Low physical performance in obese adolescent boys with metabolic syndrome

Abstract

To assess cardiorespiratory exercise function in obese children with and without metabolic syndrome (MS). Comparing three groups of subjects with different cardiovascular risk profiles. Twenty-two MS (body weight (mean+/-s.d.) 97.3+/-15.3 kg; age (mean+/-s.d.) 14.2+/-1.9 y), 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. Exercise duration (ED), resting heart rate (HR(0)), peak heart rate (HR(peak)), physical working capacity at 170 beat/min (PWC-170), peak oxygen consumption (VO(2peak)) and the lactic acidosis threshold (LAT) were determined on treadmill, using a continuous ramp protocol. 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 in the MS group, as compared to obese and control groups (P<0.05). VO(2peak) (2.2+/-0.4 l/min; 2.4+/-0.5 l/min; 2.9+/-0.4 l/min) and LAT (1.3+/-0.4 l/min; 1.5+/-0.4 l/ min; 1.8+/-0.4 l/min) normalised for body weight, were significantly shorter and lower in the MS group, as compared to control group (P<0.05). HR(0) 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). Cardiorespiratory exercise performance capacity in MS boys are reduced. It still remains to be elucidated whether the metabolic alterations or the decreased physical activity is responsible for the observed reduction in cardiorespiratory performance.