Vitamin D Predicts All-Cause and Cardiac Mortality in Females with Suspected Acute Coronary Syndrome: A Comparison with Brain Natriuretic Peptide and High-Sensitivity C-Reactive Protein

Vitamin D may not only reflect disease but may also serve as a prognostic indicator. Our aim was to assess the gender-specific utility of vitamin D measured as 25-hydroxy-vitamin D [25(OH)D] to predict all-cause and cardiac death in patients with suspected acute coronary syndrome (ACS) and to compare its prognostic utility to brain natriuretic peptide (BNP) and high-sensitivity C-reactive protein (hsCRP). Blood samples were harvested on admission in 982 patients. Forty percent were women (65.9 ± 12.6 years). Mortality was evaluated in quartiles of 25(OH)D, BNP, and hsCRP, respectively, during a 5-year follow-up, applying univariate and multivariate analyses. One hundred and seventy-three patients died; 78 were women. In 92 patients (37 women), death was defined as cardiac. In women, the univariate hazard ratio (HR) for total death of 25(OH)D in Quartile (Q) 2 versus Q1, Q3 versus Q1, and Q4 versus Q1 was 0.55 (95% CI 0.33–0.93), 0.29 (95% CI 0.15–0.55), and 0.13 (95% CI 0.06–0.32), respectively. In females, it was an independent predictor of total and cardiac death, whereas BNP and hsCRP were less gender-specific. No gender differences in 25(OH)D were noted in a reference material. Accordingly, vitamin D independently predicts mortality in females with suspected ACS. 1. Introduction Cardiovascular disease (CVD) is the primary cause of mortality both in men and women worldwide [1]. Women have been underrepresented in clinical trials [2]. They very often present with atypical symptoms and are frequently undiagnosed. Furthermore, their risk factors are understudied. Due to women’s higher age of disease manifestation, they are also more likely to have other diseases and comorbidities, rendering the diagnosis more difficult and complex. This has also resulted in less research related to the predictive utility of the established biomarkers in this gender. Recently, numerous observational and epidemiological studies suggest that vitamin D deficiency may be related to CVD and mortality [3–9] and is associated with myocardial infarction (MI) [10, 11] and sudden cardiac death (SCD) [12]. As vitamin D deficiency in men and women is increasing, we believe that the general diet does not contain a sufficient amount of this vitamin and/or that people do not spend enough time outdoors to create a sufficient amount of this vitamin upon sun exposure. In a previous study with 2-year follow-up [13], we found low levels of 25-hydroxy-vitamin D [25(OH)D] in a chest-pain population from Northern Argentina. This was an unexpected finding, as we assumed that our study