Changes in serum hypoxanthine levels by exercise in obese subjects

To study on effect of obesity on changes in serum hypoxanthine with exercis e, exercise stress testing with treadmill was performed on 7 obese subjects (body mass index [BMI]. 30.6 +/- 3.2 kg/m(2)) and 16 healthy volunteers (B MI, 21.5 +/- 2.10 kg/m(2)). Expiratory gas analysis during exercise showed that peak Vo(2) was significantly lower in the obese group than in the cont rol group (28.1 +/- 4.0 v 37.1 +/- 4.7 mL/kg/min; P < .001). Furthermore, t he obese group had lower anaerobic threshold (AT) values (P < .005), respir atory quotient at AT (P = .003), and exercise capacity reserve (P = .002) t han the control group, Baseline serum hypoxanthine levels were significantl y higher in the obese group than in the control group (3.46 +/- 3.70 v 1.23 +/- 1.16 mu mol/L; P < .05). Exercise induced a pronounced increase in ser um hypoxanthine level in the obese group compared with the control group (1 0.65 +/- 6.81 v 43.86 +/- 4.56 <mu>mol/L; P < .01). Serum levels of uric ac id before and after load were also higher in the obese group than in the co ntrol group (404 +/- 43 v 302 +/- 77 <mu>mol/L; P < .005). A pronounced inc rease in hypoxanthine with exercise may result in organ damage caused by fr ee radicals, and intermittent training from mild intensity may be less haza rdous for exercise treatment of obesity. Copyright (C) 2001 by W.B. Saunder s Company.