Poor Sleep Quality Linked to COPD Exacerbations

A new assessment from the Canadian Cohort Obstructive Lung Disease (CanCOLD) study showed that patients with worsened metrics for baseline sleep quality are at a greater risk of long-term chronic obstructive pulmonary disease (COPD) exacerbations.

The study—led by investigators at McGill University in Montreal, and funded by the Canadian Respiratory Research Network and industry partners including Astra Zeneca, Boehringer Ingelheim, GlaxoSmithKline, and Novartis—is an ongoing analysis of 2000-plus random subjects from Canada with mild to severe COPD. The team is seeking to understand the characterizations of the chronic pulmonary condition, as well as patient response and influence of individual factors.

Investigators did not respond to requests for comment at the time of publication.

Previous trials have associated COPD to an increased risk of sleep disturbance, leading to the notion that poor sleep quality could also drive an increased rate of respiratory symptoms in patients.

To evaluate the relationship between sleep quality and COPD exacerbation risk, the team observed data from 480 participants in the CanCOLD study who had completed an 18-month follow-up assessment period.

Sleep quality was measured using patient Pittsburgh Sleep Quality Index (PSQI) and 3 Factor scores at baseline. Investigators also assessed for symptom-based and event-based exacerbations, including dyspnea, sputum change, and medication or unscheduled health services uses.

The team used negative binomial regression to assess the association of PSQI with COPD exacerbation rates, and included analysis into patient exacerbation-free survival.

Of the 480 patients, 185 (38.5%) had at least 1 exacerbation during the 18-month follow-up, and 203 (42.3%) were found to have baseline PSQI scores greater than 5—denoting poor sleep quality.

Findings showed that participants with subsequent, symptomatic exacerbations also had greater median baseline PSQI scores (6.0; IQR 3.0-8.0) than those without exacerbations (5.0; IQR 2.0-7.0; P= .01). Patients with exacerbations were also more likely to have a baseline PSQI >5 (50.3% vs 37.3%; P= .01).

Greater PSQI scores were also associated with both increased symptom-based exacerbation risks (adjusted relative risks [RR] 1.09; 95% CI: 1.01 — 1.18; P= .02), and event-based exacerbation risks (RR 1.10; 95% CI: 1.00 — 1.21; P= .048).

Investigators concluded baseline poor sleep quality—as per PSQI—was associated with increased patient risk for COPD exacerbation over at least 18 months.

In an interview with MD Magazine® while at the 2018 CHEST Annual Meeting in San Antonio, TX, Barbara Phillips, MD, MPH, of the University of Kentucky College of Medicine, discussed the notable association between COPD and sleep conditions including sleep apnea. Phillips called exacerbations “the worst part” of the chronic condition, often resulting hospitalization or an antibiotic regimen.

New evidence was showing that treating comorbid sleep conditions could result in reduced exacerbations—thereby benefit both a patients’ respiratory and sleep health.

“There is now pretty good data that has come largely from Spain, showing that if a patient with COPD and sleep apnea uses CPAP, that person is less likely to die—which is kind of an important outcome,” Phillips said. “Also—almost equally important to the clinician and even some of the patients is—that patient is less likely to have a COPD exacerbation.”

The study, "Impaired Sleep Quality in COPD is Associated with Exacerbations: The CanCOLD cohort study," was published online in the CHEST journal.