Abstract

Background: Obesity and health hazards associated with it are leading cause of death worldwide. The incidents of obesity are also rising at an alarming rate in the urban Indian population. Obesity is associated with adverse cardiovascular events which could be due to the altered autonomic balance seen in these individuals. Heart rate variability (HRV) is a non-invasive economical tool to assess the autonomic function.

Aims & Objective: The present study was undertaken to evaluate the effect of obesity on heart rate variability and to establish the relationship between BMI and HRV parameters.

Materials and Methods: Forty six males in the age group of 40-55 years, who satisfied the inclusion and exclusion criteria, were included in the study. The subjects were divided into two groups as obese and non-obese based on their BMI as per WHO guidelines for Asian subjects. The ECG was recorded for a period of 10 minutes and frequency domain parameters of HRV were derived from it. Parameters obtained were compared between both the groups using independent ‘t’ test and relationship between BMI and HRV parameters was established using Pearson’s correlation test. P < 0.05 was considered as significant.

Results: Obese individuals exhibited significantly lower values of both low and high frequency and normalized high frequency parameters. The ratio between low and high frequency and normalized low frequency parameters were significantly higher in obese group. A significant negative association was also observed between BMI and normalized high frequency parameter.

Conclusion: A reduced parasympathetic activity associated with elevated sympathetic was observed in middle aged obese males in the resting state. This is suggestive of a higher risk for development of cardiovascular disorders.

Key words: Obesity; Parasympathetic Activity; Sympathovagal Balance