Oral Presentation The Joint Annual Scientific Meetings of the Endocrine Society of Australia and the Society for Reproductive Biology 2017

Serum 25-hydroxyvitamin D as a predictor of mortality and cardiovascular events: a 20 year study of a community-based cohort (#65)

Kun (Kathy) Zhu 1 2 , Matthew Knuiman 3 , Mark Divitini 3 , Ee Mun Lim 1 4 , Andrew StJohn 5 , Brian Cooke 6 , Joseph Hung 2 , John P Walsh 1 2
  1. Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, WA, Australia
  2. School of Medicine and Pharmacology, University of Western Australia, Crawley, WA, Australia
  3. School of Population Health, University of Western Australia, Crawley, WA, Australia
  4. Department of Clinical Biochemistry , PathWest Laboratory Medicine, Nedlands, WA, Australia
  5. ARC Consulting, Mount Lawley, WA
  6. Department of Clinical Biochemistry, Fiona Stanley Hospital, Murdoch, WA

Background: Previous studies suggest that vitamin D is inversely associated with mortality and cardiovascular disease (CVD) risk, but data on the association between serum 25-hydroxyvitamin D (25(OH)D) and incident heart failure are limited.

Aims: To examine serum 25(OH)D as a predictor of total mortality and cardiovascular outcomes in an Australian community-based cohort.

Methods: Serum 25(OH)D was measured in the Busselton Health Study 1994/1995 Cohort (n=3946, age 25-84 years). During 20 years follow-up (excluding the first 2 years), 889 (22.5%) participants died including 363 (9.2%) from cardiovascular disease (CVD); 944 (23.9%) experienced a CVD event including 242 (6.1%) who had a heart failure event.

Results: The mean serum 25(OH)D concentration was 60.6 (SD 18.0) nmol/L. In the full cohort, higher baseline serum 25(OH)D was associated with significantly reduced all-cause mortality (covariate-adjusted  hazard ratio [HR] 0.83 per SD of 25(OH)D, 95% CI 0.77-0.90), CVD death (HR 0.85, 95% CI 0.74-0.96) and heart failure (HR 0.81, 95% CI 0.69-0.94), but not for CVD events combined (HR 0.99, 95% CI 0.92-1.07). In restricted cubic spline regression models, serum 25(OH)D below 65 nmol/L was associated with higher total mortality and 25(OH)D below 55 nmol/L with CVD mortality and heart failure; there were no additional benefits for 25OHD above 80 nmol/L. In participants without CVD at baseline (n = 3220) results were similar, but hazard ratios were attenuated and associations with CVD mortality no longer significant.

Conclusion In a community-based cohort, lower vitamin D is associated with increased risk of all-cause mortality, CVD death and heart failure.