Association between Vitamin D and mortality risk in gout patients

Abstract

Background: The correlation between gout patients' 25-hydroxyvitamin D [25(OH)D] levels and their risk of all-cause mortality (ACM) and cardiovascular mortality (CVM) remains inconclusive.

Methods: Data from 7337 gout patients enrolled in the UK Biobank were analyzed, with death data acquired via connection to national death registries. At baseline, serum 25(OH)D levels were measured. We utilized Cox proportional hazards regression to evaluate the correlations between serum 25(OH)D levels and mortality, and mendelian randomization (MR) analyses to explore causality.

Results: During 80 176 person-years of following up (median 11.4 years), 659 all-cause deaths were recorded, including 206 cardiovascular disease-related deaths. We found an L-shaped non-linear inverse connection (P non-linearity<0.05) between serum 25(OH)D levels and ACM and CVM with a cutoff value of 45 nmol/L. In contrast to gout patients with <45 nmol/L, those with 25(OH)D levels ≥45 nmol/L had a significantly decreased likelihood of ACM [Hazard Ratio (HR) 0.72; 95% confidence interval 0.61-0.86]. Nonlinear MR also confirmed the causal connection between sufficient 25(OH)D level threshold (≥50 nmol/L) and a reduced likelihood of ACM. Additionally, raising 25(OH)D over the deficiency thresholds (25 nmol/L) could also potentially mitigate CVM (P trend = 0.02).

Conclusions: Elevated serum 25(OH)D levels are associated with a reduced likelihood of death in gout patients.

Keywords: 25-hydroxyvitamin D; UK biobank; goutmortality; non-linear mendelian randomization.