title: 25-Hydroxyvitamin D3, arterial calcifications and cardiovascular risk markers in haemodialysis patients.
abstract: BACKGROUND
  Decreased vitamin D serum levels have been recently related to arterial stiffening and vascular calcifications in haemodialysis (HD) patients, but the pathophysiology of this association is not yet clear. The aim of this study was to evaluate the relationship between vascular calcifications, cardiovascular risk factors [including brain natriuretic peptide (BNP), pulse pressure (PP) and left ventricular mass index] and 25-hydroxyvitamin D3 (25(OH)D3) and 1,25-dihydroxyvitamin D3 [1,25(OH)(2)D3] serum levels.
  
  
  METHODS
  We performed a cross-sectional study with 223 prevalent HD patients, 48% females, 27% diabetics, with the mean age of 62.7 +/- 15.3 years and the mean HD time of 42.9 +/- 39.3 months. Forty-seven percent of the patients were taking active forms of vitamin D.
  
  
  RESULTS
  Serum levels of [25(OH)D3] were low (21.6 +/- 12.2 ng/mL) and negatively correlated with age (r = -0.31, P < 0.001), diabetes mellitus (DM) (r = -0.20, P = 0.004), C-reactive protein (r = -0.25, P < 0.001), log(10) BNP (r = -0.22, P = 0.002), PP > 65 mmHg (r = -0.21, P = 0.003) and vascular calcifications (r = -0.26, P < 0.001). Levels of [25(OH)D3] were positively correlated with [1,25(OH)(2)D3] (r = 0.25, P < 0.001) and albumin (r = 0.23, P = 0.001). On multivariate analysis, levels of [25(OH)D3] were independently associated with DM (P < 0.001), lower albumin levels (P = 0.003), higher BNP values (P = 0.005), PP > 65 mmHg (P = 0.006) and a higher vascular calcification score (>or= 3) (P = 0.002).
  
  
  CONCLUSIONS
  These results suggest that lower levels of [25(OH)D3] are a cardiovascular risk marker in HD patients, since they are strongly associated with higher BNP levels, increased PP and with the presence of vascular calcifications. The exact role of [25(OH)D3] deficiency on cardiovascular morbi-mortality needs to be clarified in large randomized controlled trials.
authors.affiliation: Hemodial-Dialysis Unit, Vila Franca de Xira, Portugal. patriciajoaomatias@hotmail.com
authors.forename: Patrícia João
authors.initials: PJ
authors.lastname: Matias
authors.forename: Carina
authors.initials: C
authors.lastname: Ferreira
authors.forename: Cristina
authors.initials: C
authors.lastname: Jorge
authors.forename: Marília
authors.initials: M
authors.lastname: Borges
authors.forename: Inês
authors.initials: I
authors.lastname: Aires
authors.forename: Tiago
authors.initials: T
authors.lastname: Amaral
authors.forename: Célia
authors.initials: C
authors.lastname: Gil
authors.forename: José
authors.initials: J
authors.lastname: Cortez
authors.forename: Aníbal
authors.initials: A
authors.lastname: Ferreira
mesh_terms: D000368:Aged; D002112:Calcifediol / Q000097:blood* / Q000172:deficiency; D002114:Calcinosis / Q000097:blood* / Q000209:etiology*; D002117:Calcitriol / Q000097:blood; D002318:Cardiovascular Diseases / Q000097:blood* / Q000209:etiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood; D006435:Renal Dialysis / Q000009:adverse effects*; D012307:Risk Factors; D014652:Vascular Diseases / Q000097:blood* / Q000209:etiology*; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications
chemical_list: D020097:Natriuretic Peptide, Brain; D002117:Calcitriol; D002112:Calcifediol