Good News for Women (and Perhaps Their Doctors)
Abstract & Commentary
By Barbara A. Phillips, MD, MSPH, Professor of Medicine, University of Kentucky; Director, Sleep Disorders Center, Samaritan Hospital, Lexington. Dr. Phillips is a consultant for Cephalon, and serves on the speakers bureaus for Resmed and Respironics.
Synopsis: In women, insomnia was not associated with increased risk of death, regardless of sleep duration. In men, mortality risk was significantly increased only in insomniacs who slept less than 6 hours and who were diabetic or hypertensive at baseline.
Source: Vgontzas AN, et al. Insomnia with short sleep duration and mortality: The Penn State Cohort. Sleep 2010;33:1159-1164.
This report is one of many from the Penn State Cohort, which was initially assembled to learn more about the epidemiology of sleep apnea. The data presented here come from 1741 people (741 men, mean age 50 years; and 1000 women, mean age 47 years) who were selected at random from the population of Pennsylvania. Participants completed questionnaires and diaries, and had in-laboratory sleep studies. Insomnia was self-defined by a complaint of insomnia with a duration of at least 1 year. Normal sleeping was defined as the absence of insomnia. The cohort was divided into two groups based on the measured sleep duration during the single overnight sleep study: those who slept at least 6 hours, and those who slept less than 6 hours. After this initial evaluation, the cohort was followed for an average of 10 years for women, and 14 years for men. Over the period of follow-up, the mortality rate was 21% for men and 5% for women. The authors analyzed and presented the data separately for women and for men.
For women, neither sleep duration nor the complaint of insomnia predicted mortality, before or after adjustment for age, race, sleep apnea, diabetes, hypertension, and sampling weight. Although the authors did not comment on this, insomnia in women was robustly associated with depression.
For men, mortality risk was increased in those who slept less than 6 hours and reported insomnia at baseline. The statistics get a little complicated here. The authors report that the risk for death in these short-sleeping insomnia men remained significant even after adjusting for diabetes and hypertension, whereas the male insomniacs with short sleep but without diabetes or hypertension did not have an increased mortality risk. Part of the problem with this analysis was that there were very few male insomniacs with short sleep duration (33, in fact). Of these apparently doomed men, 23 were hypertensive, 19 had diabetes, 11 had sleep apnea, and 18 had depression. They were less healthy than the rest of the cohort, an issue the authors do not address.
Commentary
This paper received a fair amount of attention in the sleep community and the lay press, and has the potential to feed the epidemic of insomnia in this country. For those of us on the front lines of clinical care, it is important to step back and take a deep breath. First of all, insomnia was not associated with death in women. Since women are much more likely to report insomnia than are men,1 this is good news for our female patients (and for us). Second, despite some fancy statistical footwork, this study apparently failed to find that men who did not have hypertension or diabetes had an increased risk of death, even if they were short-sleeping insomniacs. In their discussion, the authors assert, "From a clinical standpoint, this finding suggests that treatment of insomnia in individuals with impaired physical health should be a medical priority." Maybe treating the "impaired physical health" should be the medical priority. It is probably worth noting that no study has shown that treating insomnia, at least with sleeping pills, improves mortality, crash risk, or medical illness. On the other hand, observational data demonstrate an association between chronic use of sleeping pills and death,2 as well as car crash.3
So, what's the clinician to do? The NIH consensus statement notes that cognitive behavioral therapy (CBT) is more effective in the long run than chronic use of hypnotics.4 Whether or not you have CBT available for your patients, remember that one of its primary purposes is to help the patient unlearn inappropriate ideas and behaviors about sleep. Believing that insomnia will kill you is bound to keep you up at night, and is an excellent example of the kind of inappropriate belief that CBT attempts to address and debunk. Articles like the current one, by failing to point out how few people actually fell into the category they headlined, and how much sicker that group was, don't help us deal with this prevalent clinical problem.
References
1. Zhang B, Wing YK Sex differences in insomnia: A meta-analysis. Sleep 2006;29:85-93.
2. Mallon L, et al. Is usage of hypnotics associated with mortality? Sleep Med 2009;10:279-286.
3. Gustavsen I, et al. Road traffic accident risk related to prescriptions of the hypnotics zopiclone, zolpidem, flunitrazepam and nitrazepam. Sleep Med 2008;9:818-822.
4. NIH State of the Science Conference statement on Manifestations and Management of Chronic Insomnia in Adults statement. J Clin Sleep Med 2005;1:412-421.
In women, insomnia was not associated with increased risk of death, regardless of sleep duration. In men, mortality risk was significantly increased only in insomniacs who slept less than 6 hours and who were diabetic or hypertensive at baseline.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content. TESTING
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