Sleep and respiratory problems are common in adults in the USA. However, sleep problems often remain undiagnosed in patients with obstructive airway diseases (OADs). This study was designed to examine the association between sleep problems and different categories of OAD amongst US adults.
We conducted an observational, cross-sectional study using a nationally representative sample of the US civilian non-institutionalized population from 2007 to 2008 National Health and Nutritional Examination Survey (NHANES). A total of 3204 study participants aged ≥35 years were stratified into four groups, using a self-reported history of asthma and data from spirometry: asthma-COPD overlap (ACO) (n = 70, 2.2%), asthma (n = 168, 5.2%), chronic obstructive pulmonary disease (COPD) (n = 412, 12.8%), and those without any OAD (normal) (n = 2554, 79.7%). After characterizing the baseline demographics and health status of the four groups, multivariate logistic regression analysis was performed to estimate the likelihood of sleep problems in adults after adjusting for age, gender, body mass index, smoking, alcohol, obstructive sleep apnea syndrome (OSAS), depression, and diabetes. The index sample was the normal group. Sleep problems were defined as any complaints which affect or involve sleep.
The participants with COPD were older (62.0 ± 11.7 years) as compared to ACO (59.1 ± 11.3 years), asthma (53.6 ± 11.3), and normal groups (53.8 ± 12.1) (p < 0.0001). Comparing baseline characteristics between the four groups, there were significant associations between OAD status and sleep problems including inadequate sleep, sleep-onset insomnia, snoring, frequent trouble sleeping, nocturnal arousals, early morning awakenings, fatigue, daytime sleepiness, use of prescription medication for sleep, leg jerks, leg cramps, difficulty in concentration, and difficulty in remembering things when tired. The multivariate logistic regression models evaluating the prevalence of sleep problems in individual OADs showed a stronger association between asthma and sleep problems as compared to COPD and ACO and sleep disorders.
All OADs are associated with a higher prevalence of sleep problems. There is a stronger association between asthma and sleep problems as compared to COPD and ACO. We speculate that the nocturnal burden of asthma contributes to sleep problems. Our results suggest that adults with OAD should be aggressively screened for sleep problems.