[Obesity and hypoventilation syndrome; effects of weight loss and treatment with respiratory stimulants].

A 32-year-old, hypertensive, morbidly obese (BMI 49 kg/m2) woman was referred to us suspected of sleep-disordered breathing. Polycythaemia, right heart and respiratory failure, restrictive ventilatory impairment, decreased hypercapnic respiratory drive, high number of very short apneas mostly of central origin (698 vs 530 obstructive), and overnight hypoxaemia were found. The diagnosis of obesity-hypoventilation syndrome was established and the treatment with almitrine, aminophylline and low-calorie diet was started. After 6 months body weight decreased significantly (BMI 38 kg/m2). RBC, spirometry, blood gas analysis, overnight oximetry, hypercapnic respiratory drive and polysomnography showed results within normal limits. Causes, pathophysiology and possible treatment of obesity-hypoventilation syndrome are discussed.