Older women who take statins may be at an increased risk for developing type 2 diabetes, researchers found. In an analysis of data from the Women's Health Initiative, postmenopausal women who were on a statin at study entry had almost a 50% greater risk of diabetes than those who weren't on the cholesterol-lowering drugs, Yunsheng Ma, MD, PhD, of the University of Massachusetts School of Medicine, and colleagues reported online in the Archives of Internal Medicine.
Recent research has suggested a potential link between statins and the development of diabetes -- most notably a meta-analysis that found a 9% increased risk of the disease with statin use (QJM 2011; 104(2): 109-124), Ma said. Yet how the risk of diabetes with statin use varies across populations hasn't been thoroughly explored, he added. So he and colleagues looked at data from the Women's Health Initiative to assess the risk in postmenopausal women.
Data were available for 153,840 women, mean age 63, who didn't have diabetes when they were enrolled in the study in 1993. About 7% of them were on statins at that time. Through follow-up ending in 2005, there were 10,242 cases of new-onset diabetes.
In initial analyses, Ma and colleagues found that statin use at baseline was associated with an increased risk of diabetes, and that association remained significant in analyses controlling for age, race, and weight. The risk was seen with all types of statins. Risks were increased for all ethnicities, although they did vary slightly, with the highest risks seen among Asians.
The researchers also found that obesity appeared to be protective against disease; statin use was associated with a higher risk of diabetes in women with a body mass index (BMI) under 25 than in those who had a BMI of 30 or higher. They said differences in phenotype, such as weight distribution, may explain the association.
These findings suggest that different populations have different risks for diabetes associated with statin use, and that women on statins should be monitored for diabetes and liver dysfunction. . It also may suggest that we may be overusing statins and should encourage more lifestyle interventions as a primary means of treating high cholesterol.
Culver added that the findings emphasize current guidelines that recommend lifestyle intervention as the primary means of treating high cholesterol.
"Too many people are put on a statin who don't have to be," Ma said. "Patients should go on a statin if they can't control [their cholesterol] through dietary intervention, but once they're on that statin they should still continue lifestyle intervention."
Suzanne Steinbaum, MD, director of women and heart disease at Lenox Hill Hospital in Bronx, N.Y., said in an email that it's not yet clear from this one study what the clinical implications are for postmenopausal women on statins. "Due to the extensive use of statins in the aging female population, it is critical that more studies are done to help understand the association with statins and the development of diabetes," she wrote. "Women who are taking statins should be aware of the need to check their blood sugars, along with their liver function tests."
The researchers said the study was limited by its observational nature, and because individual statin analysis may be confounded by the fact that women may have changed statin type before developing diabetes
Primary source: Archives of Internal Medicine
Culver AL, et al "Statin use and risk of diabetes mellitus in postmenopausal women in the Women's Health Initiative" Arch In