Abstract P063: Vitamin D and Parathyroid Hormone are Cross-sectionally Associated with Higher Levels of B-type Natriuretic Peptide: The Hoorn Study

Abstract

Background: Low serum 25-hydroxyvitamin D (25OHD) levels have been associated with increased risk of cardiovascular disease. Dysfunction of the vitamin D-parathyroid hormone (PTH)-calcium axis may play a role in the pathogenesis of heart failure. Hypothesis: We investigated whether lower serum 25OHD levels and higher PTH levels are associated with higher B-type natriuretic peptide (BNP) levels in older individuals both cross-sectionally and after 8 years of follow-up. Methods: We measured baseline serum 25OHD, PTH and BNP in 502 subjects in 2000–2001 in the Hoorn Study, a population-based cohort. Follow-up BNP was measured in 2007–2009 in 278 subjects. Subjects were categorized according to season and sex-specific 25OHD and PTH quartiles at baseline. We studied the association of 25OHD and PTH quartiles with BNP using linear regression analyses adjusting for confounders. Effect-modification by kidney function and CVD presence was examined. Results: Subjects had a mean age of 70 years, mean 25OHD level of 52±19.5 (nmol/L) and mean PTH of 6.1±2.4 (pmol/L). The lowest 25-OHD quartile was cross-sectionally associated with higher BNP, in subjects with low kidney function only (eGFR<77.3 mL/min/1.73m 2 )(=sample median). The association attenuated after adjustment for PTH. PTH was cross-sectionally associated with BNP in subjects with low kidney function only (p-for-trend < 0.05), even after adjustment for 25OHD (Figure 1). Neither 25OHD nor PTH was associated with BNP in longitudinal analyses. Conclusion: This study showed no strong association between 25OHD and BNP. However, PTH - a potential mediator in the relation between 25OHD and BNP, was associated with BNP in subjects with low kidney function.