Endocrine Abstracts

Objective: Adipocytokines appear to be important in regulating insulin sensitivity. The objective of this study was to compare the levels of adiponectin and leptin in lean, obese and obese diabetic (OD) postmenopausal female (PMF) subjects during 6 months follow-up of Metformin therapy (MT).

Methods: We examined plasma levels of adiponectin and leptin in 26 OD PMF with a mean body mass index (BMI) of 36.6±1.8, 10 obese (BMI=35.9±2.2) and 10 lean (BMI=22.3±1.9) individuals. The investigation was approved by the local ethics committees. All participants gave informed, written consent before starting the trial. Insulin resistance (IR) was assessed using the homeostasis model assessment.

Results: Baseline characteristics of all groups shown that adiponectin was significantly decreased and leptin is significantly elevated in OD PMF and obese subjects in comparison with leans (P<0.001 and P=0.003, respectively). There was a tendency for adiponectin levels to be lower in OD PMF as compared with obese individuals (P=0.053). OD PMF were more insulin resistant than obese and lean subjects (P<0.001). Results of MT shown that circulating adiponectin levels were significantly increased (16.1±3.9 vs. 19.1±6.0 ng/ml, P=0.008) with significant reduction of BMI and IR (P=0.005 and P<0.001, respectively). Leptin levels did not change significantly.

Conclusions: Circulating adiponectin levels is significantly reduced in OD PMF in comparison with obese and lean subjects. Hypoadiponectinemia in PMF may be explained by only IR because the amelioration of whole-body insulin action by MT causes the increase of serum adiponectin levels. Leptin levels in OD PMF are not significantly different from leptin levels of obese subjects, although they significantly differ from leptin levels of lean individuals.