The impact of overweight-obesity on heart rate variability among Indian adults - A cross-sectional study.

BACKGROUND

Overweight-obesity is one of the leading disorders that elevate all-cause mortality in patients with an increased body mass index (BMI), contributing to deaths from cardiovascular disease (CVD). One plausible explanation for the higher CVD in obese individuals is cardiac autonomic dysfunction. Previous studies done on overweight-obesity are majorly based on internationally accepted diagnostic cutoffs for BMI and waist circumference. Assessments in overweight and obese young Indian Adults as per the standards published in the Indian ministry's Consensus Guidelines for the Prevention and Management of Obesity and Metabolic Syndrome are very limited.

OBJECTIVE

To assess and classify the BMI of Indian subjects according to the Asian standard of BMI classification as normal weight, overweight, or obese and to compare heart rate variability (HRV) between overweight, obese, and normal weight healthy adults.

METHODS

The research involved a total of 157 participants aged 18 to 40 years. According to the Asian standard of BMI classification, 50 subjects with BMI > 25 kg/m² were classified as obese and 53 subjects with BMI between 23 and 25 kg/m² were categorized as overweight. Fifty-four subjects with BMI in the range of 18-22.9 kg/m² were healthy adult controls. Standard procedures were employed to assess short-term HRV characteristics. The ANOVA test was used to compare data across the groups.

RESULTS

The results reflect that time domain measures like SDNN, RMSSD, and pNN50% and frequency domain measures like HF (msec) and HF (nu) were significantly less in the overweight and obese groups compared to the normal weight group, while the LF (nu) and LF/HF ratio were higher in the overweight-obese group. A nonsignificant difference was observed in HRV parameters between overweight and obese group adults.

CONCLUSION

The study found that both overweight and obese young individuals exhibited altered characteristics of the autonomic nervous system, resulting in reduced parasympathetic activity and diminished heart rate variability. Increasing BMI was strongly associated with reduced cardiac parasympathetic and increased sympathetic activity in both overweight and obese individuals. Therefore, timely identification and early intervention in the initial overweight stage through weight loss is a dire necessity to prevent the progression to obesity and its cardiovascular complications.