title: [Serum level of 25(OH)D and its relevant influencing factors in patients on maintenance hemodialysis].
abstract: OBJECTIVE
  To explore the serum level of 25(OH)D and its relevant influencing factors in patients on maintenance hemodialysis.
  
  
  METHODS
  The serum level of 25(OH)D was detected by electrochemiluminescence. A total of 162 patients on maintenance hemodialysis were divided into 3 groups according to the serum level of 25(OH)D: vitamin D deficiency: 25(OH)D ≤ 15 µg/L, vitamin D insufficiency: 25(OH)D ≤ 30 µg/L and vitamin D normal: 25(OH)D > 30 µg/L. Age, gender, relevant biochemical indices, high sensitivity C-reactive protein (hsCRP) and HOMA-IR were compared among there groups. The associations between 25(OH)D and the influencing factors of its levels were analyzed by Pearson's correlation. The independent factors correlated with the level of 25(OH)D were estimated by multiple linear regression.
  
  
  RESULTS
  The average level of 25(OH)D was 10.3 (range: 4.0 - 43.5) µg/L and the prevalence of 25(OH)D insufficiency and deficiency 88.9% (144/162). Significant differences existed in age, cholesterol (CHOL), low density lipoprotein (LDL), lipoprotein(a) (LP(a)), creatinine (Cr), lg(hsCRP), lg(reductase inhibitor) (lg(RI)) and lg(vitamin D) (lg(VitD)) between three groups (all P < 0.05). Pearson's correlation analyses revealed that the serum levels of albumin (ALB), Cr and Ca(2+) were correlated positively with lg(VitD) while those of white blood cell, CHOL, LDL, Lp(a), age, RI and hsCRP were correlated negatively with VitD. Multiple linear regression analyses demonstrated that hsCRP, RI, LDL and age were the independent influencing factors of the serum levels of 25(OH)D.
  
  
  CONCLUSIONS
  The prevalence of 25(OH)D insufficiency and deficiency is high. And microinflammation and insulin resistance are closely correlated with the insufficiency and deficiency of 25(OH)D. The independent influencing factors of serum 25(OH)D are hsCRP, RI, LDL and age.
authors.affiliation: Blood Purification Center, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China.
authors.forename: Chun-hua
authors.initials: CH
authors.lastname: Zhang
authors.forename: Shen
authors.initials: S
authors.lastname: Shen
authors.forename: Shi-xiang
authors.initials: SX
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D015519:Bone Density; D002112:Calcifediol / Q000097:blood*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D006435:Renal Dialysis; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*
chemical_list: D014807:Vitamin D; D002112:Calcifediol