Resting and post exercise Heart Rate Variability in preobese individuals: a comparative study

Abstract

Background: Several studies have documented high incidence of cardiovascular and metabolic disorders in obese individuals. However, scant and contradictory reports are available in this context for the preobese people, especially in young adults. Aims and Objectives: Therefore, present study was conducted to assess the effect of high BMI (between 24-30) on the time & frequency domain measures of HRV in normal healthy adult male subjects during resting and post exercise recovery period. Materials and Methods: Healthy young male individuals with no history of any disease were selected and divided in two groups (n=15 in each) on the basis of their BMI: (i) control (BMI 19-24) & (ii) preobese (BMI 24-30). 15-20 mins of ECG recording was done in the resting state and then till 30 mins after Harvard Step Test. Comparison between groups was done using 2-tailed Mann-Whitney U-nonparametric test. Spearman’s Correlation test was used to assess the correlation between BMI and HRV parameters for each group. Results: During resting state, both groups had similar HRV/min. However, control subject had higher parasympathetic tone (high RMSSD, pNN50 & HF) and low sympathetic tone (low LF & LF/HF) as compared to preobese individuals. In the post exercise recovery period of control BMI individuals, all the indices of sympathetic measures increased and parasympathetic measures decreased significantly. However, no such changes were observed in preobese group, except significant decrease in the HRV/min. Conclusions: The blunted autonomic response in the post exercise recovery clearly indicates towards a potential risk of cardiovascular compromise in preobese individuals.

Keywords

• preobese
• body mass index
• hrv
• exercise recovery