Among adults with COPD, poorer sleep quality may contribute to risk for future exacerbations, according to new data published in Sleep.
“Among those who already have COPD, knowing how they sleep at night will tell me much more about their risk of a flare-up than knowing whether they smoked for 40 vs. 60 years,” Aaron Baugh, MD, clinical fellow at the University of California, San Francisco, School of Medicine, said in a press release issued by the NIH. “That is very surprising and is not necessarily what I expected going into this study. Smoking is such a central process to COPD that I would have predicted it would be the more important predictor in the case of exacerbations.”
The observational study included 1,647 current and former smokers with COPD confirmed via spirometry (mean age, 65.2 years; 57.2% men) from the SPIROMICS cohort. Researchers evaluated the incidence of COPD exacerbations adjusted for demographics, medical comorbidities and disease severity metrics. Using the Area Deprivation Index, researchers also adjusted for socio-environmental exposures.
During a 3-year follow-up period, the researchers recorded COPD exacerbations and compared the measurements against Pittsburgh Sleep Quality Index (PSQI) scores of participants. Participants who were at the threshold or the base level of poor sleep had a 25% increased risk for COPD exacerbations within the next year. Participants with the worst sleep had an almost 95% increased risk for COPD exacerbation in the next year.
The researchers reported a significant association between PSQI score and total and mean COPD exacerbations in unadjusted analyses (incidence rate ratio [IRR] = 1.09; 95% CI, 1.05-1.13). This association remained similar after adjustments for demographics, medical comorbidities, disease severity, medication usage and socio-environmental exposures (IRR = 1.08; 95% CI, 1.03-1.13). Increasing PSQI scores were also associated with a 5% increased risk for COPD exacerbations per point (P = .001).
In sensitivity analyses, results were similar when using complete cases and after controlling for prior COPD exacerbation history. In addition, the exploratory analysis suggested a smaller effect among individuals living in poor-quality neighborhoods (P for interaction = .035).
Researchers also observed an independent association between PSQI score and risk for hospitalization with a 7% increased risk for hospitalization for every 1-point score increase.
“Our work provides a strong rationale into paying more attention to sleep than we have in the past, from both a clinical and research perspective,” Baugh said in the release. “While we now know that sleep quality can predict future exacerbations, we don’t know whether improving sleep quality will yield direct improvements in COPD outcomes. We encourage future studies that can look at the impact of interventions, whether at the individual or community level.”