Serum 25-hydroxyvitamin D status and cardiovascular outcomes in chronic peritoneal dialysis patients: a 3-y prospective cohort study.
BACKGROUND
Patients with kidney disease are at high risk of developing 25-hydroxyvitamin D [25(OH)D] deficiency.


OBJECTIVE
We studied the association between serum 25(OH)D status and clinical outcomes of chronic peritoneal dialysis patients.


METHODS
We measured serum 25(OH)D concentrations in 230 prevalent peritoneal dialysis patients and then followed these patients prospectively for 3 y or until death.


RESULTS
Serum 25(OH)D was deficient or insufficient (ie, <75 nmol/L) in 87% of the patients. Adjusting for clinical and demographic factors, every 1-unit increase in log-transformed serum 25(OH)D was associated with a 44% reduction in the hazard of fatal or nonfatal cardiovascular events (95% CI: 0.35, 0.91; P = 0.018). However, the association was gradually lost when additional adjustment was made in a stepwise fashion for residual glomerular filtration rate (P = 0.078) and echocardiographic measures (P = 0.39). Kaplan-Meier estimates showed a significantly greater fatal or nonfatal cardiovascular event-free survival probability among patients with serum 25(OH)D > 45.7 nmol/L (median) than among patients with concentrations <or= 45.7 nmol/L (P = 0.004). In addition, patients with 25(OH)D > 45.7 nmol/L had a significantly higher cardiovascular event-free survival probability than did patients with 25(OH)D <or= 45.7 nmol/L in the stratified analysis for patients with left ventricular mass index less than the median (P = 0.013) or normal systolic function (P = 0.005).


CONCLUSIONS
A lower serum 25(OH)D concentration was associated with an increased risk of cardiovascular events in chronic peritoneal dialysis patients. Furthermore, serum 25(OH)D status appeared to show a differential influence on the cardiovascular outcomes of peritoneal dialysis patients depending on the degree of left ventricular hypertrophy and systolic dysfunction.
Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong. aymwang@hku.hk
Angela Yee-Moon
AY
Wang
Christopher Wai-Kei
CW
Lam
John E
JE
Sanderson
Mei
M
Wang
Iris Hiu-Shuen
IH
Chan
Siu-Fai
SF
Lui
Mandy Man-Mei
MM
Sea
Jean
J
Woo
D000328:Adult; D000368:Aged; D002320:Cardiovascular Physiological Phenomena; D015331:Cohort Studies; D003928:Diabetic Nephropathies / Q000628:therapy; D003971:Diastole; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000628:therapy; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D010530:Peritoneal Dialysis / Q000009:adverse effects; D011336:Probability; D011446:Prospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome; D016277:Ventricular Function, Left; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000209:etiology / Q000517:prevention & control
D014807:Vitamin D; C104450:25-hydroxyvitamin D