Clinical impact of routine sleep-assessment by peripheral arterial tonometry in patients with Chronic Obstructive Pulmonary Disease

BackgroundCoexisting obstructive sleep apnoea (OSA) in patients with chronic obstructive pulmonary disease (COPD), defined as overlap syndrome (OVS), is prevalent and underdiagnosed. Routine assessment of OSA is not common practice in COPD care. Our study assessed the clinical impact of sleep-assessment by peripheral arterial tonometry (PAT) in COPD patients.Methods105 COPD patients (mean age 68.1±9 years, BMI 28.3±6.0 kg·m−2, 44% males, GOLD stages I to IV in 2%, 40%, 42%, and 16%, respectively) underwent assessment at an outpatient COPD-clinic including anthropometrics, arterial blood gas (ABG) and spirometry in this clinical cohort study, PAT-based sleep studies were performed. Predictors of OVS and ABG were determined. Rapid Eye Movement (REM) sleep-related OSA was analyzed in OVS.Results49 COPD patients (46%) suffered from moderate to severe OSA (OVS group, mean AHI 30.8±18 n·h−1, REM-Oxygen Desaturation Index (REM-ODI) 26.9±17 n·h−1). OVS was more prevalent in males compared to females (59% and 37%, p=0.029, respectively). Age (70.1±8versus66.3±10 years), BMI (30.0±6versus26.4±7 kg·m−2) and hypertension prevalence (71%versus45%) were elevated (all p<0.03, respectively), while deep sleep (12.7±7% and 15.4±6%, p=0.029) and mean overnight oxygenation (90.6±3% and 92.3±2%, p=0.003) were lower in OVS compared to COPD alone. REM-ODI was independently associated with daytime pCO2(β=0.022, p<0.001). REM-OSA was associated with an elevated prevalence of atrial fibrillation (25% and 3%, p=0.022).ConclusionsOVS was highly prevalent, specifically in obese males. REM-related OSA showed strong association with elevated daytime pCO2 and prevalent cardiovascular disease. PAT was feasible for sleep assessment in COPD.