Levels of Growth Hormone and Large Head Circumference in Autistic Boys
Finding a “promising new lead in the quest to understand autism” is one researcher’s comment on a new study that found that boys with autism have high levels of growth hormones is of interest. These higher levels of growth hormone, the researchers think, may suggest why many autistic children have a proportionately larger head circumference than same-aged children who do not have autism. The hormones are insulin-like growth factors 1 and 2 and stimulate cellular growth. Researchers also found that autistic boys weighed more and have a higher BMI (body mass index; a ratio of a person’s weight and height)—and being the non-scientist mother of a macrocephalic, tall-for-his-age (ever since he was born) autistic boy, is why I found this study of interest.
A press release from the NIH further notes:
While it has long been noted that many children with autism have a larger head circumference than other children, few studies have investigated whether these children are also taller and heavier, Dr. Mills added.
Researchers analyzed medical records and blood samples from 71 boys diagnosed with autism and ASD who were patients at Cincinnati Children’s Hospital Medical Center from March 2002 to February 2004. The researchers compared the information on the boys with autism and autism spectrum disorders to other boys treated for other conditions at the hospital and who do not have autism. Children with conditions that may have affected their growth — such as being born severely premature, long-term illness, or the genetic condition Fragile X were not included in the study. Girls are much less likely to develop autism than are boys, and the researchers were unable to recruit a sufficient number of girls with autism to participate in the study.
Dr. Mills explained that the bone age of the boys with autism — the bone development assessed by taking X-rays and comparing the size and shape of the bones to similarly-aged children — were not more advanced in the group of boys with autism. For this reason, Dr. Mills and his coworkers ruled out the possibility that they were merely maturing more rapidly than were the other boys.
The ultra-common-sensible autism mother side of me wanted to add, perhaps some autistic boys weigh more because they have hyptonia (low muscle tone) and exercise less; perhaps they are taking medications (such as Risperdal) that come with the side effect of increased appetite; perhaps they are in the sort of educational or therapeutic program (not Charlie’s) uses food as a reinforcer. On the other hand, it has long been noted that Charlie has a big head and that he is big for his age—-I am wary of over-emphazing Charlie’s size: I have too read too many accounts emphasizing that a child “weighs X pounds” and “has the mind of a toddler”—-Charlie weighs what he weighs and, being ten years old, has the mind of a ten year old. And I am interested in finding about more about how this came to be.
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POSTED IN: Neuroscience, Science
24 opinions for Levels of Growth Hormone and Large Head Circumference in Autistic Boys
laurentius-rex
Jun 22, 2007 at 7:35 pm
It has *long* been noted that *many* ……… have a *larger*
Well I have long noted that many scientists have a lesser understanding of statistics :)
where is the precision in the press release, the much vaunted scientific method.
For the record my head circumference is smaller than average for someone of my height (indeed for most adult humans) and have always had a low BMI even now when I am heavier than ever it is not excessive. I am sure there are *many* others who don’t fit either, and indeed within the research you would expect that too.
What irks me is my suspicion that there is probably a lot of selection going on to find research subjects who already fit a lot of stereotypes. I have *long* been saying this.
What does not seem to be done at the moment is any comparitive study between these studies because I suspect that if you were to look at the genes that control certain features that some scientist find are predictive of autism you will find that there is also contradictory genetic research as well. In fact I would not be surprised if a large number of these reported traits and findings if mapped, would prove not only to have a poor overlap between the sets but might even be found to be mutually exclusive, and who is doing that research I wonder ?
Who is mapping the often contradictory and competing theries of cognitive science onto the bio-genetic ones and then controlling for the 20th and 21st centuries ?
Lolasmom
Jun 22, 2007 at 7:42 pm
Lola is tall, something like the 95th percentile. Of course, Dad is 6′3″, grandpa is 6′2″, Grandma is 5′9″, aunt is 5′10″, etc. Lola also has a big head - like 99th percentile. But so does her mom :) and her NT brother, and my mom, etc. I had always heard it wasn’t the overall size of the head so much as it was a growth spurt in head circumference - the kids that start out at 50th percentile and explode up to 95th percentile were more likely to have autism, but not so the kids whose heads had been 95th percentile since birth.
Rose
Jun 22, 2007 at 9:43 pm
Ben was always in the 95th percentile, and in the 99th for head size, two standard deviations above the norm since birth. His father and I are both fatheads…but because he’s adopted maybe it’s environmental, too….
Kristina Chew, PhD
Jun 22, 2007 at 9:45 pm
Here I will reveal that the first thing my grandfather (my dad’s dad, Yeh Yeh) said on seeing me in the hospital was “she’s got a big forehead! she’s going to be smart!”.
Daisy
Jun 22, 2007 at 10:20 pm
Fascinating — the theory and the comments. Amigo has always been large, head and body, but it does run in the family. It may or may not be relevant to his Aspergers.
Caroline
Jun 22, 2007 at 10:27 pm
Re: medications causing changes in weight - Kristina’s point about hypotonia and medications cannot be stressed enough.
so often the older children with asd and other syndromes with behavioral components are overweight from medications.
we watched our child turn from a slender child into a chunkster literally overnight from a low dose of depakote - which works quite well with another anti-seizure medication but the weight gain is alarming. It is a terrible side effect of a helpful medication.It affects girls with epilepsy as well in just the same way.
Morgan
Jun 22, 2007 at 10:50 pm
K born 9lbs 7oz and at the top of his class in height and weight until age 3 when he slowed to the mid 90th percentile. Smart as a whip, too — much more going on in that big head of his than anyone has yet plumbed.
Kristina Chew, PhD
Jun 22, 2007 at 11:05 pm
Same with Charlie—-born 8 lbs 3 oz and long.
Kathy
Jun 22, 2007 at 11:53 pm
Mark was 9lb 3oz at birth with rather a large head too.
However, fatheads run in my husbands family.
Lol!
Vicky
Jun 23, 2007 at 2:23 am
Ive literally seen hundreds of kids on the spectrum.
They or we come in all shapes and head shapes..
You really can’t generalize from some of these research papers… they are selective and will find what they are looking for by being selective..
Joe
Jun 23, 2007 at 10:10 am
Jack was 12 lb 1.2 oz. at birth (actually C-Section).
mumkeepingsane
Jun 23, 2007 at 10:17 am
Well Patrick hasn’t fit into any theory yet and here’s another one into which he doesn’t fit. He was smaller than his older brother at birth (but large, 10lbs12oz) and has a smaller head than his brother. Actually I’d say his NT’s brother’s head is larger than normal and Patrick’s is about average in size. He’s always been around 95% percentile in height and weight.
Suzanne
Jun 23, 2007 at 10:21 am
just weighing in with Ezra’s body type … tall and thin(though heavy). His head was off the charts before birth. 15” circumference at birth… continued to grow rapidly(as Lola’s Mom mentioned, the growth was the concern), causing the doc to order ultrasound before his Fontanelle closed. CAT scan around age 2 (starting the dx road)(ventricles functioning properly) His hormones were also checked and found within acceptable levels.
we have fat-heads on both sides
I also see shadow traits among fat-heads
lol
they are selective and will find what they are looking for by being selective So true Vicky. (and Larry)
Kristina Chew, PhD
Jun 23, 2007 at 11:23 am
When you’ve measured one autistic child’s head circumference, you’ve measure one child’s head circumference……..
MomtoJBG
Jun 23, 2007 at 4:44 pm
Our twins were preemies, and the only measurement that was “on the chart” was the head circumference.
They have been way, way off the charts since six months. We have big heads on both sides of the family, but the boys go far beyond that.
laurentius-rex
Jun 24, 2007 at 8:59 am
And of course there is a recent study from Palermo that is more circumspect in drawing global conclusions
“These observations suggest that an abnormal cephalic
index may characterize a *subgroup* of autism and, if
replicated, will support the existence of disturbances
between 14–28 weeks of gestation, which may correspond
to a critical period for cortical development.”
Minor physical anomalies in children with autism
spectrum disorder
Gabriele Tripi a,⁎, Sylvie Rouxb, Tatiana Canziani a,c,
Frédérique Bonnet Brilhault b, Catherine Barthélémy b, Fabio Canziani
Early Human Development 2007
The American studies seem to go with a lot of hype from there press departments trumpeting what is essentially a distortion of what the studies say in most cases.
RAJ
Jun 24, 2007 at 11:04 am
Here’s a study published in the Journal of Autism and Developmental Disorders that showed a ‘large head circumference’ in 16.7% of a large autism sample…. the same study found that 15.1 % of the sample had ’small head circumference’. Furthermore, 6% of the total population have a ‘large head circumference’.
Microcephaly and macrocephaly in autism.
Fombonne E, Rogé B, Claverie J, Courty S, Frémolle J.
J Autism Dev Disord. 1999 Apr;29(2):113-9.
“Data from a series of 126 autistic children ages 2-16 years and referred to an Autism Diagnosis Unit in South-West France were examined. Macrocephaly (head circumference > 97th centile) was observed in 16.7% of the sample, a significantly higher proportion than that expected. Macrocephaly was more frequent among older subjects but was otherwise not associated with gender, developmental level, the presence of epilepsy or of medical disorders, or severity of autistic symptomatology. Microcephaly (head circumference
laurentius-rex
Jun 24, 2007 at 5:44 pm
In other words, in autism there is an almost equal higher prevalence at either end of the bell curve of head circumferences however the majority still fall within the bell curve of “normal” head circumference. The shape of the bell is a bit different that is all in terms of the gradients of the curves but it is not overally skewed in any one direction if Fombonne and his bon hommes are correct about there bonces.
RAJ
Jun 24, 2007 at 10:25 pm
The whole topic of measuring head circumferences is too reminiscent of the 1930’s Germany where another group with suspect geneology were examined for physical attributes and psychological traits, including being measured for head circumferences. Junk science includes not having any controls or comparison groups.
Here’s another study that found ‘large heads’…. but not specific to autism.
J Intellect Disabil Res. 1999 Aug;43 ( Pt
4):279-82.Links
Is megalencephaly specific to autism?
Is megalencephaly specific to autism?
Ghaziuddin M, Zaccagnini J, Tsai L, Elardo S.
University of Michigan, Ann Arbor 48109-0390, USA. mghaziud@umich.edu
Several recent reports have described the presence of increased head circumference (megalencephaly) in patients with autism. Although some studies have described reports of megalencephaly in other disorders such as schizophrenia in adults, few such studies have been performed in children and adolescents. In the present study, the authors compared 20 subjects with autism/ pervasive developmental disorder (DSM-IV; all males; mean age = 10.9 years) with 20 controls with attention deficit hyperactivity disorder (DSM-IV; all males; mean age = 11.1 years). Four subjects and five controls had evidence of megalencephaly. In addition to their core symptoms, the autistic subjects with megalencephaly were hyperactive and impulsive. These findings suggest that megalencephaly may not be specific to autism, and when present, it may index the presence of additional symptoms such as hyperactivity and impulsivity.
Kristina Chew, PhD
Jun 24, 2007 at 10:37 pm
Thanks for the reference and the point about measuring head circumference—-when Charlie’s first pediatrician saw that he had a big head, she said “that means he has a big brain—-and that’s all.”
laurentius-rex
Jun 25, 2007 at 1:53 am
Heres another one which urges caution
Volumetric MRI in autism: Can high-tech craniometry provide neurobiological insights?
[Editorials]
Mink, Jonathan W. MD, PhD; McKinstry, Robert C. MD, PhD
This one cites Goulds mismeasure of man, which if you read it gives the sad history of craniometry.
Anyway since few of you will have access to the Neurology paper I will quote, and here it says much the same as I have about the selectivity of these various studies.
“Are there other neurobiological implications of these studies? The ability to infer brain function from brain size is clearly limited. There is a long history of failed attempts to associate brain size with intelligence both across and within species. 6,7 Although one of the foundations of modern neurology is localization of function in the nervous system, attempts to correlate specific brain region size with neurologic function (or deficit) have been fruitless. The validity of localization was initially based on the effects of focal brain lesions and is supported by modern neurophysiology and functional imaging. In autism, focal brain lesions are uncommon; when present, they do not occur in one specific location. 5 Currently, neuroimaging contributes little to our understanding of the neurobiology of autism. This potential role for structural imaging in disease has been realized for other brain disorders where targeted, hypothesis-driven neuroimaging studies have identified meaningful structure–function correlations. 8,9 These studies, motivated by established functional deficits, analyzed specific structures in a homogenous study population to address relevant neurobiological questions.
For future anatomical imaging studies to provide substantial new insight into autism, several conditions must be met. First, patient heterogeneity must be minimized because clinical heterogeneity may reflect pathophysiologic heterogeneity. Clinical subgroups of autism should be defined based on valid and reliable measures. Some studies have limited enrollment based on IQ, age, presence of seizures, or degree of language development. However, these criteria do not sufficiently limit the heterogeneity of the sample population. Consensus is needed on how to sort subjects so that inclusion–exclusion criteria may be applied consistently across studies. Second, it is important that studies use consistent methodology to acquire the structural MR data, to normalize the image data, to segment brain structures, and to report the measurements. Among studies of brain size in autism, there are nearly as many methodologic variations as there are studies. Hence, it is difficult to know whether discrepant findings are due simply to methodologic rather than neurobiological differences. Although technical progress necessarily leads to changing methodology, the fact that even contemporaneous studies by the same authors have not used identical methods is problematic. Third, studies must be hypothesis driven. The hypothesis should dictate selection of subjects, brain regions, and methods. Until the field can meet these challenges, the observations of slight variations in parts of the brain remind the casual observer of phrenology.”
I hope that satisfies all of you who are forever accusing me of not having proper citations for the allegations I make. You are lucky I am feeling generous today.
Robin
Nov 9, 2007 at 6:32 pm
My son, James, has Aspergers. He’s always been big for his age. He has a high BMI, but he has an enormous appetite. But his height and head are also large. At the age of 7, he wears an adult size hat. His head is bigger than mine. I would like to note, that even though I breast fed him exclusively until the age of at least 5 months, he was overweight and large even then. It was only recently that the link between larger kids (especially the part about the larger heads) and autism was brought to my attention, so this is quite interesting to me. I bet it will be to his doctor, too.
Kristina Chew, PhD
Nov 10, 2007 at 1:32 am
My son is the same—has worn an adult size hat and bike helmet sice he was 6 years old or so. Charlie was a big baby and tall withbig feet—-and likes to eat, too!
Rachel
Mar 30, 2008 at 3:14 pm
I didn’t think the conclusion of the study was that children with Autism are more likely to have big heads so much as they were more likely to have a much larger increase in the head circumference between birth and 3 yrs. My son was born with a head circumference on the 25th percentile and by 3 his head circumferaece was on the 95th percentile whie his height and weight remained close to the 25th percentile throughout his first 3 yrs. At 3 he was diagnosed with PDD-NOS. We put him on the GFCF diet and now his head looks average to small for the 9 yr old he now is (21″). I can’t find any head circumference charts for older US children to confirm my assesment. As far as development is concerned he had ABA at a special Autistic school for 2 yrs, was brought back into district with assistance and has been mainstreamed with no aide for the last 3 yrs with a 1 1/2 hr pull out for special help with language arts. He’s advanced for maths and his social development is perhaps about a year immature with weak social intuition being the underlying difficulty. I don’t think he’d have qualified for his diagnosis for the last few years but there’s no benefit in having it removed when he still need a little extra help.
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