A growing body of evidence suggests that poor sleep is linked to a host of health problems, including a higher risk of high blood pressure, diabetes, obesity and heart disease. Now, a recent study of middle-aged people reveals that have a combination of sleep problems – such as difficulty falling asleep, waking up in the early morning, or sleeping less than six hours a night – can nearly triple a person’s risk of heart disease.
“These new findings underscore the importance of getting enough sleep,” says Dr. Lawrence Epstein, sleep specialist and assistant professor of medicine at Harvard Medical School. Many things can contribute to a lack of sleep, he adds. Some people just don’t make enough time for sleep. Others have habits that disrupt or interfere with sleep. And some people have a medical condition or sleep disorder that disrupts the quality or quantity of their sleep.
Who was in the study?
The researchers pulled data from 7,483 adults from the Midlife Study in the United States who provided information on their sleep patterns and history of heart disease. A subset of participants (663 people) also used a wrist-worn device that recorded their sleep activity (actigraphy). Slightly more than half of the participants were women. Three-quarters declared their race as white and 16% as black. The average age was 53 years old.
The researchers chose to focus on middle-aged people because that’s when adults typically go through diverse and stressful life experiences, both in their work and family lives. It’s also when clogged heart arteries or atherosclerosis (an early sign of heart disease) and age-related sleep problems start showing up.
How did the researchers assess sleep problems?
Sleep health was measured using a composite of several aspects of sleep, including
- regularity (whether participants slept longer on work days compared to non-work days)
- satisfaction (whether they had trouble falling asleep; woke up at night or early in the morning and couldn’t get back to sleep; or felt drowsy during the day)
- alertness (how often they nap for more than five minutes)
- effectiveness (how long it took them to fall asleep at bedtime)
- duration (how many hours they usually slept each night).
To assess heart problems, researchers asked participants, “Have you ever had any heart problems suspected or confirmed by a doctor?” and “Have you ever had severe pain in the front of your chest for half an hour or more?”
A “yes” answer to either question prompted follow-up questions about the diagnosis, which included issues such as angina pectoris (chest pain due to lack of blood flow to the heart muscle) , heart attack, heart valve disease, irregular or rapid heartbeat, and heart failure.
Poor sleep linked to higher heart risk
The researchers controlled for factors that could affect the results, including family history of heart disease, smoking, physical activity, as well as gender and race. They found that each additional increase in self-reported sleep problems was linked to a 54% increased risk of heart disease compared to people with normal sleep patterns. However, the increased risk was much higher – 141% – in people providing both self-reported and wrist-worn actigraphy data, which together are considered more accurate.
Although women reported more sleep problems, men were more likely to suffer from heart disease. But overall, gender did not affect correlations between sleep and heart health.
Black participants had more sleep problems and heart problems than white participants, but in general the relationship between the two problems did not differ by race.
What does this mean for you?
If you have trouble falling or staying asleep, there are many ways to deal with these common issues, ranging from simple adjustments to your daily routine to specialized cognitive behavioral therapy that targets sleep issues. It’s worth a try, because a good night’s sleep helps in so many ways.
“Treating sleep disorders that interfere with sleep can make you feel more alert during the day, improve your quality of life, and reduce the health risks associated with poor sleep,” says Dr. Epstein.
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