The recent JUPITER (Justification for the Use of statins in Primary prevention: an Intervention Trial Evaluating Rosuvastatin) trial is another study providing evidence about the effectiveness of statin therapy in reducing cardiovascular risk. Yet, in this study significantly higher glycated hemoglobin levels and incidence rates of diabetes were observed in persons treated with rosuvastatin than the placebo group. It should be noted that adverse effects on glucose metabolism have already been reported, albeit rarely, in previous trials with statins. Although the exact mechanisms involved are unknown, it seems that statins may deteriorate glycemic control by decreasing different metabolites, including isoprenoid and ubiquinone, normally produced during the process of cholesterol synthesis. We therefore suggest that, if statins are prescribed, patients should be monitored closely for blood glucose control even though the higher incidence of diabetes by statin therapy may represent a rare finding.