Chronic Obstructive Pulmonary Disease and Sleep Apnea
Chronic obstructive pulmonary disease and obstructive sleep apnea are common chronic respiratory disorders.
The coexistence of obstructive sleep apnea and COPD is called the overlap syndrome, and it occurs in 10-20% of patients with obstructive sleep apnea.
Bottom line, that’s bad. It means increased likelihood of a number of health conditions. Patients with the overlap syndrome develop more pronounced nocturnal oxygen de-saturation, hypoxemia, and hypercapnia than those with each disease alone. This also predisposes these patients to develop pulmonary hypertension and right heart failure. Clinical trials have shown that even those individuals with severe sleep apnea alone do not develop marked pulmonary hypertension if they are free from other cardiopulmonary diseases. The presence of pulmonary hypertension has been shown to occur in those individuals with the coexistence of obstructive lung disease and daytime hypoxemia and hypercapnia.
In the overlap syndrome, obstructive sleep apnea has been shown to increase mortality in patients with COPD. Even when adjusted for COPD severity, sleep apnea remains a risk factor for death. There is also increasing evidence that both sleep apnea and COPD have increased risk for cardiovascular disease. Both COPD and sleep apnea cause system inflammation and oxidative stress. This promotes atherosclerosis, the hallmark of cardiovascular disease. The overlap syndrome is associated with greater cardiovascular morbidity and mortality than in each disorder alone.
The good news? It’s treatable.
Treatment of the overlap syndrome doesn’t differ from treatment of each of the diseases. The goal of treatment is to maintain adequate oxygenation at all times and to prevent sleep disordered breathing. CPAP remains the accepted standard treatment for sleep apnea and is the accepted standard for overlap syndrome.
Written by Dr. Nisbet