Influência do índice de massa corporal e da distribuição central e geral de gordura sobre a modulação autonômica cardíaca e a capacidade funcional em homens adultos

Abstract

BACKGROUND: Cardiovascular diseases (CVD) are the main causes of death related to excess of body fat and the place of fat distribution seems to influence in onset of these diseases. Non-invasive methods are use as CVD predictors, like heart rate variability (HRV) and heart rate (HR) recovery analysis. From these analyses it’s possible to verify the cardiac autonomic modulation. Furthermore, excess body mass can impair the functional capacity (capacity to perform daily activities). OBJECTIVE: Verify the body mass index (BMI) and measurements of central and general body fat on cardiac autonomic modulation and the functional capacity in young man with same habitual physical activity level. METHODS: Fifty-four individuals, 25 eutrophics (BMI between 18.5 and 24.9 kg/m2 ) and 29 obese (BMI ≥ 30 kg/m²) aged 18 to 35 years old participated in the study. They underwent to anthropometric evaluation (stature, body mass, waist circumference - WC, neck circumference - NC and bioimpedance), HR variability (HRV) and blood pressure (BP) at rest, incremental test on a treadmill, functional tests (balance, strength, agility and resistance) and used a pedometer (step counter). In incremental test, the R-R intervals was recorded during the exercise and recovery, for later analysis of the recovery heart rate (HRrec). The indexes used to verify the HRrec was the T30, delta of the HR (ΔHR), HR off kinetics. The balance test was performed blindfolded with support on only feet; the strength test consists to perform the maximum repetition in the barbell curl exercise with 4 kg within 30 s; in the agility test the subjects will walk through a small circuit within the shortest time, and in endurance subjects tried to walk the longest distance during 6 minutes. The verification of the daily steps was observed using the pedometer during 7 days of usual activities. RESULTS: High WC (110.89 ± 10.35 cm) and NC (44.95 ± 3.23 cm) values was observed in obese group, above cutoff points to CVD. All subjects were not classified hypertensive according to Systolic BP (SBP) (eutrophic = 107.20 ± 11.16 mmHg; obese = 119.78 ± 10.31 mmHg), diastolic BP (DBP) (eutrophic = 67.72 ± 5.98 mmHg; obese = 76.67 ± 9.50 mmHg) and mean BP (MBP) (eutrophic = 151.09 ± 12.57 mmHg; obese = 170.97 ± 15.88 mmHg), but higher values were observed for obese group (p < 0.01) and with strongly correlated to central fat distribution, WC (r = 0.62; 0.52; 0.61 for SBP, DBP, MBP, respectively) e CP (r = 0.62;0.55; 0.65 for SBP, DBP, MBP, respectively). No significant difference was found between eutrophic and obese in HRV in rest (p > 0.05). On the other hand, in HRrec indexes, only T30 should difference between groups (p < 0.001), being obese group with higher values (eutrophic 368.42 ± 169.97s vs obese 459.25 ± 268.27s). HRrec indexes mostly correlated to WC and NC. For the functional tests, the obese group presented better results in balance, agility and endurance. CONCLUSIONS: Obesity group presented a parasympathetic reactivation delay after effort and negatively influence in functional capacity. Also, central fat distribution was high related to BP rest and HRrec than general distribution.