(https://dc.etsu.edu/asrf/2024/schedule/124/)

Abstract
Background: Autism is a neurodevelopmental disorder characterized by enduring
difficulties in behavior, cognition, and social communication. Its prevalence varies
worldwide, with males being diagnosed more frequently than females. The impact of
autism extends beyond the individual, affecting family dynamics, educational
systems, and public perceptions. In the United States of America, 2.8% of children
aged 3-8 years have autism, with fourfold higher incidence among males. Factors
such as race, sex, and extreme prematurity have been associated with autism. Given
that over 54% of children with autism have intellectual disabilities, and the complex
inheritance pattern of the disease, exploring other determinants are crucial due to its
significant impacts on individuals, family, and society. Methods: This analysis used
the National Survey of Children's Health (NSCH) 2022 data, including 54,103
children aged 0-17 years. Descriptive statistics was carried out, associated
determinants were established, and logistic regression was utilized to calculate odds
ratios (OR), with autism as the dependent variable, adjusting for various factors.
Results: The odds of autism among males were 3 times higher than in females.
Children living at 0-99% of federal poverty level had 59% higher odds of autism
compared to those at 400% or greater of federal poverty level. Children reporting fair
or poor health demonstrated 10 times odds of autism than those with excellent health.
Children with unmarried parents had 31% higher odds of autism than those with
married parents, while children of unemployed parents had 64% higher odds than
those with employed parents. Children with genetic or inherited conditions exhibited
5.38 odds of autism than those without such conditions. The odds of autism among
children with low birth weight were 68% higher than in children with normal birth
weight. Additionally, for every one event of adverse childhood experience, the odds
of autism increased by 26%. Conclusion: The observed higher incidence of autism in
males compared to females aligns with previous research findings. This study
highlights the importance of adopting a comprehensive approach to address autism,
recognizing the interaction of genetic, environmental, and socioeconomic factors in its
development. Further research into the complex relationships between these
characteristics is needed. With this information, support groups, policymakers, and
healthcare professionals can collaboratively develop targeted intervention programs
aimed at mitigating the adverse effects of these risk factors and improving the lives of
individuals affected by autism.

Citation: Nwajiugo R., Zheng S., Aderinwale O., et al., 2024. Prevalence and Risk
Factors of Autism in the United States.Digital Commons @ East Tennessee State
University

Open access article: https://www.sciencedirect.com/science/article/pii/S000291652400443X

Abstract
Food and nutrition-related factors have the potential to impact development of  autism
spectrum disorder  (ASD) and  quality of life  for people with ASD, but gaps in
evidence exist. On 10 November 2022, Tufts University’s Friedman School of
Nutrition Science and Policy and Food and Nutrition Innovation Institute hosted a 1-d
meeting to explore the evidence and evidence gaps regarding the relationships of food
and nutrition with ASD. This meeting report summarizes the presentations and
deliberations from the meeting. Topics addressed included prenatal and child dietary
intake, the  microbiome , obesity, food-related environmental exposures, mechanisms
and  biological processes  linking these factors and ASD, food-related social factors,
and data sources for future research. Presentations highlighted evidence for protective
associations with prenatal  folic acid  supplementation and ASD development,
increases in risk of ASD with maternal gestational obesity, and the potential for
exposure to environmental contaminants in foods and food packaging to influence
ASD development. The importance of the maternal and child  microbiome  in ASD
development or ASD-related behaviors in the child was reviewed, as was the role of
discrimination in leading to disparities in environmental exposures and  psychosocial
factors  that may influence ASD. The role of child diet and high prevalence of food
selectivity in children with ASD and its association with  adverse outcomes  were also
discussed. Priority evidence gaps identified by participants include further clarifying
ASD development, including biomarkers and key mechanisms; interactions among
psychosocial, social, and biological determinants; interventions addressing diet,
supplementation, and the microbiome to prevent and improve quality of life for
people with ASD; and mechanisms of action of diet-related factors associated with
ASD. Participants developed research proposals to address the priority evidence gaps.
The workshop findings serve as a foundation for future prioritization of scientific
research to address evidence gaps related to food, nutrition, and ASD.

Citation: Melissa Maitin-Shepard, Perrie O’Tierney-Ginn, Aletta D Kraneveld,
Kristen Lyall, Daniele Fallin, Manish Arora, Alessio Fasano, Noel T Mueller, Xiaobin
Wang, Laura E Caulfield, Aisha S Dickerson, Rochellys Diaz Heijtz, Tomo Tarui,
Jeffrey B Blumberg, Calliope Holingue, Rebecca J Schmidt, Johan Garssen,
Katherine Almendinger, Pi-I Debby Lin, Dariush Mozaffarian,
Food, nutrition, and autism: from soil to fork, The American Journal of Clinical Nutrition, Volume 120, Issue 1,
2024, Pages 240-256

Open access article: (https://www.ingentaconnect.com/content/ben/cmc/pre-prints/content-bms-cmc-2023-157)

Abstract
Existing evidence indicates that environmental factors might contribute up to 50% of
the variance in autism spectrum disorder (ASD) risk. This structured narrative review
offers a comprehensive synthesis of current knowledge on environmental risk factors
in ASD, including evaluation of conflicting evidence, exploration of underlying
mechanisms, and suggestions for future research directions. Analysis of diverse
epidemiological investigations indicates that certain environmental factors, including
advanced parental age, preterm birth, delivery complications, and exposure to toxic
metals, drugs, air pollutants, and endocrine-disrupting chemicals, are linked to an
increased ASD risk through various mechanisms such as oxidative stress,
inflammation, hypoxia, and its consequences, changes in neurotransmitters, disruption
of signaling pathways and some others. On the other hand, pregnancy-related factors
such as maternal diabetes, maternal obesity, and caesarian section show a weaker
association with ASD risk. At the same time, other environmental factors, such as
vaccination, maternal smoking, or alcohol consumption, are not linked to the risk of
ASD. Regarding nutritional elements data are inconclusive. These findings highlight
the significance of environmental factors in ASD etiology and emphasize that more
focused research is needed to target the risk factors of ASD. Environmental
interventions targeting modifiable risk factors might offer promising avenues for ASD
prevention and treatment.

Citation: Yenkoyan Konstantin, Mkhitaryan Meri, Bjrklund Geir, Environmental Risk
Factors in Autism Spectrum Disorder: A Narrative Review,Current Medicinal
Chemistry, volume 31, issue 17, pages 2345-2360.

 Open access article:  (https://pubmed.ncbi.nlm.nih.gov/35238171/ )

Abstract

Prevalence estimates of autism are essential for informing public policy, raising awareness, and developing research priorities. Using a systematic review, we synthesized estimates of the prevalence of autism worldwide. We examined factors accounting for variability in estimates and critically reviewed evidence relevant for hypotheses about biological or social determinants (viz., biological sex, sociodemographic status, ethnicity/race, and nativity) potentially modifying prevalence estimates of autism. We performed the search in November 2021 within Medline for studies estimating autism prevalence, published since our last systematic review in 2012. Data were extracted by two independent researchers. Since 2012, 99 estimates from 71 studies were published indicating a global autism prevalence that ranges within and across regions, with a median prevalence of 100/10,000 (range: 1.09/10,000 to 436.0/10,000). The median male-to-female ratio was 4.2. The median percentage of autism cases with co-occurring intellectual disability was 33.0%. Estimates varied, likely reflecting complex and dynamic interactions between patterns of community awareness, service capacity, help seeking, and sociodemographic factors. A limitation of this review is that synthesizing methodological features precludes a quality appraisal of studies. Our findings reveal an increase in measured autism prevalence globally, reflecting the combined effects of multiple factors including the increase in community awareness and public health response globally, progress in case identification and definition, and an increase in community capacity. Hypotheses linking factors that increase the likelihood of developing autism with variations in prevalence will require research with large, representative samples and comparable autism diagnostic criteria and case-finding methods in diverse world regions over time.

Lay Summary

We reviewed studies of the prevalence of autism worldwide, considering the impact of geographic, ethnic, and socioeconomic factors on prevalence estimates. Approximately 1/100 children are diagnosed with autism spectrum disorder around the world. Prevalence estimates increased over time and varied greatly within and across sociodemographic groups. These findings reflect changes in the definition of autism and differences in the methodology and contexts of prevalence studies.

Citation: Zeidan J, Fombonne E, Scorah J, Ibrahim A, Durkin MS, Saxena S, Yusuf A, Shih A, Elsabbagh M. Global prevalence of autism: A systematic review update. Autism Res. 2022 May;15(5):778-790. doi: 10.1002/aur.2696. Epub 2022 Mar 3. PMID: 35238171; PMCID: PMC9310578.

 Open access article: (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7408756/ )

Abstract

Autism spectrum disorders (ASD) constitute a public health concern with increasing prevalence worldwide. We aimed to estimate prevalence and age at diagnosis in Greece, where no large-scale prevalence study has ever been conducted. Aggregate data were collected on ASD diagnoses by gender and calendar year of diagnosis up to 2019, for children born in 2008 and 2009, from the Centers for Educational and Counseling Support, which evaluate children to receive special educational support in school. Coverage was 87.1% of centers and 88.1% of schoolchildren born in 2008–9. ASD prevalence overall was 1.15% (1.83% males, 0.44% females; ratio 4.14:1), ranging from 0.59% to 1.50% in Greece’s 13 regions. In five regions, prevalence differed significantly between centers. Overall, only 3.8% of diagnoses were made before the fourth year after birth and 42.7% before the sixth year, with considerable variation between regions. Approximate mean age at diagnosis was six years and one month, and about three months earlier for girls than for boys. Our results provide evidence-based information to guide service planning and development at national and regional levels. Particular attention should be paid to smoothing out inequalities regarding service accessibility and provision. Emphasis should be given to earlier identification and diagnosis of ASD.

Citation: Thomaidis L, Mavroeidi N, Richardson C, Choleva A, Damianos G, Bolias K, Tsolia M. Autism Spectrum Disorders in Greece: Nationwide Prevalence in 10-11 Year-Old Children and Regional Disparities. J Clin Med. 2020 Jul 8;9(7):2163. doi: 10.3390/jcm9072163. PMID: 32650567; PMCID: PMC7408756.