title: Could decreased vitamin D levels be related with impaired cardiac autonomic functions in patients with chronic heart failure: an observational study.
abstract: OBJECTIVE
  Vitamin D status has been implicated in the pathophysiology of heart failure (HF). The aim of this study was to investigate the association between vitamin D levels with heart rate variability and heart rate turbulence in patients with heart failure whom had ischemic and non-ischemic dilated cardiomyopathy.
  
  
  METHODS
  Study designed as an observational cross-sectional study. Seventy-one patients [36 non-ischemic dilated cardiomyopathy (NIDCM), 35 ischemic dilated cardiomyopathy (IDCM)] with chronic heart failure and 25 control subject were included. It was evaluated the association between 25 hydroxyvitamin D [25(OH)D] and calcitriol levels with heart rate variability time domain (SDNN, SDANN, RMSSD) and heart rate turbulence [turbulence onset (TO), turbulence slope (TS)] parameters. Statistical analysis was performed using Kruskal-Wallis test and ANOVA.
  
  
  RESULTS
  Calcitriol levels in NIDCM patients with abnormal TO and TS were significantly lower than NIDCM patients with normal TO (17.1 ± 11.3 vs. 27.6 ± 15.5 pg/mL, p=0.05) and TS (16.6 ± 9.1 vs. 29.4 ± 16.9 pg/mL, p=.018). There was a positive correlation between 25 (OH) D with heart rate variability parameters SDNN (r=0.368, p=0.027) and SDANN (r=0.360, p=0.031). It was not found any association between vitamin D and parameters of heart rate variability and heart rate turbulence in IDCM patients.
  
  
  CONCLUSIONS
  Insufficiency of vitamin D may have deleterious effects on cardiac autonomic functions which were showed with heart rate turbulence and heart rate variability in patients with NIDCM. Vitamin D levels might be a predictor to determine the sudden cardiac death in patients with non-ischemic etiology.
authors.affiliation: Clinic of Cardiology, Çerkezköy State Hospital; Tekirdağ-Turkey. metincetin81@yahoo.com.
authors.forename: Metin
authors.initials: M
authors.lastname: Cetin
authors.forename: Güliz
authors.initials: G
authors.lastname: Kozdağ
authors.forename: Dilek
authors.initials: D
authors.lastname: Ural
authors.forename: Göksel
authors.initials: G
authors.lastname: Kahraman
authors.forename: Irem
authors.initials: I
authors.lastname: Yılmaz
authors.forename: Yaşar
authors.initials: Y
authors.lastname: Akay
authors.forename: Raşit
authors.initials: R
authors.lastname: Onuk
authors.forename: Nigar
authors.initials: N
authors.lastname: Dursun
mesh_terms: D001341:Autonomic Nervous System / Q000503:physiopathology*; D002117:Calcitriol / Q000097:blood*; D002311:Cardiomyopathy, Dilated / Q000097:blood / Q000503:physiopathology; D003430:Cross-Sectional Studies; D005260:Female; D006329:Heart Conduction System; D006333:Heart Failure / Q000097:blood / Q000503:physiopathology*; D006801:Humans; D008297:Male; D017202:Myocardial Ischemia / Q000097:blood / Q000503:physiopathology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000503:physiopathology*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002117:Calcitriol