Diabetes raises coronary artery disease risk more in women under 60

Young and middle-aged women with diabetes have about 4 times the risk of coronary artery disease (CAD) as same-age women without diabetes and similar risk to same-age diabetic men, an analysis found.

Researchers analyzed data on men and women younger than 60 who didn't have CAD at enrollment and whose diabetes was determined by physician report, use of hypoglycemic medication, and/or fasting glucose of at least 126 mg/dL. Subjects came from the GeneSTAR Study (n=1,448), the Multi-Ethnic Study of Atherosclerosis (MESA; n=3,072) and the National Health and Nutrition Examination Survey III (NHANES III) Mortality Follow-up Study (n=6,997). Follow-up ranged from 7 to 15 years. The main outcome was fatal CAD in NHANES III and any CAD event in the other 2 studies. Results were published online Oct. 31 by Diabetes Care.

After adjustment for age, race and education, women with diabetes had a CAD event rate roughly 4 times higher than that of women without diabetes (adjusted hazard ratio, 4.23; P>0.01). The presence of diabetes didn't change the risk of CAD for men, however. Among people without diabetes, CAD event rates were lower for women than men (P<0.001 in GeneStar and Mesa; P=0.07 in NHANES). After adjustment for smoking, body mass index, hypertension, HDL and non-HDL cholesterol, and use of antihypertensive and cholesterol-lowering medication, the hazard ratio of CAD was 2.43 (95% CI, 1.76 to 3.35) in men versus women without diabetes and 0.89 (95% CI, 0.43 to 1.83) for men versus women with diabetes (interaction by diabetes status, P=0.01).

Diabetes “equalized rates of CAD by gender,” the researchers concluded, by conferring a much higher CAD risk on women than men. A novel finding in this study was that the elevated risk for women applied to otherwise healthy young and middle-aged women, not just elderly women, they added. The finding that men had no elevated CAD risk with diabetes may be explained by an earlier incidence of CAD in men in general: “Male gender may represent an early CAD risk factor that ‘borrows' from the future, potentially comparable to the CAD risk observed for women later in life,” the authors wrote.

Current clinical guidelines advise an earlier start to cardiovascular prevention strategies for men than women with diabetes, and these should perhaps be revised, the authors wrote. “Aggressive preventive strategies may be as important for younger women with diabetes as they are for men,” they wrote.