Insomnia is a prevalent disorder, but there has not been much data linking it to physical disorders, like cardiovascular disease. Insomnia has been associated with the development of certain psychiatric disorders, most likely being depression. There is an abstract in the journal Circulation that assessed the risk of having a heart attack (aka 'MI' for myocardial infarction) in patients that have insomnia. The study was out of Norway and included 52,610 patients that were followed for an average of 11.4 years and assessed for incidence of MI and difficulty sleeping. The researchers adjusted the data for age, gender, marital status, education, shift work, blood pressure, lipids, diabetes, body mass index, physical activity, smoking, and alcohol consumption.
The results showed that patients who reported trouble falling asleep most nights over the previous month had a 45% higher risk for MI. Patients that reported difficulty staying asleep had a 30% increase risk for MI. And waking up unrefreshed more than once a week was associated with a 27% higher risk of MI.
The researchers do not know why difficulty sleeping would contribute to higher risk of MI. I noticed that one variable they did not account for was whether the patients had obstructive sleep apnea (OSA) or other cardiac or lung diseases that could contribute to insomnia and/or raise the risk of having an MI. OSA in particular is a common cause of chronic insomnia and several studies have linked it to heart attacks. Bottom line: If you have chronic insomnia, talk to your doctor or a sleep physician...your heart might thank you.