Abstract
STUDY OBJECTIVES: The aim of this study was to determine the prevalence of insomnia and its association with clinical and psychosocial factors in a large sample of outpatients with coronary heart disease. METHODS: The sample comprised 1,082 patients, mean age 62 years (21% female), who participated in the cross-sectional NORwegian CORonary Prevention Study. Patients who were hospitalized with myocardial infarction and/or a coronary revascularization procedure in 2011-2014 responded to a self-report questionnaire and participated in a clinical examination with blood samples 2-36 (mean, 16) months later. Insomnia was assessed using the Bergen Insomnia Scale, a questionnaire based on the criteria for the clinical diagnosis of insomnia as described in the Diagnostic and Statistical Manual of Mental Disorders, fourth version. We performed bivariate logistic regressions for crude analysis and backward stepwise logistic regressions for multiadjusted odds ratios (OR). RESULTS: In total, 488 patients (45%) reported insomnia, and 24% of these patients had used sleep medication in the previous week. Anxiety symptoms (OR: 5.61) were the strongest determinants of insomnia, followed by female sex (OR: 1.88), diabetes (OR: 1.83), eating fish fewer than three times a week (OR: 1.69), type D personality (OR: 1.69), and C-reactive protein ≥ 2 mg/L (OR:1.58), in multiadjusted analyses. CONCLUSIONS: Insomnia was highly prevalent in coronary heart disease outpatients. Psychological factors, lifestyle factors, and subclinical inflammation were associated with insomnia. Our results emphasize the need to identify patients with insomnia and provide appropriate management of insomnia in outpatients with coronary heart disease.