Obesity in Children With Autism Spectrum Disorders

Manely Ghaffari, MD; Richard P. Malone, MD; Aneela Khan, MD; Susan H. West, PhD; Mary A. Delaney, MD; Tonya Lawrence, MD; Craig J. Newschaffer, PhD; and Harold H. Hardison, MD
Drexel University College of Medicine, Philadelphia, Pennsylvania (Drs Delaney, Ghaffari, Hardison, Lawrence, Malone, and West); Einstein Hospital, Philadelphia, Pennsylvania (Dr Khan); and Drexel University School of Public Health, Philadelphia, Pennsylvania (Dr Newschaffer)

This poster presentation was supported by FDA grant FD-R-002190 and NIMH RO1 grant MH073524.

Objective: Little data exist on the prevalence of obesity in children with autism spectrum disorders.¹ This report describes findings on body mass index (BMI) and the effect of medication treatment history on BMI in a population of children screened for an on-going federally-funded long-term study of olanzapine in autism.

Methods: In all, 110 children (89 males and 21 females) aged three to 12 years (mean, 7.07±2.5), with a diagnosis of autism spectrum disorder (ASD), were screened for the study. Data collection included demographic information, BMI and BMI percentile, and past and current histories of medication treatment. The CDC criteria² were used to categorize children as obese (≥ 95th percentile for BMI), overweight (85th ≤ x < 95th percentile), healthy (5th ≤ x < 85th), and underweight (< 5th percentile). Weight categories were cross-tabbed with medication use indicator variables and chi-square statistics used to test for statistical significance (5% alpha error tolerance). Continuous BMI distributions were also compared across medication use categories. Gender differences in BMI and medication use were also considered, with analyses completed also stratified by gender.

Results: Overall, thirty-one (28.1%) of the children were obese, twenty (18.1%) overweight, fifty-six (50.9%) healthy weight, and 3 (2.7%) underweight. Those treated with antipsychotics (current and past) tended to be heavier than non-treated (40% versus 26% obese); the differences did not attain statistical significance due to sample size limitations. There were lower proportions of obese and overweight children among current, but not past, stimulant users compared to nonusers; these differences did not attain statistical significance (42% of current users versus 57% of non-users). No other statistically significant, or marked differences in BMI were noted for other medication classes. Males were significantly more obese and overweight than females (chi-square p-value=0.04). Medication use was more common among males, but it was only statistically significant for prior stimulant use. To guard against confounds, analyses were stratified by male gender and results were similar to those of the full cohort.

Conclusions: The rates of obesity in this population with ASD was greater than that previously reported in other ASD populations,¹ and rates of obese and overweight children in our sample were above those reported in the general population.³ There was a trend towards children with a history of past or present antipsychotic use having a higher BMI than non-users. In contrast, current users of stimulants had lower BMIs than non-users.

References

1. Curtin C, Bandini LG, Perrin EC, et al. Prevalence of overweight children and adolescents with attention deficit hyperactivity disorder and autism spectrum disorders: a chart review. BMC Pediatr. 2005;5:48.
2. Centers for Disease Control and Prevention. www.cdc.gov.
3. Ogden CL, Carroll MD, Flegal KM, et al. High body mass index for age among US children and adolescents, 2003–2006. JAMA. 2008;299(20):2401–2405.

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