[Respiratory changes in obesity. Functional and clinical aspects. Study of 26 cases]

A study was made, at the altitude of Mexico City, of the clinic aspects and of the pulmonary function of 26 obese subjects more than 45% overweight. This excess weight habitually produces severe disturbances in pulmonary and/or heart function. In 50% of the patients, clinic, radiologic and electrocardiographic manifestations were found which suggested the existence of pulmonary arterial hypertension. This provoked right heart failure in 19% of the cases. The most constant alterations in the pulmonary volumes was the decrease in the VER, which occurred in 96% of the cases. Most of the patients had hypoxemia (92.5), which was produced mainly by the increase in venoarterial shunts. Although the clinic manifestations were similar to those described in Pickwick's syndrome, alveolar hypoventilation was presented in only a minority of the cases. No relationship was found between the degree of obesity and alveolar hypoventilation. Altitudes of 2,200 meters or more apparently favor hypoxemia in obese patients, and "protects" them from the hypercapnea. The altitude of Mexico City may be one of the reasons why alveolar hypoventilation is observed in only 15% of the cases.