Vitamin D receptor gene polymorphisms and plasma renin activity in essential hypertensive individuals

Several studies analyzed 25-hydroxyvitamin D (25[OH]D) and blood pressure (BP) relationship with mixed results. Moreover, a relationship between the risk of hypertension and vitamin D receptor (VDR) gene polymorphisms, FokI and BsmI, was reported. This study was aimed to analyze these relationships in essential hypertensive (EH) patients. Seventy-one EH patients, 18-75 years old, were enrolled. Patients underwent clinical BP, 24-h ambulatory BP monitoring, 25[OH]D and plasma renin activity (PRA) evaluations. FokI and BsmI VDR polymorphisms were analyzed and compared with those of 72 healthy controls. In EH patients, the median 25[OH]D levels were lower than 30 ng ml-1. We found a significant negative correlation between 25[OH]D and 24-h systolic BP (r=-0.277, P=0.043). This correlation persisted in backward stepwise multivariate analyses (β=-0.337; P=0.022), after adjustment for age, gender, body mass index, glomerular filtration rate, and PRA. We did not observe statistically significant correlation between 25[OH]D and PRA. We compared the allelic frequencies and genotype distribution between patients and controls, and FokI and BsmI VDR polymorphisms were not associated either with hypertensive status or with PRA. Further wide studies are needed to clarify this relationship.