Obesity Hypoventilation Syndrome

The incidence of severe obesity has risen dramatically in the United States and around the world. A major complication of severe obesity is obesity hypoventilation syndrome (OHS). OHS has been defined by the combination of obesity and daytime hypercapnia during wakefulness occurring in the absence of an alternative cause for hypoventilation. Sleep-disordered breathing (e.g., obstructive sleep apnea or sleep hypoventilation) is a constant feature and presents with a wide range of severity. Patients with OHS have a lower quality of life with increased healthcare expenses and are at higher risk of developing pulmonary hypertension and early mortality due to cardiopulmonary complications when compared with similarly obese eucapnic patients with obstructive sleep apnea. OHS often remains undiagnosed until late in the course of the disease. With the global epidemic of obesity, the prevalence of OHS is likely to increase. Early recognition is important, as these patients have significant morbidity and mortality if left untreated. In addition to positive airway pressure therapy during sleep, treatment strategies should include obesity management, either pharmacologically or by bariatric interventions. Effective treatment can lead to significant improvement in patient outcomes, underscoring the importance of early diagnosis.