Obesity and respiratory disorders

: The prevalence of obesity has considerably increased during the past thirty years. Possible consequences of obesity on respiratory physiology include a restrictive disorder, changes in ventilatory mechanics and an alteration of respiratory drive. Apart from the well established relation between obesity and obstructive sleep apnea-hypopnea syndrome, obesity is associated with two other respiratory disorders. On one hand, epidemiological and animal data suggest a causal relationship between obesity and asthma. On the other hand, morbid obesity is associated, through an alteration of the respiratory drive involving leptin, with a diurnal and nocturnal alveolar hypoventilation defining the obesity-hypoventilation syndrome. These data emphasize the necessity for the medical practitioner to investigate any respiratory symptomatology in obese patients.