Tuesday, May 30, 2006

Grand Rounds 2:36 Is Up

the bare limbs of a hoar-frost rimmed tree are highlighted by a mixture of fog and sun against a clear blue sky: different elements co-operating to make a striking image
Grand Rounds 2:36 is up: this week it is hosted by a nephrologist who blogs on Kidney Notes. This week's online peek into the diverse world of medical researchers, healthcare workers, patients and policy makers is as interesting as ever. It put me in mind of the above image from Flickr - like everything else, good medicine relies on techno-stars but depends upon good communication and co-operation.

There is the usual mix of the hilarious (a urologist discusses a surgical procedure with a porn star that may interfere with his 'money shot'), the poignant (what happens to patients can make you cry), the controversial (Dr Crippen explores a controversy that arose during a controversy about home-births) to the thoroughly fed up (most stupid reason for duty calls and I have this problem that I want you to fix). I commend Grand Rounds to you.

Saturday, May 27, 2006

NHS Survey On Cigarette Pack Warnings

A column of cigarette smoke passes from one open mouth to another: written under the smoke are the words 'Die with me'The NHS is running a Tobacco Pack Warning Survey.
After three years on packs, we think it’s time to change the current written warnings on the back of packs to hard-hitting pictures. We’d like you to help us choose which pictures to use.
I'm not their target audience, but I doubt that the images will be effective. I was surprised at the most voted-for images so far - it's just a shame that unlike their sister site, Giving Up Smoking which allows appropriate use of their branding and logos, this consultation exercise doesn't allow the wider reproduction of the images so that the survey can be publicised. It is also disappointing that the website doesn't explain how the images will be used: e.g., the vigorous, take-no-prisoners Australian tobacco warnings must cover 30% of the front and 90% of the back of the cigarette package; and the seven warnings are rotated within brands, and after 12 months, a different set of seven warnings is used.

However, the message is clear: smoking harms those who smoke, and environmental exposure can significantly damage children's health and well-being.

Friday, May 26, 2006

Never Mind The Research, Just Trust The Credibility

Black and white image of a revolving door: text on the floor reads, 'I'm afraid of revolving doors'
There is a revolving door for medical studies: they represent a scientific breakthrough that should alter official treatment guidelines and or contribute significantly to our understanding, but then there is some equally respectable research that contradicts it. And, so it seems, medical research is sometimes stuck in a revolving door, rather than moving ahead. Reading through Brian Deer's unsettling account of why new scientific studies may not be as reliable as they seem to be, I was reminded of Never Mind The Quality, Feel The Width. It is a dispute that has been rumbling on for some time, but it does seem as time-pressed reviewers are adopting a Never Mind The Content, Look At The Provenance stance which is to the detriment of the quality of the peer-review process and the journals that rely upon it. There have been several high-profile and embarrassing withdrawals of published papers by well-respected scientists.

When people tell me about a "new research finding" I usually ask if they got their information from a press release, a newspaper, a conference paper or a recognised peer-review journal. Recent scandals and articles like Deer's make it difficult to convince concerned parents that there is merit in distinguishing between these information sources (not least because it is only when a paper is available that we know the tedious stuff that someone has to care about like the methodology and the statistical analysis). Deer quotes Dr. Joseph Sonnabend, a former virologist for the Medical Research Council, who is concerned about the recent drop in respect for the peer-review process and a decline in public confidence:
There is a crisis of credibility in medicine and science. Less and less information seems purely disinterested. You have to check everything out.
The reality check is that we can't check everything out. Not even peer-researchers in the same field can check out everything that they might need to: it is unrealistic to expect parents, readers or even researchers in a different discipline to make some of these evaluations. There has been a lot of some excellent discussion about how to improve journalists' reporting of health and scientific studies. The best advice is usually to combine the Royal Society's Guidelines on Health and Science Communication with a working knowledge of Professor Greenhalgh's excellent 10-part mini-course, How to Read a Paper. Sadly, it seems as if peer-reviewers may need similar guidance, alongside a working knowledge of how to read financial reports to track someone's financial interests (although, these are supposed to be disclosed).

----------
I've added the following on May 28th because I couldn't get the comments to work (Blogger and Haloscan, I love you but you should appear in the dictionary as an illustration of the word flaky).

Although it is a dispiriting read, it is useful to look at Ioannidis' PLoS article, Why most published research findings are false. The BBC recently carried a story from the Royal Society. The RS asks Should Science Always Be Publicised? The RS has previously issued guidelines for journalists, but these latest recommendations speculate that some misreporting has its origins in the scientific community.

The RS is concerned that journals and some conferences allow a platform for disseminating anomalous results or studies that question current best practice or scientific knowledge.
A problem arises though when controversial research designed to provoke a debate within the scientific community is reported as gospel by the general media.

At best, it reduces trust in scientists and the media; at worst, it can lead to people making poor choices and harming their health...
The RS is aware that self-censorship has its own dangers and might limit debate. This is a serious problem. I have met academics who have had negligible funding to research a particular non-conventional medical topic and have conducted a case-series with a small number of subjects because they didn't have the money to fund an RCT. When they wrote up their results and submitted them to a journal they were advised that it could not be accepted as a research paper, but could be re-submitted as a Letter or Research Note. Now, although it is useful to have some publication of the work that can be cited, a Letter or Research Note does not have much standing. And academics need publications in a respected, peer-reviewed journal in order to make the case for funding applications to carry out good quality research with a significant number of subjects.

I'm not sure that there is a ready solution to the problem of the public perception of the value of scientific research. I'm not sure that there is a decent solution for academic researchers who are investigating plausible, non-mainstream topics.

Labels: , , , , , , , ,

Wednesday, May 24, 2006

Does Environmental Exposure To Violence Contribute To Poorer Lung Function Or Asthma In Children?

Anxious and stressed young woman, her hand obscures her face which is buried in despair Children respond to what is happening around them. It is helpful that children are resilient, but their resilience should not be interpreted as conferring them with a kevlar physiology that protects them from the impact of stress as a response to what is happening around them. Preliminary results from on-going studies suggest that the stress caused by environmental exposure to violence is significantly linked to both poorer lung function in children and asthma exacerbations. There is some speculation about plausible stress mechanisms that might be responsible for this.
[The] effects of acute stress on airway functioning may be largely mediated through the autonomic nervous system, whereas chronic stress may lead to alterations in the immune system.(Laube et al. 2003; pg. 617).
There is some support for this observation. Although the immunological response is not well understood, researchers report different emotional responses that may be classified as stress responses with distinctive immunological implications. For example, Niaura et al. (2000) report that stress-related hostility can induce an imbalance between sympathetic and parasympathetic nervous system activity, adversely affecting cardiovascular, endocrine and neuroendocrine function. Hashiro and Okumura (1998) report that anxiety may affect immune function as measured by changed levels of immune markers and decreases in natural killer (NK) cell activity: however, Miller et al. (1999) report that negative emotions such as anger and cynical hostility are linked to an increase in NK activity.

Women at ease in each other's company in a canteen settingResearchers such as Kemeny and Taylor take the challenge further. Kemeny (2003) argues that different stressors elicit qualitatively distinct emotional and physiological responses (the integrated specificity model). For example, Kemeny reports that appraisals of threat (vs. challenge), uncontrollability and negative social evaluation can be shown “to provoke specific psychobiological responses” (pg 124). Taylor (2000, 2002) claims that until 1995 research into the fight-or-flight response was primarily conducted with males; females constituted 17% of the participants, and the findings therefore concealed important gender differences. Taylor argues for the existence of a predominantly female tend-and-befriend response that may be linked both to female responsiveness to oxytocin and the traditionally nurturing nature that can characterise female relationships. These challenges need further investigation and validation and explicit application to asthma research. However, they do lend some support to the notion that it may be useful to distinguish emotional arousal and stress, and that within the arena of stress there are different behavioural opportunities and responses that carry different immunological consequences.

A young man lies on the ground, trying to protect himself from the volley of kicks from the crowd of angry young people around himFor people with asthma, it seems as if there may be different immunological consequences to responding with anti-social behaviours such as hostility and aggression, rather than co-operation and conciliation. Similarly, there may be different consequences for environmental exposure to hostility and aggression that results in fear or helplessness. It is possible that allostatic load is a useful explanation for the frequently-observed time-lag response to sensitivity to allergens, or delayed asthma exacerbations following an emotional trigger or a negative stressful event. The concept of allostatic load suggests that a challenge is perceived as stressful and triggers the release of adrenal steroids and catecholamines that promote the movement of immune cells to organs and tissues (such as those lining the airways) where they are recruited to fight a challenge: they also impact the production of cytokines and chemokines. Although there may be short-term advantages to these responses, chronic over-activity of these mediators produces allostatic load with immunosuppressive consequences when these hormones are secreted chronically (as may occur with long-term stressors) or are not shut-off efficiently. There is an optimal balance of these mediators that provides a healthy, functional balance within the competitively-regulated immune system: the absence of adequate levels of glucocorticoids and catecholamines allows other immune mediators to be over-abundant and increases the risk of inflammatory responses and disorders such as asthma.

2 men fighting: men around them try to separate themAs an interesting reflection on the above, there are preliminary studies that point towards poorer lung function in children who are exposed to parental fighting at home and violence in the community or in school. Wright and her colleagues (Suglia et al, 2006) report that:
Verbal aggression in the home and community violence were significantly associated with lower lung function in children even after controlling for tobacco exposure, race, birth-weight, markers of socioeconomic status and self-reported asthma diagnosis.
The study was carried out by the same lead researcher who reported that optimism is linked to higher levels of optimism in old men. The children's study evaluated a prospective cohort of 330 children who have been followed since early gestation as part of a study on smoking in pregnancy and early childhood. The researchers say that they were careful to control for other relevant factors such as socioeconomic status, pre- and postnatal tobacco exposure etc. that are known to affect lung function. Controlling for these factors means that they are confident that their results are a reflection of the impact of stress related to exposure to violence.

The investigators collected maternal reports and various rating scales to assess the level of parental conflict and violence in the home, as well as community exposure to violence. Children older than eight were asked to self-assess their exposure to violence. Two of the outcome measures collected by the researchers were forced expiratory volume at one second (FEV1) and forced vital capacity.

The researchers findings have yet to be verified by the peer-review process, but their initial report is that verbal aggression was associated with a significant decrease both in FEV1 (P<0.05)>same or higher magnitude as those reported for postnatal and prenatal tobacco smoke exposure on lung function. These findings are bolstered by a separate study that investigated the impact of exposure to violence at school on children with asthma.

Riekert and her colleagues evaluated a sample of 1704 highschool students with asthma (Otsuki et al. 2006). The researchers say that they were careful to control for relevant factors such as age, gender, ethnicity, or urban vs. suburban setting of the school attended etc. They report that their findings indicate that adolescents with asthma who were exposed to violence in school were more likely to report having had at least one asthma exacerbation during the past year (p<.001). The researchers claim that:
[t]he present findings highlight the need for attention to the roles of violence exposure in daily social contexts in asthma morbidity among adolescents.
These findings have yet to be peer-reviewed but they are interesting. When the study is published, it would be useful to learn if the level of violence was classified according to intensity, or differentiated as verbal or physical. From the viewpoint of immunological response, it would be helpful to learn how many of the children had been prescribed preventer medication and were using it during the time of the study. As is necessary with such studies, the researchers relied upon self-reported recall of asthma exacerbations. The researcher acknowledge that the mechanism for such an association between exposure to violence at school and asthma exacerbations is not understood.

Both of the above studies report interesting preliminary results that await validation by peer-review. It would be useful to know if the researchers have collected any data on the children's responses to environmental violence: e.g., if they respond with helplessness or aggression. Future studies might investigate appropriate biomedical markers for stress that might illuminate the immunological consequences of different responses to exposure to environmental violence.

A column of cigarette smoke passes from one open mouth to another: written under the smoke are the words 'Die with me'However, the key point for public health policy and for adults who care for children is that both verbal and physical aggression can have significant negative effects on the lung function of children and adolescents, whether it takes place in the home, at school, or in the community. Research may eventually show that the toxic impact of environmental exposure to verbal and physical aggression is as great as that of environmental exposure to tobacco smoke.


References


Hashiro, M. & Okumura, M. (1998). The relationship between the psychological and immunological state in patients with atopic dermatitis. Jnl. of Dermatol. Sci. 16 (3): 231-235.
Kemeny, M.E. (2003). The psychobiology of stress. Current Directions in Psychological Science 12 (4): 124-129.
Laube, B.L., Curbow, B.A., Fitzgerald, S.D. & Spratt, K. (2003). Early pulmonary response to allergen is attenuated during acute emotional stress in females with asthma. European Respiratory Jnl. 22: 613-618.
Miller, G.E., Dopp, J.M., Myers, H.F., Stevens, S.Y. & Fahey, J.L. (1999). Psychological predictors of natural killer cell mobilization during marital conflict. Health Psychol. 18 (3): 262-271.
Niaura, R., Banks, S.M., Ward, K., Stoney, C.M., Spiro, A. III, Aldwin, C.M. Landsberg, L. & Weiss, S.T. (2000). Hostility and the metabolic syndrome in older men: The Normative Aging Study. Psychosomatic Medicine 62, 7-16.
Otsuki, M., Kalesan, B., Rand, C.S. & Riekert, K.A. (2006). School Violence Exposure and Asthma Exacerbations in Adolescents, [ATS Publication Page: A236]
Suglia, S.F., Ryan, L., Dockery, D.& Wright, R.J. (2006). Interparental Conflict and Community Violence Exposure as Indicators of Chronic Stress in Relation to Childhood Pulmonary Function. [ATS Publication Page: A237]
Taylor, S.E., Klein, L.C., Lewis, B.P., Gruenewald, T.L., Gurung, R.A.R. & Updegraff, J.A. (2000). Biobehavioral responses to stress in females: Tend-and-befriend, not fight-or-flight. Psychological Review 107, 441-449.
Taylor, S.E. (2002). The Tending Instinct: How Nurturing is Essential to Who We Are and How We Live. New York: Henry Holt.

Tuesday, May 23, 2006

Grand Rounds 2:35 Is Up

Magazine banner: the text reads: 'Grand Rounds 2:35, May 23 2006Grand Rounds 2:35 is up. Unless I am in a dentist's waiting room, I spurn voyeuristic real-life magazines that make me question what universe some people live in (but then, I'd read ingredient lists for paint-blends if I were waiting for a dentist...). However, my slightly shameful secret is that I am utterly fascinated by the insight into the working lives of people whose jobs mean that they meet other people at the best and worst times of their lives, and points in-between. So, this must serve as an explanation for my attraction to House and medblogs.

Thanks to the host, Dr. Emer of Parallel Universes, I have enough reading to dip in and out of for a full week. It is fascinating and has a clever layout along the style of a journal frontispiece. Dr. Charles has developed a protocol for identifying the Charles Sign. The Cheerful Oncologist extols the virtues of exercise (in a roundabout sort of way). Why taking medicine to treat heart-disease is seen as preferable to patients changing their lifestyle habits. There's an encounter between a jazz musician who doesn't like doctors and the doctor whom he consults. All in all, it is a fascinating read. I commend Grand Rounds to you.

Monday, May 22, 2006

Paediatric Grand Rounds 1:3 is Up!

Laughing Samuel Blackman bravely receives an injection in the upper-arm from a toy syringe wielded by a young friend in a charming sun hatPaediatric Grand Rounds 1:3 is up courtesy of Samuel Blackman of Blog MD. Samuel Blackman is a second year fellow in paediatric haematology-oncology and a keen fund-raiser for the topics and people close to his heart You must visit his profile and listen to the audio file: it is one of the funniest on-air matrimonial accounts of driving mishaps that I've ever heard. It gave me a flashback to when the fiance (Jamie) of one of my sisters was late for work. Everybody was late that day because of a road incident that had been caught by the traffic 'copter of the local radio station and excited a lot of unflattering comment about the driver. One of Jamie's co-workers said, "Were you caught up in the chaos of that car exploding on the Hudd St Gyratory?" Jamie gave a so-so sign, "Eh. That was my car that exploded on the Hudd St. Gyratory, and that was me, running around like a headless chicken."

There is an eclectic mix of posts from the analysis of the monitor readings of a baby drawing closer to death and the grief reactions of parents waiting for their child to die. There is a helpful overview of the latest thinking around the use of dummies/pacifiers and a creative account of how to harness Amazon's baby-lists to generate referrals for an enterprising paediatrician. I commend the Paediatric Grand Rounds to you!

Saturday, May 20, 2006

Buteyko Case Series In New Zealand Medical Journal

Profile head shot of beautiful boy with eyes closed, mouth closed, calmly just breathingThe New Zealand Medical Journal has published a letter from Patrick McHugh, Bruce Duncan and Frank Houghton that outlines a case series on childhood asthma carried out in Gisborne. Although the Buteyko Breathing Technique (BBT) has been assessed as an intervention for adults with asthma, and is associated with significant reductions in medication use as well as improvements in qualify of life scores, there is no previous published work that evaluates the effectiveness of BBT with children.

The researchers identified 8 children with asthma, but no other significant unstable medical conditions, between the ages of 7-16 who were eligible for inclusion in the study. The children must have received no prior instruction in BBT. The children must have a medical diagnosis of asthma and have been using asthma medication for at least 6 months. In the two weeks prior to the study, it was essential that the children must have needed significant medication to control their symptoms.

As part of the BBT, students are encouraged to breathe in and out through the nose. They also carry out a series of exercises that enourage a reduction in the volume of air that is breathed in and out. The children were taught the BBT over 5 sessions of 60-90 minutes, held over 5 consecutive days. The children's own family doctors altered medication as appropriate to the children's needs.

Before learning BBT, and three months after the course, the children and their parents/guardians completed a questionnaire that evaluated symptoms scores and medication use among other items. At the 3 month assessment, the children were also asked whether BBT had improved the self-management of their asthma.

The findings from the questionnaire indicate that:
  • reliever use was reduced by 66%
  • controller use was reduced by 41%
  • the number of courses of oral steroids dropped from a total of 11 in the 3 months prior to the course to 1 course in the 3 months post-tuition
  • there was a significant reduction in symptom score severity.
None of the children reported either "slight" or "marked deterioration" in their condition: 7/8 reported improvement and 1 reported "no change".

The changes in medication reflect similar changes in the studies and trials conducted with adults. Similarly as for the adults, the children reported an improvement in their quality of life scores. The researchers acknowledge that they worked with a very small, self-selected group of children. However, they argue that the results are sufficiently similar to those of adults to strengthen the case to explore the contribution of BBT to asthma self-management in a randomised controlled trial in children.

Friday, May 19, 2006

Does Early Antibiotic Use Increase The Risk Of Asthma?

Bronze sculpture of a figure with a migraine by Jose SacalParents like the certainty of scientific support when they make decisions that have an impact on the health of their children. So, it is irritating when the scientific research exists, but there is no clear consensus. There is a lot of controversy about the hygiene hypothesis and asthma. Those who support the hypothesis claim that increasingly sterile environments make children more vulnerable to allergies and asthma. In addition, because antibiotics disrupt the gut flora and kill good bacteria, some people say that they compromise the development of a robust immune system in children.

I recently blogged about a birth cohort study from The Netherlands. Among other items of interest, the researchers reported that antibiotic use in early life was not a risk factor for asthma in this four-year study. The researchers had access to the children's medical records and so their analysis of antibiotic use was based on recorded use rather than parental recall. The data have been collected and analysed over four years: it may need further long-term follow-up to validate the initial findings that early antibiotic use is not a risk factor for asthma in this population of children born to atopic mothers.

Moxy Malone: cartoon Dick Tracey figure who is an antibiotic detectiveHowever, another group of researchers has recently published the results of a systematic review and meta-analysis of other studies that have explored the possible relationship between antibiotic use in infancy and the later development of asthma. These researchers reported that exposure to at least one course of antibiotics during the first year of life does seem to be a risk factor for the later development of childhood asthma: approximately twice the risk.

However, the researchers did note that the association between early antibiotic use and childhood asthma was significantly greater in those studies that relied upon parent recall rather than monitoring children's medical records. Similarly, the analysis indicated that the greater the children's exposure to antibiotics, the more courses that they took, the greater the risk of asthma.

This study is another contribution to the literature on early environmental exposures and their relationship to health. Paediatricians and family doctors frequently remind parents that antibiotics should be used appropriately: e.g., antibiotic ear drops may be more appropriate than oral antibiotics as the first line of treatment for ear infections. There is a reason why doctors repeat the educational message that antibiotics are useful for treating bacterial infections but not viral infections such as colds. Dr. Bassett is the vice chairman of the public education committee of the American Academy of Allergy, Asthma and Immunology; he has a take-home message for parents:
you wouldn't want to withhold an antibiotic when it is needed because of a theoretical risk of asthma. But this research does underscore the importance of not overusing these drugs, especially early in life.

Thursday, May 18, 2006

Children Need Good Quality Sleep!

Young girl rubs her eyes and yawns: tired in the daytimeI recently wrote about the Duvet Diet and the importance of good quality sleep for children: the Breath Spa for Children project is about working with children to overcome the impacts of sleep-disordered breathing. Several people have kindly sent me a news item about a study in Australia that reports that children who sleep fewer than six hours a night may be at greater risk of becoming obese. The reports claim that the study involved looking at the sleep patterns of hundreds of children to assess whether there is a link between sleeping habits and rising levels of childhood obesity (I haven't been able to locate the paper as yet).

The lead researcher is reported to have said that a lack of sleep can affect the pre-frontal cortex: this part of the brain is responsible for memory, behaviour, moods and the delivery of appetite-suppressing and appetite-stimulating hormones. In common with the Duvet Diet, there is the suggestion that
"[h]ormone secretion is disrupted when you don't sleep properly. Less sleep equals hormone non-regulation and that means you're more likely to eat more."

The researchers also argue that lack of sleep and hormone-influenced changes in appetite, in combination with the hyperstimulation of playing electronic games or watching television until late at night may be integral to any connection between lack of sleep and obesity. The common thread throughout all of this research is that children need good quality sleep if they are to have physical, cognitive and emotional health.

Monday, May 15, 2006

More Bad News About Children And Second-Hand Smoke

Kent cigarettes' packet bearing the warning: 'Your smoking can harm others'Children are harmed by environmental exposure to tobacco smoke. The evidence of this harm is accumulating from a range of sources but parents continue to smoke in the presence of their children. The bad news about children's exposure to environmental tobacco smoke continues. Scientists have detected cancer-causing chemicals associated with tobacco smoke in the urine of nearly half the babies of smoking parents.

Professor Stephen Hecht of The Cancer Center at the University of Minnesota says, “The take home message is, ‘Don’t smoke around your kids.’” A study of 144 infants reports detectable levels of NNAL in urine from 47 percent of babies exposed to environmental tobacco smoke from cigarette smoking family members. NNAL is a cancer-causing chemical produced in the human body as it processes NNK, a carcinogenic chemical specific to tobacco.

Supine baby doll lies in a wasteland with a cigarette butt in her mouthHecht commented that, “NNAL is an accepted biomarker for uptake of the tobacco-specific carcinogen NNK. You don’t find NNAL in urine except in people who are exposed to tobacco smoke, whether they are adults, children, or infants.” The level of NNAL detected in the urine of these infants was higher than in most other field studies of environmental tobacco smoke in children and adults.”

The study's findings indicate that babies have detectable levels of NNAL when family members smoke an average of 76 cigarettes per week, in their home or car while the babies were present. Babies had undetectable levels of NNAL in their urine when the average number of cigarettes smoked by family members was 27 per week. However, Hecht claims that, “With more sensitive analytical equipment, the NNAL from urine of babies in lower frequency cigarette smoking households would most likely be detectable.”

An obvious comment on the study is that there is no clear quantification of the relationship between exposure to environmental tobacco smoke and the impact on the genetic development of babies. The study can only confirm that there is a substantial uptake of NNK leading to the production of the metabolite NNAL in infants exposed to environmental tobacco smoke. Hecht does consider that the findings are significant: “These findings support the concept that persistent exposure to environmental tobacco smoke in childhood could be related to cancer later in life.”

Stub cigarettes here: a metal borderIt seems plausible that children may have a genetic make-up that makes them particularly susceptible to respiratory illness. The cancer risk has yet to be quantified but a recent study found that nearly a quarter of children are susceptible to respiratory problems if exposed to environmental tobacco smoke. The results were sufficiently striking that Professor Frank Gillilance of the Keck School of Medicine said, "Parents or others who choose to smoke around children are causing illness and school absences, potentially affecting how well the children do in school."

Children and environmental tobacco exposure do not mix.

Friday, May 12, 2006

Indoor Pollution Linked To Asthma Symptoms In Children

Young boy using a nebuliserParents long for consistent, reliable advice that will help them to make important decisions that influence their children's health. A recent study conducted in the Netherlands claims that Exposure To Dust and Microbials Protects Children From Early Development of Asthma. An even more recently published study from Australia reports some findings that identifies increased levels of two major indoor air pollutants—nitrogen dioxide and house dust mite—as responsible for worsening symptoms in children with asthma.

Researchers looked at the relationship between nitrogen dioxide and dust mite levels and asthma symptoms in 174 asthmatic schoolchildren. Indoor nitrogen dioxide levels were measured both at home and school: sources of nitrogen dioxide are paraffin/kerosene heaters, un-vented gas stoves and heaters or environmental tobacco smoke. Levels of house dust mite allergen were assessed in dust samples from the children's mattresses.

For both nitrogen dioxide and house dust mite, higher exposure levels were linked to increased asthma symptoms. Children who were exposed to higher levels of nitrogen dioxide at school were more likely to have breathing difficulties, both during the day and at night, as well as night-time chest tightness. Higher levels of nitrogen dioxide in home kitchens were also associated with increased asthma symptoms.

Reasonable soft toy facsimile of a dust miteFor those children who were allergic to house dust mite, higher levels of mite allergen were also related to increased asthma symptoms. Beyond a cutoff point, children with higher levels of dust mite allergen exposure had increased rates of night-time wheezing, daytime cough, and daytime asthma attacks.

There are many contributory factors associated with asthma, but environmental factors are thought to play an important role in triggering asthma attacks in some people. Both house dust mite allergen and nitrogen dioxide are important indoor air pollutants. Nitrogen dioxide is a by-product of gas combustion—the school air quality measurements were made as part of a study into the impact of replacing unflued gas heaters in classrooms. In schools where unflued gas heaters were replaced, nitrogen dioxide levels declined, and the incidence of asthma symptoms decreased.

The researchers claim that:
Exposure to nitrogen oxide emitted by unflued gas appliances indoors and exposure to house dust mites in bed can exacerbate asthma in children.
The findings indicate that each pollutant triggered different types of symptoms: the authors suggest that this reflects separate components of the asthma disease process. Wheezing and coughing were associated with dust mite allergen and linked to allergic reactions. The symptoms of breathlessness and chest tightness were associated with greater exposure to nitrogen dioxide: nitrogen dioxide is frequently related to airway inflammation.

The researchers argue that
[i]n light of the strong evidence that the extent of health effects is dose dependent, exposure [to indoor air pollutants] should be minimized.
The heater replacement study has demonstrated the health benefits of reducing indoor nitrogen dioxide levels. However they say that more research is needed to determine whether reducing exposure to house dust mite would reduce asthma symptoms.

The study is interesting. However, whereas the Netherlands study followed children from birth for four-years, the 174 children in this study were older, already diagnosed as asthmatic, and were asked to keep a daily symptoms diary over 12 weeks. Home and classroom NO2 levels were measured repeatedly in winter 2000. Dust mite levels were obtained from beds. Lung function tests were performed at the beginning and at the end of the study period. Nitrogen dioxide is also part of environmental exposure to tobacco smoke which is reported to have an adverse affect on the health of asthmatic children.

Tuesday, May 09, 2006

Sick Children's Dads Continue To Smoke At Home

Kent cigarettes' packet bearing the warning: 'Your smoking can harm others'I'm a life-long non-smoker. I've hated cigarettes since I was a very small child but there is a stone in my heart for the people who are trying to stop. I understand from watching my mother's repeated struggles that it can be phenomenally difficult to stop smoking and that adults must be allowed to exercise their personal choice to their own detriment if that is their wish. I know that parents can understand that they are worsening their children's illnesses and contributing to their disturbing behaviours but they still can't bring themselves to stop smoking in the home because it seems the less of several evils that confront them.

A column of cigarette smoke passes from one open mouth to another: written under the smoke are the words 'Die with me'Nonetheless, I was still taken aback by a study from the University of Hong Kong that reported that 86% of the fathers of sick children continue to smoke at home. Just over half continued to smoke in the presence of their children. Half of the 1483 children suffered from respiratory problems - making them especially vulnerable to environmental exposure to tobacco smoke - and 60% of the children had been admitted to hospital more than once.

The usual suspects have been asked for their comments and made the obvious point that there are substantial cultural differences between the UK and Hong Kong. However, I find it truly difficult to believe that Simon Clark, the director of FOREST (the Freedom Organisation for the Right to Enjoy Smoking Tobacco), said that:
parents of a child from asthma would be advised to avoid smoking in a small enclosed room when their child is present, but there was no reason for them to give up completely
I find it beyond belief that he is reported to have said:
The anti-smoking lobby is now targeting parents who smoke at home. The idea, clearly, is to make them feel guilty about their habit by implying they are harming their children. It's a form of moral blackmail.


Cookie Monster holds a pack of cigarettes and has one in his mouth: the legend circling the picture is 'C is for cigarettes'Implying!!! Yes, it's your home, your castle and all the personal rights that go with that. But young children lack the choice and autonomy to move away from a smoky environment. If you smoke in the presence of your asthmatic child, there is credible research to indicate that you are harming their health, their development and their wellbeing. The researchers claim that they have no reason to think that the same is not true of children without respiratory problems. I'm not too sure where the charge of moral blackmail can be properly placed. With anti-smoking campaigners or with people for whom freedom is a cordon sanitaire that can not allow a discussion of the harm that passive smoking does to children beyond the grudging point about asthmatic children and "small enclosed rooms"? I thought that this parody of the Australian cigarette warnings had gone too far in depicting smokers as Zombies: the jury is out on that, but maybe it's an appropriate depiction of the people who defend it with such nonsense. Implying!?!

Grand Rounds 2:33 Is Up!

Dog sled with young woman and small childrenTara Smith of Aetiology has released Grand Rounds 2:33. It is an extensive selection of the best of medical, scientific and allied health care interest blogs. You can learn all sorts of fascinating gems about the side-effects of various drugs and their delterious effects on your sex life; speculation that there may or may not be a bacterial link to the development of several common chronic illnesses; why happiness is good for us; a close encounter with a body-snatcher, and an edge-of-the-seat account of just what it takes to see a doctor in Alaska (dog-sledding is involved).

There is enough weird, wonderful, thought-provoking and educational stuff in there to keep you informed and entertained for hours. Go and look - you won't be sorry!

Sunday, May 07, 2006

Paediatric Grand Rounds 1:2 Is Up!

Extravagantly joyful baby with arms upraisedThis baby may well be jumping for joy as the news leaks out that Paediatric Grand Rounds 1:2 is up, courtesy of the industrious Clark Bartram.

The posts range from the practice of home birth to discussions of the growing need for cardiologists to address the needs of adult survivors of paediatric heart problems, with a whistle-stop via genetics and a timely reminder that children are at risk of drowning. There is lots of excellent advice about what constitutes a healthier diet for children and a poignant description of the feeding difficulties of chronically ill children. As an added bonus, you get to learn the about the Windex of one particular paediatrician. I commend the Grand Rounds to you.

Friday, May 05, 2006

Buteyko Video From NZ Televison

side head shot of beautiful boy with eyes closed, mouth closed, calmly just breathingMy BIBH colleague Glenn White has just been involved in this video about Buteyko Breathing and asthma that has been broadcast in New Zealand.

The seven minute segment was part of a news programme that was broadcast on World Asthma day May 2. The segment features two 8 year old girls with asthma: they are currently taking a course with Glenn and their progress will be reported over the coming weeks. I will keep you posted on their outcome and any further video segments.

The clip is interesting but some of the techniques that are shown are safe for the participants because they were assessed by a practitioner. Please do not attempt these techniques without appropriate consultation.

Thursday, May 04, 2006

How Not To Treat Your Nose...

8 piece photo-montage of a young woman picking her nose in a variety of ways
I recently came across this photo-montage of how NOT to treat your nose. I have just test-run it at a Breath Spa workshop. The children responded to the photographs with shrieks, groans and great enthusiasm. They held an impromptu captioning competition for each photograph. The general feeling was that the young woman had wimped out in photograph eight. The greatest disappointment was that there is no sign of anyone actually eating the bogie/booger/slime/fill in your own nauseating...

Despite the popularity of the image, I think that everyone had the take-home message that we should treat the nose very gently and use it for breathing (in and out) rather than excavation. However, nose-picking is one of the strongest behavioural tools available to the very young judging by the response of the accompanying adults to the photos in the montage and the following images. And it has added new words to my vocabulary, although I could happily have lived the rest of my life without knowing about rhinotillexomania or mucophagy. And without people reminding me about all the news coverage given to the alleged lung specialist Dr Friedrich Bischinger's alleged claims that his research shows that people who pick their noses with their fingers and eat the contents are healthy, happier and probably better in tune with their bodies. So much so, that he advocates children should be encouraged to adopt the habit to build up their immune systems...
Eating the dry remains of what you pull of your nose is a great way of strengthening the body's immune system. In terms of the immune system the nose is a filter in which a great deal of bacteria is collected, and when this mixture arrives in the intestines it works just like a medicine.
I'm sticking with alleged and allegedly until such time as I can find Dr. Bischinger's work in Entrez PubMed. Has everyone heard the news coverage of the health message about 5-A-Day for fruit and vegetables? No. Has everyone heard about the supposed benefits of nose-picking? Absolutely. Maybe it's not just a fascination of the under-5s.
Boy excavating nostril with a finger: looks mischievousYoung girl with 2 fingers firmly plugged into her nostrils: to her side are over-loaded electrical sockets. There is a disturbing black and white symmetry about the plugged-in visuals

Wednesday, May 03, 2006

Where There's Smoke: Exposure Has Serious Behavioural Implications For Children, Especially Those With Asthma

Cookie Monster holds a pack of cigarettes and has one in his mouth: the legend circling the picture is 'C is for cigarettes'Where there's smoke, there's an asthmatic child behaving badly. It is looking like it is more important than ever to advise parents to be aware of children's vulnerability to the impacts of second-hand smoke. Yolton and her colleagues have presented preliminary findings at the Pediatric Academic Societies Annual Meeting that have emphasised the dramatic impact that environmental exposure to tobacco smoke (a.k.a. smoking in the home or children frequenting malls or venues that permit smoking)has on the wellbeing of children.

Greater environmental exposure is linked to an increase in cotinine levels (a by-product made when the body processes the nicotine from cigarette smoke). The greater the level of an asthmatic child's exposure to second-hand smoke, the higher the cotinine levels and the greater the corresponding decrease in test scores and increase in parent/teacher reports of disruptive behaviour both at school and home.

A column of cigarette smoke passes from one open mouth to another: written under the smoke are the words 'Die with me'Yolton reported that although only one in four American children is exposed to environmental tobacco smoke at home, blood analyses show that more than half of all children test positive for cotinine. Yolton argued that in line with previous studies on 4399 children that reported cognitive deficits among children even at extremely low levels of enivronmental exposure to tobacco smoke, this finding strengthens the case for setting public health standards that protect children from such exposure. Yolton acknowledged that this study only looked at consequences for elementary school-age children with asthma, but argued that it is likely that the results also apply to children without asthma.

The study evalulated 225 children between the ages of five and 12 who were participating in an asthma intervention trial. All of the children were known to be exposed to second-hand smoke from five or more cigarettes per day. The investigators used parental reports to assess children's environmental exposure to tobacco smoke and also tested for cotinine in children's serum and hair. The mean age of the participating children was 8.6 and 62% were male. The children's actual exposure to smoke from cigarettes was an average of 14.2 per day.

Cranky child with a barrage of speech bubbles saying, No; Whatever, Don't make me screamThe researchers enlisted the support of parents and teachers. Parents and teachers completed the Behavioral Assessment System for Children that is available in both parent and teacher versions and measures a child's behavioural, emotional, and adaptive problems and competencies. An analysis of the parents' ratings showed a strong link between blood cotinine levels and unwanted or inappropriate behaviour. The analysis of the teachers' reports also demonstrated a significant association between cotinine levels and behavioural disruption.

The researchers say that although their findings are preliminary they have a clear pattern. The greater the environmental exposure to tobacco smoke, the greater the likelihood of behavioural disturbance and other problems (such as decreases in test scores). Yolton is reported to have said:
Behavior problems in children have increased from 7% to 18% over the last 20 years for reasons that are poorly understood. Exposure to environmental tobacco smoke is increasingly recognized as a risk factor for child behavior problems.

Kent cigarettes' packet bearing the warning: 'Your smoking can harm others'As above, Yolton and her colleagues have previously reported that after appropriate adjustments for known variables such as sex, race, income levels and blood levels of lead, even low levels of environmental exposure to tobacco smoke is associated with decreases in the cognitive skills that underpin competency in reading, maths, logic and reasoning in children and adolescents. They found that as cotinine levels increased, test scores decreased such that children with cotinine values >3 ng/mL had test scores that were an average of 4.8 points lower out of 100 than those of children with cotinine concentrations of less than 0.1 ng/mL. Writing about these results, the researchers concluded that:
Exposure to [environmental tobacco smoke (ETS)] in U.S. children therefore has substantial public health impact beyond asthma, otitis media, and other widely recognized adverse consequences...we [estimate] that > 21.9 million children are at risk for ETS-related reading deficits.

There are plausible physiological mechanisms for the impact of sleep-disordered breathing on the physical, cognitive and emotional wellbeing of children. When assessing the impact of environmental exposure to tobacco smoke, it is difficult to disentangle the toxic impact of cotinine levels on the developing central nervous system of children from the dysfunctional breathing that is typically found in children who are exposed to second-hand tobacco smoke.

Although this is a conference paper and the findings need to be scrutinised in an appropriate journal, Yolton does make a strong case for the health benefits of reducing children's exposure to environmental tobacco smoke.

Reference: Yolton K et al. "Environmental Tobacco Smoke and Child Behaviors." Abstract 3135.3, presented April 30, 2006, at the Pediatric Academic Societies Annual Meeting