Predictors of Vitamin D deficiency in predialysis patients with stage 3-5 chronic kidney diseases in Southern China.

OBJECTIVE: Vitamin D status and risk factors of Vitamin D deficiency in chronic kidney disease (CKD) patients in China have been seldom reported before. In this study, we aim to investigate serum 25-hydroxyvitamin D [25(OH)D] status and find the predictors of Vitamin D deficiency in predialysis patients with Stage 3-5 CKDs in Southern China.

METHODS: In this retrospective cross-sectional study, hospitalized predialysis patients who were diagnosed of Stage 3-5 CKD and had taken measurement of serum 25(OH)D in a single center from January 2014 to June 2015 were included. Patients were divided into Vitamin D deficiency group and nondeficiency group depending on the cutoff serum 25(OH)D value of 37 nmol/L. Clinical and biochemical parameters were collected and evaluated for predictors of Vitamin D deficiency by logistic regression.

RESULTS: One hundred and fifty-two patients were included in this study, of which 87 (57.2%) were in Vitamin D insufficiency state while 60 (39.5%) were in Vitamin D deficiency state. Serum 25(OH)D levels of patients in Stage 4 and Stage 5 CKD were lower than that of patients in Stage 3 CKD (P = 0.002). It was discovered that female gender (odds ratio [OR] = 3.674; 95% confidence interval [CI], 1.607-8.396; P = 0.002), serum albumin level <30.0 g/L (OR = 6.816; 95% CI, 2.634-17.633; P < 0.001), and estimated glomerular filtration rate (eGFR) <30 ml/min/1.73 m2 (OR = 4.761; 95% CI, 1.353-16.754; P = 0.015) were independent predictors of Vitamin D deficiency.

CONCLUSIONS: Vitamin D insufficiency and deficiency are common in predialysis patients with Stage 3-5 CKD in Southern China. Female gender, hypoalbuminemia with serum albumin level <30.0 g/L, and severe damaged renal function with eGFR <30 ml/min/1.73 m2 are independent predictors of Vitamin D deficiency in predialysis patients with Stage 3-5 CKD.