Abstract

Introduction: Heart rate variability (HRV) has been considered a modulation mechanism of the autonomic nervous system. The reduction of HRV may be associated with metabolic syndrome (MS). Objective: To compare the HRV and health variables in individuals with and without MS. Methods: One hundred and nineteen participants were divided into two groups: without MS (WOMS, n=68) and with MS (WMS, n=51). We evaluated the spectral analysis of HRV at rest, during cardiopulmonary exercise testing (CPET) and recovery in low frequency bands (LF = 0.04-0.15 Hz), high frequency (HF = 0.15-0.4 Hz) and LF/HF ratio. Resting heart rate (HRres), maximum heart rate (HRmax), systolic blood pressure (SBP) and diastolic (DBP), blood glucose, lipid profile, peak oxygen consumption (VO2peak) and body composition were also evaluated. Results: There were no differences between HRres and VO2peak between the WMS and WOMS groups (73.3 +/- 9.1 vs. 70.1 +/- 11.0 bpm), (26.8 +/- 4.6 vs. 28.1 +/- 6.6 ml. kg(-1). min(-1)), respectively. HRV was similar between the groups at the different moments analyzed. The blood glucose levels (99.8 +/- 22.5 vs. 87.6 +/- 8.6 mg/dl) were higher in WMS compared to WOMS. Triglyceride values (159.5 +/- 68.8 vs. 89.2 +/- 34.3 mg/dl) and VLDL-c (31.9 +/- 13.8 vs. 17.8 +/- 6.9 mg/dl) were higher in WMS compared to WOMS. HDL-c (40.7 +/- 11.5 vs. 49.3 +/- 9.8 mg/dl) was lower in WMS compared to WOMS. BMI (33.1 +/- 4.7 vs. 30.8 +/- 3.8 kg/ m(2)) was higher in WMS compared to WOMS. The SBP (128.6 +/- 12.9 vs. 119.5 +/- 11.3 mmHg) and DBP (77.2 +/- 10.5 vs. 72.9 +/- 8.1mmHg) were higher in WMS compared to WOMS, p 0.05. Conclusion: The results suggest that the presence of MS is not sufficient to induce changes in HRV at rest, during cardiopulmonary exercise test (CPET), and in recovery when patients are compared to healthy individuals.