The benefit of statin therapy in primary and secondary prevention of cardiovascular events is well established with increased prescribing of statins due to continual new evidence of the decrease in morbidity and/or mortality in various patient populations.1-4 In the JUPITER trial evaluating rosuvastatin in low risk individuals with elevated C-reactive protein, a small but significant increase in the development of new-onset diabetes in those taking rosuvastatin was observed. Due to these results and other analyses, statins and the risk of developing new onset diabetes have been the hot topic of discussion.4,5
In an observational study using data from the Women’s Health Initiative (WHI), Culver and colleagues looked at whether postmenopausal women who took statins had an increased risk at developing new onset diabetes compared to those who did not take statins. The WHI was a randomized, multi-centered trial that enrolled 161,808 postmenopausal women, aged 50-79, from 1993 to 1998 in various clinical trial arms. Culver and colleagues included 153,840 women who did not have diabetes mellitus at baseline and included data through 2005. To account for differences among individual statin users that could put a woman at an increased risk for developing diabetes, subgroup analyses by age, BMI, and race/ethnicity were conducted.4
In the WHI, 7.04% of women reported taking a statin at baseline. An increased risk of diabetes was seen in statin users at baseline compared to nonusers (HR, 1.71; 95% CI, 1.61-1.83). After adjusting for confounding factors such age, BMI, and race/ethnicity, the association between statin use and risk of diabetes remained significant (HR, 1.48; 95% CI, 1.38-1.59). While all BMI categories were associated with an increased risk of diabetes, there was a greater risk of diabetes among women with a BMI of less than 25.0 (HR, 1.89; 95% CI, 1.57-2.29) compared to women with a BMI ≥ 30.0 (HR, 1.20; 95% CI, 1.09-1.33) even after adjusting for confounders. For the adjusted analyses of race/ethnicity, there was a significantly increased risk of diabetes among statin users for all ethnicities, except African-Americans.4
The investigators also looked at postmenopausal women with and without a self-reported history of cardiovascular disease (CVD). Out of the 24,842 women that self-reported CVD at baseline, there was an association between statin use and increased risk of diabetes before (HR, 1.52; 95% CI, 1.36-1.71) and after (HR, 1.46; 95% CI, 1.29-1.65) adjusting for confounding factors. These results were similar among postmenopausal women without CVD at baseline. No differences were found among the different types of statins or potency of statins.4
The authors concluded that statin use in post-menopausal women is associated with an increased risk for diabetes, but there are some important points to keep in mind when applying this study to practice. Given the observational nature of the study, duration of statin therapy, whether a statin was changed during therapy, and medication compliance could not accounted for during this study. Only five statins were evaluated given the time ...