MINNEAPOLIS / ST. PAUL (June 11, 2008) – It appears that disrupted rest and activity rhythms are associated with increased mortality rates among older men, according to new University of Minnesota research.
A group of about 3,000 men older than 67, were tested for rest and activity biological rhythms via a wrist device called an actigraph. The device tracked participants' movement, including the peak times of rest and activity, as well as the robustness of the activity for 24 hours a day for an average of about a week between Dec. 2003 and March 2005. As of January 2008, there were 180 deaths in the group, and men who had peak activity times that were the earliest or latest, in comparison with the groups' average, had a much greater risk of death.
"It's important to have a regular routine of waking and going to sleep," said Misti Paudel, M.P.H., principal investigator of the study and a member of the School of Public Health. "Waking early, staying up late, and severely disturbed sleep patterns may have a detrimental impact on health in older men, especially since this group was generally in good health. A good night sleep is important."
This is the first study to report strong associations between disturbed rest and activity rhythms and mortality rates in older men, who are still living in their homes (not institutionalized) – however, studies in cancer patients as well as institutionalized Alzheimer's patients have reported similar findings.
Paudel will be presenting information from the study during the Associated Professional Sleep Societies Conference today in Baltimore, MD.
Lack of sleep can lead to a number of problems in older adults including depression, memory problems, and decreased attentiveness, and also can lead to serious health problems such as an increased risk of obesity, cardiovascular disease, and diabetes, Paudel said.
Another key study finding is that men with more robust rest/activity rhythms had much lower mortality rates. Having greater levels of activity during the day and/or lower levels of activity during the night (better sleep quality) are characteristics of robust rhythms.
"From a sleep standpoint, getting a good night's sleep appears to be important factor for health and longevity for people of all ages, and especially for older adults – where complaints of insomnia and other sleep disturbances are much more common than in younger cohorts," she said. "It is important that anyone who has concerns about their sleep quality should consult their physician."
Future research should examine association with specific causes of death and with health related outcomes, Paudel said. The study was funded by the National Institute on Aging.