Our biological clock plays crucial role in healing from surgery
Effectiveness of anti-inflammatories following surgery depends on when you take them
January 22, 2020
Science Daily/McGill University
If you have just had knee, shoulder or hip surgery, you may want to take anti-inflammatories in the morning or at noon, but not at night. A McGill-led study shows, for the first time, that circadian clock genes are involved in healing from surgery. Indeed, the researchers demonstrated that anti-inflammatory medications are most effective in promoting post-operative healing and recovery when taken during the active periods of our biological clocks.
The study, recently published in Scientific Reports, also suggests that if anti-inflammatories are taken either in the afternoon or at night, during the resting phases of the circadian rhythm, they can severely deter healing and bone repair following surgery. That's because these are the periods when cells known as osteoblasts are rebuilding bone.
Circadian clock genes involved in healing from surgery
Although prior research has shown that circadian clock genes play a role in diseases such as cancer, Alzheimer's, arthritis and Parkinson's, this is the first study to see the effect of the circadian rhythm in any type of surgery or injury. Faleh Tamimi Marino, the Canada Research Chair for Translational Cranofacial Research is the senior co-author on the article, along with Belinda Nicolau and Laura Stone. All are McGill's Faculty of Dentistry.
Inflammation, following surgery, is crucial to healing since part of the process involves both destroying any bacteria that may be in the area, and signaling to attract the cells that will rebuild the tissues. But the process is not a constant.
"There are periods of inflammation that are actually very destructive, and there are periods that are constructive and important for healing," said Faleh Tamimi. "So many pharmaceutical companies have been trying to develop drugs that will inhibit the destructive processes during inflammation but not interfere with the helpful ones."
He adds, "The idea that I came up with in the shower one morning is that we could perhaps use the circadian variations in inflammation to our advantage. The destructive component of the circadian rhythm as it relates to bone healing occurs during the day, when cells known as osteoclasts break down bones. The constructive cells, known as osteoblasts that rebuild bones are active at night. By limiting the use of anti-inflammatories to the mornings and giving analgesics at night for the pain, I thought we might get better results in terms of bone healing than if anti-inflammatories are given throughout the day."
Significant differences in rates of healing and in genes
The researchers compared pain and bone healing in two different groups of mice with fractured tibia. One group was given constant doses of anti-inflammatories over a twenty-four hour period, while the others were given anti-inflammatories only in the morning -- during the active phases of the circadian rhythm -- and analgesics at night. The researchers found that the second group recovered from the pain of the injury, and regained bone strength more quickly and more fully. Surprisingly, they also noticed differences between the groups in the expression of over 500 genes specifically related to bone healing processes. "Its almost as if morning anti-inflammatories and evening anti inflammatories were two different drugs" adds Faleh Tamimi.
The rhythm of the body's own healing
"When I was a child, and I cut myself, my mother would say to me, don't worry, go to sleep and tomorrow you will be better," said Haider El-Waeli, the first author on the study, who wrote the paper while working on his PhD at McGill and is now a clinical resident at Dalhousie University. "It turns out she was right because most of the healing happens at night."
"The body has a rhythm," adds Tamimi. "And if you give anti-inflammatories in the morning you are working with the rhythm of the body and when you give them at night, you are working against it so you disrupt the healing."
As a next step, the researchers are collecting preliminary data from a clinical trial monitoring pain and healing related to extraction of wisdom teeth, using two different drug treatments -- one involving exclusive use of anti-inflammatories, and the other administering anti-inflammatory medications only in the morning and at noon, and analgesics in the afternoon and evening. The preliminary results are promising.
https://www.sciencedaily.com/releases/2020/01/200122100554.htm
Helping SAD Sufferers Sleep Soundly
June 27, 2013 —
Science Daily/University of Pittsburgh
Lying awake in bed plagues everyone occasionally, but for those with seasonal affective disorder, sleeplessness is routine. University of Pittsburgh researchers report in the Journal of Affective Disorders that individuals with seasonal affective disorder (SAD) -- a winter depression that leads to loss of motivation and interest in daily activities -- have misconceptions about their sleep habits similar to those of insomniacs. These findings open the door for treating seasonal affective disorder similar to the way doctors treat insomnia.
http://www.sciencedaily.com/releases/2013/06/130627142547.htm
Early Brain Stimulation May Help Stroke Survivors Recover Language Function
June 27, 2013 —
Science Daily/American Heart Association
Non-invasive brain stimulation may help stroke survivors recover speech and language function, according to new research in the American Heart Association journal Stroke.
"For decades, skilled speech and language therapy has been the only therapeutic option for stroke survivors with aphasia," said Alexander Thiel, M.D., study lead author and associate professor of neurology and neurosurgery at McGill University in Montreal, Quebec, Canada. "We are entering exciting times where we might be able in the near future to combine speech and language therapy with non-invasive brain stimulation earlier in the recovery. This could result in earlier and more efficient aphasia recovery and also have an economic impact."
In the small study, researchers treated 24 stroke survivors with several types of aphasia at the rehabilitation hospital Rehanova and the Max-Planck-Institute for neurological research in Cologne, Germany. Thirteen received transcranial magnetic stimulation (TMS) and 11 got sham stimulation. The TMS groups' improvements were on average three times greater than the non-TMS group, researchers said. They used German language aphasia tests, which are similar to those in the United States, to measure language performance of the patients.
"TMS had the biggest impact on improvement in anomia, the inability to name objects, which is one of the most debilitating aphasia symptoms," Thiel said.
http://www.sciencedaily.com/releases/2013/06/130627161434.htm
A Good Night's Sleep Increases the Cardiovascular Benefits of a Healthy Lifestyle
July 3, 2013
Science Daily/European Society of Cardiology (ESC)
A good night's sleep can increase the benefit of exercise, healthy diet, moderate alcohol consumption and non-smoking in their protection against cardiovascular disease (CVD), according to results of a large population follow-up study.(1) Results showed that the combination of the four traditional healthy lifestyle habits was associated with a 57% lower risk of cardiovascular disease (fatal and non-fatal) and a 67% lower risk of fatal events.(2) But, when "sufficient sleep" (defined as seven or more hours a night) was added to the other four lifestyle factors, the overall protective benefit was even further increased -- and resulted in a 65% lower risk of composite CVD and a 83% lower risk of fatal events.
As an explanation for the results, the investigators note that short sleep duration has been associated with a higher incidence of overweight, obesity and hypertension and with higher levels of blood pressure, total cholesterol, haemoglobin A, and triglycerides, effects which are "consistent with the hypothesis that short sleep duration is directly associated with CVD risk."
http://www.sciencedaily.com/releases/2013/07/130702202825.htm
Bad Night's Sleep? The Moon Could Be to Blame
July 25, 2013 —
Science Daily/Cell Press
https://www.sciencedaily.com/images/2013/07/130725125303_1_540x360.jpg
Many people complain about poor sleep around the full moon, and now a report appearing in Current Biology, a Cell Press publication, on July 25 offers some of the first convincing scientific evidence to suggest that this really is true. The findings add to evidence that humans -- despite the comforts of our civilized world -- still respond to the geophysical rhythms of the moon, driven by a circalunar clock.
Credit: Current Biology, Cajochen et al.
Many people complain about poor sleep around the full moon, and now a report appearing in Current Biology, a Cell Press publication, on July 25 offers some of the first convincing scientific evidence to suggest that this really is true. The findings add to evidence that humans -- despite the comforts of our civilized world -- still respond to the geophysical rhythms of the moon, driven by a circalunar clock.
The data show that around the full moon, brain activity related to deep sleep dropped by 30 percent. People also took five minutes longer to fall asleep, and they slept for twenty minutes less time overall. Study participants felt as though their sleep was poorer when the moon was full, and they showed diminished levels of melatonin, a hormone known to regulate sleep and wake cycles.
"This is the first reliable evidence that a lunar rhythm can modulate sleep structure in humans when measured under the highly controlled conditions of a circadian laboratory study protocol without time cues," the researchers say.
"In nearly every measure we had, hamsters exposed to blue light were the worst off, followed by those exposed to white light," he said. "While total darkness was best, red light was not nearly as bad as the other wavelengths we studied."
http://www.sciencedaily.com/releases/2013/07/130725125303.htm
What color is your night light? It may affect your mood
August 6, 2013
Science Daily/Ohio State University
When it comes to some of the health hazards of light at night, a new study in hamsters suggests that the color of the light can make a big difference.
In a study involving hamsters, researchers found that blue light had the worst effects on mood-related measures, followed closely by white light.
But hamsters exposed to red light at night had significantly less evidence of depressive-like symptoms and changes in the brain linked to depression, compared to those that experienced blue or white light. The only hamsters that fared better than those exposed to red light were those that had total darkness at night.
The findings may have important implications for humans, particularly those whose work on night shifts makes them susceptible to mood disorders, said Randy Nelson, co-author of the study and professor of neuroscience and psychology at The Ohio State University.
"Our findings suggest that if we could use red light when appropriate for night-shift workers, it may not have some of the negative effects on their health that white light does," Nelson said.
http://www.sciencedaily.com/releases/2013/08/130806203150.htm
Light drinking linked to lower risk of depression
August 29, 2013
Science Daily/BioMed Central Limited
Drinking wine in moderation may be associated with a lower risk of developing depression, according to new research. The reported findings suggest that the moderate amounts of alcohol consumed may have similar protective effects on depression to those that have been observed for coronary heart disease. The lowest rates of depression were seen in the group of individuals who drank two to seven small glasses of wine per week.
The main alcoholic beverage drunk by the study participants was wine. When analysed, it was shown that those who drank moderate amounts of wine each week were less likely to suffer from depression. The lowest rates of depression were seen in the group of individuals who drank two to seven small glasses of wine per week. These results remained significant even when the group adjusted them for lifestyle and social factors, such as smoking, diet and marital status.
http://www.sciencedaily.com/releases/2013/08/130829214354.htm
Even mild stress can make it difficult to control your emotions
August 26, 2013
Science Daily/New York University
Even mild stress can thwart therapeutic measures to control emotions, a team of neuroscientists has found. Their findings point to the limits of clinical techniques while also shedding new light on the barriers that must be overcome in addressing afflictions such as fear or anxiety.
"The use of cognitive techniques to control fear has previously been shown to rely on regions of the prefrontal cortex that are known to be functionally impaired by mild stress," Phelps observed. "These findings are consistent with the suggestion that the effect of mild stress on the prefrontal cortex may result in a diminished ability to use previously learned techniques to control fear."
"Our results suggest that even mild stress, such as that encountered in daily life, may impair the ability to use cognitive techniques known to control fear and anxiety," added Candace Raio, a doctoral student in NYU's Department of Psychology and the study's lead author. "However, with practice or after longer intervals of cognitive training, these strategies may become more habitual and less sensitive to the effects of stress."
http://www.sciencedaily.com/releases/2013/08/130826180520.htm
Winter depression not as common as many think
August 27, 2013
Science Daily/Oregon State University
New research suggests that getting depressed when it's cold and dreary outside may not be as common as is often believed.
"We found a very small effect during the winter months, but it was much more modest than would be expected if seasonal depression were as common as many people think it is," said Columbia University researcher Jeff Shaman, a study co-author and a former OSU faculty member. "We were surprised. With a sample of nearly 800 people and very precise measures of the weather, we expected to see a larger effect."
Kerr believes the public may have overestimated the power of the winter blues for a few reasons. These may include awareness of SAD, the high prevalence of depression in general, and a legitimate dislike of winter weather.
"We may not have as much fun, we can feel cooped up and we may be less active in the winter," Kerr said. "But that's not the same as long-lasting sadness, hopelessness, and problems with appetite and sleep -- real signs of a clinical depression."
http://www.sciencedaily.com/releases/2013/08/130827135034.htm
Sleeping in on weekends doesn’t fix all deficits caused by workweek sleep loss
October 9, 2013
Science Daily/American Physiological Society (APS)
A new study assesses the effects of extended “weekend” recovery sleep following “one workweek” of mild sleep restriction on sleepiness/alertness, inflammation and stress hormones.
Not surprisingly, the researchers found that after 5 days of restricted sleep, the subjects were significantly sleepier on both objective and subjective tests compared to baseline levels. Their interleukin-6 levels increased sharply during restricted sleep, though their cortisol levels remained the same. Their performance on the attention test deteriorated. After 2 days of recovery sleep, both objective and subjective tests showed that the volunteers were less sleepy. Their interleukin-6 levels reduced, and their cortisol levels decreased significantly compared to baseline, possibly suggesting that the volunteers were sleep deprived before the study started. Notably, their performance on the attention test didn't improve after recovery sleep.
Though many indicators of health and well being improved after recovery sleep, these findings suggest that extra sleep may not fix all the deficits caused by lost sleep during the workweek.
"Two nights of extended recovery sleep may not be sufficient to overcome behavioral alertness deficits resulting from mild sleep restriction," the authors write. "This may have important implications for people with safety-critical professions, such as health-care workers, as well as transportation system employees (drivers, pilots, etc.)."
http://www.sciencedaily.com/releases/2013/10/131009125740.htm
Depression twice as likely in migraine sufferers
October 17, 2013
Science Daily/University of Toronto
The prevalence of depression among those with migraine is approximately twice as high as for those without the disease (men: 8.4% vs. 3.4%; women 12.4% vs. 5.7%), according to a new study
The study also investigated the relationship between migraine and suicidal ideation. For both men and women, those with migraines were much more likely to have "ever seriously considered suicide or taking (their) own life" than were those without migraines (men: 15.6% versus 7.9%; women: 17.6% versus 9.1%). Migraineurs under age 30 had four times the odds of lifetime suicidal ideation in comparison to migraineurs aged 65 and over. Other factors associated with suicidal ideation among those with migraines included unmarried status, lower household income and greater activity limitations.
Co-author and former graduate student Meghan Schrumm commented "We are not sure why younger migraineurs have such a high likelihood of depression and suicidal ideation. It may be that younger people with migraines have not yet managed to find adequate treatment or develop coping mechanisms to minimize pain and the impact of this chronic illness on the rest of their lives. The much lower prevalence of depression and suicidal ideation among older migraineurs suggests a promising area for future research."
http://www.sciencedaily.com/releases/2013/10/131017114231.htm
Shorter sleep duration, poorer sleep quality linked to Alzheimer’s disease
October 21, 2013
Science Daily/Johns Hopkins Bloomberg School of Public Health
New study finds that shorter sleep duration and poorer sleep quality are associated with a greater Amyloid burden, a biomarker for Alzheimer's disease
"Our study found that among older adults, reports of shorter sleep duration and poorer sleep quality were associated with higher levels of β-Amyloid measured by PET scans of the brain," said Adam Spira, PhD, lead author of the study and an assistant professor with the Bloomberg School's Department of Mental Health. "These results could have significant public health implications as Alzheimer's disease is the most common cause of dementia, and approximately half of older adults have insomnia symptoms."
http://www.sciencedaily.com/releases/2013/10/131021162546.htm
Study with totally blind people shows how light helps activate the brain
October 28, 2013
Science Daily/Université de Montréal
Light enhances brain activity during a cognitive task even in some people who are totally blind, according to a new study. The findings contribute to scientists’ understanding of everyone’s brains, as they also revealed how quickly light impacts on cognition. “We were stunned to discoverthat the brain still respond significantly to light in these rare three completely blind patientsdespite having absolutely no conscious vision at all,” said one of the authors
"Light doesn't just allow us to see, it tells the brain whether it's night or day which in-turn ensures that our physiology, metabolism and behavior are synchronized with environmental time." "For diurnal species like ours, light stimulates day-like brain activity, improving alertness and mood, and enhancing performance on many cognitive tasks," explained senior co-author Julie Carrier. The results indicate that their brains can still "see," or detect, light via a novel photoreceptor in the ganglion cell layer of the retina, different from the rods and cones we use to see.
Scientists believe, however, that these specialized photoreceptors in the retina also contribute to visual function in the brain even when cells in the retina responsible for normal image formation have lost their ability to receive or process light. A previous study in a single blind patient suggested that this was possible but the research team wanted to confirm this result in different patients. To test this hypothesis, the three participants were asked to say whether a blue light was on or off, even though they could not see the light. "We found that the participants did indeed have a non-conscious awareness of the light -- they were able to determine correctly when the light was on greater than chance without being able to see it," explained first author Gilles Vandewalle.
The next steps involved looking closely at what happened to brain activation when light was flashed at their eyes at the same time as their attentiveness to a sound was monitored. "The objective of this second test was to determine whether the light affected the brain patterns associated with attentiveness -- and it did," said first author Olivier Collignon.
Finally, the participants underwent a functional MRI brain scan as they performed a simple sound matching task while lights were flashed in their eyes. "The fMRI further showed that during an auditory working memory task, less than a minute of blue light activated brain regions important to perform the task. These regions are involved in alertness and cognition regulation as well being as key areas of the default mode network," Vandewalle explained. Researchers believe that the default network is linked to keeping a minimal amount of resources available for monitoring the environment when we are not actively doing something. "If our understanding of the default network is correct, our results raise the intriguing possibility that light is key to maintaining sustained attention" agreed Lockley and Carrier. "This theory may explain why the brain's performance is improved when light is present during tasks."
http://www.sciencedaily.com/releases/2013/10/131028090408.htm
Drowsy Driving an Increasing Hazard
Oct. 28, 2013 —
Science Daily/Rutgers Biomedical and Health Sciences
Many of us make light of that relatively short drive home. But getting behind the wheel when you're sleepy can cost lives and lead to imprisonment and a hefty fine.
Ming suggests a few tips to help enhance driving alertness for limited periods: a 20-minute nap, two cups of coffee or similar caffeinated beverage, brightening the dashboard or purchasing a visor light box that simulates morning light for the passenger side, since light boosts alertness.
http://www.sciencedaily.com/releases/2013/10/131028162054.htm
Brain Connectivity Study Reveals Striking Differences Between Men and Women
Dec. 2, 2013 —
Science Daily/Perelman School of Medicine at the University of Pennsylvania
https://www.sciencedaily.com/images/2013/12/131202161935_1_540x360.jpg
Brain networks show increased connectivity from front to back and within one hemisphere in males (upper) and left to right in females (lower).
Credit: Ragini Verma, Ph.D., Proceedings of National Academy of Sciences
A new brain connectivity study from Penn Medicine published today in the Proceedings of National Academy of Sciences found striking differences in the neural wiring of men and women that's lending credence to some commonly-held beliefs about their behavior.
n one of the largest studies looking at the "connectomes" of the sexes, Ragini Verma, PhD, an associate professor in the department of Radiology at the Perelman School of Medicine at the University of Pennsylvania, and colleagues found greater neural connectivity from front to back and within one hemisphere in males, suggesting their brains are structured to facilitate connectivity between perception and coordinated action. In contrast, in females, the wiring goes between the left and right hemispheres, suggesting that they facilitate communication between the analytical and intuition.
"These maps show us a stark difference--and complementarity--in the architecture of the human brain that helps provide a potential neural basis as to why men excel at certain tasks, and women at others," said Verma.
For instance, on average, men are more likely better at learning and performing a single task at hand, like cycling or navigating directions, whereas women have superior memory and social cognition skills, making them more equipped for multitasking and creating solutions that work for a group. They have a mentalistic approach, so to speak.
Past studies have shown sex differences in the brain, but the neural wiring connecting regions across the whole brain that have been tied to such cognitive skills has never been fully shown in a large population.
In the study, Verma and colleagues, including co-authors Ruben C. Gur, PhD, a professor of psychology in the department of Psychiatry, and Raquel E. Gur, MD, PhD, professor of Psychiatry, Neurology and Radiology, investigated the gender-specific differences in brain connectivity during the course of development in 949 individuals (521 females and 428 males) aged 8 to 22 years using diffusion tensor imaging (DTI). DTI is water-based imaging technique that can trace and highlight the fiber pathways connecting the different regions of the brain, laying the foundation for a structural connectome or network of the whole brain.
This sample of youths was studied as part of the Philadelphia Neurodevelopmental Cohort, a National Institute of Mental Health-funded collaboration between the University of Pennsylvania Brain Behavior Laboratory and the Center for Applied Genomics at the Children's Hospital of Philadelphia.
The brain is a roadmap of neural pathways linking many networks that help us process information and react accordingly, with behavior controlled by several of these sub-networks working in conjunction.
In the study, the researchers found that females displayed greater connectivity in the supratentorial region, which contains the cerebrum, the largest part of the brain, between the left and right hemispheres. Males, on the other hand, displayed greater connectivity within each hemisphere.
By contrast, the opposite prevailed in the cerebellum, the part of the brain that plays a major role in motor control, where males displayed greater inter-hemispheric connectivity and females displayed greater intra-hemispheric connectivity.
These connections likely give men an efficient system for coordinated action, where the cerebellum and cortex participate in bridging between perceptual experiences in the back of the brain, and action, in the front of the brain, according to the authors. The female connections likely facilitate integration of the analytic and sequential processing modes of the left hemisphere with the spatial, intuitive information processing modes of the right side.
The authors observed only a few gender differences in the connectivity in children younger than 13 years, but the differences were more pronounced in adolescents aged 14 to 17 years and young adults older than 17.
The findings were also consistent with a Penn behavior study, of which this imaging study was a subset of, that demonstrated pronounced sexual differences. Females outperformed males on attention, word and face memory, and social cognition tests. Males performed better on spatial processing and sensorimotor speed. Those differences were most pronounced in the 12 to 14 age range.
"It's quite striking how complementary the brains of women and men really are," said Dr. Ruben Gur. "Detailed connectome maps of the brain will not only help us better understand the differences between how men and women think, but it will also give us more insight into the roots of neurological disorders, which are often sex related."
Next steps are to quantify how an individual's neural connections are different from the population; identify which neural connections are gender specific and common in both; and to see if findings from functional magnetic resonance imaging (fMRI) studies fall in line with the connectome data.
Co-authors of the study include Madhura Ingalhalikar, Alex Smith, Drew Parker, Theodore D. Satterthwaite, Mark A. Elliott, Kosha Ruparel, and Hakon Hakonarson of the Section of Biomedical Image Analysis and the Center for Biomedical Image Computing and Analytics.
http://www.sciencedaily.com/releases/2013/12/131202161935.htm
Feeling Defeated, Entrapped Is Linked to Anxiety, Depression
Dec. 5, 2013 —
Science Daily/British Psychological Society (BPS)
Feeling defeated and entrapped is linked to anxiety and depression. This is the conclusion of research being presented at the Annual Conference of the British Psychological Society's Division of Clinical Psychology in York by Alys Griffiths and colleagues from Manchester and Leicester Universities.
"People in socioeconomic deprivation are more likely to feel trapped in a no-win situation and develop mental health problems. This study is the first to demonstrate that defeat and entrapment are risk factors for common mental health problems within the general population. Our results suggest that screening for defeat and entrapment may help with early identification of people who may be at risk of developing mental health problems.
http://www.sciencedaily.com/releases/2013/12/131205220031.htm
Bedtime for Toddlers: Timing Is Everything
Dec. 16, 2013 —
Science Daily/University of Colorado at Boulder
https://www.sciencedaily.com/images/2013/12/131216155000_1_540x360.jpg
"There is relatively little research out there on how the physiology of toddlers may contribute to the emergence of sleep problems,” said Assistant Professor Monique LeBourgeois, a faculty member in the integrative physiology department who led the new study. “Sleeping at the wrong ‘biological clock’ time leads to sleep difficulties, like insomnia, in adults.”
Credit: Zach Ornitz/University of Colorado
The bedtime you select for your toddler may be out of sync with his or her internal body clock, which can contribute to difficulties for youngsters attempting to settle in for the night, according to a new University of Colorado Boulder study.
The study pinpointed the time when the hormone melatonin increased in the evening, indicating the start of the biological night, in a group of 14 toddlers whose sleep also was studied over the course of six days. The study showed that toddlers with later melatonin rise times took longer to fall asleep after being put to bed, said CU-Boulder Assistant Professor Monique LeBourgeois.
"There is relatively little research out there on how the physiology of toddlers may contribute to the emergence of sleep problems," said LeBourgeois, a faculty member in the integrative physiology department who led the new study. "Sleeping at the wrong 'biological clock' time leads to sleep difficulties, like insomnia, in adults."
While adults get to choose their own bedtime, toddlers rarely have this option, said LeBourgeois. "This study is the first to show that a poor fit between bedtimes selected by the parents of toddlers and the rise in their evening melatonin production increases their likelihood of nighttime settling difficulties," said LeBourgeois.
The findings are important because about 25 percent of toddlers and preschoolers have problems settling after bedtime, said LeBourgeois. Evening sleep disturbance can include difficulties falling asleep, bedtime resistance, tantrums, and episodes known as "curtain calls" that manifest themselves as calling out from bed or coming out of the bedroom, often repeatedly, for another story, glass of water or bathroom trip, she said.
Toddlers with longer intervals between the onset of nightly melatonin release and their subsequent bedtimes were shown to fall asleep more quickly and had decreased bedtime resistance as reported by their parents, according to the study.
A paper on the subject was published this month in the journal Mind, Brain and Education. Co-authors included University Children's Hospital Zurich Director of Child Development Oskar Jenni and CU-Boulder Associate Professor Kenneth Wright Jr. The National Institute of Mental Health funded the study.
Sleep problems in early childhood are predictive of later emotional and behavioral problems, as well as poor cognitive function, that can persist into later childhood and adolescence. In addition, parents of young children with sleep problems often report increased difficulties in their own sleep patterns, which can cause chronic fatigue and even marital discord, she said.
"A natural next step is to optimize our knowledge of the interactions between physiology and the environment to further understand how problems like bedtime resistance first develop and how they are maintained," LeBourgeois said.
Research in adolescents and adults has shown that exposure to light in the evening can delay the timing onset of melatonin. Whether the later rise of melatonin in some toddlers can be pushed to an earlier time by restricting evening light or by increasing morning light exposure is a question still to be answered, she said.
"We believe that arming parents with knowledge about the biological clock can help them make optimal choices about their child's activities before bedtime, at bedtime, and his or her sleeping environment," LeBourgeois said.
For the study, the research team recruited 14 families in Providence, R.I., each of which had a child between 30 and 36 months old who slept at least 10.5 hours nightly and took a daytime nap of at least 45 minutes. Saliva samples containing the children's melatonin levels were collected every 30 minutes over a six-hour period on one evening before bedtime.
Melatonin onset times varied among the 14 toddlers studied, which means the "hands" on the individual body clocks told each to be prepared to sleep at different times in the evening, she said.
Saliva was collected by having toddlers chew on dry dental cotton rolls, which were then "spun" onsite in a small centrifuge. The task of getting numerous saliva samples from a child during a single evening requires a team of three researchers called "sleep fairies" experienced at make-believe games, reading and crafts.
Because light suppresses melatonin levels, saliva samples were collected in families' homes after they were converted into "caves" of sorts by covering the windows with dark plastic, installing dimmer switches and using low-watt light bulbs.
The average evening melatonin onset for the toddlers occurred at roughly 7:40 p.m., which occurred about 30 minutes before parent-selected bedtimes, said LeBourgeois. On average, the toddlers fell asleep about 30 minutes after bedtime. "It's not practical to assess melatonin levels in every child," LeBourgeois said. "But if your child is resisting bedtime or having problems falling asleep, it is likely he or she is not physiologically ready for sleep at that time."
The study showed several toddlers who were put to bed before their rise in melatonin took 40-60 minutes to fall asleep. "For these toddlers, laying in bed awake for such a long time can lead to the association of bed with arousal, not sleep," she said. "This type of response may increase children's lifelong risk for insomnia over time."
The toddlers wore special wristwatches to measure activity, allowing the researchers to objectively assess their sleep. They also collected subjective data from parents on their toddlers' bedtime resistance and ease or difficulty falling asleep.
A 2012 study led by LeBourgeois indicated toddlers show more anxiety, less joy and interest, and a poorer understanding of how to solve problems when they missed their regular afternoon nap versus when they napped. These results suggested that children who miss out on needed sleep don't benefit from positive life experiences and have problems coping with day-to-day challenges.
LeBourgeois currently has 10 undergraduates working in her CU-Boulder lab. "The contributions of students to the research done in my lab are enormous," she said. "They not only perform the majority of data collection, but also participate in analyzing, interpreting and presenting our results to the scientific and lay communities. Their love of science, discovery and working together as a team continually inspires me."
http://www.sciencedaily.com/releases/2013/12/131216155000.htm
Re-Quit Smoking On Mondays, Worldwide Study Shows
Dec. 27, 2013 —
Science Daily/Monday Campaigns
It's that time of year. According to a study published in the Journal of Clinical Psychology, 120 million Americans will make New Year's resolutions, with health-related goals like quitting smoking topping the list. Unfortunately, most of those quitters will be puffing away by Groundhog Day.
Instead of encouraging smokers to plan one quit attempt around New Year's, which comes only once a year, experts believe a better strategy would be to follow a New Year's quit with a weekly recommitment to quit that takes advantage of natural weekly cycles.
In a 2013 study published in JAMA Internal Medicine, researchers from San Diego State University, the Santa Fe Institute, The Monday Campaigns and the Johns Hopkins Bloomberg School of Public Health monitored global Google search query logs from 2008 to 2012 in English, French, Chinese, Portuguese, Russian, and Spanish for searches related to quitting, such as "help quit smoking," to examine weekly patterns in smoking cessation contemplations for the first time. The study found that people search about quitting smoking more often early in the week, with the highest query volumes on Mondays. This pattern was consistent across all six languages, suggesting a global predisposition to thinking about quitting smoking early in the week, particularly on Mondays.
"On New Year's Day, interest in smoking cessation doubles," said the study's lead author, John Ayers of San Diego State University. "But New Year's happens one day a year. Here we're seeing a spike that happens once a week."
Besides catching smokers' attention on Mondays, weekly cues can help people stay on track with their quit attempts. Since it takes an average of seven to 10 quit attempts to succeed, encouraging people to requit or recommit to their quit attempt once a week can reduce the overall time it takes to quit for good.
http://www.sciencedaily.com/releases/2013/12/131227100232.htm
High Good, Low Bad Cholesterol Levels Are Healthy for Brain, Too
Dec. 30, 2013 —
Science Daily/University of California - Davis Health System
High levels of "good" cholesterol and low levels of "bad" cholesterol are correlated with lower levels of the amyloid plaque deposition in the brain that is a hallmark of Alzheimer's disease, in a pattern that mirrors the relationship between good and bad cholesterol in cardiovascular disease, UC Davis researchers have found.
"Our study shows that both higher levels of HDL -- good -- and lower levels of LDL -- bad -- cholesterol in the bloodstream are associated with lower levels of amyloid plaque deposits in the brain," said Bruce Reed, lead study author and associate director of the UC Davis Alzheimer's Disease Center.
The relationship between elevated cholesterol and increased risk of Alzheimer's disease has been known for some time, but the current study is the first to specifically link cholesterol to amyloid deposits in living human study participants, Reed said.
"Unhealthy patterns of cholesterol could be directly causing the higher levels of amyloid known to contribute to Alzheimer's, in the same way that such patterns promote heart disease," he said.
"This study provides a reason to certainly continue cholesterol treatment in people who are developing memory loss regardless of concerns regarding their cardiovascular health," said Reed, a professor in the UC Davis Department of Neurology.
"It also suggests a method of lowering amyloid levels in people who are middle aged, when such build-up is just starting," he said. "If modifying cholesterol levels in the brain early in life turns out to reduce amyloid deposits late in life, we could potentially make a significant difference in reducing the prevalence of Alzheimer's, a goal of an enormous amount of research and drug development effort."
http://www.sciencedaily.com/releases/2013/12/131230170344.htm
Sleep to Protect Your Brain
Dec. 31, 2013 —
Science Daily/Uppsala Universitet
A new study from Uppsala University, Sweden, shows that one night of sleep deprivation increases morning blood concentrations of NSE and S-100B in healthy young men. These molecules are typically found in the brain. Thus, their rise in blood after sleep loss may indicate that a lack of snoozing might be conducive to a loss of brain tissue. The findings are published in the journal Sleep.
http://www.sciencedaily.com/releases/2013/12/131231122123.htm