Obesity and Alveolar Hypoventilation

Pulmonary hypertension in systemic sclerosis.

“…Hypoxia may itself contribute to pulmonary hypertension (Opie, 1955;Weaver and others, 1967). Short-term hypoxia raises the pulmonary artery pressure in normal subjects (Von Euler and Liljestrand, 1946;Motley, Cournand, Werk6, Himmelstein, and Dresdale, 1947;Bergofsky and Holtzman, 1967;Bergofsky, Haas, and Porcelli, 1968), and protracted hypoxia may be associated with pulmonary hypertension and hyperplastic changes in the pulmonary arterioles and small muscular arteries (Hasleton, Heath, and Brewer, 1968;Addington, Pfeffer, and Gaensler, 1969).…”

The Problem of Obesity

“…This has been attributed to an increased oxygen demand (33,34), increased intraabdominal pressure with decreased diaphragmatic activity (35), and the increased work of breathing occasioned by the mass of the fat thorax (36). Other investigators have described upper airway obstruction (37) and a decreased sensitivity to carbon dioxide (38) or oxygen (39,40). But there is no good correlation between the presence or severity of dyspnea or alveolar hypoventilation and the body weight (39,41).…”