Circulating calcitriol concentrations and total mortality.
BACKGROUND
Evidence is accumulating that vitamin D supplementation of patients with low 25-hydroxyvitamin D concentrations is associated with lower cardiovascular morbidity and total mortality during long-term follow-up. Little is known, however, about the effect of low concentrations of the vitamin D hormone calcitriol on total mortality. We therefore evaluated the predictive value of circulating calcitriol for midterm mortality in patients of a specialized heart center.


METHODS
This prospective cohort study included 510 patients, 67.7% with heart failure (two-thirds in end stage), 64.3% hypertension, 33.7% coronary heart disease, 20.2% diabetes, and 17.3% renal failure. We followed the patients for up to 1 year after blood collection. For data analysis, the study cohort was stratified into quintiles of circulating calcitriol concentrations.


RESULTS
Patients in the lowest calcitriol quintile were more likely to have coronary heart disease, heart failure, hypertension, diabetes, and renal failure compared to other patients. They also had low 25-hydroxyvitamin D concentrations and high concentrations of creatinine, C-reactive protein, and tumor necrosis factor alpha. Eighty-two patients (16.0%) died during follow-up. Probability of 1-year survival was 66.7% in the lowest calcitriol quintile, 82.2% in the second quintile, 86.7% in the intermediate quintile, 88.8% in the fourth quintile, and 96.1% in the highest quintile (P < 0.001). Discrimination between survivors and nonsurvivors was best when a cutoff value of 25 ng/L was applied (area under the ROC curve 0.72; 95% CI 0.66-0.78).


CONCLUSIONS
Decreased calcitriol levels are linked to excess midterm mortality in patients of a specialized heart center.
Department of Cardio-Thoracic Surgery, Heart Center North Rhine-Westfalia, Ruhr University Bochum, Bad Oeynhausen, Germany. azittermann@hdz-nrw.de
Armin
A
Zittermann
Stefanie S
SS
Schleithoff
Sabine
S
Frisch
Christian
C
Götting
Joachim
J
Kuhn
Heinrich
H
Koertke
Knut
K
Kleesiek
Gero
G
Tenderich
Reiner
R
Koerfer
D000368:Aged; D002117:Calcitriol / Q000097:blood*; D015331:Cohort Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality
D002117:Calcitriol