AIM: Differences in fat accumulation and distribution might be responsible for the greater insulin resistance (IR) in type 2 diabetes. The study aims at examining the relationship between fat accumulation and distribution, and insulin secretion and action, by multilevel methodological approach.
METHODS: Thirty-three diabetic men (D), and 28 sex, age and BMI-matched controls (C) were studied for glucose and insulin during OGTT, insulin resistance and sensitivity, employing HOMA and Matsuda index respectively, and, fat accumulation and distribution by anthropometrics, Bioimpendance Analysis (BIA), and multiple slices MRI of abdomen and hip.
RESULTS: D exhibited higher HOMA compared to C (P<0.001), and lower Matsuda index (P=0.062). No differences in fat distribution by anthropometric or MRI measurements were observed; however, fat accumulation by BIA was higher in D (P=0.035). HOMA correlated to basal, AUC, and peak insulin in both groups (all P<0.001); with weight (r=0.415, P=0.031), hip circumference (HC) (r=0.482, P=0.011), %fat (r=0.400, P<0.05) in C; and with weight, BMI, total and %fat, and waist and HC when all subjects were considered as a group. Matsuda inversely correlated with basal, AUC, and peak insulin (all P<0.001), and HC (r=-0.406, P=0.032) in C. HOMA strongest correlated with L3-L4 subcutaneous (r=0.551, P=0.003) in C, and with L3-L4 visceral (r=0.456, P=0.022) in D.
CONCLUSION: The greater IR in diabetic patients may not be interpreted by differences in fat distribution. IR correlates with different fat compartments in healthy and diabetic subjects of comparable fat distribution, suggesting differences in fat function.