Associations of serum calcium/magnesium ratios with coronary artery disease in diabetes: a cross-sectional study

Objective The early detection of coronary artery disease (CAD) in diabetes mellitus is a major clinical difficulty. The purpose of this paper is to find out a convenient and economical index to help to screen for patients with CAD in diabetes mellitus. Method From January 2019 to December 2019, a total of 1028 patients hospitalized in the general department of our hospital have been enrolled in our cross-sectional study, of which 190 were diagnosed with CAD and 314 with diabetes. Differences of various factors between the CAD group and the non-CAD group were analyzed. The receiver operating characteristic (ROC) curve and the area under the curve (AUC) were used to evaluate the efficacy of each factor in predicting CAD. The correlation between calcium/magnesium (Ca/Mg) ratio and the prevalence of CAD in diabetic and non-diabetic people was compared, and the cutoff of Ca/Mg ratio to predict the risk of CAD in diabetic patients was calculated. Results Logistic regression analysis showed that serum high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, calcium, magnesium, Ca/Mg ratio, hypertension, diabetes, and smoking history were all associated with CAD. Among them, the AUC value of Ca/Mg ratio was the highest of 0.70. Furthermore, in diabetes patients, the AUC value of Ca/Mg ratio to predict the risk of CAD was 0.72, the cutoff was 2.55, the sensitivity was 77.1%, and the specificity was 53.7%. The prevalence rate of CAD was 18.5% below the cutoff, 46.9% higher than the cutoff, and the prevalence rate increased by 153.5%. Conclusion The Ca/Mg ratio is a good predictor of the risk of CAD in diabetes, higher than the cutoff, the prevalence rate was significantly increased. PLA IN LANGUAGE SUMMARY CAD brings great pain and burden to patient. However, CAD is asymptomatic in quiet a few cases of type 2 diabetes until myocardial infarction or sudden cardiac death occurs. In this study, we explored the association between CAD and various serum factor. We found that the Ca/Mg ratio is of excellent value in screening CAD, especially in diabetes. Moreover, we found that the cutoff of Ca/Mg ratio was 2.55 in diabetic population and the prevalence rate of CAD was 18.5% below the cutoff, 46.9% higher than the cutoff. The Ca/Mg ratio will provide good prediction of the risk of CAD and make early detection easier in diabetes.