Gender-related difference in relationship between insulin resistance and serum leptin level in Japanese type 2 diabetic and non-diabetic subjects

It remains controversial whether or not a correlation exists between serum leptin levels and insulin resistance, and, if such a correlation does exist , whether it is independent of adiposity. To investigate the possible exist ence of an independent correlation, we have assessed serum leptin levels an d insulin resistance in Japanese diabetic and non-diabetic subjects by mean s of Homeostatic Model Assessment (HOMA-R). Sixty-four Japanese patients wi th Type 2 diabetes mellitus (DM) (33 men and 31 women) and 53 sex-, age-, a nd body mass index (BMI)-matched non-diabetic adults (29 men and 24 women) were enrolled. The fasting plasma level of glucose (FPG) and the fasting se rum levels of immunoreactive insulin (FIRI) and leptin were determined. Mul tiple linear regression analysis demonstrated that, in both male diabetic a nd male non-diabetic subjects, HOMA-R and BMI were independently correlated with serum leptin levels. In females, BMI, but not HOMA-R, was correlated to the serum levels of leptin in both groups. There was no statistically si gnificant difference in the partial regression coefficients between male di abetic and male non-diabetic subjects. These results suggest that the corre lation of HOMA-R to the serum levels of leptin in females is dependent on B MI. In males, the relationship between serum leptin levels and the insulin resistance was not affected by the extent of glucose intolerance.