Predictors for coronary artery calcium score and differences in its distributions between populations with and without diabetes

Abstract

Background and aims Coronary artery calcium (CAC) scoring is a method of measure coronary plaque burden and has been shown as an excellent predictor for atherosclerotic cardiovascular disease (ASCVD). Diabetes mellitus (DM) is an established risk factor for ASCVD, but a certain portion of patients with DM do not have CAC (score = 0). We conducted a study to identify predictors of the CAC score other than DM and to compare distributions of the score between populations with and without DM. Methods We included participants who were referred to receive CAC scanning at a large imaging center from July 1992 to July 2020. The distribution of the CAC scores and baseline characteristics were compared between participants with and without DM. Univariate logistic regressions followed by multivariate analysis were performed using CAC score > 0 as outcome to identify independent factors contributing to the score. Results A total of 35,086 participants (mean age 58.9 ± 11.9 years, 63% male, 69% white) were included in the analysis. Of them, 11.8% had DM, 56% had hyperlipidemia, 38% had hypertension, and 7% were current smokers. A higher proportion of participants in the DM group had CAC score > 0 (82% vs 62%, p <0.01), but a substantial portion (18%) of DM patients had no CAC. Distribution of CAC score was also variable among participants with and without DM. Multivariate analysis showed that DM, age, male, hyperlipidemia, hypertension, and smoking were all independent predictors of CAC, and DM was associated with the second highest odds ratio (2.05, 95% confidence interval 1.87- 2.25) behind male (4.55, 95% confidence interval 4.17-4.76). Conclusions While DM was the second strongest predictor of CAC, nearly one fifth of persons with DM had no detectable CAC. Among DM patients, there is significant heterogeneity of scores, so an individualized approach to primary prevention for these patients is warranted.