Sleeping Beauty to Protect the Heart

CVD and coronary heart disease risk up with sleeping troubles in postmenopausal women

(RxWiki News) While some women past menopause have to deal with hot flashes and night sweats, others have to watch their sleeping patterns. How they sleep can affect their heart health.

For postmenopausal women, a new study showed that insomnia, sleeping too much and sleeping too little can increase their chances of developing heart disease and coronary heart disease.

These findings showed that sleep duration and problems sleeping are tied to diseases involving the heart.

"Get at least seven hours of sleep each night."

Previous studies have shown that plaque build up in the arteries of the heart, called coronary heart disease (CHD), and cardiovascular disease (CVD) are both affected by sleeping too long or too little. CVD, or heart disease, is a group of diseases that affect the heart.

Megan Sands-Lincoln, PhD, MPH, from the Center for Sleep and Circadian Neurobiology and the University of Pennsylvania's Perelman School of Medicine, led an investigation into whether insomnia and time spent sleeping affected coronary heart disease and cardiovascular disease risk in postmenopausal women.

Researchers looked at data from the Women's Health Initiative Observational Study, which included 86,329 postmenopausal women between 50 and 79 years of age. They were recruited from 40 clinical sites around the country between 1993 and 1998.

The women reported how long they slept each night over the previous four weeks prior to taking the survey.

They also reported how often they had difficulty falling asleep, woke up during the night, woke up earlier than planned or had trouble falling back to sleep after waking up early.

Researchers tracked the number of women who had had a heart attack, were hospitalized for chest pain or to have coronary revascularization (a surgical procedure to restore blood flow to the heart), or died. These occurrences were categorized as instances of coronary heart disease.

The number of developing cardiovascular disease cases was also tracked. In this study, the disease is defined as the total number of coronary heart disease cases or having an ischemic stroke caused by a blood clot preventing blood flow to the brain.

Researchers followed up with patients after the study and verified information through medical records and death certificates. They also took note of patients' smoking status, level of physical activity and alcohol consumption each week.

After adjusting for age and race, researchers found that women with high insomnia scores had a 38 percent higher chance of developing coronary heart disease and 27 percent higher chance of cardiovascular disease.

Postmenopausal women who slept less than five hours a night or longer than 10 hours also had a 25 percent greater chance of developing coronary heart disease and 19 percent greater chance of cardiovascular disease, though the percentages were not significant.

Women who had both high insomnia scores and slept longer than 10 hours were 93 percent more likely to develop coronary heart disease compared to women who slept seven to eight hours a night.

"When addressing these sleep characteristics in concert...participants demonstrated almost double the risk for CHD, suggesting characteristics of sleep quality may be an important factor contributing to the observed association between sleep duration and incident CHD and CVD reported in previous studies," the researchers wrote in their report

The authors noted a few limitations with their study, including that the findings can't be generalized to men or younger women since the study focused only on postmenopausal women.

The researchers also did not measure total time spent asleep or take other sleep disorders like sleep apnea or restless legs syndrome into account.

Future research should look into how exactly sleep quality changes the link between prolonged sleep duration and coronary heart disease, according to researchers.

The study, funded by the National Heart, Lung, and Blood Institute, National Institutes of Health and the US Department of Health and Human Services, was published online May 7 in the Journal of Women's Health.

The authors do not declare any competing financial interests.

Review Date: 
May 10, 2013