Correlated increase of omentin-1 and adiponectin by exenatide, avandamet and dietary change in diet-induced obese rats.

Adipokines omentin-1 and adiponectin have been reported to improve insulin resistance. It is known that insulin sensitizers exenatide, avandamet, or diet change from high-fat to normal chow ameliorate metabolic disorders. However, whether these treatments increase omentin-1 levels in high fat-diet animals and the relationship between omentin- 1 and adiponectin remain largely unknown. We investigated the effect of insulin sensitizers exenatide and avandamet, and of dietary change on these adipokine levels, body weight, and insulin sensitivity in diet-induced obese rats. Obesity was induced in rats by high-fat diet feeding for 8 weeks, and then the rats were given exenatide, avandamet and diet change to normal chow, respectively, for additional 8 weeks. Compared to the high-fat control group, exenatide and avandamet treatment significantly induced adipose gene expression and elevated the circulation levels of omentin-1 and adiponectin, whereas they decreased the leptin gene expression and circulation level, which is associated with improvement of systemic insulin sensitivity and the glucose and lipid profile. Notably, there was a significant positive correlation between omentin-1 and adiponectin in the above regimens, suggesting that omentin-1 and adiponectin may contribute to the insulin-sensitizing effect of exenatide and avandamet.