A STUDY OF HEART RATE VARIABILITY IN UNDER WEIGHT AND OVER WEIGHT YOUNG INDIVIDUAL

Abstract

Obesity is a state of excess adipose tissue mass and it is generally expressed in terms of Body Mass Index (BMI). The autonomic nervous system plays an important role in regulating energy expenditure and body fat content. Heart rate variability (HRV) is one of the tests which measure the effect of autonomic regulation on the heart. In the present study , we have determined certain HRV related traits among two group of students having BMI>25 kg/m2, considered as overweight (OW) and BMI less than 18 kg/m2, considered as underweight (UW), age ranged 19-24 years with a view to understand the variation of HRV of young individuals as influenced by their body weight. Anthropometric measurements, resting pulse, BP and 5-minute supine HRV are recorded. Unpaired t-test and correlation study is carried out to assess the effect of body weight on HRV spectrum between two groups. This study showed a significant reduction in total power (TP), High Frequency (HF), SDNN (Standard deviation of NN interval) 8 RMSSD (Square root of Mean Squared differences of successive NN interval) and higher Low Frequency Normalised Unit (LFnu) in the overweight group compared to underweight group. A significant negative correlation between Resting Pulse (RP), LFnu and HFnu among these groups were observed. These findings demonstrate an autonomic dysfunction characterized by a reduction of parasympathetic and increase in sympathetic activity for overweight group of students which may lead to an early heart related complicacy.