Obstructive sleep apnea in patients with end-stage lung disease

Little is known about the rate of obstructive sleep apnea (OSA) in patients with end stage lung disease (ESLD). Given the potential deleterious effect of OSA in these patients, we assessed the case-rate and severity of OSA and described associated patient characteristics.

Retrospective survey of 60 patients with ESLD referred for lung transplantation evaluation. Demographic, polysomnographic, spirometric, and medication utilization data were extracted and analyzed.

As demographic and polysomnographic data did not differ between obstructive and restrictive patients, we present analysis of pooled data. Demographics/physiology: median age was 58.5 years, 52% males, mean BMI 32.3 kg/m(2), 52% obstructive. Sleep variables (all medians): total sleep time (TST) 312 min, sleep efficiency 77%, minimal oxygen saturation 84%, apnea hypopnea (AHI) 9.7, respiratory disturbance index (RDI) 12.7 events/h of sleep. Sixty-seven percent had RDI > 5; 21% had RDI between 15 and 30; and 21% had RDI > 30. Periodic limb movement index ≥ 15/h sleep was present in 21.7%. An independent positive correlation between DLCO% and RDI was noted (r = 0.41, p < 0.01). The minimal oxygen saturation was negatively correlated with the RDI (r = -0.34, p < 0.01). The use of ACE inhibitors was associated with moderate-to-severe OSA (odd ratio of 4.67, CI 1.45-15.03; p = 0.017).

In patients with ESLD, organic sleep disorders are common. Greater severity of OSA was associated with the higher DLCO% and lower oxygen saturation.