Lower risk for cardiovascular mortality in oral 1α-hydroxy vitamin D3 users in a haemodialysis population

Background. Renal failure results in deficiency of active vitamin D-3 that has diverse effects on metabolism and organ functions. Treatment with active forms of vitamin D-3 ameliorates abnormalities in bone and mineral metabolism, cardiac function, immune response and others. We hypothesized that treatment with vitamin D-3 may be beneficial for survival in patients with end-stage renal disease (ESRD). Methods. We compared the risk of death between regular users (n = 162) and non-users (n = 80) of oral 1alpha-hydroxyvitamin D-3 (alfacalcidol) in a cohort of ESRD patients undergoing haemodialysis for a follow-up of 61 +/- 23 months. The daily dose of alfacalcidol ranged from 0.25 to 1.5 mug, with a median of 0.5 mug. Results. The alfacalcidol users showed a lower risk of death from cardiovascular disease than the non-users in a univariate Cox model [hazards ratio (HR) 0.287, 95% confidence interval (CI) 0.127-0.649, P = 0.003], whereas the risk for death from non-cardiovascular disease was not different between the two groups. Stepwise multivariate Cox analysis showed that cardiovascular mortality was significantly associated with age, presence of diabetes mellitus and treatment with alfacalcidol (HR 0.377, 95% CI 0.246-0.578, P = 0.022). Conclusions. These results indicate that use of oral alfacalcidol was associated with reduced risk for cardiovascular death in this cohort of ESRD patients. The result of this observational study warrants further randomized controlled trials with la-hydroxy vitamin D-3 to confirm the possibility that such medication improves survival of ESRD patients.