Impact of hypovitaminosis D and alfacalcidol therapy on survival of hemodialysis patients: results from the French ARNOS study.

BACKGROUND

In chronic kidney disease and dialysis patients, vitamin D deficiency is associated with mortality. In some observational studies, calcitriol analogue therapy was associated with a better survival rate in hemodialysis (HD) patients. The aim of this study was to determine the relationship between serum 25-hydroxyvitamin D (25-OHD) levels and alfacalcidol therapy with HD patients' outcomes.

METHODS

We measured baseline 25-OHD levels using a cross-sectional analysis in 648 HD prevalent patients from the regional ARNOS French cohort. A 42-month survival analysis was applied according to serum 25-OHD level and calcitriol analogue therapy.

RESULTS

The prevalence of 25-OHD insufficiency <30 ng/ml was high (73%), with only 22% taking native vitamin D supplementation. A baseline 25-OHD level above the median value (18 ng/ml) was associated with lower all-cause mortality [hazard ratio (HR), 0.73 (0.5-0.96); p = 0.02] after adjustment for age, gender, dialysis vintage, calcemia, phosphatemia, cardiovascular disease, and diabetes. Only in monovariate analysis was low-dose oral alfacalcidol therapy associated with a better survival rate in patients with and without 25-OHD deficiency [HR, 0.7 (0.5-0.92); p = 0.05].

CONCLUSIONS

Our study shows that, among prevalent HD patients, low 25-OHD levels affect mortality. Alfacalcidol therapy, especially in small doses, may provide compensation, but this needs to be further confirmed using prospective controlled studies comparing native and active vitamin D compounds.