People with high blood pressure who do not get enough sleep are dramatically increasing their risk of developing potentially fatal heart conditions, according to a new study.
Researchers found that sleeping for less than seven-and-a-half hours a night could quadruple the chances of suffering a heart attack, stroke, or sudden cardiac death.
The study of 1,255 patients - mostly elderly - with high blood pressure in Japan found that getting under 7.5 hours of sleep was associated with a 27% increase in risk for patients whose blood pressure did not rise at night.
However, it was far more hazardous for the small minority of patients who did experience overnight blood pressure increases, whose likelihood of experiencing a heart attack, stroke or even death more than quadrupled when they slept less than 7.5 hours.
Dr Kazuo Eguchi, from Jichi Medical University in Tochigi, Japan, and colleagues wrote in the journal Archives of Internal Medicine: "Reflecting changing lifestyles, people are sleeping less in modern societies."
"A good sleep of adequate duration is essential because sleep fragmentation and sleep deprivation, commonly seen in contemporary society, are associated with multiple health disorders, including cardiovascular diseases."