The effects of fat distribution and some adipokines on insulin resistance

The risk of developing insulin resistance and metabolic syndrome is particularly high in central obesity. In this study we evaluated the effects of fat distribution and some adipokines on insulin resistance in prediabetic patients.

Eighty-seven age- and sex-matched patients were divided into three groups according to their 75-gram oral glucose tolerance test results as follows: impaired fasting glucose group, impaired glucose tolerance group, and normal glucose tolerance group. Fasting insulin levels were measured. Homeostatic model assessment of insulin resistance was calculated. Body fat mass measurements were assessed by bioelectric impedance analyser and abdominal fat thicknesses (subcutaneous, visceral, and preperitoneal) by ultrasonography. The fasting serum levels of several adipokines [adiponectin, leptin, resistin, vaspin, visfatin, retinol-binding protein-4 (RBP-4), tumour necrosis factor-alpha (TNF-alpha)] were measured by ELISA method.

The mean body mass index, fat mass measurements, and abdominal fat thicknesses of the groups were similar. There were no differences between groups in terms of the mean fasting insulin, vaspin, RBP-4, leptin, resistin, and TNF-alpha. In comparison of the prediabetic and normal groups, the levels of adiponectin (p < 0.001) and visfatin (p < 0.001) were lower in the prediabetic group. Furthermore, we found that high body mass index (p < 0.01) and fat mass (p < 0.01) and low adiponectin (p < 0.05) levels have roles in the development of insulin resistance in the prediabetic group.

We suggested that in the prediabetic period not only obesity but also decreased adiponectin levels play some role in the pathogenesis of insulin resistance. (Endokrynol Pol 2016; 67 (3): 277-282).