The skinny on why poor sleep may increase heart risk in women

Previous studies have shown that people who get less sleep are more likely to develop obesity, type 2 diabetes, and heart disease -- and that the relationship may be partially explained by diet. But these studies were narrowly focused on specific foods or nutrients (such as fish, sweets, or saturated fat) or only measured sleep duration, not sleep quality.

The new study was designed to get a more comprehensive picture in women by examining associations between overall diet quality and multiple aspects of sleep quality.

"Women are particularly prone to sleep disturbances across the life span, because they often shoulder the responsibilities of caring for children and family and, later, because of menopausal hormones," says Brooke Aggarwal, EdD, assistant professor of medical sciences at Columbia University Vagelos College of Physicians and Surgeons and senior author of the study.

The study of nearly 500 women was published online today in the Journal of the American Heart Association.

The researchers analyzed the sleep and eating habits of an ethnically diverse group of 495 women, ages 20 to 76. The study looked at sleep quality, the time it took to fall asleep, and insomnia. The women also reported on the types and amounts of foods they typically eat throughout the year, allowing researchers to measure their typical dietary patterns.

Similar to previous studies of sleep and diet, the study found that those with worse overall sleep quality consumed more of the added sugars associated with obesity and diabetes.

Women who took longer to fall asleep had higher caloric intake and ate more food by weight.

And women with more severe insomnia symptoms consumed more food by weight and fewer unsaturated fats than women with milder insomnia.

"Our interpretation is that women with poor-quality sleep could be overeating during subsequent meals and making more unhealthy food choices," says Aggarwal.

The question remains: How might poor sleep contribute to poor eating?

"Poor sleep quality may lead to excessive food and calorie intake by stimulating hunger signals or suppressing signals of fullness," says Faris Zuraikat, PhD, postdoctoral fellow at Columbia University Vagelos College of Physicians and Surgeons and lead author of the study. "Fullness is largely affected by the weight or volume of food consumed, and it could be that women with insomnia consume a greater amount of food in an effort to feel full.

"However, it's also possible that poor diet has a negative impact on women's sleep quality," adds Zuraikat. "Eating more could also cause gastrointestinal discomfort, for instance, making it harder to fall asleep or remain asleep."

"Given that poor diet and overeating may lead to obesity -- a well-established risk factor for heart disease -- future studies should test whether therapies that improve sleep quality can promote cardiometabolic health in women," says Aggarwal.

About the Study

The women in the study were participants in the American Heart Association's Go Red for Women Strategically Focused Research Network at Columbia University Irving Medical Center.

Two other research teams in Columbia's Go Red for Women network are studying the impact of sleep restriction on risk factors for heart disease and on the cells that line blood vessels.

The study is titled "Measures of Poor Sleep Quality Are Associated with Higher Energy Intake and Poor Diet Quality in a Diverse Sample of Women from the Go Red for Women Strategically Focused Research Network."

The other contributors (all at Columbia University Irving Medical Center) are Nour Makarem, Ming Liao, and Marie-Pierre St-Onge.

The research was supported by an AHA Go Red for Women Strategically Focused Research Network Award and an AHA Soter Collaborative Award, AHA postdoctoral fellowships, and a grant from the National Heart, Lung, and Blood Institute (T32HL007343-42).