Diabetes risk with statins appears to be outweighed by reduction in overall mortality

An observational cohort study examined the effect of statins on diabetes risk and overall mortality in 13,508 normoglycemic patients and 4,563 patients with impaired fasting glucose.

Recommendations for statin use should not be affected by concerns over a 19% to 24% increased risk of developing diabetes, since the benefit of reduced mortality with statins clearly outweighs it, a study concluded.

To assess whether statin use increases the risk of developing diabetes or affects overall mortality among normoglycemic patients and patients with impaired fasting glucose (IFG), researchers conducted an observational cohort study of Mayo Clinic patients among residents of Olmsted County, Minn. Among 13,508 normoglycemic patients, 4,460 (33%) were taking statins, and among 4,563 IFG patients, 1,865 (41%) were taking statins.

Results were published online Feb. 5 by the Journal of General Internal Medicine.

After a mean of 6 years of follow-up, there were 1,182 (10%) new diagnoses of diabetes in the normoglycemic group and 1,524 (36%) in the IFG group (P<0.0001). Statin use was associated with increased risk of incident diabetes in normoglycemic and IFG patients, although the difference between statin and non-statin users was more pronounced among the IFG group, researchers said.

Statin use was found to be associated with an increased risk of incident diabetes in the normoglycemic (hazard ratio [HR], 1.19; 95% CI, 1.05 to 1.35; P=0.007) and IFG (HR, 1.24; 95% CI, 1.11 to 1.38; P=0.0001) groups. At the same time, overall mortality decreased in both normoglycemic (HR, 0.70; 95 % CI, 0.66 to 0.80; P<0.0001) and IFG (HR, 0.77; 95 % CI, 0.64 to 0.91; P=0.0029) patients who used statins.

Over 6 years of follow-up, there were 926 (7.2%) deaths in the normoglycemic group, compared with 450 (10%) in the IFG group. Overall, patients with IFG had an increased risk of death compared with normoglycemic subjects. In both groups, however, patients taking statins had a statistically significant lower risk of death than patients not taking statins (HR, 0.70 [95 % CI, 0.62 to 0.80] in the normoglycemic group vs. HR, 0.77 [95% CI, 0.64 to 0.91] in the IFG group).

“The risk of progression to overt diabetes in IFG patients over a 6-year period of follow-up was 24%, a magnitude consistent with that reported in previous studies in similar populations, and as expected, the risk was higher for IFG patients than for normoglycemic subjects,” the authors wrote. “However, this increased risk in incident diabetes was outweighed by an equal 24% reduction in overall mortality, a more important clinical outcome. Such excess risk of incident diabetes appears to be lower (19%) in normoglycemic subjects with other cardiovascular risk factors, but the benefit of reduced mortality (30%) in this group also greatly outweighs this risk.”