Showing posts with label sleep duration. Show all posts
Showing posts with label sleep duration. Show all posts

Wednesday, December 3, 2014

Exposure to different forms of violence affects kids’ sleep differently

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Exposure to different forms of violence affects kids’ sleep differently

By guest blogger Jordan Gaines Lewis

If you need an accurate assessment of your emotional health, look no further than the quality of your sleep. Have an important test coming up? Giving a big talk to your company tomorrow morning? Chances are you’re not sleeping as well as you typically would.

While most kids have fewer of these worries than adults, some unfortunately have to deal with a different type of stressor—violence. Previous work has shown that kids exposed to violence report significant sleep disturbances compared to non-abused children. It’s thought that witnessing or experiencing a violent event causes increased vigilance due to the perception that one’s safety is at stake, resulting in disturbed sleep. Most of these studies, however, employed subjective (self-reported) sleep quality measures, which can be unreliable.

A study by Jim Spilbury and colleagues published last month in Sleep Medicineset out to clarify the association between violence and sleep quality in children by adopting both longitudinal and objective measures. The authors hypothesised that different forms of violence, such as being physically assaulted versus witnessing a homicide, would affect certain sleep characteristics differently.

The researchers recruited 46 children between the ages of 8 and 16 years from a community-based violence intervention program. Measures were taken at two time points: baseline (within 7 weeks of the violent incident) and after a 3-month follow-up.

At each time point, participants wore an actigraph for one week—a wristwatch-like device that uses movement to determine when individuals are asleep. Five measures of sleep disturbance were extracted from the actigraph: bedtime, sleep duration, sleep efficiency (percentage of time actually asleep while in bed), the amount of time awake at night after initial sleep onset, and sleep duration variability over the week.

Participants also completed two surveys: the Recent Exposure to Violence Scale (which assessed a range of violent events in the kids’ neighbourhood, school, and home over the past year), and a self-reported measure of lingering trauma after a stressful event.  A parent of each participant also reported on their child’s sleep quality.

The type of violence experienced by participants varied. Family violence was witnessed by 57 per cent of the children, community violence by 43 per cent, and 41 per cent had suffered physical assault themselves.

Two particular types of violence stood out to researchers in terms of their association with sleep disturbance. Controlling for relevant confounders (such as age, gender and family income), individuals who were physically assaulted had a shortened sleep duration (by 35 minutes on average), exhibited almost three times as much wake time after sleep onset, and 6 per cent lower sleep efficiency than kids who did not experience physical assault. These effects were also seen three months later at follow-up.

On the other hand, children who witnessed a homicide had twice as much wake time after sleep onset, greater night-to-night variability in sleep duration, and more self-reported sleep problems than kids who had not witnessed a homicide. These findings, however, did not persist at follow-up.

It’s not clear why different violent experiences are associated with different objectively- and subjectively-measured sleep outcomes. The researchers suggest that, perhaps, persistence of the sleep disturbance in those who were physically assaulted, as opposed to those who witnessed a homicide, reflects how the former may be perceived as more damaging to one’s personal sense of safety, resulting in greater vigilance and nighttime arousal.

Although this was only a pilot study, its implications for public health and awareness are extremely important. Significant research over the past decade suggests that disturbed sleep in children and adolescents is associated with elevated inflammation, increased prevalence of obesity, and behavioural problems, although the causal relationship between these variables and poor sleep quality is difficult to determine. Interestingly, the researchers found no relationship between parent-reported sleep quality and the participants’ actigraphy measures, suggesting that many parents may not be aware of their children’s sleep difficulties.

While addressing a child’s emotional needs after exposure to violence is clearly important, this study suggests that assessing physical health, such as objectively measuring sleep, is also necessary to assess one’s well-being. After all, disturbed sleep may tell a whole different story of which a parent—or a child, for that matter—may not even be aware.

_________________________________ ResearchBlogging.org

Spilsbury, J., Babineau, D., Frame, J., Juhas, K., & Rork, K. (2014). Association between children's exposure to a violent event and objectively and subjectively measured sleep characteristics: a pilot longitudinal study Journal of Sleep Research, 23 (5), 585-594 DOI:10.1111/jsr.12162

Post written by Jordan Gaines Lewis, a PhD student at Penn State College of Medicine studying sleep and obesity in adolescents. She blogs about neuroscience at Gaines, on Brains. Follow on Twitter @GainesOnBrains.

Monday, May 5, 2014

Extreme sleep durations may affect brain health in later life

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PUBLIC RELEASE DATE:
1-May-2014
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Contact: Elaine St. Peter
estpeter@partners.org
617-525-6375
Brigham and Women's Hospital 

Extreme sleep durations may affect brain health in later life

Sleep habits associated with memory in old-age

BOSTON, MA – A new research study led by Brigham and Women's Hospital (BWH) published in The Journal of the American Geriatrics Society in May, shows an association between midlife and later life sleeping habits with memory; and links extreme sleep durations to worse memory in later life. The study suggests that extreme changes in sleep duration from middle age to older age may also worsen memory function.
"Sleep Duration In Midlife and Later Life In Relation to Cognition: The Nurses' Health Study," led by Elizabeth Devore, ScD, instructor in medicine in the Channing Division of Network Medicine at BWH found that women who slept five or fewer hours, or nine or more hours per day, either in midlife or later life, had worse memory, equivalent to nearly two additional years of age, than those sleeping seven hours per day. Women whose sleep duration changed by greater than two hours per day over time had worse memory than women with no change in sleep duration.
This study was the first to evaluate associations of sleep duration at midlife and later life, and change in sleep duration over time, with memory in 15,263 participants of the Nurses' Health Study. Participants were female nurses, aged 70 or older and were free of stroke and depression at the initial cognitive assessment.
"Given the importance of preserving memory into later life, it is critical to identify modifiable factors, such as sleeping habits, that may help achieve this goal," Devore stated. "Our findings suggest that getting an 'average' amount of sleep, seven hours per day, may help maintain memory in later life and that clinical interventions based on sleep therapy should be examined for the prevention of cognitive impairment."
Specifically, researchers report that:

  • Extreme sleep durations may adversely affect memory at older ages, regardless of whether they occur at mid-life or later-life.
  • Greater changes in sleep duration appear to negatively influence memory in older adults.
  • Women with sleep durations that changed by two or more hours per day from midlife to later life performed worse on memory tests than women with no change in sleep duration, equivalent to being one to two years older in age, compared to those whose sleep duration did not change during that time period.
"These findings add to our knowledge about how sleep impacts memory," said Devore. "More research is needed to confirm these findings and explore possible mechanisms underlying these associations."
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The research study was conducted within the Nurses' Health Study, with funding for this cohort from the National Institutes of Health (P01 CA87969).
Brigham and Women's Hospital (BWH) is a 793-bed nonprofit teaching affiliate of Harvard Medical School and a founding member of Partners HealthCare. BWH has more than 3.5 million annual patient visits, is the largest birthing center in Massachusetts and employs nearly 15,000 people. The Brigham's medical preeminence dates back to 1832, and today that rich history in clinical care is coupled with its national leadership in patient care, quality improvement and patient safety initiatives, and its dedication to research, innovation, community engagement and educating and training the next generation of health care professionals. Through investigation and discovery conducted at its Biomedical Research Institute (BRI), BWH is an international leader in basic, clinical and translational research on human diseases, more than 1,000 physician-investigators and renowned biomedical scientists and faculty supported by nearly $650 million in funding. For the last 25 years, BWH ranked second in research funding from the National Institutes of Health (NIH) among independent hospitals. BWH continually pushes the boundaries of medicine, including building on its legacy in transplantation by performing a partial face transplant in 2009 and the nation's first full face transplant in 2011. BWH is also home to major landmark epidemiologic population studies, including the Nurses' and Physicians' Health Studies and the Women's Health Initiative. For more information, resources and to follow us on social media, please visit BWH's online newsroom.


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