AIMS: Vitamin D status has been implicated in the pathophysiology of heart failure (HF). The aims of this study were to determine whether a low vitamin D status is associated with prognosis in HF and whether activation of the renin-angiotensin system (RAS) and inflammatory markers could explain this potential association.
METHODS AND RESULTS: We measured 25-hydroxy-vitamin D (25(OH)D), plasma renin activity (PRA), interleukin-6 (IL-6), C-reactive protein (CRP), and the incidence of death or HF rehospitalization in 548 patients with HF. Median age was 74 (64-80) years, left ventricular ejection fraction was 30% (23-42), and mean follow-up was 18 months. Low 25(OH)D levels were associated with female gender (P< 0.001), higher age (P= 0.002), and higher N-terminal pro-brain natriuretic peptide (NT-proBNP) levels (P< 0.001). Multivariable linear regression analysis showed that PRA (P= 0.048), and CRP levels (P= 0.006) were independent predictors of 25(OH)D levels. During follow-up, 155 patients died and 142 patients were rehospitalized. Kaplan-Meier analysis showed that lower 25(OH)D concentration was associated with an increased risk for the combined endpoint (all-cause mortality and HF rehospitalization; log rank test P= 0.045) and increased risk for all-cause mortality (log rank test P= 0.014). After adjustment in a multivariable Cox regression analysis, low 25(OH)D concentration remained independently associated with an increased risk for the combined endpoint [hazard ratio (HR) 1.09 per 10 nmol/L decrease; 95% confidence interval (CI) 1.00-1.16; P= 0.040] and all-cause mortality (HR 1.10 per 10 nmol/L decrease; 95% CI 1.00-1.22; P= 0.049).
CONCLUSION: A low 25(OH)D concentration is associated with a poor prognosis in HF patients. Activation of the RAS and inflammation may confer the adverse effects of low vitamin D levels.
2011. Vol. 13, no 6, 619-625 p.