The effects of pitavastatin on glucose metabolism in patients with type 2 diabetes with hypercholesterolemia

Although there have been several reports that statins cause insulin resistance that leads to the occurrence of type 2 diabetes in Caucasians, there has been no Japanese prospective studies investigating the effects of statins on the glucose metabolism system.

Our subjects were 86 Japanese patients with type 2 diabetes with hypercholesterolemia. Pitavastatin 2mg/day was administered for 12 months and the lipid-related values, glucose metabolism values, and the presence/absence of side effects were investigated.

None of these factors was found to differ between before and after administration of pitavastatin in overall analysis of all subjects. In subgroup analysis, fasting blood glucose showed a decrease in the BMI ≥ 25 group and there was a significant difference between the BMI<25 and BMI ≥2 5 groups (P-values: 0.021 and 0.0036). Although HbA1c showed an increase both in the group switched to pitavastatin and the BMI<25 group (P-values: 0.035 and 0.033) and HOMA-β showed a decrease in the BMI<25 group (P-values: 0.044), there were no significant differences in changes between each divided group and their counterparts.

In the Japanese obese group with BMI ≥ 25, pitavastatin elicited a significant decrease in fasting blood glucose. It is not clear whether or not this is due to improved insulin resistance as a direct effect of pitavastatin, but in contrast to findings in Caucasians pitavastatin does not worsen insulin resistance in Japanese patients with type 2 diabetes complicated by hypercholesterolemia.