Previous reports suggest asthmatics have an increase incidence of sleep disturbances and excessive daytime sleepiness. However, these studies have been limited due to reliance on population surveys or by small numbers of participants. We sought to directly measure sleep quality and daytime sleepiness in a cohort of well-characterized asthmatics participating in a prospective clinical trial.
Data were collected in sub-study of a large multi-center randomized double-masked controlled trial of mild-moderate asthmatics evaluating the effect of low dose theophylline on asthma control in comparison to montelukast and placebo. Each participant was administered sleep symptom questionnaires at randomization and at the final visit (6 months after randomization). These included the Pittsburgh Sleep Quality Questionnaire (PSQI) and the Epworth Sleep Scale (ESS). Sleep questionnaire treatment group differences were analyzed using Wilcoxon rank-sum tests due to non-normality of the responses.
Data were available for 487 participants. Baseline mean values were: age 40 + 15, 74% female, FEV1 79 +16 percent predicted, Juniper Asthma Control Questionnaire score 2.35 + 0.63, PSQI 7.8 +4, and ESS 8.5+4.9 (39% with ESS > 10). Insomnia was reported by 45% of participants. There were no significant differences in the PSQI, ESS, or reported incidence of insomnia between the three treatment groups. There were significant correlations between the Juniper score and PSQI (r2 = .215; p=.0000), and ESS (r2 = .035; p = .0003), but not between either ESS or PSQI and FEV1. The incidence of patients with symptoms highly suggestive of sleep apnea (ESS >10 and snoring > 3 times a week was 9.2%.
Asthmatics suffer significant sleep quality disturbances with a resultant increase in daytime sleepiness.
Sleep disturbances are common in asthmatics and may adversely affect their quality of life. Further, sleep related symptoms are predictors of disease-specific indices of quality of life. Clinicians caring for asthmatics should incorporate objective measures of sleep disturbances in their routine care of these patients.
J.G. Mastronarde, None.