Chronic obstructive pulmonary disease and obstructive sleep apnea. Association, consequences and treatment.

Obstructive sleep apnea syndrome (OSAS) and chronic obstructive pulmonary disease (COPD) are two diseases that often co-exist within an individual. This co-existence, known as overlap syndrome (OS), is the result of chance rather than a pathophysiological linkage and epidemiological studies indicate a prevalence of 1% in adult males. Patients vith OS have a more important sleep-related O2 desaturation than COPD patients with the same degree of bronchial obstruction and show an increased risk of developing hypercapnic respiratory failure and pulmonary hypertension when compared with patients affected by only one of he diseases. COPD and OSAS are independent risk factors for cardiovascular events and their co-existence in OS probably increases this risk. Evidence of systemic inflammation in COPD and sleep apnea and consequentely OS, is interesting because it may contribute to the pathogenesis of cardiovascular diseases. Treatment consists of continuous positive airway pressure (CPAP) or non-invasive positive pressure ventilation (NIPPV), with or without associated O2, for correction of the upper airway obstructive episodes and hypoxemia during sleep.