Impact of obesity on autonomic modulation, heart rate and blood pressure in obese young people

Abstract Introduction Obesity can be understood as a comorbidity of increasing systemic impact, including a deficit in the autonomic nervous system. Objective To analyze cardiac autonomic behavior and hemodynamic parameters in obese young people. Methods 92 individuals (20.58 ± 1.48 years) were evaluated, divided into two groups: obese and eutrophic. Heart rate (HR) was captured for 30 min in the supine position whilst breathing spontaneously. Blood pressure (BP) values were obtained prior to performance of the protocol. For the autonomic analysis, 1000 beats were used for the calculation of heart rate variability indices in the time (Mean RR, SDNN and RMSSD) and frequency (LF, HF and LF/HF) domains, in addition to the Poincaré plot (SD1 , SD2 , SD1 /SD2 and qualitative visual analysis). Results The obese group presented higher baseline BP and HR values compared to the eutrophic. Regarding autonomic modulation a significant decrease was observed in the RMSSD; SD1 , HFms and HFnu indices in the obese group, indicating a decrease in vagal activity and reduced SDNN and SD2 rates, with statistical significance for the former, suggesting a reduction in overall variability. The high value of the LFnu index and decrease in Mean RR in the obese group pointed to relative sympathetic predominance in these individuals. The visual analysis of the Poincaré plot showed less dispersion of the points in the obese group. Conclusion The obese group presented higher BP and HR values at rest and autonomic impairment, characterized by a reduction in parasympathetic activity and relative predominance of sympathetic activity.