Sex-differences in insulin sensitivity and insulin secretion in subjects with impaired fasting glucose and impaired glucose tolerance

Aims: To assess sex-related differences in whole-body insulin sensitivity and insulin secretion in a group of Caucasian subjects with varying degrees of glucose tolerance. Methods: Sex-related differences in insulin sensitivity using the hyperinsulinemic-euglycemic clamp technique and insulin secretion using validated indexes obtained during an oral glucose tolerance test were examined among 570 non-diabetic offspring individuals having only one parent with type 2 diabetes. Participants were classified as having with NGT, isolated impaired fasting glucose (IFG), isolated impaired glucose tolerance (IGT) and combined IFG/IGT. Results: Isolated IFG, isolated IGT, and combined IFG/IGT women exhibited greater relative differences in BMI, waist circumference, and insulin-stimulated glucose disposal than their male counterparts. Formal tests for glucose tolerance status x sex interaction were statistically significant for BMI (P = 0.05) waist circumference (P = 0.04), and insulin-stimulated glucose disposal (P = 0.01) suggesting a sex-specific association. By contrast, tests for glucose tolerance status x sex interaction regarding both insulinogenic and disposition indexes were not significant. Conclusions: This study suggests that deterioration of glucose homeostasis in women is associated with a greater fat accumulation and worsening in insulin sensitivity as compared with men.