4.8 mmol/L and eGFR ≥60: Uptitrate 10 mg → 20 mg
   • If K+ 4.9-5.5 mmol/L: Continue current dose; recheck K+ in 4 weeks
   • If K+ > 5.5 mmol/L: Hold finerenone; dietary K+ restriction; recheck K+ in 1 week
3. Months 2, 3, 6, 9, 12: K+, eGFR
4. Every 6 months thereafter: K+, eGFR

Contraindications:

• K+ > 5.0 mmol/L at baseline
• eGFR less than 25 mL/min/1.73m²
• Addison's disease (adrenal insufficiency)
• Concomitant strong CYP3A4 inhibitors (ketoconazole, itraconazole, ritonavir) – use 10 mg dose

Role in DKD:

• Add to ACEi/ARB + SGLT-2 inhibitor in patients with persistent albuminuria (ACR > 30 mg/mmol) despite dual therapy
• Emerging "triple therapy" paradigm: ACEi/ARB + SGLT-2i + Finerenone
• Combined RRR from trials: ~50-60% reduction in ESRD (additive effects from three mechanistically distinct pathways)

Practical Use: Currently recommended as third-line therapy in KDIGO 2022 guidelines for patients with:

1. T2DM with CKD G2-4
2. ACR > 30 mg/mmol despite maximised ACEi/ARB + SGLT-2i
3. K+ ≤5.0 mmol/L
4. Willing to adhere to K+ monitoring

---

5. Cardiovascular Risk Reduction

DKD patients have 2-4 fold increased CV risk. [19] Aggressive CV risk management is essential as 80% die from CV events before ESRD.

---

6. Dietary and Lifestyle Modification

---

7. Avoid Nephrotoxins

"Sick Day Rules" for ACEi/ARB + SGLT-2i: Provide written card to all DKD patients:

STOP the following medications during acute illness (vomiting, diarrhoea, fever, reduced oral intake):

• ACE inhibitor (Ramipril, Enalapril, Perindopril)
• ARB (Losartan, Irbesartan, Candesartan)
• SGLT-2 inhibitor (Dapagliflozin, Empagliflozin, Canagliflozin)
• Diuretics (Furosemide, Indapamide)
• Metformin

RESTART once eating and drinking normally for 24-48 hours. SEEK MEDICAL ADVICE if illness persists > 48 hours or if passing less urine.

---

8. Management of CKD Complications

Anaemia (CKD G3-5)

Target Hb: 100-120 g/L (avoid > 120 g/L – increased CV risk from ESA therapy).

CKD-Mineral Bone Disease (CKD-MBD)

Monitor: Calcium, Phosphate, PTH, Alkaline Phosphatase, 25-OH Vitamin D.

• CKD G3: Every 6-12 months
• CKD G4-5: Every 3-6 months

Metabolic Acidosis (Bicarbonate less than 22 mmol/L)

Treatment: Sodium bicarbonate 500-1000 mg TDS (titrate to bicarbonate 22-24 mmol/L).

Evidence: Slows CKD progression (UBI trial: 1.88 mL/min/1.73m²/year slower eGFR decline with bicarbonate therapy). [24]

Caution: Sodium load may worsen hypertension/fluid retention; monitor BP and weight.

Hyperkalaemia (K⁺ > 5.5 mmol/L)

Management Algorithm:

---

9. Renal Replacement Therapy (ESRD)

Indication: eGFR less than 15 mL/min/1.73m² with uraemic symptoms or refractory complications (fluid overload, hyperkalaemia, acidosis, pericarditis).

Preparation: Initiate nephrology referral at eGFR less than 30 (CKD G4) for pre-dialysis education, vascular access planning, transplant assessment.

Dialysis Modalities

Vascular Access for Haemodialysis

Planning: Refer to vascular surgery for arteriovenous fistula (AVF) creation when eGFR less than 20 mL/min/1.73m² (fistula maturation takes 3-6 months).

Fistula First Initiative: Nephrologists advocate for AVF creation early (eGFR ~20) to maximise maturation time and minimise catheter dependence.

Dialysis Timing and Initiation

Traditional Approach: Start dialysis when eGFR less than 10 mL/min/1.73m² or uraemic symptoms.

IDEAL Trial (2010): Early-start dialysis (eGFR 10-14) vs late-start (eGFR 5-7) showed no survival benefit from early initiation; late-start group had fewer complications and equivalent quality of life. [DOI: 10.1056/NEJMoa1000552]

Current Practice: Individualised approach based on:

• Symptoms: Uraemic symptoms (nausea, vomiting, fatigue, encephalopathy, pericarditis) → Initiate dialysis regardless of eGFR
• Volume Overload: Refractory to diuretics (pulmonary oedema) → Dialysis
• Metabolic Complications: Refractory hyperkalaemia (K+ > 6.5 despite medical therapy), severe metabolic acidosis (bicarbonate less than 15) → Dialysis
• Nutrition: Progressive malnutrition despite dietitian input → Consider dialysis

Typical eGFR at Dialysis Initiation: 8-10 mL/min/1.73m² in developed nations (varies by symptom tolerance and patient preference).

Pre-emptive Transplantation: Preferred in suitable candidates; transplant before dialysis initiation (when eGFR 15-20 mL/min/1.73m²) if living donor available. Superior outcomes vs post-dialysis transplant.

---

10. Monitoring Strategy

---

11. When to Refer to Nephrology

---

8. Complications

---

9. Prognosis & Outcomes

Natural History (Untreated)

Impact of Modern Therapy

Clinical Implication: A patient with DKD on ACEi/ARB + SGLT-2i + Finerenone ("triple therapy") with optimised glycaemic control (HbA1c less than 53 mmol/mol) and BP less than 130/80 has an estimated 60-70% reduction in ESRD risk compared to untreated historical controls. This translates to median time to ESRD of 15-20 years (vs 5-10 years untreated).

Cardiovascular Outcomes

• Leading Cause of Death: 80% of DKD patients die from CV events (MI, stroke, heart failure) before reaching ESRD. [19]
• CV Risk Amplification: Each doubling of ACR or halving of eGFR → 1.5-2x increased CV risk (independent of traditional risk factors). [19]
• SGLT-2 Inhibitors: Reduce heart failure hospitalisation by 30-40%, CV death by 15-20% (independent of renal effects). Benefit seen even in non-diabetic CKD. [4,13]
• Statins: High-intensity statin (Atorvastatin 20-80 mg) reduces major CV events by ~25% in CKD patients (SHARP trial). No clear renoprotective benefit. [DOI: 10.1016/S0140-6736(11)60739-3]

Dialysis and Transplant Outcomes

---

10. Evidence & Guidelines

International Guidelines

Key Trials Summary

---

11. Exam Scenarios

Scenario 1: Diagnosis and Initial Management (Microalbuminuria)

Stem: A 55-year-old man with Type 2 Diabetes (diagnosed 8 years ago, HbA1c 64 mmol/mol on Metformin) attends for annual review. Routine screening shows: ACR 18 mg/mmol (repeat ACR 22 mg/mmol), eGFR 68 mL/min/1.73m², BP 142/88 mmHg. Retinal screening shows background diabetic retinopathy.

Questions:

1. What is the diagnosis and CKD staging?
2. What is the pathophysiological significance of this finding?
3. Outline your comprehensive management plan.

Model Answer:

1. Diagnosis: Diabetic Kidney Disease with microalbuminuria (incipient nephropathy). CKD Staging: G2 A2 (eGFR 60-89 with moderately increased albuminuria 3-30 mg/mmol). KDIGO Heat Map Risk: Yellow (Moderate risk for CKD progression and CV events).

2. Pathophysiological Significance: Microalbuminuria reflects podocyte injury and increased glomerular permeability secondary to glomerular hyperfiltration, AGE accumulation, and TGF-β-mediated mesangial expansion. At this stage, renal injury is potentially reversible with intensive intervention – approximately 30-40% of patients can achieve regression to normoalbuminuria with optimal therapy. [7]

3. Management Plan:

   • ACEi/ARB Initiation: Start Ramipril 2.5 mg OD, titrate to 10 mg over 4-8 weeks (target BP less than 130/80 mmHg). Recheck U&E in 1-2 weeks (acceptable eGFR dip less than 25%, K+ less than 5.5 mmol/L). Expect 30-50% reduction in ACR over 3-6 months. [5,6]

   • SGLT-2 Inhibitor: Add Dapagliflozin 10 mg OD (renoprotection + glycaemic benefit + CV protection). Dapagliflozin approved for CKD with eGFR ≥25 and ACR ≥30, but KDIGO 2022 recommends considering for ACR > 3 if eGFR less than 60. [10] Expect initial eGFR dip of 3-5 mL/min (benign haemodynamic effect).

   • Glycaemic Optimisation: Intensify therapy to achieve HbA1c less than 53 mmol/mol. Consider adding GLP-1 RA (Semaglutide 1 mg weekly SC) for weight loss (BMI likely > 30), CV benefit, and renal protection (SUSTAIN-6 showed 36% reduction in new/worsening nephropathy).

   • Cardiovascular Risk Reduction: High-intensity statin (Atorvastatin 20-80 mg OD). Target LDL-C less than 1.8 mmol/L. [19]

   • Lifestyle Modification: Smoking cessation (if applicable), weight loss (target BMI less than 25 or ≥10% weight loss), exercise (150 min/week), dietary sodium restriction (less than 5-6 g/day).

   • Monitoring: ACR + eGFR every 6 months, U&E at 1-2 weeks post-ACEi initiation then every 3-6 months, HbA1c every 3-6 months, BP monitoring (home BP if possible).

   • Patient Education: Avoid NSAIDs (use Paracetamol); sick day rules for ACEi/ARB + SGLT-2i (stop during acute illness); importance of medication adherence.

---

Scenario 2: Rapid GFR Decline (Red Flag)

Stem: A 62-year-old woman with Type 1 Diabetes (28 years' duration) and known DKD (CKD G3a A3) on Ramipril 10 mg and Dapagliflozin 10 mg presents with 6-month follow-up results: eGFR declined from 52 to 38 mL/min/1.73m² (decline of 14 mL/min over 6 months = 28 mL/min/year). ACR 450 mg/mmol (previously 380). BP 136/82. She reports starting Ibuprofen 400 mg TDS for osteoarthritis 4 months ago.

Questions:

1. What is concerning about the eGFR trajectory and what does it suggest?
2. What is the likely causative factor?
3. Outline your immediate management.

Model Answer:

1. Concerning Feature: Rapid GFR decline > 5 mL/min/1.73m²/year (this patient: 28 mL/min/year) – far exceeding expected decline in DKD on optimal treatment (~2-4 mL/min/year with ACEi/ARB + SGLT-2i). [14] This is a RED FLAG for acute kidney injury (AKI) superimposed on CKD or alternative pathology (acute interstitial nephritis, renovascular disease, glomerulonephritis). Rapid progressors (> 5 mL/min/year) constitute ~20% of DKD population but account for majority of ESRD cases.

2. Likely Cause: NSAID-induced AKI ("triple whammy": NSAIDs + ACEi + SGLT-2i → afferent vasoconstriction + efferent vasodilation + volume depletion → reduced renal perfusion → AKI). NSAIDs inhibit prostaglandin synthesis (PGE₂, PGI₂) which normally maintain afferent arteriolar vasodilation – loss of this compensatory mechanism in setting of ACEi/ARB (efferent vasodilation) causes critical reduction in intraglomerular pressure and GFR.

3. Immediate Management:

   • STOP Ibuprofen immediately. Advise Paracetamol 1g QDS for analgesia (safe in CKD). If inadequate pain control, consider topical NSAIDs (diclofenac gel – minimal systemic absorption) or referral to orthopaedics for intra-articular corticosteroid injection.

   • Recheck U&E in 1 week to assess recovery. Expect eGFR to improve by 5-10 mL/min within 1-2 weeks if NSAID-induced AKI.

   • Review medications: Ensure adequate hydration. Consider temporarily holding Ramipril if eGFR continues to decline (restart once stable). Continue Dapagliflozin (unless acute illness with volume depletion).

   • Urinalysis + Microscopy: Exclude active sediment (haematuria, pyuria, WBC/RBC casts). If present → Consider renal biopsy for acute interstitial nephritis (AIN) or rapidly progressive glomerulonephritis (RPGN).

   • Urgent Nephrology Referral (within 2 weeks as per KDIGO guidelines for rapid progression > 5 mL/min/year). [14] Nephrology will:

     • Assess for superimposed pathology (AIN, renovascular disease, ANCA vasculitis)
     • Consider renal biopsy if atypical features
     • Optimise renoprotective therapy
     • Counsel on ESRD planning (now CKD G3b → may progress to G4 within 1-2 years)

   • Patient Education: Provide written nephrotoxin avoidance list (NSAIDs, ibuprofen, naproxen, diclofenac) and sick day rules card. Emphasise importance of alerting healthcare providers to CKD status before any procedure/contrast imaging.

---

Scenario 3: Atypical Features (Biopsy Indication)

Stem: A 48-year-old man with Type 1 Diabetes (10 years' duration) presents with ACR 280 mg/mmol and eGFR 42 mL/min/1.73m². Retinal screening is normal (no diabetic retinopathy). Urinalysis shows 2+ blood (microscopy: dysmorphic RBCs, no casts). BP 138/84. HbA1c 58 mmol/mol.

Questions:

1. What atypical features raise concern for non-diabetic kidney disease?
2. What are the differential diagnoses?
3. What investigations are indicated?

Model Answer:

1. Atypical Features:

   • Absence of diabetic retinopathy: > 90% of T1DM patients with DKD have concurrent retinopathy. [8] In T1DM, retinopathy and nephropathy usually coexist due to shared microvascular pathology. Absence of retinopathy in presence of significant proteinuria (ACR 280 mg/mmol = macroalbuminuria) suggests alternative renal diagnosis.

   • Haematuria with dysmorphic RBCs: Suggests glomerulonephritis (glomerular origin of RBCs → dysmorphic morphology due to passage through damaged GBM). Not typical of DKD – DKD typically has proteinuria without significant haematuria or active sediment.

   • Relatively short diabetes duration (10 years) for advanced CKD (G3b): In T1DM, significant DKD typically develops 15-20 years post-diagnosis. Earlier onset raises suspicion for non-diabetic pathology.

2. Differential Diagnosis: Non-diabetic kidney disease (primary glomerulonephritis) ± coexistent DKD:

   • IgA Nephropathy: Most common primary glomerulonephritis. Presents with haematuria (often episodic, post-URTI), proteinuria, progressive CKD. Renal biopsy: Mesangial IgA deposition (immunofluorescence), mesangial proliferation (light microscopy).

   • Membranous Nephropathy: Nephrotic-range proteinuria, hypoalbuminaemia. Associations: Autoimmune (PLA2R antibodies), malignancy (especially > 60 years), drugs (NSAIDs, gold). Biopsy: GBM thickening with "spikes" (silver stain), granular IgG/C3 (immunofluorescence).

   • ANCA-associated Vasculitis (Granulomatosis with Polyangiitis, Microscopic Polyangiitis): Rapidly progressive glomerulonephritis (RPGN), systemic features (haemoptysis, sinusitis, rash, arthralgia). Biopsy: Crescentic glomerulonephritis, pauci-immune (negative immunofluorescence).

   • Focal Segmental Glomerulosclerosis (FSGS): Nephrotic syndrome, progressive CKD. Associations: Obesity, HIV, genetic (podocin mutations). Biopsy: Segmental sclerosis affecting some glomeruli.

   • Superimposed diabetic nephropathy + IgA nephropathy: Possibility of dual pathology (DKD + IgAN) – biopsy may show features of both.

3. Investigations:

   • Renal Biopsy (definitive investigation): To establish diagnosis and guide treatment. Histology may reveal non-diabetic pathology (IgAN, membranous, ANCA vasculitis) ± coexistent diabetic changes.

   • Autoimmune/Vasculitis Screen:

     • ANA (Systemic Lupus Erythematosus – can cause lupus nephritis)
     • ANCA (c-ANCA/PR3, p-ANCA/MPO) – ANCA vasculitis
     • Anti-GBM antibodies – Goodpasture syndrome (rare)
     • Complement (C3, C4) – Low in SLE, post-infectious GN, MPGN

   • Serum Protein Electrophoresis + Immunofixation: Exclude myeloma (especially if age > 60, anaemia, bone pain, hypercalcaemia). Myeloma can cause cast nephropathy (acute renal failure) or AL amyloidosis (nephrotic syndrome).

   • Hepatitis/HIV Serology: Hepatitis B/C (membranous nephropathy, cryoglobulinaemia, MPGN), HIV (FSGS, HIV-associated nephropathy).

   • Renal Ultrasound: Assess kidney size (normal/enlarged suggests acute process; small less than 9 cm suggests chronic), exclude obstruction, assess for structural abnormalities.

   • Urine Protein:Creatinine Ratio (PCR) or 24-hour Urine Protein: Quantify total proteinuria (if nephrotic range > 3.5 g/24h → suggests membranous, FSGS, or severe DKD).

Management: Urgent nephrology referral (within 2 weeks) for consideration of renal biopsy. If biopsy confirms non-diabetic pathology (e.g., IgA nephropathy), treatment will differ from standard DKD management (may require immunosuppression with corticosteroids, cyclophosphamide, mycophenolate, rituximab depending on diagnosis).

---

Scenario 4: SGLT-2 Inhibitor Initiation and Expected eGFR Dip

Stem: A 68-year-old woman with T2DM and CKD G3b A3 (eGFR 38, ACR 220) on Ramipril 10 mg is started on Dapagliflozin 10 mg. At 4-week follow-up, eGFR is 34 mL/min/1.73m² (drop of 4 mL/min). She is asymptomatic. U&E: K+ 4.8 mmol/L, Creatinine 152 μmol/L (previously 142 μmol/L).

Questions:

1. Is the eGFR drop concerning? What is the mechanism?
2. What should you do next?
3. How would you counsel the patient about this finding?

Model Answer:

1. Not Concerning: Initial eGFR dip of 3-5 mL/min is expected with SGLT-2 inhibitor initiation. This represents a benign haemodynamic effect due to reduction in glomerular hyperfiltration. [20] The eGFR dip is protective long-term – it signifies restoration of normal tubuloglomerular feedback and reduced intraglomerular pressure (key mechanism of SGLT-2i renoprotection).

   Mechanism:

   • Normal State (without SGLT-2i): In diabetes/CKD, proximal tubule SGLT-2 reabsorbs excess glucose + Na+ → Reduced Na+ delivery to macula densa → Macula densa senses "low Na+" → Signals afferent arteriolar vasodilation (tubuloglomerular feedback dysfunction) → Glomerular hyperfiltration → Podocyte stress and injury.

   • With SGLT-2i (Dapagliflozin): SGLT-2 blockade → Reduced proximal tubule glucose/Na+ reabsorption → Increased Na+ delivery to macula densa → Macula densa senses "adequate Na+" → Signals afferent arteriolar vasoconstriction → Reduced intraglomerular pressure → Reduced GFR (initial dip) → Reduced podocyte stress → Long-term GFR preservation.

   • The initial eGFR dip (3-5 mL/min) typically stabilises by 4-8 weeks, and long-term GFR trajectory improves substantially (GFR decline slows from ~4-6 mL/min/year with ACEi/ARB alone to ~2-3 mL/min/year with ACEi/ARB + SGLT-2i). [4]

2. Action:

   • Continue Dapagliflozin (do not stop unless eGFR drop > 25% or absolute drop > 10 mL/min, or acute symptomatic AKI).

   • Recheck U&E in 4 weeks to confirm eGFR stabilisation (expect eGFR to remain stable at ~34-36 mL/min, not continue declining).

   • Reassure patient: Explain expected eGFR dip and long-term renal benefits (see counselling below).

   • Ensure adequate hydration and avoid concurrent nephrotoxins (NSAIDs, contrast agents). Review medications to ensure no concomitant diuretic dose increase (may potentiate volume depletion).

   • Monitor for adverse effects: Genital mycotic infections (counsel on perineal hygiene, treat with topical clotrimazole if occurs), increased urination (osmotic diuresis – normal).

3. Patient Counselling:

   "Mrs X, your kidney function test (eGFR) has dropped slightly from 38 to 34 after starting Dapagliflozin. This is completely expected and not a cause for concern. Let me explain why:

   Why the drop? Your kidneys have been working too hard (hyperfiltration) due to diabetes, which was causing damage over time. Dapagliflozin relaxes the pressure inside your kidney filters, which initially reduces the eGFR number – but this is actually protecting your kidneys from long-term damage.

   What happens next? Your eGFR will stabilise at this new level over the next 4-8 weeks. Importantly, the medication will slow down future kidney damage by about 40% (based on the DAPA-CKD trial) [4]. Without it, your kidney function would decline by about 4-6 points per year; with Dapagliflozin, it will decline much more slowly (about 2-3 points per year).

   What should you do?

   • Continue taking Dapagliflozin every day – it is protecting your kidneys and heart.
   • Drink enough water (1.5-2 litres per day unless told otherwise).
   • Avoid ibuprofen and anti-inflammatory painkillers – use Paracetamol instead.
   • Stop Dapagliflozin temporarily if you develop severe vomiting, diarrhoea, or become unwell with an infection (restart once recovered).
   • We will recheck your kidney function in 4 weeks to ensure it has stabilised.

   This medication is one of the best things we can do to protect your kidneys long-term. Do you have any questions?"

Key Teaching Point: The initial eGFR dip with SGLT-2i is a marker of drug efficacy (restoration of tubuloglomerular feedback), not harm. Clinicians must resist the reflex urge to stop SGLT-2i based on initial eGFR decline – doing so deprives patients of substantial long-term renoprotection.

---

12. Triage: When to Refer

---

13. Patient/Layperson Explanation

What is Diabetic Kidney Disease?

Diabetic Kidney Disease (DKD) happens when high blood sugar over many years damages the tiny filters (glomeruli) in your kidneys. These filters normally clean your blood and remove waste. When damaged, they:

1. Leak protein into your urine (albuminuria)
2. Eventually stop filtering waste effectively (kidney failure)

How Common Is It?

About 1 in 3 people with diabetes will develop some kidney damage. It usually takes 10-20 years to develop, but early detection and treatment can slow or stop progression.

How Do We Detect It?

Two simple tests, done every year:

1. Urine Test (ACR – Albumin:Creatinine Ratio): Looks for tiny amounts of protein (albumin) leaking into your urine – the earliest sign of kidney damage.

   • Normal: less than 3 mg/mmol
   • Microalbuminuria (early damage): 3-30 mg/mmol
   • Macroalbuminuria (advanced damage): > 30 mg/mmol

2. Blood Test (eGFR – estimated Glomerular Filtration Rate): Measures how well your kidneys are filtering waste.

   • Normal: > 90 mL/min/1.73m²
   • CKD Stage 3: 30-59 (moderate damage)
   • CKD Stage 4: 15-29 (severe damage)
   • CKD Stage 5: less than 15 (kidney failure – need dialysis)

What Are the Stages?

• Early (Microalbuminuria, ACR 3-30): Small amounts of protein in urine. Kidneys still working well. This stage is often reversible with treatment. [7]
• Advanced (Macroalbuminuria, ACR > 30): More protein in urine. Kidney function starting to decline.
• Kidney Failure (ESRD, eGFR less than 15): Kidneys can't clean blood effectively. Dialysis or transplant needed.

How Is It Treated?

Good news: We now have very effective treatments to slow kidney damage.

1. Blood Pressure Tablets (ACE Inhibitors or ARBs)

• Examples: Ramipril, Losartan
• How they help: Protect your kidneys by reducing pressure inside the filters
• Important: Take even if your blood pressure is normal – they protect your kidneys directly, not just through BP lowering [5,6]
• Dose: Your doctor will gradually increase the dose to the maximum you can tolerate (higher doses = better kidney protection)

2. SGLT-2 Inhibitors (Game-Changer)

• Examples: Dapagliflozin (Forxiga), Empagliflozin (Jardiance), Canagliflozin (Invokana)
• How they help: Remove extra sugar through your urine AND reduce pressure in your kidneys. Reduce kidney damage by 40% (DAPA-CKD trial). [4] Also help your heart (reduce heart failure and heart attacks).
• Side effects: Increased urination (normal – the drug is working), genital thrush (~10% – easily treated with cream), very rare risk of diabetic ketoacidosis (stop drug if vomiting/very unwell)
• Important: Your kidney function test (eGFR) may dip slightly (3-5 points) when you start – this is normal and protective. It means the drug is reducing harmful pressure in your kidneys.

3. Blood Sugar Control

• Target: HbA1c below 53 mmol/mol (7%) if possible
• Why: High blood sugar damages kidney filters over time. Intensive control reduces kidney damage by 39% (DCCT/EDIC study). [17]

4. Healthy Lifestyle

• Quit smoking: Smoking accelerates kidney damage (1.5-2x faster decline)
• Healthy weight: Lose weight if overweight (target BMI less than 25)
• Reduce salt: Less than 1 teaspoon per day (6g) – helps BP and protects kidneys
• Exercise: 30 minutes, 5 days/week (walking, cycling, swimming)

5. AVOID Kidney-Damaging Medications

• NO ibuprofen, diclofenac, naproxen (anti-inflammatory painkillers) – these can cause sudden kidney failure, especially with ACE inhibitors
• USE Paracetamol instead (safe in kidney disease)
• Tell all doctors/dentists you have kidney disease before any procedure

What Happens If My Kidneys Fail?

If kidneys stop working despite treatment (eGFR less than 15):

• Dialysis: Machine cleans your blood
  • "Haemodialysis: Hospital, 3 times/week, 4 hours/session"
  • "Peritoneal dialysis: At home, daily exchanges"
• Kidney Transplant: Best option. New kidney from living or deceased donor. 10-year survival ~75% (much better than dialysis).

Most people do NOT reach kidney failure if they:

• Take their medications every day (especially ACE inhibitors and SGLT-2 inhibitors)
• Keep blood sugar (HbA1c less than 53) and blood pressure (less than 130/80) controlled
• Attend annual screening
• Avoid ibuprofen and NSAIDs

Key Counselling Points

✅ "Your Tablets Protect Your Kidneys – Take Them Every Day": Even if you feel well, Ramipril and Dapagliflozin are preventing kidney damage. Studies show they reduce kidney failure by 40-50%.

✅ "Get Tested Every Year": Urine (ACR) and blood (eGFR) tests detect problems early when treatment works best.

✅ "Avoid Ibuprofen – Use Paracetamol": Ibuprofen damages kidneys, especially with your blood pressure tablets (ACE inhibitors). Paracetamol is safe.

✅ "Control Blood Sugar and Blood Pressure": These are the most important things you can control to protect your kidneys.

✅ "Early Detection = Early Treatment = Prevent Kidney Failure": If we catch microalbuminuria early (ACR 3-30), we can often reverse it or stop it getting worse.

✅ "Sick Day Rules": If you develop vomiting, diarrhoea, or severe illness, temporarily stop Ramipril and Dapagliflozin (restart once eating/drinking normally). This prevents sudden kidney injury from dehydration.

---

14. Quality Markers: Audit Standards

| Standard | Target | Rationale | |----------|--------|-----------
| Annual ACR + eGFR screening in all diabetic patients | ≥95% | Early detection enables timely intervention. KDIGO/ADA guidelines. [10,30] | | ACEi/ARB prescribed for all diabetics with ACR ≥3 mg/mmol (microalbuminuria) | ≥90% | Proven renoprotection (20-40% RRR in ESRD). [5,6] | | SGLT-2 inhibitor prescribed for DKD (eGFR ≥20, ACR ≥30 or eGFR less than 60 with ACR ≥3) | ≥80% | 30-40% reduction in CKD progression (DAPA-CKD, CREDENCE). [4,13] Major practice gap – current prescribing rates ~20-30% in eligible patients. | | BP less than 130/80 mmHg achieved in DKD patients | ≥70% | Reduces GFR decline and CV events. KDIGO 2022 target. [18] | | HbA1c less than 53 mmol/mol (or individualised target) in diabetics | ≥60% | Reduces microvascular complications (DCCT/EDIC). [17] | | High-intensity statin prescribed for all DKD patients | ≥90% | Reduces CV events (leading cause of death in DKD – 80% die from CV events before ESRD). [19] | | Nephrology referral for eGFR less than 30 or rapid decline (> 5 mL/min/year) | 100% | Timely pre-dialysis planning (vascular access creation, transplant workup) and intervention. [14] | | Avoidance of NSAIDs documented/counselled in DKD patients | ≥95% | Prevent AKI and accelerated CKD progression. Common cause of preventable AKI. | | Annual retinal screening in all diabetic patients | ≥95% | Retinopathy co-exists with nephropathy in > 90% T1DM; absence warrants investigation. [8] | | ACEi/ARB dose optimisation (uptitrated to maximum tolerated dose, not just BP target) | ≥70% | Renoprotection is dose-dependent; higher doses confer greater antiproteinuric effect. Practice gap: many patients on suboptimal doses. |

---

15. Historical Context

Milestones in DKD Understanding and Treatment

Evolution of Terminology

• 1936-1990s: "Diabetic Nephropathy" (emphasis on proteinuria and glomerular pathology – Kimmelstiel-Wilson nodules)
• 2000s-present: "Diabetic Kidney Disease (DKD)" (broader term encompassing albuminuria, GFR decline, and heterogeneous pathology in T2DM – recognises that not all diabetic kidney disease follows classic Mogensen progression or exhibits nodular sclerosis)

---

16. References

1. United States Renal Data System (USRDS). 2023 Annual Data Report: Epidemiology of Kidney Disease in the United States. Am J Kidney Dis. 2024;83(3 Suppl 1):S1-S478. PMID: 38358847. DOI: 10.1053/j.ajkd.2023.07.001

2. Jha V, et al. Chronic kidney disease: global dimension and perspectives. Lancet. 2013;382(9888):260-272. PMID: 23727169. DOI: 10.1016/S0140-6736(13)60687-X

3. Tervaert TW, et al. Pathologic classification of diabetic nephropathy. J Am Soc Nephrol. 2010;21(4):556-563. PMID: 20167701. DOI: 10.1681/ASN.2010010010

4. Rossing P, et al. Predictors of mortality in insulin dependent diabetes: 10 year observational follow up study. BMJ. 1996;313(7060):779-784. PMID: 8842069. DOI: 10.1136/bmj.313.7060.779

5. Gregg EW, et al. Changes in diabetes-related complications in the United States, 1990-2010. N Engl J Med. 2014;370(16):1514-1523. PMID: 24738668. DOI: 10.1056/NEJMoa1310799

6. Thomas MC, et al. Diabetic kidney disease. Nat Rev Dis Primers. 2015;1:15018. PMID: 27188921. DOI: 10.1038/nrdp.2015.18

7. Gross JL, et al. Diabetic nephropathy: diagnosis, prevention, and treatment. Diabetes Care. 2005;28(1):164-176. PMID: 15616252. DOI: 10.2337/diacare.28.1.164

8. Wanner C, et al. Empagliflozin and Progression of Kidney Disease in Type 2 Diabetes. N Engl J Med. 2016;375(4):323-334. PMID: 27299675. DOI: 10.1056/NEJMoa1515920

9. Hallan SI, et al. Screening strategies for chronic kidney disease in the general population: follow-up of cross sectional health survey. BMJ. 2006;333(7577):1047. PMID: 17062598. DOI: 10.1136/bmj.39001.657755.BE

10. Heerspink HJL, et al. Dapagliflozin in Patients with Chronic Kidney Disease (DAPA-CKD). N Engl J Med. 2020;383(15):1436-1446. PMID: 32970396. DOI: 10.1056/NEJMoa2024816

11. Lewis EJ, et al. The effect of angiotensin-converting-enzyme inhibition on diabetic nephropathy (Captopril Collaborative Study). N Engl J Med. 1993;329(20):1456-1462. PMID: 8413456. DOI: 10.1056/NEJM199309303291401

12. Brenner BM, et al. Effects of losartan on renal and cardiovascular outcomes in patients with type 2 diabetes and nephropathy (RENAAL). N Engl J Med. 2001;345(12):861-869. PMID: 11565518. DOI: 10.1056/NEJMoa011303

13. Perkins BA, et al. Regression of microalbuminuria in type 1 diabetes. N Engl J Med. 2003;348(23):2285-2293. PMID: 12788992. DOI: 10.1056/NEJMoa021835

14. Parving HH, et al. Prevalence and risk factors for microalbuminuria in a referred cohort of type II diabetic patients: a global perspective. Kidney Int. 2006;69(11):2057-2063. PMID: 16612330. DOI: 10.1038/sj.ki.5000439

15. Mogensen CE. Microalbuminuria predicts clinical proteinuria and early mortality in maturity-onset diabetes. N Engl J Med. 1984;310(6):356-360. PMID: 6690964. DOI: 10.1056/NEJM198402093100605

16. KDIGO 2022 Clinical Practice Guideline for Diabetes Management in Chronic Kidney Disease. Kidney Int. 2022;102(5S):S1-S127. PMID: 36272764. DOI: 10.1016/j.kint.2022.06.008

17. Bakris GL, et al. Effect of Finerenone on Chronic Kidney Disease Outcomes in Type 2 Diabetes (FIDELIO-DKD). N Engl J Med. 2020;383(23):2219-2229. PMID: 33264825. DOI: 10.1056/NEJMoa2025845

18. Pitt B, et al. Cardiovascular Events with Finerenone in Kidney Disease and Type 2 Diabetes (FIGARO-DKD). N Engl J Med. 2021;385(24):2252-2263. PMID: 34449181. DOI: 10.1056/NEJMoa2110956

19. Perkovic V, et al. Canagliflozin and Renal Outcomes in Type 2 Diabetes and Nephropathy (CREDENCE). N Engl J Med. 2019;380(24):2295-2306. PMID: 30990260. DOI: 10.1056/NEJMoa1811744

20. Krolewski AS, et al. Fast renal decline to end-stage renal disease: an unrecognized feature of nephropathy in diabetes. Kidney Int. 2017;91(6):1300-1311. PMID: 28187985. DOI: 10.1016/j.kint.2017.01.013

21. Groop PH, et al. The presence and severity of chronic kidney disease predicts all-cause mortality in type 1 diabetes. Diabetes. 2009;58(7):1651-1658. PMID: 19401416. DOI: 10.2337/db08-1543

22. Freedman BI, et al. Genetic factors in diabetic nephropathy. Clin J Am Soc Nephrol. 2012;7(3):543-554. PMID: 22300737. DOI: 10.2215/CJN.07850811

23. The Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) Research Group. Intensive Diabetes Treatment and Cardiovascular Outcomes in Type 1 Diabetes: The DCCT/EDIC Study 30-Year Follow-up. Diabetes Care. 2016;39(5):686-693. PMID: 26861924. DOI: 10.2337/dc15-2143

24. Emdin CA, et al. Blood pressure lowering in type 2 diabetes: a systematic review and meta-analysis. JAMA. 2015;313(6):603-615. PMID: 25668264. DOI: 10.1001/jama.2014.18574

25. Go AS, et al. Chronic kidney disease and the risks of death, cardiovascular events, and hospitalization. N Engl J Med. 2004;351(13):1296-1305. PMID: 15385656. DOI: 10.1056/NEJMoa041031

26. Cherney DZI, et al. Renal hemodynamic effect of sodium-glucose cotransporter 2 inhibition in patients with type 1 diabetes mellitus. Circulation. 2014;129(5):587-597. PMID: 24334175. DOI: 10.1161/CIRCULATIONAHA.113.005081

27. Reidy K, et al. Molecular mechanisms of diabetic kidney disease. J Clin Invest. 2014;124(6):2333-2340. PMID: 24892707. DOI: 10.1172/JCI72271

28. Pagtalunan ME, et al. Podocyte loss and progressive glomerular injury in type II diabetes. J Clin Invest. 1997;99(2):342-348. PMID: 9006003. DOI: 10.1172/JCI119163

29. ONTARGET Investigators. Telmisartan, ramipril, or both in patients at high risk for vascular events. N Engl J Med. 2008;358(15):1547-1559. PMID: 18378520. DOI: 10.1056/NEJMoa0801317

30. Ikizler TA, et al. KDOQI Clinical Practice Guideline for Nutrition in CKD: 2020 Update. Am J Kidney Dis. 2020;76(3 Suppl 1):S1-S107. PMID: 32829751. DOI: 10.1053/j.ajkd.2020.05.006

31. Alicic RZ, et al. Diabetic Kidney Disease: Challenges, Progress, and Possibilities. Clin J Am Soc Nephrol. 2017;12(12):2032-2045. PMID: 28522654. DOI: 10.2215/CJN.11491116

32. Tuttle KR, et al. Molecular mechanisms and therapeutic targets for diabetic kidney disease. Kidney Int. 2022;102(2):248-260. PMID: 35667476. DOI: 10.1016/j.kint.2022.05.012

33. Neal B, et al. Canagliflozin and Cardiovascular and Renal Events in Type 2 Diabetes (CANVAS Program). N Engl J Med. 2017;377(7):644-657. PMID: 28605608. DOI: 10.1056/NEJMoa1611925

34. Wiviott SD, et al. Dapagliflozin and Cardiovascular Outcomes in Type 2 Diabetes (DECLARE-TIMI 58). N Engl J Med. 2019;380(4):347-357. PMID: 30415602. DOI: 10.1056/NEJMoa1812389

35. de Boer IH, et al. Diabetes and Hypertension: A Position Statement by the American Diabetes Association. Diabetes Care. 2017;40(9):1273-1284. PMID: 28830958. DOI: 10.2337/dci17-0026

---

---

18. Differential Diagnosis: Non-Diabetic Kidney Disease in Diabetics

When diabetic patients present with renal impairment, always consider non-diabetic kidney disease (NDKD) or mixed pathology (DKD + NDKD). Studies suggest 20-40% of biopsied diabetic patients have NDKD (isolated) or mixed pathology.

Clinical Features Suggesting NDKD

Common NDKD in Diabetic Patients

1. IgA Nephropathy

• Most common NDKD in diabetic patients (30-40% of NDKD cases)
• Presentation: Episodic macroscopic haematuria (often post-URTI), persistent microscopic haematuria, proteinuria (range: mild to nephrotic)
• Biopsy: Mesangial IgA deposition (immunofluorescence), mesangial proliferation ± crescents (light microscopy)
• Treatment: ACEi/ARB (reduce proteinuria), SGLT2i (DAPA-CKD included IgAN patients), corticosteroids if proteinuria > 1g/day despite maximal RASi (per TESTING/STOP-IgAN trials), consider mycophenolate/cyclophosphamide if crescentic

2. Membranous Nephropathy

• Second most common (20-30% of NDKD)
• Presentation: Nephrotic syndrome (proteinuria > 3.5g/24h, hypoalbuminaemia, oedema), gradual onset
• Associations: Primary (PLA2R antibodies 70-80%), secondary (malignancy in 10-20% if > 60y, NSAIDs, SLE, hepatitis B)
• Biopsy: GBM thickening with subepithelial "spikes" (silver stain), granular IgG/C3 (immunofluorescence), subepithelial deposits (EM)
• Treatment: If PLA2R+: Immunosuppression (rituximab first-line, or cyclical cyclophosphamide + steroids). If secondary: Treat underlying cause. Supportive: ACEi/ARB, SGLT2i, statins, anticoagulation if albumin less than 20g/L

3. ANCA-Associated Vasculitis (Microscopic Polyangiitis, GPA)

• Rapidly progressive glomerulonephritis (RPGN)
• Presentation: Acute kidney injury (creatinine rise over days-weeks), haematuria (dysmorphic RBCs, RBC casts), oliguria, systemic features (haemoptysis, sinusitis, purpura, arthralgia, constitutional symptoms)
• Investigations: ANCA positive (c-ANCA/PR3 in GPA, p-ANCA/MPO in MPA), elevated CRP/ESR
• Biopsy: Crescentic glomerulonephritis, necrotising lesions, pauci-immune (negative immunofluorescence)
• Treatment: Urgent (dialysis-dependency risk if untreated). Induction: Cyclophosphamide or rituximab + high-dose steroids (methylprednisolone 500mg-1g IV x3 days, then prednisolone 1mg/kg). Plasma exchange if dialysis-dependent or pulmonary haemorrhage. Maintenance: Azathioprine or rituximab

4. Focal Segmental Glomerulosclerosis (FSGS)

• Presentation: Nephrotic syndrome, progressive CKD
• Associations: Obesity (obesity-related glomerulopathy), HIV (HIVAN), genetic (podocin mutations), secondary to hyperfiltration (single kidney, reflux nephropathy)
• Biopsy: Segmental sclerosis affecting some (not all) glomeruli, podocyte foot process effacement (EM)
• Treatment: ACEi/ARB + SGLT2i (reduce proteinuria + slow GFR decline). If primary FSGS with nephrotic syndrome: Corticosteroids (prednisolone 1mg/kg x4-6 months). If steroid-resistant: Calcineurin inhibitors (tacrolimus, ciclosporin), rituximab, mycophenolate

5. Acute Interstitial Nephritis (AIN)

• Drug-induced (NSAIDs 30-40%, PPIs 10-20%, antibiotics [β-lactams, rifampicin, sulfonamides], allopurinol)
• Presentation: Subacute AKI (over days-weeks), sterile pyuria, eosinophiluria (60% sensitive), ± rash/fever/eosinophilia (classic triad only 10-15%)
• Biopsy: Interstitial oedema, inflammatory infiltrate (lymphocytes, eosinophils, plasma cells), tubulitis
• Treatment: Stop offending drug. If severe/progressive: Corticosteroids (prednisolone 1mg/kg x4-6 weeks, taper over 2-3 months). Supportive: Dialysis if oliguric AKI

When to Biopsy

Definite Indications (High likelihood NDKD):

• Absence of diabetic retinopathy in T1DM with proteinuria/CKD
• Haematuria (especially dysmorphic RBCs, RBC casts)
• Rapid GFR decline (> 5 mL/min/y) without clear cause (NSAIDs, AKI)
• Short diabetes duration (less than 5y T1DM, less than 10y T2DM) with significant CKD
• Nephrotic syndrome in T2DM without retinopathy
• Systemic features (rash, arthralgia, haemoptysis suggesting vasculitis/SLE)

Consider Biopsy (Moderate likelihood NDKD):

• T2DM with rapidly progressive proteinuria (ACR 0 → > 100 within 6 months)
• Unexplained AKI superimposed on CKD (no clear nephrotoxin/dehydration)
• Diabetic duration > 15 years but no retinopathy (unusual; typically coexist)

Biopsy Not Needed (Classic DKD):

• T1DM > 15 years' duration, concurrent retinopathy, gradual albuminuria progression, no haematuria, no systemic features
• T2DM with retinopathy, hypertension, gradual CKD progression (eGFR decline 3-5 mL/min/y)

Mixed Pathology (DKD + NDKD)

Prevalence: 10-20% of biopsied diabetic patients have dual pathology (e.g., diabetic glomerulosclerosis + superimposed IgA nephropathy or membranous nephropathy)

Management Implications:

• If IgAN + DKD: Standard DKD treatment (ACEi/ARB + SGLT2i) often sufficient. Add corticosteroids if proteinuria > 1g/day despite maximal therapy
• If membranous + DKD: Requires immunosuppression if primary (PLA2R+) or treat underlying cause if secondary
• If ANCA vasculitis + DKD: Urgent immunosuppression (cyclophosphamide/rituximab + steroids) – do not delay for biopsy if high clinical suspicion

---

19. Procedure: Renal Biopsy in Diabetic Patients

Indications (as per Section 18)

• Atypical features suggesting non-diabetic kidney disease
• Rapid GFR decline > 5 mL/min/year
• Absence of retinopathy in T1DM with proteinuria
• Active urinary sediment (haematuria, casts)
• Systemic features (vasculitis, SLE)

Pre-Biopsy Assessment

Medication Adjustments:

• Stop 7-10 days pre-biopsy: Aspirin, clopidogrel, NSAIDs (irreversible platelet inhibition)
• Stop 5 days pre-biopsy: Warfarin (bridge with LMWH if high VTE risk; stop LMWH 24h pre-biopsy)
• Stop 48h pre-biopsy: DOACs (apixaban, rivaroxaban, dabigatran)
• Continue: ACEi/ARB, SGLT2i (no bleeding risk)

Procedure

Technique: Ultrasound-guided percutaneous core needle biopsy (16-18 gauge needle), lower pole left or right kidney

Anaesthesia: Local anaesthetic (1% lignocaine infiltration)

Samples: 2-3 cores (light microscopy, immunofluorescence, electron microscopy)

Duration: 30-60 minutes (including post-procedure observation)

Post-Biopsy Protocol

Immediate (0-6 hours):

• Strict bed rest, supine position
• Sandbag on biopsy site (external compression)
• Vital signs every 15 minutes x4, then hourly x6 hours
• Monitor for: Flank pain (haematoma), hypotension (bleeding), gross haematuria

6-24 hours:

• Mobilise gradually if stable
• Check Hb at 6h and 24h post-biopsy (compare to baseline)
• Urinalysis (haematuria expected transiently)

Discharge Criteria (24 hours post-biopsy):

• Haemodynamically stable (BP, HR normal)
• Hb drop less than 20 g/L from baseline
• No gross haematuria (microscopic haematuria acceptable)
• Pain controlled with oral analgesia

Complications

Histological Findings in DKD

• Glomeruli: Kimmelstiel-Wilson nodules (30-50%), diffuse mesangial expansion (90%), GBM thickening (> 400nm), glomerulosclerosis
• Tubules/Interstitium: Tubulointerstitial fibrosis (correlates with eGFR), tubular atrophy, Armanni-Ebstein lesion (glycogen in tubular cells – rare)
• Vessels: Arteriolar hyalinosis (afferent + efferent; efferent involvement more specific for DKD)
• Immunofluorescence: Typically negative (linear IgG may be seen in advanced disease)
• EM: GBM thickening, podocyte foot process effacement, mesangial matrix expansion

---

20. Special Populations

Pregnancy and Diabetic Kidney Disease

Pre-Conception Counselling:

• Assess baseline renal function: eGFR, ACR
• Optimise before conception: HbA1c less than 48 mmol/mol (6.5%), BP less than 135/85, ACR as low as possible
• STOP nephrotoxic medications:
  • "ACEi/ARB: Teratogenic (renal agenesis, oligohydramnios, IUGR). STOP before conception. Switch to methyldopa (250-500mg TDS) or labetalol (100-400mg BD) for BP control"
  • "SGLT2i: Limited pregnancy data. STOP before conception"
  • "Finerenone: No pregnancy data. STOP before conception"
  • "Statins: Teratogenic. STOP 3 months pre-conception"

Pregnancy Risks with DKD:

Management During Pregnancy:

• BP control: Target less than 140/90 mmHg (avoid less than 110/70 – placental hypoperfusion). Use methyldopa (first-line), labetalol, nifedipine
• Proteinuria monitoring: ACR increases physiologically in pregnancy. Superimposed pre-eclampsia if: ACR rise > 3-fold, HTN ≥140/90, thrombocytopaenia, elevated transaminases
• Glycaemic control: Target fasting less than 5.3 mmol/L, 1h post-prandial less than 7.8 mmol/L, 2h less than 6.4 mmol/L. Use insulin (safe in pregnancy). Metformin acceptable (especially in pre-existing T2DM)
• Renal function monitoring: Creatinine, eGFR monthly (expect slight eGFR decline due to increased maternal blood volume, hyperfiltration)
• Fetal surveillance: Serial growth scans (IUGR risk), umbilical artery Doppler, CTG from 32 weeks
• Delivery timing: Aim 37-38 weeks if well-controlled. Earlier if pre-eclampsia, IUGR, declining renal function

Post-Partum:

• Resume ACEi/ARB if not breastfeeding (safe if breastfeeding: enalapril, captopril – avoid others)
• Resume SGLT2i if breastfeeding stopped (insufficient lactation data)
• Expect eGFR recovery to baseline by 3-6 months post-partum (if reversible pregnancy-related decline)
• Contraception: Progesterone-only pill, LNG-IUS, copper IUD safe. Avoid COCP if CKD G3+ (VTE risk)

Elderly Patients (> 75 years) with DKD

Special Considerations:

• Competing risks: CV death often precedes ESRD (median survival less than 10 years if age > 75 + CKD G4)
• Polypharmacy: Average 8-12 medications; drug-drug interactions, adherence challenges
• Frailty: Sarcopenia (reduced creatinine production → eGFR overestimation; use cystatin C-based eGFR if discrepancy suspected)
• Hypoglycaemia risk: Reduced renal insulin clearance → prolonged hypoglycaemia

Management Adjustments:

• HbA1c target: Relaxed to 58-64 mmol/mol (avoid hypoglycaemia; tight control less beneficial if limited life expectancy)
• BP target: less than 140/90 mmHg (avoid aggressive lowering less than 130/80 – orthostatic hypotension, falls risk)
• ACEi/ARB: Continue if tolerated (CV benefit, slows GFR decline). Monitor closely for hyperkalaemia (reduced GFR + age-related aldosterone deficiency)
• SGLT2i: Beneficial (CV + renal protection). Caution: Genital infections (more complicated if frail), volume depletion (reduce diuretic dose)
• Dialysis: Individualised decision (consider quality of life, frailty, patient preference). Conservative kidney management (CKM) without dialysis increasingly recognised as acceptable pathway if extensive comorbidities, frailty, limited functional status

Type 1 Diabetes and Advanced Technology

Continuous Glucose Monitoring (CGM) + Insulin Pumps:

• Advantage: Reduced hypoglycaemia (CGM alerts prevent prolonged hypoglycaemia), improved time-in-range (70-180 mg/dL)
• DKD relevance: Hypoglycaemia worsens in CKD (reduced renal gluconeogenesis, reduced insulin clearance). CGM reduces hypoglycaemia by 40-50% vs finger-prick monitoring
• Automated insulin delivery (AID) systems: Hybrid closed-loop (adjust basal insulin automatically based on CGM). Particularly beneficial in CKD (reduce nocturnal hypoglycaemia)

Insulin Dose Adjustments in CKD:

---