Familiar aggregation of insomnia in a sample of portuguese teachers.

Abstract

Background: Insomnia is a common sleep disorder. Epidemiologic studies have linked the occurrence of insomnia with genetic and environmental factors. The aim of this study was to analyze the association between family history and other risk factors with the occurrence of insomnia in a sample of portuguese adults. Methods: In a cross-sectional study we assessed teachers of sixteen public elementary schools of the district of Viseu, Portugal. Data was collected using a self-administered questionnaire. We obtained a final sample of 864 teachers (631 female,73.0%), age=43.2±7.7 years. Insomnia was defined as the presence of one or more of the following symptoms: i)difficulty initiating sleep, ii)difficulty maintaining sleep, iii)early morning awakening and difficulty getting back to sleep, iv)non-restorative sleep, that lasts for a period of 1 month. Prevalence was expressed in proportions with 95% confidence intervals (CI), and compared by the chi-square test. Results: The prevalence of insomnia was 42.0% (95%CI=38.6-45.4). The prevalence of difficulty initiating sleep, difficulty maintaining sleep, early morning awakening with difficulty getting back to sleep, non-restorative sleep was 14.6% (95%CI=11.7-16.4), 29.4% (95%CI=26.5-32.7), 20.2% (95%CI=17.5-22.9) and 21.1% (95%CI=18.6-24.2), respectively. Insomnia was associated with gender (female, OR=1.3, 95%CI=1.0-1.8), use of any medication in the previous 12 months (OR=2.3,95%CI=1.7-3.2); depressive symptoms (OR=2.8,95%CI=1.8-4.3); sports practice (OR=0.8,95%CI=0.7-1.0); and drug consumption (OR=2.4,95%CI=1.3-4.6). After adjustment by non-conditional logistic regression for gender, use of medication, depressive symptoms and sports practice, the family history was associated with insomnia (OR=2.8,95%CI=1.38-5.76). Conclusion: Insomnia was associated with genetic factors, such as family history, and environmental variables.