Meta-Analysis of Statin Effects in Women Versus Men
Does statin therapy impact cardiovascular risk reduction differently among men and women?
This meta-analysis identified 18 randomized clinical trials of statins that were included in this analysis, from 2,315 identified. A systematic search of MEDLINE, the Cochrane Library, the Central Register of Controlled Trials, Web of Science, and ClinicalTrials.gov was performed to identify eligible studies defined as randomized, double-blind clinical trials of statin therapy where sex-specific data were presented through June 30, 2010. If sex-specific all-cause mortality data were not published, investigators were contacted to request these data. Studies with fewer than 100 patients or fewer than five deaths/randomized group were excluded. Odds ratios (ORs) and 95% confidence intervals (CIs) for cardiovascular events were calculated for women and men separately with random-effects meta-analyses.
A total of 141,235 participants were included (40,275 women), among which 21,468 cardiovascular events and 13,710 deaths occurred. Statins used atorvastatin (four trials), lovastatin (one trial), pravastatin (six trials), rosuvastatin (three trials), and simvastatin (four trials). Eight trials were designed as primary prevention trials and 10 were designed as secondary prevention trials. The cardiovascular event rate was lower among those randomized to statin intervention than in those randomized to control (low-dose statin in four studies, placebo in 11 studies, usual care in three studies). The risk reduction associated with statin intervention was similar among women (OR, 0.81; 95% CI, 0.75-0.89; p < 0.0001), as compared to men (OR, 0.77; 95% CI, 0.71-0.83; p < 0.0001). The benefit of statins was statistically significant in both sexes, regardless of the type of control, baseline risk, or type of endpoint, and in both primary and secondary prevention. All-cause mortality was also lower with statin therapy both in women and men without significant interaction by sex (p for interaction = 0.4457).
The investigators concluded that statin therapy is associated with significant decreases in cardiovascular events and in all-cause mortality in both women and men.
This meta-analysis supports the use of statin therapy among women. However, as the authors note, limitations to such analysis include potential publication biases. It should be also noted that all but one of the trials included were industry funded. Last, a fuller understanding of the potential risks of statins particular to women is warranted.
Keywords: Hydroxymethylglutaryl-CoA Reductase Inhibitors, MEDLINE
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