Eating disorders are characterised by a persistent disturbance of eating-related behaviour that results in the altered consumption or absorption of food, and significantly impairs physical health or psychosocial functioning.1 Hypoglycaemia is common in eating disorders. An US cohort study of adult inpatients with severe anorexia nervosa (AN) found that a blood glucose level (BGL) < 3.3mmol/L occurred in 44% of patients and a BGL < 2.2 mmol/L occurred in 12% of patients.2 Severe derangement of liver enzymes predicted the development of mild hypoglycaemia.2
Hypoglycaemia may have deleterious effects on patients' ability to perform high risk tasks safely, especially when there is impaired hypoglycaemia awareness. The pathophysiology of hypoglycaemia in eating disorders is multifactorial. Dietary restriction and excessive exercise results in the depletion of hepatic glycogen stores and impaired hepatic gluconeogenesis.3 Impaired glucagon secretion has also been described.4 Refeeding can also result in hypoglycaemia, particularly in those with prolonged and severe malnutrition. An Australian cohort study of inpatients at a specialist eating disorders unit found that, following a mixed meal, 22% of patients recorded a postprandial BGL <3.5 mmol/l and 3.9% of patients recorded a postprandial BGL < 2 mmol/L.5 Only low BMI significantly predicted postprandial hypoglycaemia.5
There is limited case report data to suggest that postprandial hypoglycaemia may occur with refeeding after starvation as a result of exaggerated insulin secretion during the very early phase.6 Early studies in people with AN produced inconsistent results regarding insulin sensitivity7, 8, and the glucose and insulin response post-glucose load has been shown to vary based on OGTT results prior to refeeding.9 There is limited data to suggest that insulin clearance is significantly increased in people with AN10.
This presentation will include a critical review of the existing literature on hypoglycaemia and eating disorders, and we will also discuss usual practice and management strategies in the context of existing guidelines.