People with a common cluster of symptoms that puts them at increased risk of heart disease and diabetes are two times as likely to die as people without those risk factors if they get less than six hours of sleep per night.
That was the finding of a new study conducted by researchers at Pennsylvania State College of Medicine and reported in the Journal of the American Heart Association.
So-called metabolic syndrome is marked by elevated blood sugar, high blood pressure and cholesterol, and excess fat around the waistline. A diagnosis of metabolic syndrome also includes a high body mass index (BMI), a measurement of a person's weight relative to his height.
People with a high BMI and other symptoms of metabolic syndrome are at increased risk of developing heart disease and diabetes.
In the study, a group of 1,344 adults agreed to spend one night in a sleep clinic. Almost 40 percent of the participants were found to have at least three of the risk factors of metabolic syndrome.
When the participants were followed up an average of 16 years later, 22 percent of them had died.
Compared with those without metabolic syndrome, investigators found those with a cluster of heart disease and diabetes risk factors were 2.1 times more likely to have died of stroke if they slept less than six hours during their night in the lab.
If they had slept more than six hours, those with metabolic syndrome were about 1½ times more likely to have suffered a fatal stroke than normal participants.
Finally, those with metabolic syndrome who slept less than six hours were almost two times more likely to have died of any cause compared with those without the heart disease and diabetes risk factors.
The study is the first to examine the impact of sleep duration on the risk of death in patients with metabolic syndrome.
More trials planned
If you have metabolic syndrome, the study's authors note it is important to notify your doctor if you are not getting enough sleep to reduce the risk of death from heart attack or stroke.
The researchers plan future clinical trials to determine whether increasing the length of quality sleep, in addition to lowering blood pressure and glucose, improves the prognosis for people with metabolic syndrome.
The American Heart Association recently issued a scientific statement noting that an increasing number of Americans suffer from sleep difficulties, either involuntarily or because they'd rather stay up late, and this trend may be associated with increased cardiovascular risks and outcomes.