Nonlinear relationship between HbA1c and coronary artery calcium score progression: a secondary analysis based on a retrospective cohort study

Objective Coronary artery calcium score and glycated hemoglobin(HbA1c) are both considered risk factors for coronary heart disease. However, the relationship between coronary artery calcium score and HbA1c is still unclear. Consequently, the present study was undertaken to explore HbA1c association with coronary artery calcium score progression in South Korea. Methods This study is a secondary analysis based on a retrospective cohort study in which 8151 participants received Health examination kits at the Health Promotion Center, Samsung Medical Center in Seoul, South Korea, from March 1, 2003–December 31, 2013. Cox proportional-hazards regression model was then used to evaluate the independent relationship between HbA1c and coronary artery calcium score progression. Results After adjusting potential confounding factors (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), it was revealed that there was a nonlinear relationship between HbA1c and coronary artery calcium score progression, while the scoring point was 5.8%. The effect size was 2.06 to the left of the inflection point, while the 95% CI was 1.85 to 2.29. Whereas, the effect size was 1.04, on the right side of the inflection point while 95% CI was 0.99 to1.10. Conclusion The relationship between HbA1c and coronary artery calcium score progression is nonlinear. HbA1c is positively related to coronary artery calcium score progression when HbA1c level was less than 5.8%.

The Atherosclerotic Profile of a Young Symptomatic Population between 19 and 49 Years: Coronary Computed Tomography Angiography or Coronary Artery Calcium Score?

(1) Background: Whether coronary computed tomography angiography (CTA) or the coronary artery calcium score (CACS) should be used for diagnosis of coronary heart disease, is an open debate. The aim of our study was to compare the atherosclerotic profile by coronary CTA in a young symptomatic high-risk population (age, 19–49 years) in comparison with the coronary artery calcium score (CACS). (2) Methods: 1137 symptomatic high-risk patients between 19–49 years (mean age, 42.4 y) who underwent coronary CTA and CACS were stratified into six age groups. CTA-analysis included stenosis severity and high-risk-plaque criteria (3) Results: Atherosclerosis was more often detected based on CTA than based on CACS (45 vs. 27%; p < 0.001), 50% stenosis in 13.6% and high-risk plaque in 17.7%. Prevalence of atherosclerosis was low and not different between CACS and CTA in the youngest age groups (19–30 y: 5.2 and 6.4% and 30–35 y: 10.6 and 16%). In patients older than >35 years, the rate of atherosclerosis based on CTA increased (p = 0.004, OR: 2.8, 95%CI:1.45–5.89); and was higher by CTA as compared to CACS (34.9 vs. 16.7%; p < 0.001), with a superior performance of CTA. In patients older than 35 years, stenosis severity (p = 0.002) and >50% stenosis increased from 2.6 to 12.5% (p < 0.001). High-risk plaque prevalence increased from 6.4 to 26.5%. The distribution of high-risk plaque between CACS 0 and >0.1 AU was similar among all age groups, with an increasing proportion in CACS > 0.1 AU with age. A total of 24.9% of CACS 0 patients had coronary artery disease based on CTA, 4.4% > 50% stenosis and 11.5% had high-risk plaque. (4) Conclusions: In a symptomatic young high-risk population older than 35 years, CTA performed superior than CACS. In patients aged 19–35 years, the rate of atherosclerosis was similar and low based on both modalities. CACS 0 did not rule out coronary artery disease in a young high-risk population.