Table 1.

Diagnostic criteria for obesity hypoventilation syndrome

Criteria	Description
Obesity	Body mass index >30 kg/m2
Hypoventilation	Awake arterial hypercapnia (PaCO2 >45 mmHg)
Sleep-disordered breathing	Polysomnography reveals sleep hypoventilation with nocturnal hypercapnia with or without obstructive apnea/hypopnea events
Rule out other causes of hypoventilation	Severe chronic obstructive pulmonary disease, severe interstitial lung disease, chest wall disorders, thyroid disorders and congenital hypoventilation syndromes