Association of serum 25-hydroxyvitamin D concentrations with all-cause and cause-specific mortality among individuals with gout and hyperuricemia

BackgroundWe aimed to probe the association of serum 25-hydroxyvitamin D [25(OH)D] concentrations with all-cause and cause-specific mortality among patients with gout and hyperuricemia (HUA).MethodsThe study included 1169 gout patients and 7029 HUA patients from the National Health and Nutrition Examination Survey (NHANES) 2007-2018 and 2001-2018, respectively. The association between serum 25(OH)D and mortality was evaluated by Cox proportional hazard and restricted cubic spline models.ResultsAmong participants with gout and HUA, the weighted mean concentrations of serum 25(OH)D were 71.49 +/- 30.09 nmol/L and 64.81 +/- 26.92 nmol/L, respectively. Vitamin D deficiency occurred in 29.68% of gout patients and 37.83% of HUA patients. During 6783 person-years of follow-up among gout patients, 248 all-cause deaths occurred, among which 76 died from cardiovascular disease (CVD) and 49 died from cancer. 1375 HUA patients were recorded for all-cause mortality during 59,859 person-years of follow-up, including 427 CVD deaths and 232 cancer deaths. After multifactorial adjustment, per one-unit increment in natural log-transformed 25(OH)D was associated with lower risk of 55% all-cause mortality and 61% CVD mortality among gout patients, and a 45% reduced risk of cancer mortality among HUA patients. Restricted cubic splines showed a U-shaped relationship with all-cause and CVD mortality among HUA patients, with inflection points of 72.7 nmol/L and 38.0 nmol/L, respectively. The results were robust in subgroup and sensitivity analyses.ConclusionsSerum 25(OH)D was negatively linearly correlated with mortality among gout patients, whereas U-shaped correlated with mortality in HUA patients. These results indicate that adequate vitamin D status could prevent premature death.