Statins' benefits outweigh their association with diabetes incidence

Statins' benefits outweigh the risk of diabetes for patients taking the drugs for secondary prevention and those at high risk of major adverse coronary events, a study found.

Researchers used data from the Taiwan National Health Insurance Research Database (a universal, state-operated health program covering more than 98% of the population) and focused on men 45 years or older and women 55 years and older. There were 8,412 and 33,648 eligible subjects in the statin (30 days or more of use) and control groups (nonusers).

Controls were matched to statin users on a 4:1 ratio by age, sex, atherosclerotic comorbidities, and year of their entry. Study outcomes were diabetes, major adverse cardiovascular events (the composite of myocardial infarction and ischemic stroke), and in-hospital deaths.

Results were published online Aug. 8 by the Journal of the American College of Cardiology.

There were 5,754 cases of incident diabetes during the median follow-up of 7.2 years. Statin use increased diabetes rates (hazard ratio [HR], 1.15; 95% CI, 1.08 to 1.22; P<0.001). There were 769 myocardial infarctions, 2,961 ischemic strokes, and 3,484 in-hospital deaths in the total study population.

Statin users had fewer myocardial infarctions, (HR, 0.82; 95% CI, 0.68 to 0.98; P=0.028) and a trend toward fewer ischemic strokes (HR, 0.94; 95% CI, 0.86 to 1.03; P=0.176), leading to overall fewer major adverse cardiovascular events (HR, 0.91; 95% CI, 0.84 to 0.99; P=0.031) and in-hospital deaths (HR, 0.61; 95% CI, 0.55 to 0.67; P<0.001)

To evaluate the prognoses of diabetic subjects after exposure, four groups were created: nondiabetic controls (n=29,332), diabetic controls (n=4,316), diabetic patients with prior statin use (n=1,387) and nondiabetic patients with prior statin use (n=7,025). Major adverse cardiovascular events were 12, 21, 16 and 12 per 1,000 person-years, respectively, and the annual in-hospital mortality rates were 1.4%, 2.0%, 1.6% and 0.8%, respectively.

Overall risk-benefit analysis showed that statin treatment was favorable in high-risk (HR, 0.89; 95% CI, 0.83 to 0.95) and secondary prevention (HR, 0.89; 95% CI, 0.83 to 0.96) populations, the researchers reported. In general, treatment of statins prevented one fatal event in 202 subjects and led to one case of diabetes in 301 patients per year, concluded researchers.

Researchers cautioned that the incidence of diabetes in this study was 21 per 1,000 person-years, relatively more than what has been reported in other research. This, and reports of ethnic differences in diabetes occurrence and susceptibility to statins, may have resulted in overestimation of the potential risk for diabetes against the benefits of statins. Continuous surveillance for dysglycemia should be incorporated into care to optimize overall risk management, researchers added.