Low physical performance in obese adolescent boys with metabolic syndrome

OBJECTIVE: To assess cardiorespiratory exercise function in obese children with and without metabolic syndrome (MS). DESIGN: Comparing three groups of subjects with different cardiovascular ri sk profiles. SUBJECTS: Twenty-two MS (body weight (mean +/-s.d.) 97.3 +/- 15.3kg; age (m ean +/-s.d.) 14.2 +/-1.9y), 17 obese (82.6 +/- 15.7 kg; 14.2 +/- 2.6 y) and 29 normal weight control (64.3 +/- 8.5 kg; 15.3 +/- 1.0 y) boys. MEASUREMENTS: Exercise duration (ED), resting heart rate (HR0), peak heart rate (HRpeak), physical working capacity at 170 beat/min (PWC-170), peak ox ygen consumption VO2peak) and the lactic acidosis threshold (LAT) were dete rmined on treadmill, using a continuous ramp protocol. RESULTS: ED (MS (mean +/- s.d.); 655 +/- 86 s; obese 703 +/- 64 s; control 750 +/-0 s) in absolute value and PWC-170 normalised for body weight (139 /- 40 w; 177 +/- 40 w; 211 +/- 40 w) were significantly shorter and lower i n the MS group, as compared to obese and control groups (P < 0.05). VO2peak (2.2 +/- 0.41/min; 2.4 +/- 0.51/min; 2.9 +/- 0.41/min) and LAT (1.3 +/- 0. 41/min; 1.5 +/- 0.41/ min; 1.8 +/- 0.41/min) normalised for body weight, we re significantly shorter and lower in the MS group, as compared to control group (P < 0.05). HR0 was significantly higher (P < 0.05) in MS group than in obese and control groups (88 +/- 12 bpm; obese 78 +/- 10 bpm; 73 +/- 10 bpm). CONCLUSION: Cardiorespiratory exercise performance capacity in MS boys are reduced. It still remains to be elucidated whether the metabolic alteration s or the decreased physical activity is responsible for the observed reduct ion in cardiorespiratory performance.