Coronary Artery Calcification at Electron Beam Computed Tomography is Increased in Asymptomatic Type 2 Diabetics Independent of Traditional Risk Factors 1

Abstract

Background The risk of cardiovascular disease (CVD) is two- to fourfold greater in type 2 diabetics than in non-diabetics and cannot be accounted for by traditional risk factors alone. Coronary artery calcification (CAC) at electron beam computed tomography (EBCT) is a non-invasive index of coronary atherosclerosis. We hypothesized that the presence and extent of CAC would be greater in asymptomatic type 2 diabetics than in non-diabetics independent of traditional risk factors.

Methods We reviewed CAC data of all asymptomatic subjects referred for EBCT between 1996–1999 and compared CAC scores in type 2 diabetics (n = 71) to all non-diabetics (n = 1481) and to a randomly selected group of non-diabetics matched for all traditional CVD risk factors (n = 71).

Results CAC scores were greater in type 2 diabetics (272 ± 472, median 41) than in all non-diabetics (104 ± 288, median 4; P < 0.01) and matched non-diabetics (188 ± 354; P < 0.05, median 12; P < 0.05). The odds ratio (OR) for the presence of CAC (scores > 0) in type 2 diabetics was 2.9 [95% confidence intervals (CI) 1.1–7.8] after adjustment for traditional CVD risk factors. Type 2 diabetes was also associated (adjusted OR 2.15, 95%CI 1.3–3.6) with the extent of CAC when categorized as an ordinal outcome (CAC scores 0, 1–79, 80–399 and > 400). In type 2 diabetics, age, sex and body mass index were associated with extent of CAC.

Conclusions CAC scores at EBCT are greater in type 2 diabetics than non-diabetic subjects, cannot be accounted for by traditional risk factors alone and may be useful for identifying novel factors for coronary atherosclerosis in type 2 diabetes.