Thursday, 2 February 2017

Hyperuricemia present in both medicated and unmedicated kids with autism

I was intrigued to read the findings reported by Natchaya Vanwong and colleagues [1] talking about the presence of hyperuricemia - an excess of uric acid in the blood - in their cohort of children and young adults diagnosed with an autism spectrum disorder (ASD). Intrigued not only because the authors discuss how the use of the atypical antipsychotic risperidone might *correlate* with elevations of uric acid but also how: "Hyperuricemia was present in 44.70% of risperidone-naïve patients with ASD."

Uric acid, more readily associated with the condition gout, has been mentioned before on this blog in the context of autism (see here) and other conditions/states (see here) not totally unfamiliar to autism. It's therefore not necessarily new news that elevations of the stuff might have been found again. The Vanwong study looked at uric acid levels in "127 children and adolescents with ASD treated with risperidone and 76 age-matched risperidone-naïve patients with ASD" alongside a few other biological parameters. They concluded that yes, quite a few participants in their cohort presented with hyperuricemia "defined as the level of uric acid concentration in the blood >5.5 mg/dL" bearing in mind no 'not-autism' control group was included for direct study (including those not diagnosed with autism but in receipt of risperidone).

Implications following the Vanwong study? Well, bearing in mind that gout is traditionally seen as a disease of middle-to-older age, the first thing would be to screen for gout in those with high uric acid levels and keep monitoring just in case gout develops. Next up would be to perhaps also look at some of the "rare inherited genetic disorders that cause hyperuricemia" and whether they might 'overlap' with the presentation of autism; y'know in the context that 'autism genes are probably not just genes for autism' and all that. At this point, I'm also minded to remind readers of the important (but often forgotten work) by Mary Coleman and Ted Page [2] on the topic of autism and uric acid, bringing in purine metabolism 'issues' as something potentially important to some autism (uric acid comes about as a consequence of the metabolism of purines). This, in the context of the autisms (plural)...

Insofar as the potential correlation posed between uric acid and risperidone usage, a word of caution is perhaps warranted but big words about 'risperidone causing hyperuricemia' are not required at this point in time without further study. Remember: "Hyperuricemia was present in 44.70% of risperidone-naïve patients with ASD and 57.50% of ASD patients treated with risperidone." I say this mindful that there are biological parameters that do need careful inspection when such antipsychotic therapy is put in place (see here) but the data is not yet so convincing when it comes to uric acid elevations and risperidone use.

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[1] Vanwong N. et al. Hyperuricemia in Children and Adolescents with Autism Spectrum Disorder Treated with Risperidone: The Risk Factors for Metabolic Adverse Effects. Front. Pharmacol. 2017. 5 Jan.

[2] Page T. & Coleman M. Purine metabolism abnormalities in a hyperuricosuric subclass of autism. Biochim Biophys Acta. 2000 Mar 17;1500(3):291-6.

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ResearchBlogging.org Vanwong N, Srisawasdi P, Ngamsamut N, Nuntamool N, Puangpetch A, Chamkrachangpada B, Hongkaew Y, Limsila P, Kittitharaphan W, & Sukasem C (2017). Hyperuricemia in Children and Adolescents with Autism Spectrum Disorder Treated with Risperidone: The Risk Factors for Metabolic Adverse Effects. Frontiers in pharmacology, 7 PMID: 28105014