(NaturalNews) Researchers from the West Virginia University (WVU) School of Medicine have determined that getting seven hours of sleep is optimal for maintaining heart health. Getting too much, or too little, sleep can increase a person's chances of developing cardiovascular disease, according to the study.
More than 30,000 people participated in the 2005 National Health Interview Survey, which researchers used to obtain study data. What they found was that people who sleep only five hours a day -- including naps -- have a doubled risk of suffering from angina, coronary heart disease, heart attack or stroke, compared to people who sleep seven hours a day.
The team also found that people who sleep nine or more hours a day have a 150 percent increased risk of developing cardiovascular disease, while those who sleep either six or eight hours have only an "elevated but less dramatic risk".
According to Doctors Charumathi Sabanayagam and Anoop Shankar, authors of the study, people over the age of 60 who sleep five hours or less a night are at the highest risk of developing cardiovascular disease. People in this category are at a 300 percent higher risk than those who sleep seven hours a night.
Additionally, women who get only five hours of sleep a night are at a 250 percent increased risk compared to those who get seven hours a night.
"The authors of the WVU study were unable to determine the causal relationship between how long a person sleeps and cardiovascular disease," explained Karin Zeitvogel, an AFP reporter, in an article. "But they pointed out that sleep duration affects endocrine and metabolic functions, and sleep deprivation can lead to impaired glucose tolerance, reduced insulin sensitivity and elevated blood pressure, all of which increase the risk of hardening the arteries."