Poor sleep may increase the risk for cardiovascular disease, new research suggests.
Researchers assigned “sleep scores” on a scale of zero to five to 385,292 British men and women, giving one point for having each of five indicators of healthy sleep: being an early bird, sleeping seven to eight hours a night, having no insomnia, not snoring and not being sleepy during the day. The scores depended on self-reports of sleep behavior.
Over the following eight years, there were 4,667 cases of coronary heart disease and 2,650 strokes. They found that the lower the sleep score, the higher the person’s risk for these diseases.
The poorest sleepers, about 2 percent of the group, scored 0 or 1. Compared to them, those who scored 5 had a 34 percent reduced risk for both coronary heart disease and stroke. The study is in the European Heart Journal.
The researchers also looked at genetic variations known to be associated with cardiovascular disease. They found that among people genetically at high risk for cardiovascular disease, good sleep habits were protective, putting them at lower risk than poor sleepers with similarly high genetic risk.
“Unlike previous studies, we analyzed sleep behaviors in combination,” looking at a variety of factors tied to sleep quality, said the senior author, Dr. Lu Qi, a professor of epidemiology at Tulane University. “We found that when we put all the behaviors together, the association between sleep and cardiovascular disease was even stronger than with each behavior separately.”