Effects of statin therapy on glycemic control and insulin resistance: A systematic review and meta-analysis

Aims: To update the evidence about the diabetogenic effect of statins.Methods: We searched for randomized-controlled trials reporting the effects of statin therapy on glycosylated hemoglobin (HbA1c) and/or homeostatic model insulin resistance (i.e., HOMA-IR) as indexes of diabetes. Studies were classified between the ones testing normal vs individuals with already altered glycemic control (HbA1c >= 6.5%; and HOMA-IR >= 2.15). Furthermore, studies were separated by statin type and dosage prescribed. Data are presented as mean difference (MD) and 95% confidence intervals.Results: A total of 67 studies were included in the analysis (>25,000 individuals). In individuals with altered glycemic control, statins increased HbA1c levels (MD 0.21%, 95% CI 0.16-to-0.25) and HOMA-IR index (MD 0.31, 95% CI 0.24-to-0.38). In individuals with normal glycemic control, statin increased HbA1c (MD 1.33%, 95% CI 1.31-to-1.35) and HOMA-IR (MD 0.49, 95% CI 0.41-to-0.58) in comparison to the placebo groups. The dose or type of statins did not modulate the diabetogenic effect.Conclusions: Statins, slightly but significantly raise indexes of diabetes in individuals with adequate or altered glycemic control. The diabetogenic effect does not seem to be influenced by the type or dosage of statin prescribed.