Relative energy deficiency in sport and athlete nutrition — formative SAQs

SAQ 1 (10 marks) — The fifteen-year-old runner with shin pain and no period for four months

Stem: A fifteen-year-old competitive cross-country runner presents with six weeks of progressive right shin pain that now forces her to stop running, and her mother reports she has not had a menstrual period for four months. She trains six days a week and her mother believes her food intake has not changed despite the increased training. Her body mass index has fallen from the fortieth to the twenty-fifth centile over the year. She is afebrile, her heart rate is forty-eight beats per minute, and she has focal tibial tenderness. Outline your assessment, investigations, and management. [9] [4]

Model answer

Assessment and risk stratification (3 marks). This adolescent female endurance athlete has the classic Female Athlete Triad presentation — a bone stress injury, the secondary amenorrhoea of four months, and the falling body mass index that signals the low energy availability. The heart rate of forty-eight beats per minute is the bradycardia of the physiological down-regulation. The secondary amenorrhoea is defined as the absence of menses for three or more months, and it is the most reliable clinical marker of the energy deficit. The falling body mass index and the unchanged intake against the increased training point to the inadvertent undereating, and the energy availability is below the threshold. The fellowship skill is to treat every bone stress injury in a young female athlete as the tip of the energy-deficiency iceberg. [9] [4]

Investigations (3 marks). The endocrine laboratory tests confirm the functional hypothalamic amenorrhoea — the low or low-normal gonadotropins and the low oestradiol of the hypogonadotrophic hypogonadism — and exclude the mimics, with the prolactin, the thyroid-stimulating hormone, and the morning cortisol. The nutritional tests screen the ferritin for the iron deficiency and the 25-hydroxyvitamin D for the deficiency, with the sufficiency defined as fifty nanomoles per litre or above. The bone density is measured by the dual-energy X-ray absorptiometry at the lumbar spine and reported with the age-matched Z-score, never the T-score. The tibial pain is imaged with the magnetic resonance imaging, which reveals the bone marrow oedema of the stress reaction and the fracture line, because the high-risk site must be excluded and the delay risks the displacement. [6] [9]

Management (4 marks). The definitive management is the energy restoration as the first-line treatment, with the increase in the dietary intake toward the optimal energy availability of approximately forty-five kilocalories per kilogram of fat-free mass per day and the reduction in the training load. The Endocrine Society guideline frames the energy restoration as the first-line treatment for the functional hypothalamic amenorrhoea, and the combined oral contraceptive pill is not the first-line treatment because it does not restore the bone and it masks the menstrual signal. The calcium is optimised toward thirteen hundred milligrams per day for the adolescent, the vitamin D is supplemented to maintain the level at fifty nanomoles per litre or above, and the iron is supplemented when the ferritin is low. The tibial stress injury is managed with the protected weight-bearing and the graded rehabilitation, and the high-risk athlete is restricted from the training and the competition until the energy availability is restored, the menstrual function is recovering, and the bone is healed. The multidisciplinary team of the paediatrician, the dietitian, the psychologist, and the physiotherapist owns the clearance, and the premature return risks the recurrent fracture and the irreversible bone loss. [6] [4]

SAQ 2 (10 marks) — The sixteen-year-old dancer with a sacral stress fracture and a falling weight

Stem: A sixteen-year-old ballet dancer presents with three weeks of low-back and buttock pain that is worse with activity and a limp. She restricts her food intake to maintain her leanness for performance, and her body mass index has fallen across the centiles to the fifteenth. Her last menstrual period was eight months ago. Her heart rate is forty-four beats per minute and her blood pressure is ninety over fifty-five with a postural drop. Outline your assessment, investigations, and management. [4] [9]

Model answer

Assessment and risk stratification (3 marks). This is the high-risk athlete with the manifest eating disorder driving the energy deficit — the drive for thinness with the food restriction, the falling body mass index to the fifteenth centile, the prolonged secondary amenorrhoea of eight months, and the bradycardia and the orthostatic hypotension that mark the advanced deficit. The buttock pain with the limp in this context is the sacral stress fracture, a high-risk site, until the imaging proves otherwise. The risk stratification by the Female Athlete Triad Cumulative Risk Assessment places her in the high-risk category, and she is restricted from the training and the competition. The fellowship skill is to frame the eating disorder as the medical condition that drives the highest-risk deficit and to escalate to the urgent pathway. [4] [9]

Investigations (3 marks). The endocrine laboratory tests confirm the functional hypothalamic pattern and exclude the mimics, with a pregnancy test performed before the endocrine workup in the sexually active adolescent. The electrolytes, the phosphate, the magnesium, and the renal and the liver function frame the medical stability and the refeeding risk. The electrocardiogram confirms the bradycardia and screens for the arrhythmia of the advanced deficit. The bone density is measured by the dual-energy X-ray absorptiometry with the Z-score, and the sacral pain is imaged urgently with the magnetic resonance imaging to confirm the stress fracture and exclude the displacement. The pelvic and the sacral imaging is prioritised because the high-risk site demands the urgent pathway. [6] [9]

Management (4 marks). The medical instability with the bradycardia, the orthostatic hypotension, and the marked weight loss demands the hospital admission, the cardiac monitoring, and the careful, supervised refeeding with the phosphate, the magnesium, and the potassium monitoring and the thiamine before the first feed, because the rapid refeeding carries the refeeding syndrome. The sacral stress fracture is managed with the protected weight-bearing and the pain control. The energy restoration is the definitive treatment, with the increase in the intake toward the optimal energy availability and the weight restoration, delivered by the dietitian. The psychological management is the load-bearing part, and the specialist eating-disorder service is engaged for the drive for thinness. The combined oral contraceptive pill is not the first-line treatment for the bone. The high-risk athlete is restricted from play until the energy is restored, the menstrual function is recovering, the bone is healed, and the eating disorder is treated, and the multidisciplinary team owns the clearance. [6] [4]