Objective: This study aimed to examine the association between glycohemoglobin (A1C) and coronary artery calcification (CAC) in nondiabetic men and women without overt cardiovascular disease or diabetes mellitus after accounting for fasting glucose and traditional cardiovascular disease risk factors.
Approach and results: A cross-sectional study was performed in 25,564 Korean adults (41.4 ± 7.0 years) with no diabetes mellitus (fasting glucose, ≥ 7.0 mmol/L or a history of diabetes mellitus) and no clinically evident cardiovascular disease, who underwent a health checkup, including a cardiac computed tomography estimation of CAC scores and measurements of cardiovascular risk factors. The presence of CAC was defined as a CAC score >0; CAC was observed in 12.0% of men and 4.9% of women. Age-adjusted odds ratios (95% confidence interval) for CAC comparing A1C of 5.5% to 5.6%, 5.7% to 5.9%, and 6.0% to 6.4% with A1C <5.5% were 1.12 (0.99-1.28), 1.44 (1.27-1.63), and 1.63 (1.39-1.90) in men and 1.76 (0.96-3.25), 1.86 (1.05-3.29), and 3.09 (1.68-5.70) in women, respectively. After adjusting for potential confounders, the odds ratios (95% confidence interval) comparing A1C of 5.5% to 5.6%, 5.7% to 5.9%, and 6.0% to 6.4% with A1C of <5.5% were 1.04 (0.91-1.19), 1.21 (1.07-1.38), and 1.25 (1.05-1.48) in men and 1.75 (0.94-3.29), 1.59 (0.88-2.87), and 2.48 (1.29-4.74) in women, respectively. These associations persisted in subjects without any metabolic abnormalities, including fasting glucose ≥ 100 mg/dL.
Conclusions: A higher A1C level was found to have a modest and independent association with the subclinical coronary atherosclerosis, even in metabolically healthy individuals.
Keywords: Hb A1c; cardiovascular disease; coronary artery disease; glycohemoglobin A; vascular calcification.