Study objectives: To determine the prevalence and polysomnographic correlates of insomnia in subjects with self-reported medical disorders.
Design: Prospective cross-sectional study.
Participants: Community-based sample of 3282 men and women aged 18 to 65 years old, with a subset who underwent polysomnography.
Measurements: Self-reported measures of sleep habits and current health, and polysomnographic sleep variables.
Results: The prevalence of insomnia was 21.4%. The adjusted odds of insomnia were 2.2 times as high in persons with any medical disorders as in those without medical disorders. Specifically, odds of insomnia were higher in people with heart disease (OR = 1.6 [95% CI: 1.2-23], P = 0.004), hypertension (1.5 [12-18], P < 0.001), diabetes (1.4 [105-20], P = 0.04), stomach ulcers (2.1 [1.6-2.7], P < 0.001), arthritis (1.8 [1.5-2.2], P < 0.001), migraine (1.8 [1.5-2.1], P < 0.001), asthma (1.6 [1.3-2.0], P = 0.04), COPD (1.9 [1.5-2.5], P < 0.001), neurological problems (2.0 [1.5-2.7], P < 0.001), and menstrual problems (1.7 [1.3-2.1], P < 0.001) than in people without these disorders. Prevalence of insomnia increased with increasing number of medical disorders. However, polysomnographic sleep was not significantly different in persons with or without medical disorders for most disorders assessed.
Conclusion: This large population-based study suggests that insomnia is highly prevalent in diverse chronic medical disorders. However, polysomnographic evidence of disturbed sleep is present in only a subset of comorbid insomnia populations.
Keywords: Insomnia; arthritis; comorbid; hypertension; medical disorders; prevalence; stroke.