Shocker alert: gut problems in autism impact on sleep (again)

"Increased odds of sleep problems were most frequently associated with gastrointestinal distress (GID) and non-verbal IQ (NVIQ), followed by male sex and age."

That was one of the findings reported by Ann Johansson and colleagues [1] who set out to examine "the relationship between sleep problems and characteristics of children with ASD [autism spectrum disorder] in a large, nationwide sample." Mention of the words 'Simons Simplex Collection' in the Johansson article provides a clue as to the source population examined in this study and some of the hows-and-whys of the research. From what I also understand, this paper is part of a doctoral thesis by Johansson looking at some of the possible genetics of sleep with autism in mind (see here). Indeed, if one scrolls to page 70 of the thesis, one finds the study in question...

The Simons Simplex Collection Sleep Interview (SSCSI) was the instrument of choice for assessing sleep issues. This is a short parent-report questionnaire that includes both a composite score for total sleep issues and subscale scores for things like 'sleep duration issues'. Alongside, GID was classified "if they were reported (yes/no) to have bloating/excess gas, celiac disease, constipation, diarrhea, ulcers, gastroesophageal reflux disease, inflammatory bowel disease (Crohn’s disease, ulcerative colitis), irritable bowel syndrome, abdominal pain, unusual stools, vomiting, and/or other GID." Throw in scores on the ADOS "used to measure ASD severity" and crunch the data...

I've inserted the word 'again' into the title of this post because this is not the first time that functional gastrointestinal issues 'over-represented' in autism have been connected to sleep issues (see here). This time around, researchers mention that over 40% of their cohort (2000+ children) "were categorized as having mild or moderate/severe sleep problems" according to their SSCSI composite score. 'Difficulty falling asleep' seemed to be one of the more frequently reported issues. GID - gastrointestinal distress - was the strongest factor linked to sleep issues (odds ratio = 2.79), again based on the SSCSI composite score for sleep issues. There were other combinations of symptoms potentially linking to sleep noted by the authors but I'm minded to put them to one side for now.

Caveats? Well, one big caveat sticks out: the reliance on parent-reported responses to a questionnaire about sleep without any reference to objective measures of sleep. I've gone on and on (and on) about the use of actigraphy when it comes to sleep research relating to various diagnostic labels (see here and see here for examples) and well, keep coming to the same conclusion about a strong requirement for such objective measures on sleep-wake cycles. I appreciate that there may be some 'consumer resistance' to wearing a wristband for example, to measure activity and rest cycles (see here), but surely someone, somewhere can engineer something when kids don't want to wear such gadgets? Insofar as the classification of GID also relying on parental report, I'm a little kinder to this because the evidence is pretty good for suggesting that parents might be tuned into what is typical and what is not typical from a functional bowel habits perspective in their offspring (see here)...

No mind, the results do accord with other independent data on how gut issues present in autism can seemingly have some far-reaching effects. As to 'how', well, I would always start with the obvious explanation: pain and discomfort caused by bowel issues affecting sleep, and then work back from there. Indeed, as if I need to say it again, bowel issues (both functional and more pathological) are truly 'over-represented' when it comes to a diagnosis of autism (see here) and science and clinical practice really need to do a lot more to tackle such issues as and when they are reported/detected...

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[1] Johansson AEE. et al. Characteristics of sleep in children with autism spectrum disorders from the Simons Simplex Collection. Research in Autism Spectrum Disorders. 2018; 53: 18-30.

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