10/08/2005 09:12 PMLosing a Little Sleep Affects More Than Attention SpanPage 1 of 3http://www.washingtonpost.com/wp-dyn/content/article/2005/10/08/AR2005100801405_pf.htmlwashingtonpost.comLosing a Little Sleep Affects MoreThan Attention SpanBy Rob SteinWashington Post Staff WriterSunday, October 9, 2005; A01With a good night's rest increasingly losing out to the Internet,e-mail, late-night cable and other distractions of modern life,a growing body of scientific evidence suggests that too littleor erratic sleep may be taking an unappreciated toll onAmericans' health.Beyond leaving people bleary-eyed, clutching a Starbucks cupand dozing off at afternoon meetings, failing to get enough sleep or sleeping at odd hours heightens the risk fora variety of major illnesses, including cancer, heart disease, diabetes and obesity, recent studies indicate."We're shifting to a 24-hour-a-day, seven-day-a-week society, and as a result we're increasingly not sleepinglike we used to," said Najib T. Ayas of the University of British Columbia. "We're really only now starting tounderstand how that is affecting health, and it appears to be significant."A large, new study, for example, provides the latest in a flurry of evidence suggesting that the nation's obesityepidemic is being driven, at least in part, by a corresponding decrease in the average number of hours thatAmericans are sleeping, possibly by disrupting hormones that regulate appetite. The analysis of a nationallyrepresentative sample of nearly 10,000 adults found that those between the ages of 32 and 49 who sleep lessthan seven hours a night are significantly more likely to be obese.The study follows a series of others that have found similar associations with other illnesses, including severalreports from the Harvard-run Nurses' Health Study that has linked insufficient or irregular sleep to increasedrisk for colon cancer, breast cancer, heart disease and diabetes. Other research groups scattered around thecountry have subsequently found clues that might explain the associations, indications that sleep disruptionaffects crucial hormones and proteins that play roles in these diseases."There has been an avalanche of studies in this area. It's moving very rapidly," said Emmanuel Mignot ofStanford University, who wrote an editorial accompanying the new obesity study in the October issue of thejournal Sleep. "People are starting to believe that there is an important relationship between short sleep and allsorts of health problems."Not everyone agrees, with some experts arguing that any link between sleep patterns and health problemsappears weak at best and could easily be explained by other factors."There are Chicken Little people running around saying that the sky is falling because people are not sleepingenough," said Daniel F. Kripke of the University of California at San Diego. "But everyone knows that peopleare getting healthier. Life expectancy has been increasing, and people are healthier today than they weregenerations ago."Other researchers acknowledge that much more research is needed to prove that the apparent associations arereal, and to fully understand how sleep disturbances may affect health. But they argue that the case is rapidlygetting stronger that sleep is an important factor in many of the biggest killers.10/08/2005 09:12 PMLosing a Little Sleep Affects More Than Attention SpanPage 2 of 3http://www.washingtonpost.com/wp-dyn/content/article/2005/10/08/AR2005100801405_pf.html"We have in our society this idea that you can just get by without sleep or manipulate when you sleep withoutany consequences," said Lawrence Epstein, president of the American Academy of Sleep Medicine. "Whatwe're finding is that's just not true."While many aspects of sleep remain a mystery -- including exactly why we sleep -- the picture that appears tobe emerging is that not sleeping enough or being awake in the wee hours runs counter to the body's internalclock, throwing a host of basic bodily functions out of sync."Lack of sleep disrupts every physiologic function in the body," said Eve Van Cauter of the University ofChicago. "We have nothing in our biology that allows us to adapt to this behavior."The amount of necessary sleep varies from person to person, with some breezing through their days on just afew hours' slumber and others barely functioning without a full 10 hours, experts say. But most peopleapparently need between about seven and nine hours, with studies indicating that an increased risk for diseasestarts to kick in when people get less than six or seven, experts say.Scientists have long known that sleep disorders, such as sleep apnea, narcolepsy and chronic insomnia, can leadto serious health problems, and that difficulty sleeping may be a red flag for a serious illness. But the first cluesthat otherwise healthy people who do not get enough sleep or who shift their sleep schedules because of work,family or lifestyle may be endangering their health emerged from large epidemiological studies that foundpeople who slept the least appeared to be significantly more likely to die."The strongest evidence out there right now is for the risk of overall mortality, but we also see the associationfor a number of specific causes," said Sanjay R. Patel of Harvard Medical School, who led one of the studies,involving more than 82,000 nurses, that found an increased risk of death among those who slept less than sixhours a night. "Now we're starting to get insights into what's happening in the body when you don't get enoughsleep."Physiologic studies suggest that a sleep deficit may put the body into a state of high alert, increasing theproduction of stress hormones and driving up blood pressure, a major risk factor for heart attacks and strokes.Moreover, people who are sleep-deprived have elevated levels of substances in the blood that indicate aheightened state of inflammation in the body, which has also recently emerged as a major risk factor for heartdisease, stroke, cancer and diabetes."Based on our findings, we believe that if you lose sleep that your body needs, then you produce theseinflammatory markers that on a chronic basis can create low-grade inflammation and predispose you tocardiovascular events and a shorter life span," said Alexandros N. Vgontzas of Pennsylvania State University,who recently presented data at a scientific meeting indicating that naps can help counter harmful effects ofsleep loss.Other studies have found that sleep