Nonlinear Relationship Between HbA1c and Coronary Artery Calcium Score Progression: A Secondary Analysis Based on a Retrospective Cohort Study

ObjectiveSome previous studies was to clarify the correlation between glycated hemoglobin(HbA1c) and coronary heart disease (CHD) and the evidence regarding the correlation was still debated. However, there are fewer scientific dissertations about the correlation between HbA1c and coronary artery calcium score progression. Consequently, the present study was undertaken to explore the link of HbA1c on coronary artery calcium score progression in South Korea.MethodsThis study is a secondary analysis based on a retrospective cohort study. 8151 participants received a health check-up program at the Health Promotion Center of the Samsung Medical Center in Seoul, South Korea, from March 1, 2003 to December 31, 2013. We then used Cox proportional-hazards regression model to evaluate the independent relationship between HbA1c and coronary artery calcium score progression.ResultsAfter adjusting potential confounders (age, sex, BMI, height, weight, SBP, DBP, TC, LDL-C, HDL-C, triglycerides,smoking status, alcohol consumption, reflux esophagitis status, hypertension, diabetes, dyslipidemia, ischemic heart disease and cerebrovascular disease), non-linear relationship was detected between HbA1c and coronary artery calcium score progression, whose point was 5.8%. The effect sizes and the confidence intervals on the left and right sides of inflection point were 2.05 (1.85 to 2.27) and 1.04 (0.99 to 1.10) , respectively. ConclusionThe relationship between HbA1c and coronary artery calcium score progression is non-linear. HbA1c is positively related with coronary artery calcium score progression when HbA1c was less than 5.8%.