Statins Equally Effective in Men and Women

Both sexes gain from statins for secondary prevention of cardiovascular events, a meta-analysis found, though pooling enough data to prove that there is a statistically significant benefit in women appears to be a challenge.

Both sexes saw a similar, significant overall cardiovascular benefit from the lipid-lowering drugs in high-quality clinical trials, Jose Gutierrez, MD, MPH, of Columbia University in New York City, and colleagues reported.

All-cause mortality and stroke benefits weren't as significant for women as they were for men, but interaction terms didn't suggest a real difference, they cautioned in the June 25 issue of the Archives of Internal Medicine.

"These differences are likely secondary to the small proportion of women included in the trials and a worse cardiovascular health status in these same women," they wrote.

Rather than change prescribing of statins to women after a coronary event, the group encouraged awareness of the disparity and public policies to address it.

"Focusing on a lack of statistical significance in the findings for women is misleading," Fiona Taylor, PhD, and Shah Ebrahim, DM, both of a Cochrane review group at the London School of Hygiene and Tropical Medicine, argued in an accompanying commentary.

They pointed to the effect size of statins as being materially similar between genders, criticizing "over-interpretation of imprecisely estimated effects" among other failings of the current meta-analysis.

A prior, larger meta-analysis of mixed primary and secondary prevention trials did show a significant all-cause mortality reduction with statins for both sexes.

Gutierrez's analysis included 11 randomized, double-blind, placebo-controlled secondary prevention trials with at total of 43,193 patients. Open-label and observational studies did not qualify.

The overall effect sizes for cardiovascular event risk reduction came in virtually the same with statin therapy versus placebo between the genders:

• For women, the relative risk was 0.81 (95% CI 0.74 to 0.89)
• For men, the relative risk was 0.82 (95% CI 0.78 to 0.85)

Risk also came in lower with statins than with placebo for both women and men with regard to myocardial infarction (overall RR 0.73, 95% CI 0.65 to 0.81) and cardiac interventions (overall RR 0.76, 95% CI 0.71 to 0.82).

The all-cause mortality risk reduction with statins didn't reach statistical significance in women (RR 0.92, 95% CI 0.76 to 1.13), unlike in men (RR, 0.79, 95% CI 0.72 to 0.87).

The same was true for stroke prevention, with a relative risk of 0.92 for women taking a statin (95% CI 0.76 to 1.10) versus 0.81 for men on a statin (95% CI 0.72 to 0.92).

However, the interaction of sex and treatment didn't reach significance for either all-cause mortality (P=0.78) or stroke (P=0.99), which Taylor and Ebrahim called more important.

"If a statistical test is wanted, the appropriate P-value is for the sex interaction for the outcome by sex," they wrote. "We suggest that statins work just as well in women as in men."

Adverse events were reported to be no different between men and women in two of the studies; one study suggested more breast cancer with statin than placebo and the remainder did not break out risks separately for the sexes.

The biggest limitation of the meta-analysis was that women represented only 20% of the population in the trials studied overall, which likely underpowered the results for them, the researchers noted.

In an editor's note, Rita F. Redberg, MD, MSc, of the University of California San Francisco, agreed that there's a real need for more women in the clinical trials to settle such issues.

"Are the benefits of statins less in women and risks greater than men, or are there just not enough women in the clinical trials to demonstrate benefit in women," she asked. "Unless we increase inclusion of women in clinical trials and report sex-specific data, there will never be sufficient data to achieve optimal care of all of our patients."

Gutierrez J, et al "Statin therapy in the prevention of recurrent cardiovascular events: A sex-based meta-analysis"Arch Intern Med 2012; 172: 909-919.

Tomado de: Medpagetoday.com