MONDAY, Oct. 24 (HealthDay News) -- Insomnia symptoms are associated with a moderate increase in the risk of acute myocardial infarction (AMI), according to a study published online Oct. 24 in Circulation.
Lars E. Laugsand, M.D., from the Norwegian University of Science and Technology in Trondheim, and colleagues investigated the association between insomnia and the risk of AMI in a cohort of 52,610 men and women who completed a questionnaire on insomnia. The participants were followed up for 11.4 years, during which time 2,368 incident AMIs occurred. The association of insomnia symptoms with AMI risk was assessed following adjustment for age, gender, marital status, education, shift work, blood pressure, lipids, diabetes mellitus, body mass index, physical activity, smoking, and alcohol consumption.
The investigators found that, compared to those who never experienced sleep difficulties, the risk of AMI was moderately increased for those with difficulty initiating sleep almost every night (hazard ratio [HR], 1.45), for those with difficulty maintaining sleep almost every night (HR, 1.30), and for those with a feeling of nonrestorative sleep more than once a week (HR, 1.27), after multivariable adjustments. There was a significant, dose-dependent association between the number of symptoms and AMI risk when the symptoms were combined. Use of alternative multivariable models and sensitivity analyses indicated the results were robust, particularly regarding trouble initiating sleep.
"Insomnia is associated with a moderately increased risk for AMI," the authors write. "Evaluation of insomnia might provide additional information in clinical risk assessment that could be useful in cardiovascular prevention."