poor sleep

Poor sleep quality linked to lower physical activity

poor sleep

A new study shows that worse sleep quality predicts lower physical activity in people with post-traumatic stress disorder (PTSD).Results show that PTSD was independently associated with worse sleep quality at baseline, and participants with current PTSD at baseline had lower physical activity one year later.

Further analysis found that sleep quality completely mediated the relationship between baseline PTSD status and physical activity at the one-year follow-up, providing preliminary evidence that the association of reduced sleep quality with reduced physical activity could comprise a behavioral link to negative health outcomes such as obesity.

“We found that sleep quality was more strongly associated with physical activity one year later than was having a diagnosis of PTSD,” said lead author Lisa Talbot, postdoctoral fellow at the San Francisco VA Medical Center and the University of California, San Francisco. “The longitudinal aspect of this study suggests that sleep may influence physical activity.”

Study results are published in the July 15 issue of the Journal of Clinical Sleep Medicine, which is published by the American Academy of Sleep Medicine.
“This study adds to the literature that shows that better sleep leads to healthier levels of exercise, and previous research has shown that better sleep leads to healthier food choices,” said American Academy of Sleep Medicine President Dr. Timothy Morgenthaler. “It is clear that healthy sleep is an essential ingredient in the recipe for a healthy life.”

The study involved data from the Mind Your Heart Study, a prospective cohort study of 736 outpatients recruited from two Department of Veterans Affairs (VA) medical centers. PTSD was assessed with the Clinician-Administered PTSD Scale (CAPS). At baseline participants rated their sleep quality overall during the last month, and at baseline and again one year later they reported how physically active they have been during the last month. Of the 736 military veteran participants, 258 had current or subsyndromal PTSD.

According to Talbot, the results suggest that behavioral interventions to increase physical activity should include an assessment for sleep disturbance.
“The findings also tentatively raise the possibility that sleep problems could affect individuals’ willingness or ability to implement physical activity behavioral interventions,” she said. “Sleep improvements might encourage exercise participation.”

The research was performed in collaboration with principal investigator Dr. Beth Cohen of the San Francisco VA Medical Center and the Department of Medicine at the University of California, San Francisco. Research funding was provided by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH), the Irene Perstein Foundation, and the Mental Illness Research and Education Clinical Center of the U.S. Veterans Health Administration.

According to the National Center for PTSD of the U.S. Department of Veterans Affairs, PTSD symptoms such as nightmares or flashbacks usually start soon after a traumatic event, but they may not appear until months or years later. Symptoms that last longer than four weeks, cause great distress or interfere with daily life may be a sign of PTSD.

Source: science daily

TV again tied to poor sleep among kids

In another blow to kids’ pleas to watch more television before bed, a new study suggests increased TV time is linked to less sleep. What’s more, black, Latino and other minority children slept less when they had TV sets in their bedrooms.

“Inadequate sleep in childhood is associated with health outcomes, including attention problems, school performance and an increased risk of obesity,” Elizabeth Cespedes told Reuters Health. Cespedes is the study’s lead author from the Harvard School of Public Health in Boston.

“We wanted to know if television viewing may be associated with shorter sleep duration in children,” she said. For the new report, she and her colleagues used data from an existing study of mothers and children who lived in the Boston area. The study included 1,864 children who were born between 1999 and 2003. Mothers reported how much television their child watched at six months old and then every year until age seven.

Mothers also reported whether children slept with a television in their bedroom every year starting midway through the study.

The average time children slept each day decreased from about 12 hours at six months to about 10 hours at seven years, and total TV viewing increased from about one hour per day to 1.6 hours.

The proportion of children who slept with a TV in their bedroom increased from 17 percent to 23 percent between ages four and seven years, too. Children typically sleep less as they get older, the researchers noted. Still, each extra hour of TV watching added to their lifetime average was tied to a seven-minute decrease in daily sleep.

That association was stronger for boys than girls, according to findings published in Pediatrics. “I think in our case it’s possible that the content of the television watched may be different for boys than girls,” Cespedes said. “The content may be especially disruptive.”

She and her colleagues also found that sleeping with a TV in the bedroom was tied to 31 fewer minutes of sleep per day among racial and ethnic minority children. The effect of a TV in the bedroom was not as strong among white, non-Hispanic children.

Cespedes said it’s hard to know why minority children would be more affected by having a TV in the bedroom. “At all time points, racial and ethnic minority children in our study were sleeping a bit less and watching more television,” she said.

Dr. Heidi Connolly, a sleep specialist who was not involved with the new study, said the research is one of several recent papers that point toward a negative effect of TV on sleep.

“This doesn’t seem like very much, but if you think about it, seven minutes every night by the time you get to the end of the week you’re already a half hour short on sleep,” Connolly, from the University of Rochester Medicine’s Golisano Children’s Hospital in New York, said.

The American Academy of Pediatrics recommends against children younger than two years old watching any television. It also recommends limiting older children’s screen time to no more than one or two hours per day.

“I think it’s unreasonable to expect that kids aren’t going to watch TV,” Connolly told Reuters Health. “It’s pervasive in our culture. But you do want to limit screen time to less than two hours per day.” Connolly also said people sometimes say their children need the TV on to sleep, but that’s not the case.

She said consistent bedtimes, regular bedtime routines and a TV-free comfortable sleeping environment are good sleep behaviors.

Source: orlando sentinel

Poor sleep speeds cancer growth

Poor-quality sleep marked by frequent awakenings can speed cancer growth and increase tumour aggressiveness, a new study has warned.

The study is the first to demonstrate, in an animal model, the direct effects of fragmented sleep on tumour growth and invasiveness.

“Fragmented sleep changes how the immune system deals with cancer in ways that make the disease more aggressive,” said study director David Gozal, chairman of pediatrics at the University of Chicago Comer Children’s Hospital.

“Fortunately, our study also points to a potential drug target,” he said.

“Toll-like receptor 4, a biological messenger, helps control activation of the innate immune system. It appears to be a lynchpin for the cancer-promoting effects of sleep loss. The effects of fragmented sleep that we focused on were not seen in mice that lacked this protein,” Gozal said.

Gozal and colleagues from the University of Chicago and the University of Louisville devised a series of experiments to measure the effects of disrupted sleep on cancer.

They used mice, housed in small groups. During the day – when mice normally sleep – a quiet, motorised brush moved through half of the cages every two minutes, forcing those mice to wake up and then go back to sleep. The rest of the mice were not disturbed.

After seven days in this setting, both groups of mice were injected with cells from one of two tumour types (TC-1 or 3LLC). All mice developed palpable tumours within 9 to 12 days. Four weeks after inoculation the researchers evaluated the tumours.

They found that tumours from mice with fragmented sleep were twice as large, for both tumour types, than those from mice that had slept normally.

A follow-up experiment found that when tumour cells were implanted in the thigh muscle, which should help contain growth, the tumours were much more aggressive and invaded surrounding tissues in mice with disrupted sleep.

The difference appeared to be driven by cells from the immune system, called tumour-associated macrophages (TAMs), which cluster at the site of tumours.

TAMs are a hallmark of the immune system’s response to cancer. Some, labelled M1, promote a strong immune response and can eliminate tumours cells. Others, known as M2, suppress the immune response and instead promote the growth of new blood vessels – which encourages tumour growth.

Well-rested mice had primarily M1-type TAMs, concentrated in the core of the tumours. Sleep-fragmented mice had primarily M2-type TAMs, researchers said.

The study was published in the journal Cancer Research.

Source: Zee news

Poor sleep affects mood, lifestyle in obese

Scientists have linked inadequate sleep to mood disturbances and lower quality of life in extremely obese people, said a study.

“There was a clear association between the sleep problems such as short sleep duration, and the psychological disorders, and with quality of life,” said G. Neil Thomas, lead supervisor, study methodology lead, and reader in epidemiology at the Department of Public Health, Epidemiology and Biostatistics at the University of Birmingham in Britain.

The study results appear in the December issue of the journal Sleep, reports the Science Daily.

“This study emphasizes the need for physicians to conduct routine screenings for sleep problems among people with severe obesity,” said M. Safwan Badr, president of the American Academy of Sleep Medicine.

“Improving sleep quality, and quantity will provide a physical, mental, and emotional boost for people, who are making the difficult lifestyle changes involved in managing obesity.”

Source: Times of India