title: Heart rate variability and its correlation with pulmonary function test of smokers.
abstract: BACKGROUND
  Though many studies have been conducted on the effect of chronic smoking on pulmonary function test (PFT) and heart rate variability (HRV), no study has found a correlation between the pulmonary function test and heart rate variability parameters so far.
  
  
  OBJECTIVE
  The aim was to study if there was a correlation, if any, between PFT and HRV.
  
  
  METHODS
  Thirty male subjects who were chronic smokers of at least 10 pack years and another 30 nonsmoking healthy males were included in the study and were matched for age, height, weight, and body surface area.
  
  
  METHODS
  PFT and HRV were performed on these subjects and a correlation was statistically derived.
  
  
  METHODS
  Spearman's correlation coefficient was used for the analysis of HRV and PFT. Multiple stepwise regression analysis was used subsequently.
  
  
  RESULTS
  HF and LF showed correlation coefficients of 0.378 and-0.383 with forced expiratory volume in the first second (FEV 1) and peak expiratory flow rate (PEFR), respectively. It was found that only FEV 1/FVC was having a statistically significant regression coefficient with HF the R-value was found to be 0.425 while with other parameters, it was not significant.
  
  
  CONCLUSIONS
  We conclude that smoking affects all the parameters of PFT and HRV. Since there is a correlation between PFT parameters (PEFR and FEV1) and HRV parameter (LF and HF), this can help us in predicting cardiac morbidity in chronic smokers. So HRV should be included as a routine test along with PFT in chronic smokers for early diagnosis of cardiac involvement.
authors.affiliation: Department of Physiology, Post Graduate Institute of Medical Sciences, Haryana, India.
authors.forename: Joshil Kumar
authors.initials: JK
authors.lastname: Behera
authors.forename: Sushma
authors.initials: S
authors.lastname: Sood
authors.forename: Naresh
authors.initials: N
authors.lastname: Kumar
authors.forename: Kirti
authors.initials: K
authors.lastname: Sharma
authors.forename: Reshmi
authors.initials: R
authors.lastname: Mishra
authors.forename: Prasanta Saha
authors.initials: PS
authors.lastname: Roy
keywords: Heart rate variability; parasympathetic; pulmonary function test; smoking