To compare the coronary atherosclerotic burden in patients with and without type-2 diabetes using CT Coronary Angiography (CTCA).

147 diabetic (mean age: 65 ± 10 years; male: 89) and 979 nondiabetic patients (mean age: 61 ± 13 years; male: 567) without a history of coronary artery disease (CAD) underwent CTCA. The per-patient number of diseased coronary segments was determined and each diseased segment was classified as showing obstructive lesion (luminal narrowing >50%) or not. Coronary calcium scoring (CCS) was assessed too.

Diabetics showed a higher number of diseased segments (4.1 ± 4.2 vs. 2.1 ± 3.0; p < 0.0001); a higher rate of CCS > 400 (p < 0.001), obstructive CAD (37% vs. 18% of patients; p < 0.0001), and fewer normal coronary arteries (20% vs. 42%; p < 0.0001), as compared to nondiabetics. The percentage of patients with obstructive CAD paralleled increasing CCS in both groups. Diabetics with CCS ≤ 10 had a higher prevalence of coronary plaque (39.6% vs. 24.5%, p = 0.003) and obstructive CAD (12.5% vs. 3.8%, p = 0.01). Among patients with CCS ≤ 10 all diabetics with obstructive CAD had a zero CCS and one patient was asymptomatic.

Diabetes was associated with higher coronary plaque burden. The present study demonstrates that the absence of coronary calcification does not exclude obstructive CAD especially in diabetics.