HEART RATE VARIABILITY IN INDIAN OBESE YOUNG ADULTS

Abstract

Background: Obesity which is characterised by haemodynamic and metabolic alterations has become an epidemic problem. In obese children and adults it is shown that there is autonomic dysfunction. The objective of this study was to assess Heart Rate Variability (HRV) in obese Indian young adults and to establish association between HRV indices and obesity indices. Methods: This study included 60 young adult subjects in the age group 18–20 years. According to BMI subjects were classified into obese group (BMI ≥25 Kg/m²) and normal weight group (BMI 18–22.9 Kg/m²). Obesity indices like Waist Circumference, Hip Circumference, Waist Hip Ratio, Waist Stature Ratio and Body Fat percentage were measured and calculated. ECG was recorded in each subject in lead II for 5minutes using PowerLab^® system and analysis was done using HRV module LabChart^® 7.1 software. Results: There was significant increase in the mean heart rate, LF (nu) and LF/HF ratio whereas SDNN, SDANN, rMSSD, pNN50, Total power, HF(AV) and HF (nu)were significantly lower (p<0.05) in obese group. Pearson’s correlation analysis showed significant correlation between HRV and obesity indices. On regression analysis BMI was the major predictor for HRV variations. Conclusions: The study demonstrates decrease in overall HRV. The HRV indices indicating sympathetic activity were increased whereas those indicating parasympathetic activity were decreased in obese young adults showing autonomic imbalance in them. BMI was the major predictor for HRV variations.