Low 25-Hydroxyvitamin D Levels and Mortality in Non–Dialysis-Dependent CKD

Abstract

Background Low 25 hydroxyvitamin D (25[OH]D) levels are common among patients with non-dialysis-dependent chronic kidney disease (CKD). The associations between low 25(OH)D levels and mortality among non-dialysis dependent CKD patients are unclear. Study Design Retrospective cohort study. Setting & Participants Patients with stages 3–4 CKD (estimated glomerular filtration rate of 15–59 ml/min/1.73m2) (n = 12,673) who had 25(OH)D levels measured after the confirmation of CKD in Cleveland Clinic Health System. Predictor Levels of 25(OH)D categorized into 3 groups: 25(OH)D <15 ng/ml, 15–29 ng/ml. and ≥ 30 ng/ml Outcomes We examined factors associated with low 25(OH)D levels and associations between low 25(OH)D levels and all-cause mortality (ascertained using the Social Security Death Index and our electronic medical record) using logistic regression, Cox-proportional hazard models and Kaplan-Meier survival curves. Measurements 25(OH)D was measured using chemiluminescence immunoassay. Results Out of 12,763 CKD patients, 15% (n=1970) had 25(OH)D <15 ng/ml while 45% (n=5749) had 25(OH)D 15–29 ng/ml. Male gender, African American race, diabetes, coronary artery disease and lower eGFR were significantly associated with 25(OH)D <30 ng/ml. A graded increase in the risk for 25(OH)D <30 ng/ml was evident across increasing BMI levels. Patients who had 25(OH)D levels measured in Fall through Spring had higher odds for 25(OH)D <30 ng/ml. After covariate adjustment, CKD patients with 25(OH)D <15 ng/ml had a 33% increased risk for mortality (95% CI, 1.07–1.65). The 25(OH)D 15–29 ng/ml group did not exhibit a significantly increased risk for mortality (HR, 1.03; 95% CI, 0.86–1.22) compared to patients with 25(OH)D ≥30 ng/ml. Limitations Single center observational study, lack of data on albuminuria and other markers of bone and mineral disorders, and attrition bias Conclusions 25(OH)D <15 ng/ml was independently associated with all-cause mortality in non-dialysis dependent CKD.

Cinacalcet Improves Endothelial Dysfunction and Cardiac Hypertrophy in Patients on Hemodialysis with Secondary Hyperparathyroidism

“…However, this association was abolished by the administration of active vitamin D sterols, suggesting that the use of such active sterols improves patient outcomes [34,35,36]. In our study, the patients had low 25-OH vitamin D levels, which were not elevated by the cinacalcet treatment but were decreased at the end of treatment.…”

“…Several studies had associated low 25-OH vitamin D levels with increased mortality and morbidity in non-dialysis-dependent patients with CKD [34,35] and ESRD [36]. However, this association was abolished by the administration of active vitamin D sterols, suggesting that the use of such active sterols improves patient outcomes [34,35,36].…”

What is the optimal level of vitamin D in non-dialysis chronic kidney disease population?

“…These findings confirm the data reported in the biggest retro spective observational study analyzing VD and mortality in CKD patients. Navaneethan et al [40] Taking all these data together, we agree with the Institute of Medicine recommendation to consider sufficient 25(OH)D levels of at least 20 ng/mL, given that serum 25(OH)D concentrations above 30 ng/ mL are not consistently associated with increased benefit [27,40] . In addition, most clinical trials have only confirmed the neutral effect of VD supplementation on hard outcomes [41] , whereas some controlled studies have shown positive results in spite of the mean VD concentration not reaching the optimal recommended levels of ≥ 30 ng/mL [16] .…”

Arterial stiffness and 25-hydroxyvitamin D levels in chronic kidney disease patients

“…3,15,16,27 Vitamin D deficiency is associated with cardiovascular disease, all-cause mortality, morbidity, poor clinical outcomes and rapid decline of eGFR in patients with CKD. 25,34,35 Our study has some limitations. First, 25(OH)D tended to decrease as PWV and CKD stage increased.…”