Abstract
Background: Obesity is a chronic disease that impacts negatively on the heart rate variability (HRV) and on the functional capacity. Objectives: To evaluate and compare cardiac autonomic modulation in obese and eutrophic women in response to active postural changes (APC) as well as to a 70-80% of maximal oxygen uptake physical exercise (PE) on a treadmill. Methods: Fourteen women were allocated in obese group (OG), and 15 in eutrophic group (EG). The heart rate (HR) and R-R intervals (RRi) were recorded during APC (supine (S), standing (St) and sitting positions (Si)) and PE. Linear (mean HR; standard deviation of RRi, SDNN; high frequency (HF) and low frequency (LF)) and nonlinear (standard deviation of the Poincaré plot along the line of identity, SD2; short-term correlation properties of RRi, DFAα1) indices of HRV were analyzed. Results: Compared to EG, OG presented a significant impaired response from S to St in LF (34±24 vs 43±10un; p=0.03) and HF (-30±24 vs -41±12un; p=0.04) and from St to Si in HF (17±14 vs -25±20un; p<0.05). During the PE, overall variability indexes were depressed in OG compared to EG (mean HR: 156±18 vs 141±17bpm, p=0.04; SDNN: 3±2 vs 8±4ms, p=0.01; and, SD2: 8±6 vs 15±9, p=0.02). DFAα1 showed lower values in the OG than in EG (0.7±0.4 vs 1.1±0.3, p<0.05). There is a negative moderate correlation between the walking work (the product of body weight and walking distance) and DFAα1 (r=-0.56, p<0.05). Conclusions: Obesity is associated to a reduced HRV response to APC and PE. In addition, nonlinear index of HRV is negatively related to walking work in this population.
Financial Support: FAPESP: 2009/01842-0; CNPq 141331/2011-9.
- © 2013 ERS
