Waist Circumference as a Marker of Obesity Is More Predictive of Coronary Artery Calcification than Body Mass Index in Apparently Healthy Korean Adults: The Kangbuk Samsung Health Study

BACKGROUND: We aimed to assess the risk for coronary artery calcification (CAC) according to groups subdivided by body mass index (BMI) and waist circumference (WC) in apparently healthy Korean adults. METHODS: Thirty-three thousand four hundred and thirty-two participants (mean age, 42 years) in a health screening program were divided into three groups according to BMI: <23 kg/m² (normal), 23 to 25 kg/m² (overweight), and >25 kg/m² (obese). In addition, the participants were divided into two groups according to WC. Coronary artery calcium score (CACS) was measured with multi-detector computed tomography in all participants. Presence of CAC was defined as CACS >0. RESULTS: When logistic regression analysis was performed with the presence of CAC as the dependent variable, the risk for CAC increased as BMI increased after adjusting for confounding variables (1.102 [95% confidence interval (CI), 1.000 to 1.216]; 1.284 [95% CI, 1.169 to 1.410]; in the overweight and obese groups vs. the normal weight group). When the participants were divided into six groups according to BMI and WC, the subjects with BMI and WC in the obese range showed the highest risk for CAC (1.321 [95% CI, 1.194 to 1.461]) and those with BMI in the overweight range and WC in the obese range showed the second highest risk for CAC (1.235 [95% CI, 1.194 to 1.461]). CONCLUSION: Participants with obesity defined by both BMI and WC showed the highest risk for CAC. Those with BMIs in the overweight range but with WC in the obese range showed the second highest risk for CAC, suggesting that WC as a marker of obesity is more predictive of CAC than BMI.