Obesity and heart rate variability: A cross-sectional study in obese young adults

Abstract

CONTEXT: Obesity is one of the important causative factors for multiple co-morbid conditions that can lead to metabolic and cardiac disorders. Many research studies indicate the association of obesity and sudden cardiac deaths. AIMS: This study was aimed to evaluate the cardiac autonomic nervous system activity, given by the changes in heart rate variability (HRV) in healthy obese young adults. SETTINGS AND DESIGN: This cross-sectional study included thirty obese young adult males of 18–25 years and 30 age-matched healthy adult males. Power spectral analysis of HRV was used to determine the autonomic imbalance. SUBJECTS AND METHODS: HRV was performed using HRV software (Lab Chart 7). Numerical data of absolute values of low frequency (LF) and high frequency (HF) (in ms2), normalized units of LF and HF (in nu) and LF/HF ratio were expressed as mean ± standard deviation and analyzed. RESULTS: On statistical analysis, it was found that HF in normalized units was significantly low in obese young adults compared to age-matched controls. LF (nu) and LF/HF ratio were higher in obese subjects compared to controls, though they were not statistically significant. Although there was negative correlation between HRV parameters and body mass index in obese individuals, it was not significant. CONCLUSIONS: These results suggest that obese young adults present with changes in the autonomic nervous system, characterized by decrease in parasympathetic activity.

Keywords

• frequency domain analysis
• heart rate variability
• obesity
• sympathovagal balance