Although the reasons are unclear, researchers said lack of sleep appeared to be linked to increased blood pressure, which is known to raise the risk of heart attacks and stroke.
A 17-year analysis of 10,000 government workers showed those who cut their sleep from seven hours a night to five or less faced a 1.7-fold increased risk of death from all causes and more than double the risk of cardiovascular death.
The findings highlight a danger in busy modern lifestyles, Francesco Cappuccio, professor of cardiovascular medicine at the University of Warwick's medical school, told the annual conference of the British Sleep Society in Cambridge.
"A third of the population of the UK and over 40 percent in the U.S. regularly sleep less than five hours a night, so it is not a trivial problem," he said in a telephone interview.
"In terms of prevention, our findings indicate that consistently sleeping around seven hours per night is optimal for health," he said.