The association of serum parathyroid hormone and severity of coronary artery diseases

Introduction The serum level of parathyroid hormone (PTH) has been shown to be a predictor of cardiovascular mortality. Data on the association between PTH level and degree of atherosclerosis severity are lacking. The objective of this study was to determine the relationship of serum PTH level and number of stenotic coronary arteries. Patients and methods The present article is a descriptive cross-sectional study on 476 patients who had undergone coronary angiography according to documented indications and had coronary lesion more than 50% in at least one main vessel during 2010-2012. The outcome was evaluated by comparison between PTH levels and the number of stenotic coronary arteries. Results Demographic data of the patients, severity, and number of stenotic vessels were evaluated. Of the 476 patients included, 183 (38.4%) had PTH more than 40 pg/ml. There was a significant association between PTH level and severity and number of coronary lesion: 80% of three-vessel disease patients had PTH more than 40 pg/ml but only 7% of single-vessel disease patients had PTH more than 40 pg/ml (P < 0.001). The mean levels of PTH serum in single-vessel, two-vessel, and three-vessel disease were 24.8, 35.8, and 49.8 pg/ml, respectively (P < 0.001). Individuals with the higher PTH level had longer history of hypertension and lower left ventricular ejection fraction (P < 0.01 and P < 0.002, respectively). Conclusion In this relatively small prospective study, serum PTH level is associated with the number of stenotic coronary arteries. There is a correlation between high PTH level with hypertension and low ejection fraction. A prospective study that evaluates the additional value added (by ROC analysis) by PTH to already known cardiac risk factors is recommended.