GENDER DIFFERENCES IN COUNTERREGULATION TO HYPOGLYCEMIA

To investigate the effect of gender on catecholamine responses to hypo glycaemia, single-step euglycaemic-hypoglycaemic clamps have been perf ormed in 14 healthy men and 17 women. Adrenaline responses were 44 % l ower in females (p < 0.01) and noradrenaline 17% lower (p = 0.08). In response to low-dose intravenous insulin infusion (0.3 mU - kg-1 . min -1), plasma glucose fall and counterregulation in seven men and seven women had a different course (p < 0.001), with different glucose kinet ics. In men, endogenous glucose output recovered quickly to levels tha t exceeded basal; in women suppression of endogenous glucose output wa s more prolonged, without rates ever exceeding basal (p < 0,05). Perip heral glucose uptake was stimulated in men only. The hormones of acute glucose counterregulation (catecholamines and glucagon) did not diffe r between the sexes during this challenge, the catecholamine response in the women being supported by the continuous fall in plasma glucose. These results suggest that: 1) catecholamine responses to moderately controlled hypoglycaemia are diminished in women, and 2) peripheral in sulin sensitivity in men is enhanced over that of women but hepatic se nsitivity to insulin may be greater in women.