Intensive statin therapy and diabetes.

High-dose statin therapy has been linked with a higher incidence of diabetes when compared with moderate-dosage statins, which are used to lower cholesterol levels. However, the cardiovascular benefits of intensive-dose statins are considered a greater a benefit than the increased risk of diabetes.

A meta-analysis of randomized trials was conducted to compare high-dose with moderate-dose statins in 1,000 patients. Patients were observed for more than a year. Five of the studies meeting criteria compared moderate doses of atorvastatin (Lipitor[R]), simvastatin (Zocor[R]), or pravastatin (Pravachol[R]) with high doses of atorvastatin or simvastatin alone. The total number of enrolled patients who did not have diabetes at the outset was 32,752. Patients were followed for a mean of almost five years. Diabetes was identified through reports of adverse events, by prescriptions of glucose-lowering medications, or by elevated fasting plasma glucose measurements. During the follow-up, diabetes occurred more often in patients receiving intensive-dose developed diabetes than in those receiving standard-dose statin therapy.

For every 1,000 patients per year, two additional cases came about as a result of treatment with high-dose statins as well as a number-needed-to- harm of 498 per year. Statins were associated with 6.5 fewer major cardiovascular events for every 1,000 patients each year. Therefore, 155 patients needed to be treated to prevent one cardiovascular event. The benefits of statins were similar for all cardiovascular endpoints, either with nonfatal stroke or myocardial infarction, coronary revascularization, and cardiovascular death.

The high-dose statin regimen had no effect on overall mortality rates, and no bias was noted in the meta-analysis. No differences between diabetes risk and cardiovascular benefit were found in groups of patients classified by age or body mass index (BMI). The increased risk of diabetes was similar with intensive doses of either atorvastatin or simvastatin; however, the overall cardiovascular benefits, compared with standard-dose therapy, were significantly higher with high-dose atorvastatin.

It was not clear why there was an increased risk of diabetes, but the finding of a relationship in dose-dependent effects is significant.

(Source: Journal of the American Medical Association, June 22, 2011.)