Association of vitamin D status with all-cause mortality and outcomes among Chinese individuals with diabetic foot ulcers.

Abstract

The aim of this study was to examine the correlation between serum vitamin D concentrations and prognosis among Chinese individuals with diabetic foot ulcers (DFUs). We retrospectively recruited 488 adults with DFUs in West China Hospital from 1 January 2012 to 31 December 2019. After telephone follow up, 275 patients were finally included. We compared serum vitamin D concentrations among DFUs patients with different prognostic status, and examined the association of vitamin D status with prognostic variables by Kaplan-Meier analysis. Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals for all-cause mortality. The median concentration of serum vitamin D of patients with DFUs was 37.78 nmol/L (interquartile range 27.91-50.66 nmol/L), with 31.6% having vitamin D deficiency (<30 nmol/L) and 42.2% having insufficient vitamin D (<50 nmol/L). During a median follow-up period of 52 months, 65 patients died, with an all-cause mortality of 23.64%. Vitamin D deficiency was independently linked to increased all-cause mortality after multivariable adjustments (hazard ratio 0.565, 95% confidence interval 0.338-0.946, P = 0.030). There were no significant differences between vitamin D concentrations and other outcomes of DFUs. Patients who suffered amputations had a tendency of lower vitamin D concentrations (34.00 [interquartile range 26.90-41.81] vs 40.21 [interquartile range 29.60-53.96] nmol/L, P = 0.053). Vitamin D deficiency was significantly associated with increased all-cause mortality in Chinese individuals with DFUs. Vitamin D supplementation might be a potential therapy for DFUs to prevent premature death and improve outcomes.