The researchers found that about 40 percent of the men and the women were classified as poor sleepers, defined as having frequent problems falling asleep, taking 30 or more minutes to fall asleep or awakening frequently during the night. But while their sleep quality ratings were similar, men and women had dramatically different risk profiles.
We found that for women, poor sleep is strongly associated with high levels of psychological distress, and greater feelings of hostility, depression and anger. In contrast, these feelings were not associated with the same degree of sleep disruption in men, says Suarez.
Women who reported higher degree of sleep disruption also had higher levels of all the biomarkers tested. For women, poor sleep was associated with higher levels of C-reactive protein and interleukin-6, measures of inflammation that have been associated with increased risk of heart disease, and higher levels of insulin. The results were so dramatic that of those women considered poor sleepers, 33 per cent had C-reactive protein levels associated with high risk of heart disease, says Suarez.
Interestingly, it appears that its not so much the overall poor sleep quality that was associated with greater risk, but rather the length of time it takes a person to fall asleep that takes the highest toll, says Suarez. Women who reported taking a half an hour or more to fall asleep showed the worst risk profile.
The study was supported by a grant from the National Institutes of Health.
Suarez says hes planning further studies to understand the complex relationship between health risk and poor sleep in men and women. He believes that the gender differences may be due, in part, to variation in the activity of a number of naturally occurring substances in the body, such as tryptophan, an amino
|Contact: Michelle Gailiun|
Duke University Medical Center