High ventilatory response to hypoxia observed in obese Judo athletes

Fifty-two active Judo athletes were examined using an isocapnic progressive hypoxia test. The results were analyzed by the hyperbola ventilation equation V = VO + A/(PETO2--C), where V is observed ventilation, VO the horizontal asymptote in ventilation for infinite end-tidal PO2(PETO2), A the slope constant indicating magnitude of hypoxic sensitivity, and C the vertical asymptote in PETO2 for infinite ventilation. Hypoxic sensitivity, A, was positively correlated with body weight (BW). Such correlation in the light and middleweight groups (BW less than 95 kg) and the heavyweight group (BW greater than 95 kg) with Röhrer's index being less than 200 became insignificant when the A value was recalculated after normalization of ventilation for 70 kg body mass. However, the heavyweight group with Röhrer index of higher than 200 still exhibited a significantly higher A value than the light and middleweight groups after normalization of ventilation. These results indicated that body weight plus obesity were determining factors in the increase of hypoxic sensitivity in our subjects.