Little sleep linked to heart disease risk

TOCHIGI, Japan, Nov. 11 (UPI) -- Sleeping less than seven-and-a-half hours per day may be associated with future risk of heart disease, researchers in Japan warn.

Dr. Kazuo Eguchi of Jichi Medical University in Tochigi, Japan, and colleagues monitored the sleep of 1,255 individuals with hypertension -- average age 70.4 -- and tracked them for an average of 50 months. Researchers noted patients' sleep duration, daytime and nighttime blood pressure and cardiovascular disease events such as stroke, heart attack and sudden cardiac death.

The study, published in the Archives of Internal Medicine, found sleep duration of less than 7.5 hours was associated with incident cardiovascular disease.

"The incidence of cardiovascular disease was 2.4 per 100 person-years in subjects with less than 7.5 hours of sleep and 1.8 per 100 person-years in subjects with longer sleep duration," the study authors said in a statement. "Shorter duration of sleep is a predictor of incident cardiovascular disease in elderly individuals with hypertension."