The effect of statins on the development of new-onset type 2 diabetes: a meta-analysis of randomized controlled trials

Objective: To determine the ability of statins to prevent the development of new-onset type 2 diabetes mellitus through a meta-analysis of randomized, controlled trials.

Research design and methods: A systematic literature search through November 6, 2007 was conducted to identify randomized, placebo-controlled trials of statins that reported data on the incidence of new-onset diabetes mellitus. Incidence of new-onset type 2 diabetes mellitus was treated as a dichotomous variable. Weighted averages were reported as relative risk (RR) with associated 95% confidence intervals (CI). A random-effects model was used.

Results: Five prospective, randomized controlled trials (n = 39,791) were identified. Upon meta-analysis, the use of a statin did not significantly alter a patient's risk of developing new-onset type 2 diabetes mellitus (relative risk, 1.03; 95% confidence interval 0.89-1.19). Subgroup and sensitivity analyses did not significantly change the results. There was statistical heterogeneity that stemmed from pravastatin's tendency towards a reduction in risk and the other statins showing an increase in risk. The funnel plot could not rule out publication bias.

Conclusions: Statins, as a class, do not demonstrate a statistically significant positive or negative impact on a patient's risk of developing new-onset type 2 diabetes mellitus.