March 1, 2023 – People with insomnia – a sleep disorder that makes it difficult to fall asleep or stay asleep – and those who slept only a few hours a night had a greater risk of heart attack than others, a new study shows.
Specifically, people with insomnia had a 69% greater risk of having a heart attack than those without insomnia.
And those who slept 5 or fewer hours a night had a 59% greater risk of heart attack than those who slept 7 to 8 hours a night. But sleeping 9 hours or more appeared to be equally risky.
These findings are from an analysis that combined results from nine smaller studies in several countries, in a total of more than a million adults who were, on average, 50 years old, almost all without a previous heart attack.
The study looked at new heart attacks in these patients over the next 9 years, on average.
"Many people choose to sleep less and don’t prioritize sleep and proper sleep hygiene," said study author Yomna E. Dean, a medical student at Alexandria University in Egypt.
But they may not realize that getting the right amount of sleep (not too little or too much) is part of a healthy lifestyle and is associated with a lower risk of heart attack.
This study highlights the importance of adequate sleep for heart health, showing that insomnia was linked to a higher risk of heart attack in people 65 and younger as well as in older people.
Women with insomnia had a higher risk of heart attack than other women, and this was slightly higher than the increased risk from insomnia in men.
Among people who had high blood pressure, high cholesterol, or diabetes, those with insomnia had a higher risk of heart attack than those without insomnia.
People who had a hard time falling asleep or staying asleep – two symptoms of insomnia – had a 13% higher risk of heart attack, compared to people without these difficulties.
But people who slept an adequate number of hours but did not wake up refreshed and felt tired during the day – which is common – did not have a higher risk of heart attack, compared to other people.
The people answered questionnaires to report their sleep habits and whether they had a disease such as diabetes that might introduce error, says Jennifer L. Martin, PhD, president of the American Academy of Sleep Medicine, who was not involved with this research.
Nevertheless, this analysis "adds to the growing evidence that poor quality or insufficient sleep is associated with poor health," she says.
It reminds people that adequate sleep (not too little or too much) is important.
The American Heart Association includes “Get healthy sleep” as one of “Life’s Essential 8” for heart health, and gives tips on how to do this.
"A good night’s sleep is key to taking care of your heart. If you have insomnia, get help," Martin says. "Start with a trusted health care provider and ask for a referral to a sleep medicine specialist or sleep psychologist.
"Most people with insomnia need more than basic tips for healthy sleep, and benefit greatly from cognitive behavioral therapy for insomnia (CBT-I)," she says. "This treatment is a short psychotherapy (usually 4-8 sessions) that is recommended as the first-line treatment for insomnia disorder."
Patients can go to sleepeducation.org to find an accredited sleep center near them, or go to behavioralsleep.org to find a provider that is trained to deliver CBT-I, Martin notes.
The study was published online on Feb. 25 in Clinical Cardiology. It is also scheduled to be presented March 6 at the American College of Cardiology Scientific Session/World Congress of Cardiology2023.
