Obstructive sleep apnea and heart attack protection?

This article discusses a study showing that patients with obstructive sleep apnea (OSA) may have less heart muscle damage during a non-fatal heart attack. These results contradict other studies showing an increased risk of heart attack with untreated OSA.

Some of the doctors in the study urge caution saying that perhaps the chronically low level of oxygen in OSA sufferers may protect some heart attack victims. Also, the study showed that the frequency of heart attacks was not decreased by OSA, just the damage to the heart muscle from the heart attack. Interesting study and more studies will be needed to sort this out.

Insomnia and Heart Attack

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.

Restless Legs Syndrome, Heat Damage and Heart Attack

Data was presented at a study at the American College of Cardiology about Restless Legs Syndrome (RLS) and cardiovascular health. RLS affects an estimated 12 million Americans. Researchers measured leg movements in patients with RLS during an overnight sleep study and then assessed their heart health. They divided the patients into two groups - those whose legs twitched more or less than 35 times per hour. Patients whose legs twitched more than 35 times per hour were more likely to have thickened heart muscle. In the three years of follow up, those with the most leg twitches and thickest heart walls were more than twice as likely to have suffered a heart attack or died. It's not clear if treating the RLS lowers cardiovascular risk. The study authors suggest that patients with restless legs symptoms consult with their doctor about monitoring their heart health.

Sleep Duration and Cardiovascular Disease

The August edition of the journal Sleep has an article about the association of sleep duration and cardiovascular disease. It was based on a survey of over 30,000 Americans. The results showed that cardiovascular disease was more common in people who reported that they slept less than or greater than seven hours per night. These results were independent of age, sex, race, ethnicity, smoking, alcohol use, body mass index, physical activity, diabetes, high blood pressure, and depression.

The authors of the study did not determine the reason why sleep duration could affect cardiovascular disease, but they provided some theories. Hormonal and metabolic changes can occur in people who sleep less than seven hours, and these changes could impact cardiovascular health. People who sleep longer than seven hours could be sleeping that long due to an underlying sleep disorder, such as obstructive sleep apnea (OSA). OSA can impact cardiovascular health in a negative way.

Getting seven hours of sleep each night may not prevent you from having a heart attack, but getting the right amount of sleep can be an important part of overall good health.