Correlation of Vitamin D Deficiency With Severity of Chronic Heart Failure As Assessed by Functional Class and N-Terminal Pro-Brain Natriuretic Peptide Levels

Introduction Chronic heart failure (CHF) is a major cause of mortality and morbidity in spite of tremendous advances in medical therapies. Vitamin D deficiency has been increasingly recognised in heart failure and its therapeutic as well as prognostic implications are debated. This study was carried out to examine the relationship of Vitamin D levels with severity of heart failure as assessed by NYHA functional class and serum N-terminal pro-brain natriuretic peptide (NT-pro-BNP) levels in vitamin D deficient patients with CHF. Methodology and results In this cross-sectional analysis, 119 patients of symptomatic CHF presenting to the outpatient/inpatient department of cardiology in a tertiary care institute in North India were screened. Patients were categorised according to their functional class as New York Heart Association (NYHA) class II, III, IV and their serum levels of vitamin D and NT-pro-BNP were measured. Out of 119 patients, 107 (90%) were found to have low vitamin D levels which were classified as insufficient (20-30 ng/ml) (n=25, 23%) or deficient (<20 ng/ml) (n=82,77%). The mean NT-pro-BNP levels increased significantly across functional class as 3783±6132 pg/ml, 7866±4383 pg/ml, 21115±11905 pg/ml in NYHA class II, III and IV respectively (p=0.000). The respective mean serum Vitamin D3 levels of 11.6±5.8ng/ml, 12.2±7.9 ng/ml, 14.4±8.9 ng/ml were not significantly different between classes (p=0.234). We found no correlation between serum NT-pro-BNP and serum vitamin D levels in the study cohort across various NYHA classes. In multivariate regression model, after adjusting for various co-variates, vitamin D levels were not significantly associated with NT-pro-BNP or functional class in patients with CHF. Conclusion Patients with CHF have a high prevalence (90%) of vitamin D deficiency. Although NT-pro-BNP levels increase significantly, vitamin D levels do not vary significantly with worsening NYHA classes. Further, no consistent significant correlation of vitamin D deficiency with NT-pro-BNP across different NYHA classes was observed. Thus, low levels of vitamin D didn't predict the severity and prognosis of patients with heart failure. .