After about 10 years of follow-up for women and 14 years for men, 248 participants (14 percent) were deceased. The 14-year adjusted mortality rate for men was 9.1 percent for "good sleepers" and 51.1 percent for insomniacs who slept less than six hours.
Previously published studies based on the same cohort also have shown that chronic insomnia with short sleep duration is associated with deficits in neurocognitive function and increased risks of both type 2 diabetes and hypertension.
"We believe that cumulatively these findings will increase the awareness among physicians and scientists that insomnia should be diagnosed early and treated appropriately," said Vgontzas.
The current study also found an even higher risk of death when men with chronic insomnia and a short sleep duration also had hypertension or diabetes. Insomniacs who slept less than six hours and were diabetic or hypertensive at baseline had a much higher mortality risk (OR = 7.17) than short-sleeping insomniacs without diabetes or hypertension at baseline (OR = 1.45). According to the authors, this suggests that the treatment of insomnia in people with impaired physical health should be a medical priority.
The authors cautioned that six hours of sleep is not recommended as the optimum sleep duration for the general population. They used a six-hour cut-off point only for the statistical evaluation of the severity of insomnia. The American Academy of Sleep Medicine reports that most adults need seven to eight hours of nightly sleep to feel alert and well rested during the day.
The authors also noted that it is unclear why the mortality risk was increased in men but not in women. One explanation may be that the mean follow-up duration was 3.6 years shorter for women than for men, and the sample of women had fewer deaths (103) than the men (145).
|Contact: Emilee McStay|
American Academy of Sleep Medicine