By james art 
In recent years, sleep has become a major factor in maintaining heart health, with studies linking sleep to better blood pressure, lower cholesterol, and a reduced risk of heart attack and stroke.
New research shows that sleep can also repair a heart that has already been damaged. The study, published Oct. 30 in Nature , found that sleep is vital to the recovery of mice that have survived a heart attack.
The new research also found clues — from samples collected as part of a sleep restriction study conducted by sleep researchers at Columbia — that suggest sleep may play the same role in humans.
We spoke with Marie-Pierre Saint-Onge, associate professor of nutritional medicine at Columbia University’s Vagelos College of Physicians and Surgeons, who led the original sleep study and is a co-author of the new Nature study, about the research and why sleep is so important.
What did your initial Columbia sleep study show?
Until recently, it was unclear whether lack of sleep caused an increased risk of heart disease or simply correlated with cardiovascular disease.
We designed our study to determine whether lack of sleep is a causative factor in the development of heart disease. Measuring the health effects of chronic sleep loss in humans is difficult. We asked our participants, all of whom had adequate sleep duration to begin with, to reduce their sleep by 90 minutes each night for six weeks, which was difficult for them.
Our study showed that poor sleep — even the mild sleep deficit experienced by two-thirds of Americans — causes changes in the body that increase the risk of heart disease.
It is one of the first to show a causal relationship between long-term, mild sleep deprivation and the risk of heart disease.
How did this study help show that sleep is necessary for the heart to heal after a heart attack?
In the new Nature study, our colleagues at Mount Sinai found that after a mouse suffered a heart attack, the brain released factors that promote sleep. Sleep, in turn, helps the heart heal. Mice deprived of sleep after a heart attack had an influx of inflammatory cells to the heart, impaired heart function and higher mortality.
When our collaborators analyzed blood samples from participants in our sleep study, they found similar migrating inflammatory cells when the study participants were sleep-restricted compared to those when they got adequate sleep.
Our participants were healthy—none had a heart attack—but the finding shows that what happens in sleep-deprived mice after a heart attack also happens in sleep-deprived humans.
Should people who are recovering from a heart attack be prescribed sleep?
At the end of the day, what we want to do is help people. It is important to see if people with cardiovascular disease can improve their heart condition by improving their sleep.
But this needs to be tested. Our lab is interested in investigating the impact of improving sleep for better cardiovascular health.
After people have a heart attack, the focus is usually on diet changes, more exercise, and weight loss. Based on what we know now, it seems imperative to add sleep to the lifestyle recommendations for these patients.