Thursday, 7 February 2013

More GI symptoms reported in cases of autism

The real Star Wars... @ Wikipedia  
The paper by Susie Chandler and colleagues* adds to the quite voluminous literature on bowel issues and autism by suggesting that "Parents report more GI symptoms in children with ASD than children with either SEN or TD children".

A translation if it is needed: according to mums and dads, kids diagnosed with an autism spectrum disorder (ASD) have more toilet-related issues than those without autism or those with a physical / learning disability (SEN) which does not include a diagnosis of autism.

Realisation

If there's one thing comorbidity-wise that the autism research community is starting to realise when it comes to the autism spectrum disorders (ASDs) it's that gastrointestinal symptoms - whether functional bowel issues or more chronic disease pathology - do seem to be a feature of quite a few cases of autism but not all, particularly in children with autism. Perhaps even forming a specific endophenotype of autism?

And quite a few parents with children with autism have been saying that for many, many years.

A few details from the Chandler study:

  • Three groups of children participated in the study: ASD (n=132), SEN (special educational needs) but no autism (n=81), and typically developing kids (n=82) based on the snappily titled SNAP (Special Needs and Autism Project) cohort. The ASD group were also subdivided into broad (n=89) and narrow autism (n=43).
  • A questionnaire was used to collect parental views on offspring gastrointestinal (GI) symptoms (vomiting, constipation, diarrhoea, etc.) during the course of interviews for diagnostic assessment. This was accompanied by a food diary type questionnaire (over 3 days) and a blood draw from some of the participants to look for some of the signs and symptoms of GI-related pathology such as coeliac (celiac) disease (CD).
  • Quite a few results: one child with ASD (1/68) came up positive for anti-endomysial antibodies and was subsequently diagnosed with CD.
  • Almost half of the kids with ASD were reported to have at least one GI symptom in their lifetime compared with around a quarter of kids from the other groups.
  • Children with ASD also had significantly higher rates of current GI symptoms than the other groups, especially things like soiling. Same goes for rates of past GI symptoms among the ASD group.
  • Things can only get better? Well, it did appear that "fewer GI symptoms were reported currently compared to the past in all groups" but there's not very much in the way of information as to why this might have occurred (maturity? intervention?).
  • Gender, a history of regression, "faddy diet" or autism severity showed no significant association with the reported presence of GI issues.

Complexity

Those with a keen eye on the autism research field might recognise some of the authorship group on the Chandler paper as being the same which, for example published on the 1% prevalence rate of autism in London, UK** and an important 'regression happens in some cases of autism' paper*** to name just a few. Oh, and this paper****...

The notion of a GI element comorbid to cases of autism still has the ability to exact some eye-rolling from some people based to a large extent on "that research paper" (now retracted but still cited by Chandler et al) or more precisely what happened following its publication. All I have to say is that the GI - autism link has been with us for at least 40 years (see this post on the paper by Goodwin published in 1971) probably longer, and as yet, no-one really knows the precise hows and whys, which are likely to be complex and possibly as multiple as autism is itself.

Who said it

Whilst the Chandler findings are not necessarily new news to the autism research world nor to many parents of children with autism, I personally do find them to be significant insofar as who reported them. Without hopefully speaking out of turn, I've touched upon the topic of hierarchy in autism research, and how the translation of research findings from lab to real-life is not necessarily just about what has been found but also by who. Both here in the UK and beyond, the SNAP group members comprise some of the movers and shakers in autism research as per not only the 1% autism prevalence study from 2006 but also the overlap with, for example the PACT trial (discussed in this post). Indeed even some of the UK NICE guidance on autism (final strand due August 2013) is chaired by a member and corresponding author of the Chandler study. Don't discount this important variable.

I'm also very happy to report that alongside their findings, Chandler et al carry reference to the very important paper by Phillip Gorrindo and colleagues***** which should answer some questions about how parental report of GI symptoms in cases of autism might not necessarily be a million miles away from "evaluations by pediatric gastroenterologists". In other words, parents might actually know when their children present with potentially significant bowel issues. A shocker, I know.

Comorbidity

What's more to be said about the study? Well, that one case of CD comorbid to autism reiterates the fact that a diagnosis of autism is seemingly protective of nothing and further enhances the view that screening for CD should perhaps be undertaken when an autism diagnosis is given. The fact that the child's CD presentation was described as clinically silent: ".. but had no GI symptoms" should also figure in any discussions about CD screening. My mind also wanders back to that case study paper by Stephen Genuis****** on what happened to autistic symptoms when a gluten-free diet was installed, and whether any follow-up was made on the child identified with CD during the Chandler study. Don't even get me started on the whole non-coeliac gluten intolerance area requiring further investigation; something which some other important movers and shakers seem to be taking quite seriously.

I've also talked previously about the Kushak paper (see this post) and their suggestion that bowel issues might also be indicative of lactose intolerance, or at least the requirement for another potential screening parameter following the autism diagnosis. Food for thought indeed, bearing in mind GI issues may intersect with other facets of autism presentation too.

Final words

But perhaps the take-home message from the Chandler study is that now we all know that GI issues can occur alongside quite a sizable proportion of children with autism, there really is no point in sticking our heads in the sand about this anymore. Assuming that one can see past autism as just being the sum of the dyad of presented symptoms (which didn't seem a problem when it came to that recent optimal outcome paper) and in order to correct some of those quite startling health inequalities that seem to be emerging, should we not be more widely implementing the Buie recommendations (here and here) and perhaps doing something about such bowel issues when they are present? Or at least committing a few more resources to looking at the hows and whys? Y'know for the sake of quality of life, self-dignity, self-esteem and such like?

To close, Jimi at his very best.

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* Chandler S. et al. Parent-reported gastro-intestinal symptoms in children with autism spectrum disorders. J Autism Dev Disord. February 2013.

** Baird G. et al. Prevalence of disorders of the autism spectrum in a population cohort of children in South Thames: the Special Needs and Autism Project (SNAP). Lancet. 2006; 368: 210-215.

*** Baird G. et al. Regression, developmental trajectory and associated problems in disorders in the autism spectrum: the SNAP study. J Autism Dev Disord. 2008; 38: 1827-1836.

**** Baird G. et al. Measles vaccination and antibody response in autism spectrum disorders. Arch Dis Child. 2008; 93: 832-837.

***** Gorrindo P. et al. Gastrointestinal dysfunction in autism: parental report, clinical evaluation, and associated factors. Autism Res. 2012; 5: 101-108.

****** Genuis S. & Bouchard TP. Celiac disease presenting as autism. J Child Neurol. 2010; 2 :114-119.

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ResearchBlogging.org Chandler S, Carcani-Rathwell I, Charman T, Pickles A, Loucas T, Meldrum D, Simonoff E, Sullivan P, & Baird G (2013). Parent-Reported Gastro-intestinal Symptoms in Children with Autism Spectrum Disorders. Journal of autism and developmental disorders PMID: 23371507