The relation of sleep complaints to respiratory symptoms in a general population.

Based on data obtained from the Tucson Epidemiologic Study of Chronic Lung Disease that included body weight, questionnaire responses, and spirometry, we found that among subjects with no respiratory symptoms, 28.0 percent reported insomnia (difficulty initiating or maintaining sleep) and 9.4 percent reported daytime sleepiness. Among subjects with respiratory symptoms, cough and/or wheeze, the rates of sleep complaints increased. With one symptom, 39.1 percent reported insomnia and 12.4 percent reported daytime sleepiness. With both symptoms, the rates were 52.8 percent and 22.8 percent, respectively. Overall, we found significant relationships between rates of respiratory symptoms and sleep complaints (trend chi 2 = 73.9, p < 0.001 for insomnia; trend chi 2 = 37.9, p < 0.001 for daytime sleepiness). In separate analyses, obesity, snoring, and a diagnosis of lung disease also influenced the rate of sleep complaints but, when we employed logistic regression, we found that obesity, respiratory symptoms, gender, and age were the only variables related to the risk of insomnia or daytime sleepiness.