Kids Who Sleep Poorly at Risk for Being Overweight (HealthDay)

MONDAY, Aug. 4 (HealthDay News) -- Getting too little sleep ornot spending enough time in rapid eye movement (REM) sleep is associatedwith being overweight among children and teens, a new U.S. study.

For three consecutive nights, researchers assessed the sleep patternsof 335 youngsters, aged 7 to 17. They looked at total sleep time, timespent in REM, and time it took to fall asleep. Body-mass index was checkedat the start of the study, and 45 participants (13.4 percent) wereoverweight, while 49 (14.6 percent) were at risk for becomingoverweight.

Compared to normal-weight children, those who were overweight sleptabout 22 minutes less per night and had lower sleep efficiency (percentageof time in bed that a person is asleep), shorter REM sleep, less eyeactivity during REM sleep, and a longer wait before the first REMperiod.

After they adjusted for other factors, the researchers concluded thatone hour less of total sleep was associated with a twofold increased riskof being overweight. One hour less of REM sleep was associated with athreefold increased risk.

Although the precise mechanisms are currently under investigation, theassociation between short sleep duration and overweight may be attributedto the interaction of behavioral and biological changes as a result ofsleep deprivation, wrote Dr. Xianchen Liu, of the Western PsychiatricInstitute and Clinic in Pittsburgh, and colleagues.

They explained that sleep loss causes changes in hormone levels thatmay affect hunger, and less sleep also means a person has more wakinghours in which to eat. Sleep loss also contributes to fatigue thefollowing day, which may lead to less physical activity and fewer caloriesburned.

Given the fact that the prevalence of overweight among children andadolescents continues to increase and chronic sleep insufficiency becomesmore prevalent in modern society, family- and school-based sleepinterventions that aim to enhance sleep hygiene and increase sleepduration may have important public health implications for the preventionand intervention of obesity and type 2 diabetes in children, the authorsconcluded.

"Furthermore, our results demonstrate an important relationship betweenREM sleep and high BMI and obesity, suggesting that the shortsleep-obesity association may be attributed to reduced REM sleep time anddecreased activity during REM sleep," they wrote.

The study was published in the August issue of the Archives ofGeneral Psychiatry.

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