Longitudinal associations between sleep disturbance and disease severity in patients with COPD

Influence of Impaired Diffusing Capacity and Sleep-disordered Breathing on Nocturnal Hypoxemia and Health Outcomes in Men with and without Human Immunodeficiency Virus

Rationale: Nocturnal hypoxemia is common in sleep-disordered breathing (SDB) and is associated with increased morbidity and mortality. Although impaired diffusing capacity of the lung for carbon monoxide (DlCO) is associated with daytime hypoxemia, its influence on SDB-related nocturnal hypoxemia is not known. Objectives: To characterize the effects of DlCO impairment on SDB-related nocturnal hypoxemia and associated health outcomes. Methods: Data from a multicenter cohort of men with and without human immunodeficiency virus (HIV) infection, with concomitant measures of DlCO and home-based polysomnography (n = 544), were analyzed. Multivariable quantile regression models characterized associations between DlCO and several measures of SDB-related hypoxemia (e.g., total sleep time with oxygen saturation as measured by pulse oximetry [SpO2] < 90% [T90]). Structural equation models were used to assess associations of impaired DlCO and SDB-related hypoxemia measures with prevalent hypertension and type 2 diabetes. Results: DlCO impairment (<80% predicted) was associated with sleep-related hypoxemia. Participants with severe SDB (apnea-hypopnea index ⩾ 30 events/h) and impaired DlCO had higher T90 (median difference, 15.0% [95% confidence interval (CI), 10.3% to 19.7%]) and average SDB-related desaturation (median difference, 1.0 [95% CI, 0.5 to 1.5]) and lower nadir SpO2 (median difference, -8.2% [95% CI, -11.4% to -4.9%]) and average SpO2 during sleep (median difference, -1.1% [95% CI, -2.1% to -0.01%]) than those with severe SDB and preserved DlCO. Higher T90 was associated with higher adjusted odds of prevalent hypertension (odds ratio, 1.39 [95% CI, 1.14 to 1.70]) and type 2 diabetes (odds ratio, 1.25 [95% CI, 1.07 to 1.46]). Conclusions: DlCO impairment in severe SDB was associated with sleep-related hypoxemia, prevalent hypertension, and type 2 diabetes. Assessment of SDB should be considered in those with impaired DlCO to guide testing and risk stratification strategies.

The Impact of Lung Function Parameters on Sleep Among Aboriginal Australians - A Polysomnography and Spirometry Relationship Study

Background

Sleep disorders such as obstructive sleep apnoea (OSA) are known to overlap significantly with airway diseases in various populations. This study assessed the relationship between lung function parameters against polysomnography (PSG) and continuous positive airway pressure (CPAP) adherence data amongst an Aboriginal Australian population.

Methods

Patients who undertook both a diagnostic PSG and spirometry were included. Restrictive, obstructive, and mixed impairments were assessed via global lung function initiative (GLI-2012, ATS/ERS) criteria/guidelines. PSG and CPAP data were evaluated between patients with or without spirometry impairments.

Results

Of the total 771 patients, 248 had PSG and spirometry data available (52% female, 44% remote residents, 78% obese). The majority (89%) had OSA (51% severe), 95 (38%) were observed to have a restrictive impairment, and 31 (13%) had an obstructive or mixed impairment on spirometry. Compared to patients with no spirometric impairment, those with restrictive or obstructive/mixed impairments demonstrated significantly lower sleep efficiency (median 84% vs 79% and 78%), higher apnoea-hypopnea index (AHI) during rapid eye movement (REM) sleep (median 32 vs 52 and 55 events/hour), reduced REM oxygen saturation (SpO₂) (median 94.0% vs 92.0% and 92.5%) and reduced adherence to CPAP therapy (median 39% vs 22% and 17%). Differences in sleep efficiency, REM AHI, and NREM SpO₂ held for patients with obstructive/mixed impairments in multivariate modelling.

Conclusion

Aboriginal Australian patients with OSA have a higher concurrent lung function' impairment. Spirometric impairment appears to negatively influence sleep efficiency, nocturnal SpO₂ and CPAP adherence. This may have substantial implications for OSA management among Aboriginal Australians.

Total Sleep Time in the Taiwan Obstructive Lung Disease Cohort

Patients with chronic obstructive pulmonary disease (COPD) have been reported to have poor sleep quality. However, total sleep time has not been evaluated in detail among patients with COPD. This retrospective, observational, multicenter research study was performed across six participating hospitals in Taiwan, with a total of 421 adult patients enrolled. Pulmonary function, the Modified British Medical Research Council Dyspnea Scale, the COPD Assessment Test and basic clinical data were assessed. The Pittsburgh Sleep Quality Index was also administered to patients, and the total sleep time was extracted for further analysis. The patients whose total sleep time was between 6 and 7 h had better pulmonary function, and the patients who slept less than 5 h had worse comorbidities. There was a significant higher total sleep time in Global Initiatives for Chronic Obstructive Lung Disease (GOLD) group B compared to GOLD group A. COPD patients who sleep between 5 and 6 h used fewer oral steroids and were less likely to use triple therapy (long-acting beta-agonist, long-acting muscarinic antagonist, inhaled cortical steroid). COPD patients sleeping from 5 to 7 h had better clinical features than those sleeping less than 5 h in terms of pulmonary function, comorbidities and medication usage.