The effect of oral vitamin D on serum level of N-terminal pro-B-type natriuretic peptide

BACKGROUND: The risk of cardiovascular disease in dialysis patients is higher than the general population. Vitamin D receptors exist in myocardium inhibit cardiac hypertrophy. N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) is a neurohormone secreted by the heart in response to ventricular mass increase. This study aimed to evaluate the effect of oral vitamin D on serum level of pro-B-type natriuretic peptide (pro-BNP) in peritoneal dialysis patients. MATERIALS AND METHODS: In a randomized clinical trial, 84 peritoneal dialysis patients (49 males and 35 females) were randomly divided into two groups. The intervention group received 50000 units oral vitamin D per week, for 12 weeks if 25-hydroxy-vitamin D level was <10 ng/ml and for 8 weeks if it was between 10 ng/ml and 30 ng/ml. The control group received placebo. Parathyroid hormone, calcium, phosphor, 25-hydroxy-vitamin D, albumin and NT-pro-BNP were evaluated before and after the study. RESULTS: The mean serum level of pro-BNP in patients receiving vitamin D and placebo group before the study was 875 pg/ml and 793 pg/ml, respectively. There was 895.9 pg/ml in the intervention group and 736.7 pg/ml in the control group (P = 0.7). Mean serum level of 25(OH) D in patients receiving oral vitamin D and placebo group before the study was 16.9 ng/ml and 31.9 ng/ml, respectively. There was 28.9 ng/ml in the intervention group and 12.9 ng/ml in the control group (P = 0.001). There were no significant differences regarding other indices (Alb, P, Ca, intact parathyroid hormone) between two groups. CONCLUSION: Vitamin D did not significantly change the serum level of pro-BNP in peritoneal dialysis patients.