Hemoglobin A1C Levels are Independently Associated with the Risk of Coronary Atherosclerotic Plaques in Patients without Diabetes: A Cross-Sectional Study

Aim: Coronary atherosclerotic plaques can be detected in asymptomatic subjects and are related to low-density lipoprotein cholesterol (LDL) levels in patients with coronary artery disease. However, researchers have not yet determined the associations between various plaque characteristics and other lipid parameters, such as HDL-C and TG levels, in low-risk populations. Methods: One thousand sixty-four non-diabetic subjects (age, 57.86 ± 9.73 years; 752 males) who underwent coronary computed tomography angiography (CCTA) were enrolled and the severity and patterns of atherosclerotic plaques were analyzed. Results: Statin use was reported by 25% of the study population, and subjects with greater coronary plaque involvement (segment involvement score, SIS) were older and had a higher body mass index (BMI), blood pressure, unfavorable lipid profiles and comorbidities. After adjusting for comorbidities, only age (β = 0.085, p < 0.001), the male gender (β = 1.384, p < 0.001), BMI (β = 0.055, p = 0.019) and HbA1C levels (β = 0.894, p < 0.001) were independent factors predicting the greater coronary plaque involvement in non-diabetic subjects. In the analysis of significantly different (> 50%) stenosis plaque patterns, age (OR: 1.082, 95% CI: 10.47–1.118) and a former smoking status (OR: 2.061, 95% CI: 1.013–4.193) were independently associated with calcified plaques. For partial calcified (mixed type) plaques, only age (OR: 1.085, 95% CI: 1.052–1.119), the male gender (OR: 7.082, 95% CI: 2.638–19.018), HbA1C levels (OR: 2.074, 95% CI: 1.036–4.151), and current smoking status (OR: 1.848, 95% CI: 1.089–3.138) were independently associated with the risk of the presence of significant stenosis in mixed plaques. Conclusions: A higher HbA1c levels is independently associated with the presence and severity of coronary artery atherosclerosis in non-diabetic subjects, even when LDL-C levels are tightly controlled.