The malignant obesity hypoventilation syndrome (MOHS).

We have coined the term 'malignant obesity hypoventilation syndrome' (MOHS) to describe a severe multisystem disease due to the systemic effects of obesity. Patients with this syndrome have severe obesity-related hypoventilation together with systemic hypertension, diabetes and the metabolic syndrome, left ventricular hypertrophy with diastolic dysfunction, pulmonary hypertension and hepatic dysfunction. This syndrome is largely unrecognized as physicians do not make the association between the patients' multiple medical problems and obesity. Because of the delayed diagnosis and progressive morbidities of this condition, all patients with a body mass index of more than 40 kg m(-2) should be screened for MOHS. The management of patients with MOHS includes short-term measures to improve the patients' medical condition and long-term measures to achieve enduring weight loss. Bariatric surgery reverses or improves the multiple metabolic and organ dysfunctions associated with MOHS and should be strongly considered in these patients.