Impact of Diabetes Control on Subclinical Atherosclerosis: Analysis from Coronary Computed Tomographic Angiography Registry

Background: There are limited data on the impact of diabetes control on the risk of subclinical coronary atherosclerosis. Methods: We analyzed 6,434 consecutive asymptomatic individuals without previous history of coronary artery disease who underwent coronary computed tomographic angiography (CCTA) (mean age, 53.7 +/- 7.6 years and 4,694 men [73.0%]). The degree and extent of subclinical coronary atherosclerosis were assessed by CCTA, and >= 50% diameter stenosis was defined as significant. A cardiac event was defined as a composite of all-cause death, myocardial infarction, unstable angina, or coronary revascularization. Study participants were categorized as normal (n = 5,319), controlled diabetes (glycosylated hemoglobin [HbA1c] < 7%, n = 747), or uncontrolled diabetes (HbA1c = 7%, n=368), respectively. Results: Compared with normal individuals, there were no statistically significant differences in the risk of for any atherosclerotic plaque (odds ratio [OR], 1.16; 95% confidence interval [CI], 0.98 to 1.38; P=0.086) and significant coronary artery stenosis (OR, 1.08; 95% CI, 0.82 to 1.42; P = 0.583) in controlled diabetic individuals. In contrast, uncontrolled diabetic individuals had consistently higher risks of any atherosclerotic plaque (OR, 2.16; 95% CI, 1.70 to 2.75; P<0.001) and significant coronary artery stenosis (OR, 3.34; 95% CI, 2.52 to 4.43; P < 0.001) than normal individuals. During a follow-up of median 5.4 years, there was no significant difference in cardiac events between normal and controlled diabetic individuals (P = 0.365). However, uncontrolled diabetes was associated with an increased risk of cardiac events compared with normal individuals (P<0.001) and controlled diabetic individuals (P=0.023). Conclusion: Asymptomatic uncontrolled diabetes was associated with significant subclinical coronary atherosclerosis with subsequent high risk for cardiac events.