Long-term, low-dose aspirin did not prevent type 2 diabetes

No link found between aspirin, development of diabetes in women.

One-hundred mg of aspirin was not effective for the prevention of type 2 diabetes in otherwise healthy, American women generally at low risk for the disease.

Researchers examined whether aspirin therapy reduced the incidence of type 2 diabetes in the treatment groups of the Women’s Health Study. Between 1992 and 1995, they enrolled 38,716 women aged ≥45 years who did not have diabetes. Participants were randomly assigned to receive a low-dose aspirin on alternate days (n=19,326) or placebo (n=19,390); they were followed for a median of 10.2 years.

No association found

There was no difference in the incidence of type 2 diabetes between the aspirin group and the placebo group, according to the study results. There were 849 cases of diabetes in the group assigned to aspirin and 847 cases in the group assigned to placebo (RR=1.01; 95% CI, 0.91-1.11).

When newly diagnosed diabetes was considered, treatment with aspirin was associated with a RR of 0.99 (95% CI, 0.86-1.15) for the first five years of follow-up vs. 1.01 (95% CI, 0.90-1.15) after five years.

“Stratification by diabetes risk factors including age, BMI, family history, physical activity, HbA1c and high-sensitivity C-reactive protein, did not support a modulating effect of these variables,” the researchers wrote. No beneficial effects were observed when accounting for treatment duration and adherence either.

There were higher rates of bleeding episodes and other adverse events in the aspirin group compared with the placebo group, according to the study. The rate for any bleeding event was 4.5% in the aspirin group and 3.7% in the placebo group (RR=1.22; P<.001). For transfusion-requiring bleeding, the rate was 0.6% for those in the aspirin group and 0.4% (RR=1.37; P=.03) for those receiving placebo.

The rate for peptic ulcer was 2.7% in the aspirin group and 2.1% in the placebo group (RR=1.30; P<.001). The rate for hematuria was 15.2% for aspirin and 14.4% for placebo (RR=1.06; P=.02), and for epistaxis, the rate was 19.0% for aspirin and 16.5% for placebo (RR=1.17, P<.001), according to the study.

“The increasing incidence of diabetes, high treatment costs and disproportionate impact on cardiovascular disease in women highlight the need to identify prevention strategies applicable on a broad population basis,” the researchers wrote. “Preventive measures with potential dual effects on cardiovascular and diabetes risk reduction are particularly appealing because cardiometabolic risk factors often coincide in the same individual.” – by Christen Haigh

Diabetes Care. 2009;32:3-8.

This finding is not surprising since low dose aspirin was utilized. High dose aspirin or other salicylates, which are truly anti-inflammatory, have been shown to decrease insulin resistance and perhaps improve beta cell function. Clinical trials to evaluate the effects of high dose salicylates are being performed in patients with type 2 diabetes and the results of these trials will be more meaningful.

– David S. H. Bell, MD
Endocrine Today Editorial Board member