Vitamin D deficiency--prognostic marker or mortality risk factor in end stage renal disease patients with diabetes mellitus treated with hemodialysis--a prospective multicenter study

PLoS One. 2015 May 12;10(5):e0126586. doi: 10.1371/journal.pone.0126586. eCollection 2015.

Abstract

Background: End stage renal disease (ESRD) patients on renal replacement therapy (RRT) with diabetes mellitus (DM) have a higher mortality rate and an increase prevalence of vitamin D deficiency compared to those without DM. It is still debated if vitamin D deficiency is a risk factor or a prognostic marker for mortality in these patients. This study investigated the prevalence of vitamin D deficiency and its impact on all-cause mortality in HD patients with DM.

Methods: Our prospective non-interventional cohort study included 600 patients on hemodialysis therapy (HD) (median aged 56, interquartile range (19) years, 332 (55.3%) males) recruited from 7 HD centers, from all main geographical regions of Romania. The prevalence of DM was 15.3%. They were then followed regarding: dialysis duration, dialysis efficiency, renal anemia, CKD-MBD, inflammatory status and comorbidities: coronary artery disease (CAD), peripheral vascular disease (PVD) and stroke. The deficiency of 25-OH vitamin D was defined as a value lower than 12 ng/mL.

Results: Patients were followed for 3 years. The overall 3 year mortality was 25.5% (153 individuals), being higher in patients with DM as compared to those without DM (33.7% vs. 24.0%; P = 0.049). The time-related prognosis was also influenced by the presence of DM, at the survival analysis resulting in a HR of 1.52 [1.03 to 2.26] 95% CI, P = 0.037, for death in dialyzed patients with DM. In DM patients, 25-OH vitamin D deficiency was significantly higher (37.0% compared to 24.0%, P = 0.009). Furthermore, in patients with DM we observed a shorter dialysis duration (2 vs. 3 years, P<0.001) and a lower intact parathyroid hormone (iPTH) (258.0 pg/ml vs. 441.9 pg/ml, P = 0.002). Regarding the presence of comorbidities at the inclusion in the study, the presence of diabetes in dialyzed patients was associated with increased prevalence of CAD (87.0% vs. 58.1%, P<0.001), PVD (67.4% vs. 17.3%, P<0.001) and history of stroke (29.3% vs. 14.0%, P<0.001). In patients with DM the presence of 25-OH vitamin D deficiency increased the probability of death (50.0% vs. 24.1%; P = 0.011). In multiple Cox proportional hazards analysis, vitamin D deficiency remained an independent predictor for mortality in dialysis patients with DM (HR = 1.71, 95% CI 1.21 to 2.43, P = 0.003). In the same time, multiple Cox proportional hazards analysis showed that age (HR = 1.02 per one year increase, P = 0.004), CAD (HR = 1.55, P = 0.046) and PVD (HR = 1.50, P = 0.029) were independent predictors for mortality in dialysis patients with DM.

Conclusions: ESRD patients with DM treated with HD have a higher overall mortality than non-DM patients. Vitamin D deficiency is significantly more prevalent in HD patients with DM. Low 25-OH vitamin D levels were associated with increased all-cause mortality in these patients. According to our data, in HD patients with DM, screening for vitamin D deficiency (and its correction) should be mandatory for an optimal risk reduction strategy.

Publication types

  • Clinical Study
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Diabetes Mellitus / blood*
  • Diabetes Mellitus / mortality
  • Diabetes Mellitus / pathology
  • Female
  • Humans
  • Kidney Failure, Chronic / blood*
  • Kidney Failure, Chronic / complications
  • Kidney Failure, Chronic / pathology
  • Male
  • Middle Aged
  • Prognosis*
  • Renal Dialysis
  • Risk Factors
  • Vitamin D / blood
  • Vitamin D Deficiency / blood*
  • Vitamin D Deficiency / mortality
  • Vitamin D Deficiency / pathology

Substances

  • Vitamin D

Grant support

The funder -BBraun Avitum Ltd Romania. The funder provided support in the form of salaries for author(s) OS, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.