Impact of prediabetic status on coronary atherosclerosis: a multivessel angioscopic study.

Objective: To determine if prediabetes is associated with atherosclerosis of coronary arteries, we evaluated the degree of coronary atherosclerosis in nondiabetic, prediabetic, and diabetic patients by using coronary angioscopy to identify plaque vulnerability based on yellow color intensity.
Research Design and Methods: Sixty-seven patients with coronary artery disease (CAD) underwent angioscopic observation of multiple main-trunk coronary arteries. According to the American Diabetes Association guidelines, patients were divided into nondiabetic (n = 16), prediabetic (n = 28), and diabetic (n = 23) groups. Plaque color grade was defined as 1 (light yellow), 2 (yellow), or 3 (intense yellow) based on angioscopic findings. The number of yellow plaques (NYPs) per vessel and maximum yellow grade (MYG) were compared among the groups.
Results: Mean NYP and MYG differed significantly between the groups (P = 0.01 and P = 0.047, respectively). These indexes were higher in prediabetic than in nondiabetic patients (P = 0.02 and P = 0.04, respectively), but similar in prediabetic and diabetic patients (P = 0.44 and P = 0.21, respectively). Diabetes and prediabetes were independent predictors of multiple yellow plaques (NYPs ≥2) in multivariate logistic regression analysis (odds ratio [OR] 10.8 [95% CI 2.09-55.6], P = 0.005; and OR 4.13 [95% CI 1.01-17.0], P = 0.049, respectively).
Conclusions: Coronary atherosclerosis and plaque vulnerability were more advanced in prediabetic than in nondiabetic patients and comparable between prediabetic and diabetic patients. Slight or mild disorders in glucose metabolism, such as prediabetes, could be a risk factor for CAD, as is diabetes itself.