Roles of Serum Parathyroid Hormone and Vitamin D Levels in Severity of Coronary Artery Disease and Left Ventricular Systolic Function

Vitamin D and parathyroid hormone (PTH) are related but impact cardiovascular functions differently.

This study investigated the roles of PTH and vitamin D serum levels in the severity of coronary artery disease and left ventricular systolic function (LVSF).

This cross-sectional study was conducted on 271 participants who underwent elective coronary angiography at Dr. Heshmat Hospital, selected by convenience sampling over four months. 25-hydroxyvitamin D (25 (OH) D) and PTH levels were obtained from patients’ blood samples. Vitamin D levels were categorized into three categories. The SYNTAX score was used to evaluate the severity of coronary artery disease (CAD), classified across three categories. The chi-squared test, independent samples t-test, and multivariable logistic regression were used for statistical analysis. Data were analyzed by SPSS ver.21.

Diabetes, hypertension, dyslipidemia, and lower vitamin D levels were independent variables affecting patients’ high-risk conditions. The highest SYNTAX score was in patients with vitamin D deficiency (P < 0.001). Patients with different ejection fractions did not have statistically significant differences in vitamin D (25.38 ± 14.23) and PTH levels (66.62 ± 17.39) (P = 0.4). The severity of CAD in patients with PTH > 40 was higher than in patients with PTH ≤ 40, but this was not statistically significant (P = 0.06).

Our results showed an inverse relation between CAD and vitamin D. However, the CAD risk did not change with PTH levels.