Abstract

Objective: To compare the risk of cardiovascular disease (CVD) death and the impact of hyperglycemia on the risk of CVD mortality associated with type 1 diabetes to that associated with type 2 diabetes.

Research Design and Methods: The study comprised 173 participants with type 1 diabetes, 834 participants with type 2 diabetes, and 1294 nondiabetic participants, aged 45–64 years at baseline and free of CVD. The age of onset of diabetes was >30 years in both diabetic groups.

Results: During an 18-year follow-up 86 participants with type 1 diabetes, 567 participants with type 2 diabetes, and 252 nondiabetic participants died. CVD mortality rates per 1000 person-years (95% CI) were 23.1 (16.9–31.9) in type 1 diabetic, 35.3 (30.8–40.4) in type 2 diabetic and 4.6 (3.8–5.7) in nondiabetic participants. Adjusted hazard ratio (95% CI) for CVD mortality in participants with type 1 diabetes vs no diabetes was 3.6 (2.2–5.7) in men and 13.3 (6.9–22.5) in women, and in participants with type 2 diabetes vs. no diabetes 3.3 (2.5–4.5) in men and 10.1 (6.7–17.4) in women. Increment of 1 unit (%) of GHb increased CVD mortality by 52.5% (28.4–81.3%) in type 1 diabetic and by 7.5% (4.3–10.8%) in type 2 diabetic participants.

Conclusions: The impact of type 1 and type 2 diabetes on CVD mortality was similar. The effect of increasing hyperglycemia on the risk of CVD mortality was more profound in type 1 diabetic than in type 2 diabetic subjects.