Published: January 09, 2012
Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco and
Dorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner
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.
"This study urges us to further evaluate the risk-benefit profile of statins," Ma told MedPage Today, adding that the ratio will likely vary by patient population.
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 (HR 1.71, 95% CI 1.61 to 1.83), and that association remained significant in multivariate analyses controlling for age, race, and weight (HR 1.48, 95% CI 1.38 to 1.59).
Ma said the risk was seen with all types of statins. "It appears to be a class effect," he told MedPage Today.
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.
Risk of diabetes also was similarly elevated -- by about 50% -- for women with and without heart disease, and was similar if women used either high- or low- potency statins (HR 1.45, 95% CI 1.36 to 1.61; and HR 1.48, 95% CI 1.36 to 1.61, respectively).
"The take-home message is that different populations have different risks for diabetes" associated with statin use, Annie Culver, BPharm, of the University of Massachusetts and a co-author on the study, told MedPage Today. "When a statin is indicated, it's very important to continue to monitor for diabetes as well as for the statin effects, so the dose can be adjusted along the way."
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.
From the American Heart Association:
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 Intern Med 2012; DOI:10.1001/archinternmed.2011.625.