You’ve tried dietary supplements, relaxation techniques, exercise — even warm milk, but you can’t fall or stay asleep.
You’re not alone. Insomnia is the most common sleep complaint among Americans.
According to the National Center on Sleep Disorders Research at the National Institutes of Health, about 50 to 70 million Americans say they have some symptoms of insomnia within a given year, and about 10 to 15 percent of adults say they have chronic insomnia.
The role sleep plays in keeping us healthy is becoming better understood. For instance, researchers are looking at various links between sleep, interruption of the natural circadian rhythms, and the risk of chronic illness, such as cancer development.
Researchers in Iceland found men who reported sleep problems — including difficulty falling asleep and staying asleep — were twice as likely to develop prostate cancer compared to those with no sleep disruptions. This is according to data published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.
“Women with sleep disruption have consistently been reported to be at an increased risk for breast cancer, but less is known about the potential role of sleep problems in prostate cancer,” said Lara G. Sigurdardóttir, M.D., a researcher at the University of Iceland in Reykjavik who led the study.
Researchers have suspected for some time that a disruption in circadian rhythms, a person’s natural internal 24-hour clock, is linked to increased risk of cancer as well as other diseases and health conditions.
Previous studies have generated conflicting results for an association between sleep disruption from working night shifts and the risk for prostate cancer. Sigurdardóttir and her colleagues wanted to know what role, if any, sleep played in influencing prostate cancer risk.
“Prostate cancer is one of the leading public health concerns for men and sleep problems are quite common,” Sigurdardóttir said in a written statement.
The researchers followed 2,102 older Icelandic men without prostate cancer, aged 67 to 96, for five years. Upon enrollment in the study, participants answered four questions about sleep disruption:
- Whether they took medications to sleep
- Whether they had trouble falling asleep
- Whether they woke up during nights and had difficulty going back to sleep
- Whether they woke up early in the morning and had difficulty going back to sleep
Among the participants, 8.7 percent and 5.7 percent reported severe and very severe sleep problems, respectively, when entering the study. During the five-year study, 6.4 percent of the participants were diagnosed with prostate cancer.
Since older men tend to develop prostate cancer at higher rates than their younger counterparts, the researchers adjusted their findings for age and then compared those findings with men who reported no problems with sleeping. They found the risk for prostate cancer increased proportionately with reported severity of problems falling and staying asleep, from 1.6-fold to 2.1-fold.
Further, the association was stronger for advanced prostate cancer than for overall prostate cancer, with more than three times the risk for advanced prostate cancer associated with “very severe” sleep problems.
To rule out the possibility that participants with insomnia were not sleeping because of undiagnosed prostate cancer or an enlarged prostate, the researchers reanalyzed the data. They excluded men with symptoms of sleep disturbance that might be indicative of nocturia — waking up during the night to urinate. The results remained unchanged.
Sigurdardóttir said the findings should be confirmed with a larger cohort having longer observation times. “If our results are confirmed with further studies, sleep may become a potential target for intervention to reduce the risk for prostate cancer.
Lynette Summerill is an award-winning writer and Scuba enthusiast who lives in San Diego with her husband and two beach loving dogs. In addition to writing about cancer-related issues for EmpowHER, her work has been seen in publications internationally.
Sources:
“Sleep Disruptions Among Older Men and Risk of Prostate Cancer.” Lara G. Sigurdardottir, et al. Cancer Epidemiol Biomarkers Prev May 2013 22:872-879; doi:10.1158/1055-9965.EPI-12-1227-T.
http://cebp.aacrjournals.org/content/22/5/872.abstract
“Sleep Problems May Increase Risk for Prostate Cancer”. American Association for Cancer Research Media Release. May 7, 2013. Jeremy Moore.
http://www.aacr.org/home/public--media/aacr-in-the-news.aspx?d=3109
“Sleep Disorders Research Plan”, 2011. National Center for Sleep Disorders Research, National Institutes of Health.
Download at: http://www.nhlbi.nih.gov/health/prof/sleep/201101011NationalSleepDisordersResearchPlanDHHSPublication11-7820.pdf
“Can’t Sleep? What to Know About Insomnia” National Sleep Foundation.
http://www.sleepfoundation.org/article/sleep-related-problems/insomnia-and-sleep
Reviewed May 14, 2013
by Michele Blacksberg RN
Edited by Jody Smith