Insomnia in central Pennsylvania.

Objective: Establish the association between insomnia and various physical and mental health symptoms as well as objective measures of sleep disturbance while controlling for age, gender and BMI in a large random sample of the general public.

Methods: A subsample (N=1741) was selected for a single-night sleep laboratory evaluation from a larger random sample (N=16,583) of the general public (20-100 years old).

Results: The prevalence of insomnia was 7.5% and difficulty sleeping an additional 22.4%. The complaints were more frequent in women and in non-Caucasian minorities. A multivariate logistic regression analysis indicated that depression was the single strongest factor followed by female gender associated with either insomnia or difficulty sleeping. Minority status and a history of colitis, hypertension and anemia were also associated, but to a lesser degree. The final model did not include age, BMI as well as any of the sleep laboratory findings.

Conclusion: These findings support the conclusion that mental health variables have the primary independent association with a complaint of insomnia. Other factors including minorities and hypertension are also independently associated, though to a lesser degree. Other primary sleep disorders, e.g., sleep apnea, do not seem to play a major role in insomnia. These findings underscore the fact that insomnia is a symptom associated with a wide variety of mental and physical health problems requiring a proper psychiatric and medical management.