Gender differences in hypoglycaemia in type 1 and insulin-treated type 2 diabetes: the Hypo-METRICS study

The aim of this study was to explore associations between gender and hypoglycaemia experience among people with type 1 diabetes or insulin-treated type 2 diabetes in a free-living environment in the Hypo-METRICS study.

The Hypo-METRICS study was a 10-week prospective, cross-sectional observational study of the hypoglycaemia experience. Participants (274 with type 1 diabetes and 321 with type 2 diabetes) wore blinded continuous glucose monitor (CGM) devices and recorded their hypoglycaemia symptoms in real time using a bespoke Hypo-METRICS app. Symptomatic hypoglycaemia was defined as a glucose level <4 mmol/l or any episode of hypoglycaemic symptoms that was resolved by carbohydrate ingestion. Hypoglycaemia symptoms were defined as autonomic (hunger, sweating, shaking, palpitations) or neuroglycopenic (confusion, difficulty speaking, coordination difficulties, headache). Differences between genders were assessed using χ², Fisher's exact and Wilcoxon rank-sum tests and combination analyses.

In the type 1 diabetes cohort, 54% were women and 76% of the entire cohort used CGM routinely. In the type 2 diabetes cohort, 63% were men and 41% of the entire cohort used CGM routinely. There were no significant differences in time in hypoglycaemia between genders in either cohort (all p>0.05), but women reported more episodes of symptomatic hypoglycaemia per week (4.3 vs 3.3 episodes/week in the type 1 diabetes cohort [p=0.003]; 1.4 vs 1.0 episodes/week in the type 2 diabetes cohort [p=0.006]). In the type 1 diabetes cohort, women reported a broader range of symptom combinations, spanning autonomic and neuroglycopenic symptoms. Confusion was the only reported symptom of hypoglycaemia in 0.9% of episodes in women and 2.3% of episodes in men. In the type 2 diabetes cohort, there were more symptom combinations, and both genders reported a combination of autonomic and neuroglycopenic symptoms. Confusion alone accounted for 0.3% of symptomatic episodes in men in the type 2 diabetes cohort; confusion alone was not observed in women.

Despite similar exposures to hypoglycaemia, there were differences in hypoglycaemia symptoms between genders in this free-living environment. Further work is needed to elucidate the potential underlying causes of these findings.