title: Deterioration of heart rate recovery index in patients with non-alcoholic fatty liver disease (NAFLD).
abstract: BACKGROUND
  Non-alcoholic fatty liver disease (NAFLD) has been considered as a benign disease often associated with central obesity and insulin resistance and, in general, with factors of the metabolic syndrome. Heart rate recovery after exercise is a function of vagal reactivation, and its impairment is an independent prognostic indicator for cardiovascular and all-cause mortality. The aim of our study was to evaluate the heart rate recovery index in patients with NAFLD.
  
  
  METHODS
  The study population included 59 patients with NAFLD (mean age=42.3±9.3 years) and 22 healthy subjects as controls (mean age=40.7±6.5 years). Basal electrocardiography, echocardiography, and treadmill exercise testing were performed on all patients and controls. The heart rate recovery index was defined as the reduction in the heart rate from the rate at peak exercise to the rate at the 1st minute (HRR1), 2nd minute (HRR2), 3rd minute (HRR3), and 5th minute (HRR5) after stopping exercise stress testing.
  
  
  RESULTS
  There were significant differences in HRR1 and HRR2 indices between patients with ED and the control group (19.9±8.2 vs. 34.1±9.6; p<0.001 and 24.3±5.4 vs. 40.5±9.1; p=0.006, respectively). Similarly, HRR indices after the 3rd and 5th minutes of the recovery period were significantly lower in patients with NAFLD compared with those indices in the control group (32.3±8.5 vs. 58.4±6.5; p=0.001 and 58±18.2 vs. 75.1±15.8; p<0.001). Effort capacity was markedly lower (11±1.9 vs. 12.5±1.5 METs; p=0.001) among the patients with NAFLD.
  
  
  CONCLUSIONS
  The heart rate recovery index is deteriorated in patients with NAFLD. When the prognostic significance of the heart rate recovery index is considered, these results may help explain the increased occurrence of cardiac death. It points to the importance of the heart rate recovery index in the identification of high-risk patients.
authors.affiliation: Department of Cardiology, Yeditepe University, Medical School, Istanbul, Turkey.
authors.forename: Olcay
authors.initials: O
authors.lastname: Ozveren
authors.affiliation: Department of Cardiology, Firat University, Medical School, Elazig, Turkey.
authors.forename: Orhan
authors.initials: O
authors.lastname: Dogdu
authors.affiliation: Department of Cardiology, Kosuyolu Educational and Research Hospital, Istanbul, Turkey.
authors.forename: Cihan
authors.initials: C
authors.lastname: Sengul
authors.affiliation: Department of Cardiology, Yeditepe University, Medical School, Istanbul, Turkey.
authors.forename: Veysel
authors.initials: V
authors.lastname: Cinar
authors.affiliation: Department of Cardiology, Yeditepe University, Medical School, Istanbul, Turkey.
authors.forename: Elif
authors.initials: E
authors.lastname: Eroglu
authors.affiliation: Department of Cardiology, Yeditepe University, Medical School, Istanbul, Turkey.
authors.forename: Zekeriya
authors.initials: Z
authors.lastname: Kucukdurmaz
authors.affiliation: Department of Cardiology, Yeditepe University, Medical School, Istanbul, Turkey.
authors.forename: Muzaffer
authors.initials: M
authors.lastname: Degertekin
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D065626:Non-alcoholic Fatty Liver Disease / Q000000981:diagnostic imaging / Q000503:physiopathology*; D014463:Ultrasonography