Coronary artery calcium in type 2 diabetes: a nested case‑control study

INTRODUCTION The use of classic risk scores in patients with type 2 diabetes have numerous limitations. Relationships between coronary artery calcium score (CACS) and traditional risk factors are derived from statistical analyses. At present, there are no data on the evaluation of the CACS on 64‑slice multi-detector computed tomography in patients with type 2 diabetes and ischemic symptoms based on a head‑to‑head comparison with matched nondiabetics.
OBJECTIVES We aimed to examine the associations between traditional risk factors and the CACS in a nested case‑control study.
PATIENTS AND METHODS We performed a retrospective analysis of data from 2482 consecutive symptomatic subjects with known CACS. We identified 325 patients with type 2 diabetes. From the remaining subjects, 325 controls matched for age, sex, and risk factors were selected. 
RESULTS Higher CACS values were observed in patients with diabetes (median, 50 Agatston units [AU]; range, 0–4330) compared with nondiabetic controls (9 AU, 0–3036, P <0.001). Positive CACS values were more common in diabetic patients (73.5%) compared with nondiabetic controls (60.9%, P <0.001). The highest CACS value was observed in men (95.5 AU, 0–3755). The median CACS value in nondiabetic men was comparable to those in diabetic women (24.5 AU, 0–3036 vs. 24.5 AU, 0–3755). The lowest CACS values were observed in control women (3 AU, 0–2144). Coronary artery calcium was more diffused in diabetic patients compared with controls (P <0.01). A multivariate analysis showed that older age and male sex were independent predictors of the CACS. Traditional risk factors accounted only for 10% of interindividual variance in the presence of calcified atherosclerotic plaques. 
CONCLUSIONS Coronary calcified lesions are more frequent in symptomatic patients with type 2 diabetes compared with matched nondiabetic subjects. Our results seem to provide evidence that traditional risk factors do not explain more common, diffuse, and extensive calcified lesions in diabetic subjects.