Statins Associated With Significant Increase in Diabetes Risk
BOSTON, MA - According to a new study, statins (cholesterol-lowering drugs) may significantly increase the risk of diabetes in postmenopausal women. The study was published online January 9 in the Archives of Internal Medicine by researchers at the University of Massachusetts Medical School in Boston.
The researchers reviewed new data from the Women's Health Initiative (WHI), which suggested that the risk of diabetes is higher than that noted by previous studies; the Boston researchers reported a 48% increased risk of diabetes among the women taking cholesterol-lowering medications.
"With this study, what we're seeing is that the risk of diabetes is particularly high in elderly women, and this risk is much larger than was observed in another previous meta-analysis," noted senior investigator Dr Yunsheng Ma. "For doctors treating patients, we would like them to really look at the risk-benefit analysis, especially in different age groups, such as older women."
Annie Culver (Mayo Clinic; Rochester, MN), a pharmacist and lead investigator of the study, noted that "close monitoring and an individualized risk-versus-benefit assessment is really a good thing, as well as an emphasis on continued lifestyle changes." She added that as the population ages, and because these patients have a higher vulnerability to diabetes anyway, monitoring for diabetes in statin-treated patients becomes more important.
Recently published data noted the potential risk of diabetes with statin therapy. In June, Dr Kausik Ray (St George's University; London, UK) and colleagues published a meta-analysis of “PROVE-IT, A to Z, TNT, IDEAL, and SEARCH.” The meta-analysis, which is a complication of studies on a particular topic, evaluated five trials that involved high-dose statin therapy. The researchers reported a significantly increased in the risk of diabetes with higher doses of statins. Another meta-analysis published in the journal Lancet in 2010 by Dr Naveed Sattar (University of Glasgow, UK) also found that cholesterol-lowering medications were associated with a 9% increased risk of diabetes.
In the Boston study, the researchers reviewed WHI data of 153,840 postmenopausal women aged 50–79 years old. Information about statin use was obtained at enrollment and three years later; the Boston analysis includes data up until 2005. At baseline, 7.0% of women were taking statins, with 30% of women taking simvastatin, 27% taking lovastatin, 22% taking pravastatin, 12.5% taking fluvastatin, and 8% taking atorvastatin. During the study period, 10,242 cases of diabetes were reported.
Statin use at baseline was associated with a 71% increased risk of diabetes; however, after adjusting for potential confounding variables, the risk of diabetes associated with statin therapy dropped to 48%. The association was observed for all types of statins. Dr. Ma noted, "The association between diabetes risk and statin therapy was not observed with any one type of statin, and it seems to be a class effect."
A significantly increased risk of diabetes was observed in Caucasian (49%), Hispanic (57%), and Asian (78%) women. Among African Americans, who comprised 8.3% of the population studied, there was an 18% increased diabetes risk associated with statin use at baseline. This increase was not statistically significant. Statin use and diabetes risk was also observed in women across a range of body mass indices (BMIs less than 25.0, 25.0–29.9, and greater than 30.0 kg/m2). Women with the lowest BMI ( less than 25.0 kg/m2), appeared to be at a higher risk of diabetes compared with obese women; the investigators theorized that this finding was related to hormonal differences between the women.
In an editorial, Dr. Kirsten Johansen (University of California, San Francisco), Editor of the Archives, noted that the increased risk of diabetes in women without cardiovascular disease has "important implications for the balance of risk and benefit of statins in the setting of primary prevention in which previous meta-analyses show no benefit on all-cause mortality."
Only 7% of women in the WHI study were taking statins; however, currently that number would be significantly higher, making the potential risk of diabetes for postmenopausal women significantly more widespread. Dr. Ma noted that physicians need to evaluate the risk of diabetes as well as the potential benefits of statin therapy in elderly female patients, and start statins after lifestyle interventions have been attempted.
Source: Archives of Internal Medicine