HealthDay News — Higher levels of neighborhood sound are associated with adolescent sleep loss, and restricted sleep in adolescents decreases alpha and sigma power on sleep electroencephalogram (EEG), according to two studies published online Jan. 28 in SLEEP.
Stephanie L. Mayne, Ph.D., from the University of Pennsylvania in Philadelphia, and colleagues used actigraphy to assess sleep outcomes among 110 adolescents and examine the influence of built environment. The researchers found that each standard deviation increase in neighborhood sound was associated with sleep onset of 16 minutes later (ß = 0.28) and reduced odds of sleeping for at least eight hours (odds ratio, 0.75). Associations were seen for a one-standard deviation increase in neighborhood tree canopy with sleep onset of 18 minutes earlier (ß = −0.31) and sleep offset of 10 minutes earlier (ß = −0.17).
Ian G. Campbell, Ph.D., from the University of California, Davis, and colleagues studied 77 participants aged 9.9 to 16.2 years over three years to examine the effects of age and time in bed (TIB) on total sleep time (TST) and nonrapid eye movement (NREM) and rapid eye movement (REM) EEG. Participants adhered to four consecutive nights of seven, 8.5, and 10 hours of TIB. The researchers found that TST was modified by altering TIB. Although the effects were small, shorter sleep durations produced higher delta power in both NREM and REM. Alpha power was reduced more substantially in both NREM and REM sleep by restricted sleep. Sleep restriction strongly reduced the all-night accumulation of sigma EEG activity and the rate of sigma production in NREM sleep.
“These two studies provide a snapshot of the research we fund to understand the harms of sleep deficiency and its causes,” Marishka Brown, director of the National Center on Sleep Disorders Research, said in a statement.