Some members of the armed forces are strikingly short on sleep, according to a review of medical records of U.S. military personnel.
The study, which appears online January 31 in Sleep, uses data from active-duty military people who sought out, or were referred to, a clinic because they had a sleep complaint. Even though the study is not a random sample, some scientists believe the low levels of sleep found in the records raise serious questions about the health of the armed forces. Sleep problems in the study sample were often associated with conditions such as chronic pain, anxiety, brain injury and post-traumatic stress disorder.
Scientists know that sleep deprivation can affect mood, concentration, reaction time and cognitive function. But little information is available specifically about sleep loss in the military.
"It's really the first study to take a good epidemiological look at sleep in military personnel," says Alan Peterson, a psychologist at the University of Texas Health Science Center at San Antonio who wasn't involved in the study.
Researchers reviewed the charts of every person who was admitted to Madigan Army Medical Center in Tacoma, Wash., in 2010 for sleep-related complaints and underwent polysomnography, a diagnostic test that measures physiological changes during sleep. The 725 people whose records were analyzed served in the Army, Navy or Air Force and had an average age of 36. The vast majority of the medical charts belonged to people who had been in combat, and many had been deployed to war zones multiple times.
Of the people, 85 percent had sleep problems meriting treatment, with sleep apnea and insomnia the most common. Both can cause daytime sleepiness and fatigue. People who didn't have a sleep disorder mainly snored or had other mild symptoms.
Nearly 42 percent of the people in the study said they got five hours of sleep or less per night on average, and another 26.5 percent reported only six hours, the reviewers found. "That was the most surprising finding," says study coauthor Vincent Mysliwiec, a pulmonary and sleep physician at Madigan.
The risks of sleep deprivation in combat might seem obvious but actually aren't well understood, he says. "When you're getting shot at, you just don't fall asleep," soldiers have told him.
The findings suggest that the military needs to think about sleep as a resource that has value, much like fuel or water, he says. Vehicles need fuel and soldiers need water, and neither is sent into combat without enough, he says. "Sleep should be viewed with the same perspective."
Instead, soldiers are taught to find downtime to catch up on sleep. "All soldiers need to rest and recover," Mysliwiec says. "How much is possible in a wartime environment depends on the unit you're deployed with."
Caffeinated beverages such as coffee or so-called energy drinks may contribute to sleep problems as well, the Centers for Disease Control and Prevention reported in November. A survey of service members deployed to Afghanistan in 2010 found that those who consumed three or more such beverages per day were more likely than those who drank two or fewer to experience sleep disruption or to fall asleep in briefings or on guard duty – but not while riding in convoys.
Researchers have long known about the military's culture of insufficient sleep, say Nita Lewis Shattuck and Stephanie Brown of the Naval Postgraduate School in Monterey, Calif., writing in the same issue of Sleep. "For many individuals in the military, sleep is considered a luxury or even a weakness." The new findings highlight the need for policy changes, they conclude.
http://www.sciencenews.org/view/generic/id/347980/description/Some_service_members_sleep_too_little
