Study examines relationship between sleep duration and heart disease

Sleeping 7 hours is best

MORGANTOWN, W.Va. – Adults who regularly sleep seven hours a night have the lowest rates of coronary heart disease, according to a study by a faculty member in the West Virginia University School of Medicine.

The study, conducted by Anoop Shankar, M.D., Ph.D., associate professor in the Department of Community Medicine, examined almost 60,000 adults of Chinese ethnicity in Singapore. At the time of the study, Dr. Shankar was an associate professor in the Department of Community, Occupational and Family Medicine at the National University of Singapore. He came to WVU in June 2008.

This study is part of a secondary study to a large, ongoing examination funded by the National Institutes of Health of the role of Asian dietary factors in the development of cancer and cardiovascular disease.

Shankar’s study was published in the Dec. 15 edition of the American Journal of Epidemiology.

“A normal man spends approximately one-third of his life span in sleep. Yet, we know so little about long-term health effects of sleep disturbances. It is increasingly being recognized that abnormalities in sleep, including the duration and quality of sleep, are associated with cardiovascular disease,” Shankar said.

Population-based studies have found that compared with people reporting seven hours of usual sleep duration, those with both shorter and longer sleep durations are more likely to develop obesity, diabetes and high blood pressure – all strong predictors of cardiovascular disease development.

For this study, Shankar and his fellow researchers from the University of Singapore and the University of Minnesota followed adults who were free of cardiovascular disease at their initial examination in 1993. They collected detailed information regarding their sleep habits and other lifestyle factors such as smoking, alcohol use and dietary habits. The researchers followed those individuals annually until 2006 and identified all those who died of coronary heart disease during the 12-year period.

“Compared with people with a sleep duration of seven hours, those with a sleep duration of five hours or less had a 60 percent higher risk of death from coronary heart disease and those with a sleep duration of nine hours or more had an 80 percent higher risk during the 12-year follow-up period. These results suggest that sleep duration may be an important marker for the development of cardiovascular disease,” Shankar said.

For more information on the Department of Community Medicine, see http://www.hsc.wvu.edu/som/cmed.


For more information:
Angela Jones, HSC News Service, 304-293-7087

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