Showing posts with label cortisol. Show all posts
Showing posts with label cortisol. Show all posts

Friday, June 26, 2015

Children with autism have higher cortisol levels

According to a recent study, children with autism were found to have elevated cortisol levels.

Researchers at the Institute for Autism Research at Canisius College have found that functional level appears to play a critical role in the stress levels of children with autism spectrum disorder (ASD). Specifically, lower-functioning children with ASD (LFASD) exhibited significantly higher levels of cortisol, the primary stress hormone in humans, than both high-functioning children with ASD (HFASD) and typical children.
Prior research has suggested that individuals with ASD experience elevated stress and related problems such as anxiety, however, many of the studies relied on informant rating scales and behavioral observations which have significant limitations for children with ASD. Attempts to more directly measure stress in this population using physiological measures such as cortisol have yielded mixed results. According to Susan K. Putnam PhD, chair and professor of psychology, the study's lead author, some of the inconsistent results may have been due to the prior studies not taking into account the significant differences in functional levels of individuals with ASD. "The inclusion of functionally-different individuals with ASD in studies has led to a need for studies of more precisely-defined subgroups with ASD, including subgroups based on functional level," said Putnam. This was the first study to assess cortisol (stress) levels in groups that were clearly differentiated based on functional level, specifically cognitive level.
Given the limitations in existing studies, the research team attempted to examine stress levels in ASD by examining the pattern of salivary cortisol across the day (morning, midday, and evening) and potential differences between lower-functioning children with ASD (LFASD IQ below 70), high-functioning children with ASD (HFASD IQ 85 or higher), and typical children. "It was important to determine whether the ASD groups exhibited the typical diurnal pattern of high cortisol in the morning, followed by a decrease at midday, and a further decline in the evening to determine if this typical pattern was present, and then examine the effect of functional level on stress level," said IAR co-director, Marcus Thomeer PhD, one of the study authors. Saliva samples were collected three times per day over four days on weekends from 13 children with LFASD, 16 children with HFASD, and 14 typical children. Results indicated that all three groups showed the typical pattern in which cortisol levels were highest at waking, followed by midday, and were lowest at bedtime. These findings are consistent with several prior studies of individuals with ASD.
The most significant finding, however, was that cortisol levels differed between the groups across the day. "Children with LFASD had significantly higher cortisol, the stress indicator, across the day than both the HFASD and typical children and, interestingly, children with HFASD did not significantly differ from the typical children across the day," said Putnam.
These findings have significant implications as they suggest that differences in cortisol levels and stress may be linked to the functional level, specifically IQ, of children with ASD. According to Putnam, this is an area in need of further study as it is unknown whether the elevated cortisol in the children with LFASD (compared to HFASD) is indicative of more significant neurological impairment and/or greater sensitivity to environmental stressors (associated with ASD symptoms), or whether a bi-directional relationship exists. IAR co-director Christopher Lopata PsyD, one of the study authors, noted that "identifying stress-level differences between functionally-differentiated groups with ASD has critical implications for how we assess and treat stress and stress-related reactions and conditions in children with ASD."
Findings from the study were recently published online first in the Journal of Developmental and Physical Disabilities.
Read more here

Wednesday, June 11, 2014

Elevated steroid hormones in the womb could lead to autism

A study found that mothers of children with autism had elevated levels of steroid hormones in the womb.

Scientists from the University of Cambridge and the Statens Serum Institute in Copenhagen, Denmark have discovered that children who later develop autism are exposed to elevated levels of steroid hormones (for example testosterone, progesterone and cortisol) in the womb. The finding may help explain why autism is more common in males than females, but should not be used to screen for the condition.
Funded by the Medical Research Council (MRC), the results are published today in the journalMolecular Psychiatry.
The team, led by Professor Simon Baron-Cohen and Dr Michael Lombardo in Cambridge and Professor Bent Nørgaard-Pedersen in Denmark, utilized approximately 19,500 amniotic fluid samples stored in a Danish biobank from individuals born between 1993-1999. Amniotic fluid surrounds the baby in the womb during pregnancy and is collected when some women choose to have an amniocentesis around 15-16 weeks of pregnancy. This coincides with a critical period for early brain development and sexual differentiation, and thus allows scientists access into this important window in fetal development. The researchers identified amniotic fluid samples from 128 males later diagnosed with an autism spectrum condition and matched these up with information from a central register of all psychiatric diagnoses in Denmark.
Within the amniotic fluid the researchers looked at 4 key 'sex steroid' hormones that are each synthesized, step-by-step from the preceding one, in the 'Δ4 sex steroid' pathway: progesterone, 17α-hydroxy-progesterone, androstenedione and testosterone. They also tested the steroid hormone cortisol that lies outside this pathway. The researchers found that levels of all steroid hormones were highly associated with each other and most importantly, that the autism group on average had higher levels of all steroid hormones, compared to a typically developing male comparison group.
Professor Baron-Cohen said: "This is one of the earliest non-genetic biomarkers that has been identified in children who go on to develop autism. We previously knew that elevated prenatal testosterone is associated with slower social and language development, better attention to detail, and more autistic traits. Now, for the first time, we have also shown that these steroid hormones are elevated in children clinically diagnosed with autism. Because some of these hormones are produced in much higher quantities in males than in females, this may help us explain why autism is more common in males."
He added: "These new results are particularly striking because they are found across all the subgroups on the autism spectrum, for the first time uniting those with Asperger Syndrome, classic autism, or Pervasive Developmental Disorder Not-Otherwise-Specified. We now want to test if the same finding is found in females with autism."
Dr Michael Lombardo said: "This result potentially has very important implications about the early biological mechanisms that alter brain development in autism and also pinpoints an important window in fetal development when such mechanisms exert their effects."
Steroid hormones are particularly important because they exert influence on the process of how instructions in the genetic code are translated into building proteins. The researchers believe that altering this process during periods when the building blocks for the brain are being laid down may be particularly important in explaining how genetic risk factors for autism get expressed.
Dr Lombardo adds: "Our discovery here meshes nicely with other recent findings that highlight the prenatal period around 15 weeks gestation as a key period when important genetic risk mechanisms for autism are working together to be expressed in the developing brain."
Professor Baron-Cohen said: "These results should not be taken as a reason to jump to steroid hormone blockers as a treatment as this could have unwanted side effects and may have little to no effect in changing the potentially permanent effects that fetal steroid hormones exert during the early foundational stages of brain development."
He cautioned further: "Nor should these results be taken as a promising prenatal screening test. There is considerable overlap between the groups and our findings showed differences found at an average group level, rather than at the level of accurately predicting diagnosis for individuals. The value of the new results lies in identifying key biological mechanisms during fetal development that could play important roles in atypical brain development in autism."
Read more here

Thursday, August 22, 2013

Ways to get children to sleep more

This article discusses why children may not be sleeping much and how to get them to sleep more.

Asking sleep experts for advice on how to put children to bed often feels like an exercise in futility. The standard tips are banal and predictable: avoid caffeine; remove the TV from their bedroom; don’t sleep on a full stomach; put up dark blinds. You have the feeling the experts are holding out on us—there has to be something more. And there is. Here’s the stuff they’d love to tell you, if they weren’t afraid of overwhelming you with science.
• Ever wonder why most people sleep better when their bedrooms are cool? It’s because the circadian rhythm system that helps regulate sleep cycles is not just light sensitive, it’s temperature sensitive. Anything above a neutral air temperature both slows the body’s initiation of sleep and changes sleep patterns—a hotter room means an increase in non-REM sleep.
• 77 percent of children use television as part of their pre-bedtime routine. Sitting still and vegging out for half an hour should, theoretically, help a child unwind, as long as they’re not watching a show that excites them too much. However, the brightness of the screen undermines the theory. The light from a television or computer can delay both the necessary drop in core body temperature and melatonin production—and thus delaying sleep onset—by two hours.
• We’re all familiar with the agony of being super exhausted, yet not being able to fall asleep for hours. What gives? It’s because after just a few days of shortened sleep, the brain starts making extra stress hormone cortisol. It takes six times as long for this stress hormone to drop to a low-enough level that sleep is possible.
• In one study of 170 children, those in white-collar families tended to be in bed later and get up earlier than those in working-class families. Yet they actually got more actual sleep. How is that possible? It’s because their bedtimes and wake-times were more consistent; they stuck to their routine. This made their sleep more efficient—they rolled around in bed far less.
• Inconsistent bedtimes are, for all practical purposes, homemade jet lag—the desynchronization of the two systems that regulate sleep, the circadian rhythm and the homeostatic pressure system. Staying up three hours later on weekends is equivalent to flying across three time zones every weekend.
• With children averaging three hours of television per day, it’s hard to make the case children are universally overscheduled. But the most driven children are the most overscheduled—and the most sleep deprived. In some ways, these busy overachievers are those who concern the experts the most. According to University of Minnesota’s Dr. Kyla Wahlstrom, a motivated student can sacrifice sleep to maintain high GPAs, but she may pay for that success with higher levels of depression and stress. Teen boys who have a high number of extracurriculars are significantly more likely to be involved in a fall-asleep car crash. And those with part-time jobs both sleep less and have lower grades.
• For the majority of kids, rather than thinking it’s a choice between sleep and activities, the opposite is true: Students who sleep more are involved in more afterschool activities—with no detriment to their grades. They have the energy to be involved. Schools that have delayed start times have seen their students sleep more and increase their participation in sports and extracurriculars.
• Naps are not quite the salve we imagine. They appease the homeostatic pressure system, but not the circadian. You wake up feeling better—a two-hour nap is equivalent to 150 mg of caffeine—but naps do nothing to repair diminished cognitive functioning. The intellect is just as dulled after the nap as before. Kindergartners who take long naps, for instance, do worse on puzzle-solving.
• 16 percent of kids snore a few times a week. As recently as 2002, the American Academy of Pediatrics opined that children’s snoring was a benign condition not warranting treatment. Just five years later, researchers now caution that kids’ snoring is not like adult snoring at all—even a little snoring is a major cause for concern, because their developing brains can be deprived of oxygen.
• Common sleep disorders such as nightmares, restless leg syndrome, and frequent night waking can have a startlingly negative impact on children’s development—from using drugs at 14 to having clinical-level anxiety as adults. Research by University of Michigan’s Dr. Ronald Chervin indicates as many as 25 percent of kids diagnosed with ADHD have an underlying sleep disorder causing their symptoms. If treated for their sleep disorder, the ADHD would magically disappear. Despite the risks posed by sleep disturbance, the number of children treated for them is “vanishingly small.” Parents should consult a qualified sleep specialist—few pediatricians have expertise with sleep problems. Waiting to see if a child grows out of a sleep problem isn’t the answer.

Read more here

Saturday, March 16, 2013

Exercise helps ward off stress in children

Research shows that exercise plays an important role in helping children shield off stress.

Exercise may play a key role in helping children cope with stressful situations, according to a recent study accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM).

When they are exposed to everyday stressors, the study found sedentary children had surges of cortisol -- a hormone linked to stress. The most active children had little or no increase in their cortisol levels in similar situations.
"The findings suggest physical activity plays a role in mental health by buffering children from the effects of daily stressors, such as public speaking," said the study's lead author, Silja Martikainen, MA, of the University of Helsinki, Finland.
The cross-sectional study monitored physical activity and cortisol levels in a birth cohort of eight-year-old children. The 252 participants wore accelerometer devices on their wrists to measure physical activity. Saliva samples were taken to measure cortisol levels. To measure reactions to stress, children were assigned arithmetic and story-telling tasks. The study is the first to find a link between physical activity and stress hormone responses in children.
The children were divided into three groups -- most active, intermediate and least active. The most active children's cortisol levels were the least reactive to stressful situations. The most active children exercised more vigorously and for longer periods of time than their counterparts.
"Clearly, there is a link between mental and physical well-being, but the nature of the connection is not well understood," Martikainen said. "These results suggest exercise promotes mental health by regulating the stress hormone response to stressors."
Read more here

Tuesday, February 19, 2013

Study: Poor Stress Responses May Lead to Obesity in Children

Children who overreact have higher levels of cortisol which may result in obesity later in life.

Children who overreact to stressors may be at risk of becoming overweight or obese, according to researchers at Penn State and Johns Hopkins University.

"Our results suggest that some children who are at risk of becoming obese can be identified by their biological response to a stressor," said Lori Francis, associate professor of biobehavioral health. "Ultimately, the goal is to help children manage stress in ways that promote health and reduce the risks associated with an over- or under-reactive stress response."
Francis and her colleagues -- Douglas Granger, director of the Center for Interdisciplinary Salivary Bioscience Research at Johns Hopkins University, and Elizabeth Susman, Jean Phillips Shibley Professor of Biobehavioral Health at Penn State -- recruited 43 children ages 5- to 9-years-old and their parents to participate in the study.
To examine the children's reactions to a stressor, the team used the Trier Social Stress Test for Children, which consists of a five-minute anticipation period followed by a 10-minute stress period. During the stress period, the children were asked to deliver a speech and perform a mathematics task. The team measured the children's responses to these stressors by comparing the cortisol content of their saliva before and after the procedure.
The researchers also measured the extent to which the children ate after saying they were not hungry using a protocol known as the Free Access Procedure. The team provided the children with lunch, asked them to indicate their hunger level and then gave them free access to generous portions of 10 snack foods, along with a variety of toys and activities. The children were told they could play or eat while the researchers were out of the room.
The results appeared online in the December 2012 issue of the journal Appetite.
The team found that, on average, the children consumed 250 kilocalories of the snack foods during the Free Access Procedure, with some consuming small amounts (20 kilocalories) and others consuming large amounts (700 kilocalories).
"We found that older kids, ages 8 to 11, who exhibited greater cortisol release over the course of the procedure had significantly higher body-mass indices [BMI] and consumed significantly more calories in the absence of hunger than kids whose cortisol levels rose only slightly in response to the stressor," Francis said. "We also found that kids whose cortisol levels stayed high -- in other words, they had low recovery -- had the highest BMIs and consumed the greatest number of calories in the absence of hunger."
According to Francis, the study suggests that children who have poor responses to stressors already are or are at risk of becoming overweight or obese. In her future work, she plans to examine whether children who live in chronically stressful environments are more susceptible to eating in the absence of hunger and, thus, becoming overweight or obese.
"It is possible that such factors as living in poverty, in violent environments, or in homes where food is not always available may increase eating in the absence of hunger and, therefore, increase children's risk of becoming obese," she said.
Read more here