Pioglitazone-induced body weight gain is prevented by combined administration with the lipoprotein lipase activator NO-1886

Pioglitazone improves insulin resistance in diabetics but often causes body weight gain. The lipoprotein lipase activator NO-1886 has been shown to exert both anti-obesity and anti-insulin-resistance effects. In this study, we investigated the effect of the combined administration of pioglitazone with NO-1886 (pioglitazone + NO-1886) in preventing body weight gain in insulin-resistant, high-fat fed rats. The rats were fed a standard or high-fat diet for 16 weeks. The high-fat fed rats were randomized at week 9 into 4 groups (i.e., control, pioglitazone (30 mg/kg/day), NO-1886 (100 mg/kg/day), and pioglitazone + NO-1886 (30 and 100 mg/kg/day, respectively)). The high-fat fed control rats developed obesity and insulin resistance. After 7 weeks of drug treatment, pioglitazone + NO-1886 was found to prevent the body weight gain caused by pioglitazone alone (pioglitazone + NO-1886: Δ76.0 ± 16.8 g vs. pioglitazone: Δ127.8 ± 39.5 g, P < 0.05) and to increase glucose infusion rate during insulin clamp, compared with the results in the high-fat fed control group. No differences in plasma nonesterified fatty acid, leptin, adiponectin, glucose, or insulin levels were observed between the pioglitazone + NO-1886 and the pioglitazone-alone groups. However, plasma total cholesterol and HDL-cholesterol levels were significantly increased and plasma triglyceride levels were slightly decreased in the pioglitazone + NO-1886 group, compared with the values in the pioglitazone-alone group. In summary, the combined administration of pioglitazone and NO-1886 prevented the pioglitazone-induced body weight gains and ameliorated insulin resistance observed in high-fat fed rats. These results indicate that combined therapy with pioglitazone and NO-1886 may be beneficial for the treatment of type 2 diabetes.