Environmental risk factors and biomarkers for autism spectrum disorder: an umbrella review of the evidence

Environmental pollutant exposure and adverse neurodevelopmental outcomes: An umbrella review and evidence grading of meta-analyses

BACKGROUND

Exposure to environmental pollutants during foetal and childhood development has been associated with neurodevelopmental disorders; however, existing evidence remains fragmented and lacks comprehensive credibility assessments.

METHODS

PubMed, Embase, PsycINFO, and the Cochrane Database of Systematic Reviews were systematically searched from database inception through January 2025, supplemented by reference list searches. Eligible studies were meta-analyses of observational research examining the associations between environmental pollutant exposure and adverse neurodevelopmental outcomes, with quality assessment performed using the AMSTAR 2 tool. Summary effect estimates were re-analysed using random-effects models, accompanied by heterogeneity I² statistics, 95 % prediction intervals, and evaluations of small-study effects and excess significance bias. Evidence was graded according to established criteria as follows: convincing, highly suggestive, suggestive, weak, or not significant. Reporting adhered to PRISMA guidelines, and the study protocol was pre-registered with PROSPERO (CRD42022339292).

RESULTS

A total of 45 studies, comprising 256 unique meta-analyses, were included in the umbrella review. Of these, 88 meta-analyses demonstrated statistical significance; however, 62 % of these exhibited small-study effects and/or excess significance bias. According to the quantitative grading criteria, highly suggestive evidence was identified for the association between PM2.5 exposure and attention deficit hyperactivity disorder (ADHD) (odds ratio [OR] 1.82 [1.52, 2.18]), as well as for lead (Pb) exposure (OR 1.96 [1.57, 2.46]) and ADHD. Childhood fluoride exposure was also graded as highly suggestive evidence for cognitive deficit (OR 3.80 [2.42, 5.97]). Suggestive evidence included the associations between pregnancy O3 exposure and autism spectrum disorder (ASD), childhood lead exposure with decreased intelligence quotient (IQ), decreased blood magnesium (Mg) levels in children with ADHD, and first-trimester pregnancy exposure to PM2.5 and ASD. Sensitivity analyses indicated that results derived from the Restricted Likelihood Maximum (REML) estimator demonstrated greater robustness compared to the widely used DerSimonian and Laird (DL) estimator, reflecting a 13 % increase in significant associations.

CONCLUSIONS AND RELEVANCE

Neurodevelopmental disorders associated with environmental pollutants from industrial and human activities pose a critical public health challenge. Future research necessitates cautious analytical strategies and enhanced methodological transparency to improve the credibility of findings.

Association between maternal diabetes and neurodevelopmental outcomes in children: a systematic review and meta-analysis of 202 observational studies comprising 56·1 million pregnancies

BACKGROUND

Maternal diabetes might alter fetal brain development. However, well-designed systematic analyses are needed to comprehensively assess and quantify the association between maternal diabetes and neurodevelopmental outcomes in children. We aimed to synthesise and evaluate the available evidence on the effects of maternal diabetes on neurodevelopmental outcomes in children.

METHODS

For this systematic review and meta-analysis we searched PubMed, Web of Science, Embase, and EBSCO databases from inception to Dec 1, 2024, for studies exploring neurodevelopmental outcomes of children born to mothers with diabetes. The primary outcome was neurodevelopmental disorders, as defined by the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition and International Classification of Diseases 11th Revision. Data were extracted from published reports. Data were pooled with random-effects models and presented as risk ratios or standard mean differences with 95% CIs. This study was prospectively registered on PROSPERO (CRD42023395464).

FINDINGS

202 studies, involving 56 082 462 mother-child pairs, were included in the meta-analysis. Of these, 110 (54%) examined gestational diabetes, while 80 (40%) investigated pre-gestational diabetes. Among the total studies reviewed, 169 (84%) exclusively focused on children and adolescents aged up to 18 years. In studies adjusting for at least one key confounder, maternal diabetes was associated with increased risks of all types of neurodevelopmental disorders as well as lower intelligence and psychomotor scores. In studies adjusting for multiple confounders (n=98, 49%), children exposed to maternal diabetes had an increased risk of any neurodevelopmental disorder (risk ratio 1·28; 95% CI 1·24-1·31), autism spectrum disorder (1·25; 1·20-1·31), attention-deficit hyperactivity disorder (1·30; 1·24-1·37), intellectual disability (1·32; 1·18-1·47), specific developmental disorders (1·27; 1·17-1·37), communication disorder (1·20; 1·11-1·28), motor disorder (1·17; 1·10-1·26), and learning disorder (1·16; 1·06-1·26), compared with unexposed children. Maternal pre-gestational diabetes was more strongly associated with the risk of most neurodevelopmental disorders in children than gestational diabetes (risk ratio 1·39; [95% CI 1·34-1·44] vs 1·18 [1·14-1·23]; subgroup difference p<0·0001).

INTERPRETATION

Maternal diabetes is associated with an increased risk of neurodevelopmental disorders and impaired neurodevelopmental performance in children. Further high-quality research is needed to establish causality and clarify the associations between specific types of diabetes and the full spectrum of neurodevelopmental disorders.

FUNDING

The National Natural Science Foundation of China, and the Science and Technology Innovation Program of Hunan Province.

TRANSLATION

For the Mandarin translation of the abstract see Supplementary Materials section.

Multi-level treatment outcome evaluation in adolescents with autism spectrum disorder

BACKGROUND

Aberrant resting state electroencephalography (rsEEG) is a well-established indicator of psychopathological brain activity in clinical disorders. In Autism Spectrum Disorder (ASD), a substantial body of research reports reduced Alpha activity in the electrocortical resting state of affected individuals. However, effective interventions based on neurophysiological patterns and objective biological markers of treatment outcome remain scarce.

METHODS

In this randomized controlled trial, the primary objective was to examine rsEEG changes in adolescents with ASD following 24 sessions of slow cortical potential neurofeedback training (n = 21) compared to a treatment-as-usual control group (n = 20). A repeated-measures analysis of variance was used to assess group differences over time. Additionally, Pearson correlation analyses were conducted to exploratorily investigate associations between rsEEG measures and clinical psychopathology and affective well-being, as assessed via parental and self-report questionnaires at baseline and post-intervention.

RESULTS

Analyses revealed significant differences in the development of rsEEG between the intervention groups: while Alpha activity increased in the experimental neurofeedback group, it decreased in the control group, demonstrating an opposite trend. Exploratory analyses showed that Delta activity decreased in both groups, with a more pronounced decrease in the experimental group. Correlational analyses revealed significant associations between subjective-psychological and electrocortical levels: lower alpha power at baseline was related to greater severity of ASD symptoms, while both lower alpha and higher delta power were associated with greater negative affect at baseline. Increases in alpha power after NF-training were linked with enhanced positive affect, whereas reductions in delta power corresponded to decreases in negative affect.

CONCLUSIONS

This study provides insights into changes in resting-state neural activity before and after clinical interventions alongside clinical-psychological assessment, overcoming single-level assessments and emphasizing the need for multi-level outcome measures for a more comprehensive treatment evaluation.

CLINICAL TRIAL REGISTRATION

DRKS00012339.

The Gut Microbiome in Anxiety Disorders

PURPOSE OF REVIEW

We aim to update readers on the latest evidence regarding the role of the gut microbiome in generalized anxiety disorder (GAD), panic disorder (PD), agoraphobia, and social anxiety disorder (SAD). This review summarises the literature on microbiome composition and function in these conditions, provides insights about causality and mechanisms and evaluates current evidence for microbiome-based interventions in anxiety disorders.

RECENT FINDINGS

Most studies exploring the microbiome in anxiety disorders are small, cross-sectional studies. Nevertheless, some consistent findings emerge. Bacterial taxa such as Eubacterium, Coprococcus and Faecalibacterium may be depleted in GAD. Studies in PD and SAD are scarce and, to our knowledge, there have been no studies conducted in agoraphobia. Probiotics may help reduce anxiety symptoms, although the majority of studies have been in non-clinical cohorts. Large, prospective studies are required to further elucidate the role of the microbiome-gut-brain axis in anxiety disorders. Microbiome-based interventions hold promise, but randomised controlled trials in clinical populations with relevant diagnoses are now warranted and urgently required.

Combining the Risk: The Poly-Environmental Risk Score and Psychotic Symptoms in Adolescents

BACKGROUND AND HYPOTHESIS

Psychotic symptoms are common in adolescents and predictive of psychiatric disorders. Numerous risk factors have been shown to precede psychiatric disorders. However, investigating individual risk factors does not account for the cumulative effect these risk factors may have. Therefore, we combined well-researched environmental risk factors for psychotic disorder in a composite measure: the poly-environmental risk score (PERS).

STUDY DESIGN

Risk factors were assessed in a cohort of 801 adolescents (aged 15) at risk for psychopathology. Binarized risk factors included winter birth, low gestational age, low birth weight, ethnic minority status, urban living environment, cannabis use, victim of bullying, emotional abuse, physical abuse, sexual abuse, high paternal age, parental severe mental illness, parental divorce, and parental death. The PERS was weighted with the log odds derived from recent meta-analyses. At age 18, self-reported psychotic experiences (PE) and clinician-rated psychotic symptoms (PS) were assessed. This updated PERS was compared to previous PERS models, which included fewer risk factors and different weightings.

STUDY RESULTS

The PERS was associated with PE and PS. Specifically, a PERS between 3 and 4, and PERS > 4 corresponded with a 2.2- and 5.2-fold increase in the odds of psychotic symptoms in late adolescence. The updated 14-item PERS performed better compared to previous compositions of the PERS.

CONCLUSIONS

A composite score of childhood and adolescent risk factors measured at age 15 was associated with psychotic symptoms at age 18. Future research should consider the cumulative effect of risk factors when examining the determinants of psychopathology.

The effectiveness of hyperbaric oxygen therapy in children and adolescents and with autism spectrum disorders: A systematic review and meta-analysis

BACKGROUND

Hyperbaric oxygen therapy (HBOT) is considered a potential treatment for autism spectrum disorders, aiming to improve the underlying pathophysiological mechanisms. It has been studied in several clinical trials, but the effectiveness is still controversial.

PURPOSE

This systematic review aimed to systematically evaluate the effectiveness of hyperbaric oxygen therapy in the treatment of autism in children and adolescents.

METHODS

We systematically searched seven databases (PubMed, Embase, Cochrane Libraries, Web of Science, CNKI, Wanfang, and SinoMed) up to March 20, 2024, as well as references lists. The included studies evaluated the effect of HBOT on improving the core symptoms of autism and other specific symptoms (e.g., communication, sociability, cognitive awareness, behavior), including RCTs and quasiexperimental studies. The Cochrane Collaboration's Risk of Bias Assessment Tool for Randomized Trials (RoB2.0) and the JBI Risk of Bias Tool for Quasi-Experimental Studies were used as quality assessment tools. A random effects model was used to conduct a meta-analysis of the core and specific symptoms of autism. Sensitivity analyses and meta-regression were performed to identify sources of heterogeneity and assess result robustness. A Grading of Recommendations Assessment, Development, and Evaluation (GRADE) evidence certainty analysis was performed for outcomes. This systematic review is registered with PROSPERO (CRD42024527220).

RESULTS

A total of 17 studies with 890 patients were ultimately included in the metaanalysis. The meta-analysis revealed moderately large, significant effects of hyperbaric oxygen therapy, reducing core symptoms of autism [SMD = -0.66, 95 % CI (-1.04, -0.28), P = 0.0006], and improving three aspects of daily performances (communication [SMD = -0.88, 95 % CI (-1.71,-0.04), P = 0.04], cognitive awareness [SMD = -0.93, 95 % CI (-1.51, -0.35), P = 0.002], and behavior [SMD = -0.80, 95 % CI (- 1.46, -0.13), P = 0.02] in children and adolescents with autism. This systematic review and meta-analysis have limitations such as poor quality and high heterogeneity of the included study.

CONCLUSION

These findings underscore the potential benefits of hyperbaric oxygen therapy in managing autism-related symptoms and improving daily functioning in affected children and adolescents. Future rigorously designed, high-quality studies are required to confirm the efficacy of hyperbaric oxygen therapy and establish standard treatment protocols.

Enlarged perivascular spaces under the dorso-lateral prefrontal cortex and severity of autism

The glymphatic system allows cerebrospinal fluid (CSF) flow along the brain's perivascular spaces (PVS), aiding in the removal of harmful substances into the venous system. Previous studies have suggested that younger males with severe autism spectrum disorder (ASD) exhibit enlarged PVS (ePVS), although the specific regions or extent of PVS enlargement remain unclear. Additionally, it is still unknown whether the localization of ePVS correlates with specific ASD symptoms. Using automated MRI-based PVS quantification, we conducted a descriptive observational study to map the number, diameter, and volume of PVS across 72 brain areas, correlating these features with the clinical severity of autism and the presence or absence of three distinct ASD symptoms: language impairment, stereotypies, and hypersensoriality. The study involved 36 children with ASD (ages 1-9 years). A thorough analysis of ePVS in the white matter underlying 72 cortical areas revealed that different ASD symptoms exhibit specific ePVS localizations. Moreover, ePVS in the white matter beneath the two rostral middle frontal regions were associated with the overall clinical severity of ASD as well as specific symptoms (verbal dysfunction, stereotypies, and hypersensoriality). When these prefrontal subregions experience excessive PVS enlargement, it may lead to hypoactivity in the dorsolateral prefrontal cortex (DLPFC), contributing to the manifestation of ASD symptoms.

Mechanistic insights into retinoic-acid treatment for autism in the improvement of social behavior: Evidence from a multi omics study in rats

BACKGROUND

Autism spectrum disorder (ASD) is a lifelong condition. It is characterized by complex etiologies, including disruptions in exogenous retinoic acid (RA) signaling, which may serve as an environmental risk factor. Targeting the RA pathway presents a promising therapeutic avenue, though the precise mechanisms remain to be elucidated.

METHODS

Female Sprague-Dawley rats were treated with valproic acid (VPA) during pregnancy to induce an ASD model in their offspring. Some offspring received RA treatment postnatally. Social behavior and brain-functional connectivity were assessed using behavioral tests and functional magnetic resonance imaging (fMRI), respectively. Transcriptomics analysis and proteomics analysis of the hypothalamus identified differentially expressed genes (DEGs) and differentially expressed proteins (DEPs). These were intersected with ASD pathogenic genes (APGs) and ASD pathogenic proteins (APPs) to identify differentially expressed APGs (DE-APGs) and differentially expressed APPs (DE-APPs), which were validated by real-time reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting. Analyses of enrichment of signaling pathways were done using the Kyoto Encyclopedia of Genes and Genomes database.

RESULTS

RA treatment significantly improved social behaviors and revealed distinct patterns of hypo- and hyper-connectivity across various brain regions, with notable changes involving the hypothalamus and facial nerve. Differential analysis revealed 4165 DEGs (DEG 1) and 329 DEPs (DEP 1) between control and VPA groups, and 1610 DEGs (DEG 2) and 197 DEPs (DEP 2) between VPA and RA supplementation (RAS) groups. Twenty-two DE-APGs and five DE-APPs were identified, with key associations found between proteins such as Tbl1xr1 and Myo5a and >13 genes including Nrxn1, Cacna1e, and Gabrb2. Significant alterations in DE-APGs, including Grin2b, Nrxn1, Cacna1e, and Gabrb2, were confirmed via real-time RT-PCR and western blotting. In addition, 22 key signaling pathways were enriched in DEPs and DEGs.

CONCLUSION

RA supplementation in ASD rats induced by VPA may ameliorate social deficits and modulated functional connectivity, especially in the hypothalamus and facial nerve regions. This suggests potential therapeutic benefits for neural circuitry dysregulation in ASD. Additionally, RA altered critical gene and protein expressions in hypothalamus, implicating its role in modulating key signaling pathways to mitigate social deficits in ASD. This study provides new insights into the molecular mechanisms of ASD and supports the development of novel therapeutic strategies.

Folic acid and autism: updated evidences

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition that impairs communication, socialization, and behavior. The association of ASD with folic acid has been investigated due to the importance of this vitamin for neurological health. This study is an update of the publication 'Folic acid and autism: What do we know?' and aims to systematically review studies examining the relationship between folic acid and ASD. The search resulted in 2,389 studies on folic acid and ASD, which were selected by two reviewers based on their titles and abstracts. Studies meeting the inclusion criteria were fully read. The 52 included studies involved 10,429 individuals diagnosed with ASD and assessed the intake of vitamin B6, folic acid, and vitamin B12; serum levels of these vitamins, homocysteine, and methionine; therapeutic interventions using folic acid; and the association between maternal exposure to this vitamin and the risk of ASD. The evidence of insufficient folic acid intake in most individuals with ASD remains consistent in this update. No association was found between maternal exposure to folic acid and the risk of ASD in their children. Despite observed improvements in communication, socialization, and behavior in individuals with ASD following folic acid interventions, it is crucial to consider the individuality and complexity of ASD. Given the relevance of the topic, there remains a need for more high-quality research and clinical trials characterized by rigorous methodological designs.

Investigation of chromosomal anomalies and copy number variations in children diagnosed with autism spectrum disorder by array CGH method

This study aimed to identify the chromosomal anomalies and copy number variations (CNVs) in autism spectrum disorder (ASD) and to provide genotype/phenotype correlations. Fifty-four patients diagnosed with ASD between March 2021 and June 2022 were included in the study. Patients were evaluated by cytogenetic analysis and array comparative genomic hybridisation analysis (aCGH). The structural and numerical chromosomal anomaly was detected in 3.7%, and the CNVs were identified in 18.52% of patients. Of the CNVs detected, 27.3% were identified as pathogenic, 18.2% as likely pathogenic and 54.5% as VUS. The copy number gain rate of the detected CNVs was higher than the copy number losses rate, 70% and 30% respectively. As an important finding in the study, a new pathogenic CNV with a 6.3-mb copy number gain in the 3p22.3p22.2 region, whose gene region had not been previously defined in OMIM, was detected. Identifying a genetic aetiology may provide clinicians with more information about disease prognosis and risk of recurrence.

Developing a simplified measure to predict the risk of autism spectrum disorders: Abbreviating the M-CHAT-R using a machine learning approach in China

BACKGROUND

Early screening for autism spectrum disorder (ASD) is crucial, yet current assessment tools in Chinese primary child care are limited in efficacy.

OBJECTIVE

This study aims to employ machine learning algorithms to identify key indicators from the 20-item Modified Checklist for Autism in Toddlers, revised (M-CHAT-R) combining with ASD-related sociodemographic and environmental factors, to distinguish ASD from typically developing children.

METHODS

Data from our prior validation study of the Chinese M-CHAT-R (August 2016-March 2017, n = 6,049 toddlers) were reviewed. We extracted the 20-item M-CHAT-R data and integrated 17 sociodemographic and environmental risk factors associated with ASD development to strengthen M-CHAT-R's machine learning screening. Five feature selection methods were used to extract subsets from the original set. Six machine learning algorithms were applied to identify the optimal subset distinguishing clinically diagnosed ASD toddlers from typically developing toddlers.

FINDINGS

Nine features were grouped into three subsets: subset 1 contained unanimously recommended items (A1 [Follows point], A3 [Pretend play], A9 [Brings objects to show], A10 [Response to name] and A16 [Gazing following]). Subset 2 added two items (A17 [Gaining parent's attention] and A18 [Understands what is said]), and subset 3 included two more items (A8 [Interest in other children] and child's age). The top-performing algorithm resulted in a seven-item classifier of subset 2 with 92.5 % sensitivity, 90.1 % specificity, and 10.0 % positive predictive value.

CONCLUSIONS

Machine learning classifiers effectively differentiate ASD toddlers from typically developing toddlers using a reduced M-CHAT-R item set.

CLINICAL IMPLICATIONS

This highlights the clinical significance of machine learning-optimized models for ASD screening in primary health care centers and broader applications.

Human pluripotent stem cell (hPSC)-derived models for autism spectrum disorder drug discovery

INTRODUCTION

Autism spectrum disorder (ASD) is a prevalent and complex neurodevelopmental disorder (NDD) with genetic and environmental origins. Currently, there are no effective pharmacological treatments targeting core ASD features. This leads to unmet medical needs of individuals with ASD and requires relevant human disease models recapitulating genetic and clinical heterogeneity to better understand underlying mechanisms and identify potential pharmacological therapies. Recent advancements in stem cell technology have enabled the generation of human pluripotent stem cell (hPSC)-derived two-dimensional (2D) and three-dimensional (3D) neural models, which serve as powerful tools for ASD modeling and drug discovery.

AREAS COVERED

This article reviews the applications of hPSC-derived 2D and 3D neural models in studying various forms of ASD using pharmacological perturbation and drug screenings, highlighting the potential use of these models to develop novel pharmacological treatment strategies for ASD.

EXPERT OPINION

hPSC-derived models recapitulate early human brain development spatiotemporally and have allowed patient-specific mechanistic investigation and therapeutic development using advanced molecular technologies, which will contribute to precision medicine for ASD therapy. Improvements are still required in hPSC-based models to further enhance their physiological relevance, clinical translation, and scalability for ASD drug discovery.

Associations between colonization with Helicobacter pylori and risk of gastrointestinal tract cancers: An umbrella review of meta-analyses

BACKGROUND

Several studies have investigated the association between Helicobacter pylori colonization and gastrointestinal malignancies. However, inconsistent results have been found, leaving no clear consensus.

MATERIALS AND METHODS

Umbrella review of meta-analyses of observational studies aiming to understand the association between Helicobacter pylori colonization and gastrointestinal cancers in humans. MEDLINE, the Cochrane Library of Systematic Reviews, EMBASE, Scopus and Google Scholar were searched from their inception to January 2025. Quality assessment was performed with the AMSTAR 2 tool. The study was registered on PROSPERO (CRD42024523832).

RESULTS

Of 1320 records, 38 meta-analyses were included, investigating biliary tract, colorectal, oesophageal, gastric, liver and pancreatic cancers. After dealing with primary study overlap and updating meta-analyses with over 160 studies, Helicobacter pylori was positively associated with biliary tract [OR 2.67 (1.57-4.52)], colorectal [OR 1.40 (1.23-1.60)], gastric [OR 2.10 (1.34-3.31)], liver [OR 5.13 (3.14-8.38)] and pancreatic [OR 1.24 (1.04-1.48)] cancers, while oesophageal adenocarcinoma (EAC) was inversely associated with it [OR .58 (.46-.72)]. The cytotoxic-associated gene A (CagA) protein was positively associated with biliary [OR 2.19 (1.07-4.50)], colorectal [OR 2.04 (1.47-2.82)], oesophageal squamous cell carcinoma [OR 1.56 (1.30-1.89)] and gastric cancers [OR 2.53 (1.94-3.30)], and inversely associated with EAC [OR .60 (.44-.81)] and pancreatic [OR .85 (.75-.97)] cancers. Our results sprout from mostly critically low-quality meta-analyses and moderate to high quality primary studies.

CONCLUSION

Exposure to Helicobacter pylori colonization and its proteins is associated with not only gastric cancer, but also other GI tract cancers. Directionally different results may be seen when specific virulence factors/organ sites are investigated.

Preconception and gestational versus postnatal exposure to air pollutants and risk of autism spectrum disorder: a systematic review and meta-analysis

PURPOSE

The rising prevalence of ASD has prompted extensive research into potential environmental risk factors, with air pollution particularly emerging as a major concern. A systematic review and meta-analysis on the effect of air pollutants and time of exposure (particularly, PM2.5, PM10, NO2, and O3) and the risk of ASD was therefore performed.

METHODS

Following PRISMA guidelines and PROSPERO registration (Ref: CRD42023464592), a thorough literature search was conducted across multiple databases, including Scopus, PubMed/MEDLINE, Embase, PsycINFO, Web of Science, and Cochrane Library. The analysis included 27 studies encompassing 369,460 participants, 47,973 of whom were diagnosed with ASD.

RESULTS

Preconception exposure to air pollutants showed a protective trend for PM2.5, PM10, and O3 with a 10%, 5%, and 19% reduced risk of ASD, whereas NO2 had a 28% higher likelihood of ASD. During gestation, PM2.5 exposure increased ASD risk by 15%, with 13% and 9%, 25% and 7%, and 25% and 10% increases in ASD risk with PM2.5 and NO2 for the first, second, and third trimesters, respectively. In the first year of life, 20%, 8%, 33%, and 14% increases in risk were found for PM2.5, PM10, NO2, and O3, respectively, while such risk estimates increased to 179%, 60%, 12%, and 179% for the second year of life.

CONCLUSIONS

In this meta-analysis, the relationships between air pollutants and ASD risk revealed significant associations, particularly for PM2.5 and NO2. Exposure during preconception exhibited a protective trend, while postnatal exposure, particularly during the second year of life uncovered substantially higher ASD risk.

From womb to world: The interplay between maternal immune activation, neuroglia, and neurodevelopment

This chapter introduces and discusses maternal immune activation (MIA) as a contributing factor in increasing the risk of neurodevelopmental disorders, particularly in relation to its interactions with neuroglia. Here we first provide an overview of the neuroglia-astroglia, oligodendroglia, microglia, and radial glial cells-and their important role during early brain development and in adulthood. We then present and discuss MIA, followed by a critical overview of inflammatory molecules and temporal stages associated to maternal inflammation during pregnancy. We provide an overview of animal and human models used to mimic and study MIA. Furthermore, we review the possible interaction between MIA and neuroglia, focusing on the current advances in both modeling and therapeutics. Additionally, we discuss and provide preliminary and interesting insights into the most recent pandemic, COVID-19, and how the infection may be associated to MIA and increased risk for neurodevelopmental disorders. Finally, we provide a critical overview of challenges and future opportunities to study how MIA may contribute to higher risk of developing neurodevelopmental disorders.

Deficiency of FABP7 Triggers Premature Neural Differentiation in Idiopathic Normocephalic Autism Organoids

Autism spectrum disorder (ASD), which is caused by heterogeneous genetic and environmental factors, is characterized by diverse clinical phenotypes linked to distinct pathological mechanisms. ASD individuals with a shared clinical phenotype might contribute to revealing the molecular mechanism underlying ASD progression. Here, it is generated induced pluripotent stem cell (iPSC)-derived cerebral organoids from normocephalic individuals with ASD in a prospective birth cohort with a shared clinical diagnosis. Multiple cell lines and time series scRNA-seq combined with a histomorphological analysis revealed premature neural differentiation of neural stem cells (NSCs) and decreased expression of Fatty acid binding protein 7 (FABP7) in ASD organoids. It is subsequently revealed alterations in the phosphorylation levels of Mitogen-Activated Protein Kinase Kinase 1/2 (MEK1/2), which are downstream of FABP7, and the regulation of the FABP7/MEK pathway reversed improper neural differentiation in the ASD organoids. Moreover, both Fabp7-knockdown and MEK2-overexpressing mice exhibited repetitive stereotyped behaviors and social defects relevant to autism. This study reveals the role of the FABP7/MEK pathway in abnormal NSC differentiation in normocephalic individuals with ASD, which might provide a promising therapeutic target for ASD treatment.

Transcriptomic Evidence Reveals the Dysfunctional Mechanism of Synaptic Plasticity Control in ASD

BACKGROUND/OBJECTIVES

A prominent endophenotype in Autism Spectrum Disorder (ASD) is the synaptic plasticity dysfunction, yet the molecular mechanism remains elusive. As a prototype, we investigate the postsynaptic signal transduction network in glutamatergic neurons and integrate single-cell nucleus transcriptomics data from the Prefrontal Cortex (PFC) to unveil the malfunction of translation control.

METHODS

We devise an innovative and highly dependable pipeline to transform our acquired signal transduction network into an mRNA Signaling-Regulatory Network (mSiReN) and analyze it at the RNA level. We employ Cell-Specific Network Inference via Integer Value Programming and Causal Reasoning (CS-NIVaCaR) to identify core modules and Cell-Specific Probabilistic Contextualization for mRNA Regulatory Networks (CS-ProComReN) to quantitatively reveal activated sub-pathways involving MAPK1, MKNK1, RPS6KA5, and MTOR across different cell types in ASD.

RESULTS

The results indicate that specific pivotal molecules, such as EIF4EBP1 and EIF4E, lacking Differential Expression (DE) characteristics and responsible for protein translation with long-term potentiation (LTP) or long-term depression (LTD), are dysregulated. We further uncover distinct activation patterns causally linked to the EIF4EBP1-EIF4E module in excitatory and inhibitory neurons.

CONCLUSIONS

Importantly, our work introduces a methodology for leveraging extensive transcriptomics data to parse the signal transduction network, transforming it into mSiReN, and mapping it back to the protein level. These algorithms can serve as potent tools in systems biology to analyze other omics and regulatory networks. Furthermore, the biomarkers within the activated sub-pathways, revealed by identifying convergent dysregulation, illuminate potential diagnostic and prognostic factors in ASD.

HERVs Endophenotype in Autism Spectrum Disorder: Human Endogenous Retroviruses, Specific Immunoreactivity, and Disease Association in Different Family Members

Increasing evidence indicates that human endogenous retroviruses (HERVs) are important to human health and are an underexplored component of many diseases. Certain HERV families show unique expression patterns and immune responses in autism spectrum disorder (ASD) patients compared to healthy controls, suggesting their potential as biomarkers. Despite these interesting findings, the role of HERVs in ASD needs to be further investigated. In this review, we discuss recent advances in genetic research on ASD, with a particular emphasis on the implications of HERVs on neurodevelopment and future genomic initiatives aimed at discovering ASD-related genes through Artificial Intelligence. Given their pro-inflammatory and autoimmune characteristics, the existing literature suggests that HERVs may contribute to the onset or worsening of ASD in individuals with a genetic predisposition. Therefore, we propose that investigating their fundamental properties could not only improve existing therapies but also pave the way for new therapeutic strategies.

PsyRiskMR: A Comprehensive Resource for Identifying Psychiatric Disorder Risk Factors Through Mendelian Randomization

BACKGROUND

Psychiatric disorders pose an enormous economic and emotional burden on individuals, their families, and society. Given that the current analysis of the pathogenesis of psychiatric disorders remains challenging and time consuming, elucidating modifiable risk factors is crucial for the diagnosis and management of psychiatric disorders. However, inferring causal risk factors for these disorders from disparate data sources is challenging due to constraints in data collection and analytical capabilities.

METHODS

By leveraging the largest available genome-wide association study summary statistics for 10 psychiatric disorders and compiling an extensive set of risk factor datasets, including 71 psychiatric disorder-specific phenotypes, 3935 brain imaging traits, and over 30 brain tissue/cell-specific quantitative trait loci datasets (covering 6 types of quantitative trait loci), we performed comprehensive Mendelian randomization analyses to explore the potential causal links between various exposures and psychiatric outcomes using genetic variants as instrumental variables.

RESULTS

After Bonferroni correction for multiple testing, we identified multiple potential risk factors for psychiatric disorders (including phenotypic-level and molecular-level traits) and provided robust Mendelian randomization evidence that supports these associations utilizing rigorous sensitivity analyses and colocalization analyses. Furthermore, we have established the PsyRiskMR database (http://bioinfo.ahu.edu.cn/PsyRiskMR/), which serves as an interactive platform for showcasing and querying risk factors for psychiatric disorders.

CONCLUSIONS

Our study offers a user-friendly PsyRiskMR database for the research community to browse, search, and download all Mendelian randomization results, potentially revealing new insights into the biological etiology of psychiatric disorders.

Maternal adiposity and perinatal and offspring outcomes: an umbrella review

Maternal adiposity deleteriously affects obstetrical health and has been associated with long-term adverse consequences in offspring. Here we conducted an umbrella review encompassing 194 observational meta-analyses, 10 Mendelian randomization studies and 748 interventional meta-analyses to appraise the published evidence on the associations between maternal adiposity and perinatal and offspring outcomes. Evidence grading suggested that 17 (8.8%) observational meta-analyses were supported by convincing evidence for 12 outcomes: maternal adiposity was associated with an increased risk of caesarean delivery following labour induction, infant mortality, Apgar score <7 at 1 min, antenatal depression, offspring overweight and obesity, early timing of puberty onset in daughters, attention deficit hyperactivity disorder, cerebral palsy, congenital heart disease and spina bifida (OR/RR ranging from 1.14 to 2.31), as well as increased offspring body fat percent and fat mass (SMD 0.31 and 0.35, respectively). Among these outcomes, interventional meta-analyses supported that maternal weight loss interventions significantly reduced the risk of antenatal depression but not low Apgar scores; these interventions also could not reduce offspring fat mass or body fat percent. Evidence from Mendelian randomization studies supported a causal relationship between maternal adiposity and gestational diabetes mellitus, preeclampsia, birth size and offspring adiposity. Our findings highlight that while observational meta-analyses reveal associations between maternal adiposity and various adverse perinatal and offspring outcomes, convincing, unbiased evidence or support from Mendelian randomization studies is limited. Maternal pre-conceptional and prenatal weight loss interventions can reduce some, but not all, of these adverse effects.

A assessment of the effects of parental age on the development of autism in children: a systematic review and a meta-analysis

OBJECTIVE

There has been conflicting evidence in earlier research on the association between parental age and autism risk. To clarify this association, we conducted a comprehensive meta-analysis of observational studies. The primary objective of this study was to determine the association between parents' age and the risk of autism in the offspring.

METHODS

PubMed, EMBASE and Web of Science were searched for reports published up to November 2023. Results from relevant studies were pooled using random effects models. Subgroup analyses and meta-regression were performed to examine heterogeneity between the studies. Studies were included in this meta-analysis that focused on children with autism and examined the relationship between parents' age (mother or father) and the risk of autism.The quality of studies was assessed using the Newcastle-Ottawa Scale (NOS).

RESULTS

This meta-analysis included 41 articles. The low age of mother (OR = 0.96, (95% CIs: 0.88-1.05) and father (OR = 1.11, (95% CIs: 0.98-1.24) was not significantly associated with lower risk of autism in children. Conversely, greater paternal and maternal ages were associated with an increased risk of autism in their children. The adjusted odds ratios for mothers' and fathers' ages were 1.47 (95% CIs: 1.33-1.62) and 1.51 (95% CIs: 1.40-1.62), respectively.

CONCLUSION

Increased risk of autism in children is significantly associated with greater parents' ages. Further research is needed to gain further insight into the mechanisms responsible for the effects of parents' ages on the risk of autism in children. The findings of previous studies on the association between parents' ages and their children's autism risk have been mixed. Therefore, by carefully examining a number of previous investigations, in this study we aimed to determine the exact relationship between parental age and autism risk. According to the study's findings, parents who are older have a higher chance of their child getting autism. In other words, children of older parents are more likely to develop autism. The exact causes of this relationship, however, are still unclear. This study shows that higher age of parents can be one of the risk factors for autism in their childs.

The impact of paternal mental illness on child development: an umbrella review of systematic reviews and meta-analyses

Whilst there is growing evidence highlighting the importance of paternal mental illness (PMI) on child development, this relationship still remains under-studied and often over-looked. Considering the increasingly active role of fathers in their children's upbringing, a comprehensive overview of the impact of PMI on child development is overdue. This study aimed to combine and synthesise currently available evidence on the relationship between PMI and multiple domains of child development. Narrative synthesis of systematic reviews and meta-analyses on the relationship between PMI and child development (mental health and social, emotional, language, cognitive or adaptive behaviour), published between 1980 to December 2021, was conducted in line with PRISMA 2020 guidelines. Review quality was assessed based on AMSTAR-2 criteria and respective study confidence was interpreted in line with GRADE scoring. All relevant meta-analytic effect sizes were converted to odds ratios (OR) and grouped using a random effects model. Grouped meta-analyses saw PMI to have a significant, detrimental effect on all studied domains of child development [OR: 1.54; 95% CI (1.36-1.74)]. Subgroup analyses saw PMI affecting both internalising [OR: 1.62; 95% CI (1.27-2.08)] and externalising [OR: 1.63; 95% CI (1.28-2.08)] child behaviours to a similar extent. However, included reviews were of poor methodological quality, demonstrating either low or critically low confidence. These results show a consistent and influential effect of PMI on child development. The relationship between fathers' mental illness and child development warrants further investigation, as current research is limited in scope, particularly regarding cognitive domains of child development and non-affective PMI diagnoses.

Adverse pregnancy outcomes and multiple cancers risk in both mother and offspring: an umbrella review of systematic reviews with meta-analyses of observational studies

BACKGROUND

Adverse pregnancy outcomes have reached epidemic proportions in recent years with serious health ramifications, especially for diverse cancers risk. Therefore, we carried out an umbrella review to systematically evaluate the validity and strength of the data and the extent of potential biases of the established association between adverse pregnancy outcomes and cancers risk in both mother and offspring.

METHODS

PubMed, Embase, and Web of Science databases were searched from inception until 18 January 2024. Meta-analyses of observational studies investigating the relationship between adverse pregnancy outcomes and multiple cancers risk in both mother and offspring were included. Evidence certainty was assessed using Grading of Recommendations, Assessment, Development, and Evaluation. The protocol for this umbrella review was prospectively registered in PROSPERO (CRD42023470544).

RESULTS

The search identified 129 meta-analyses of observational studies and 42 types of cancer. Moderate certainty of evidence, exhibiting statistical significance, has been observed linking per kilogram increase in birth weight to a heightened risk of breast cancer (OR = 1.07, 95% CI = 1.02-1.12), prostate cancer (OR = 1.02, 95% CI = 1.00-1.05), leukemia (OR = 1.18, 95% CI = 1.13-1.23), and acute lymphoblastic leukemia in offspring (OR = 1.18, 95% CI = 1.12-1.23); rubella infection during pregnancy to an increased risk of leukemia in offspring (OR = 2.79, 95% CI = 1.16-6.71); and a linear dose-response association between an increase in the proportion of optimal birth weight and an elevated risk of acute lymphoblastic leukemia in offspring (OR = 1.16, 95% CI = 1.09-1.24), respectively.

CONCLUSIONS

Although some adverse pregnancy outcomes have clinically promising associations with risk of several cancers in both mother and offspring, it is essential to conduct additional research to solidify the evidence, evaluate causality, and ascertain clinical utility.

Risk factors, prevention and treatment of weight gain associated with the use of antidepressants and antipsychotics: a state-of-the-art clinical review

INTRODUCTION

People with severe mental illness have poor cardiometabolic health. Commonly used antidepressants and antipsychotics frequently lead to weight gain, which may further contribute to adverse cardiovascular outcomes.

AREAS COVERED

We searched MEDLINE up to April 2023 for umbrella reviews, (network-)meta-analyses, trials and cohort studies on risk factors, prevention and treatment strategies of weight gain associated with antidepressants/antipsychotics. We developed 10 clinical recommendations.

EXPERT OPINION

To prevent, manage, and treat antidepressant/antipsychotic-related weight gain, we recommend i) assessing risk factors for obesity before treatment, ii) monitoring metabolic health at baseline and regularly during follow-up, iii) offering lifestyle interventions including regular exercise and healthy diet based on patient preference to optimize motivation, iv) considering first-line psychotherapy for mild-moderate depression and anxiety disorders, v)choosing medications based on medications' and patient's weight gain risk, vi) choosing medications based on acute vs long-term treatment, vii) using effective, tolerated medications, viii) switching to less weight-inducing antipsychotics/antidepressants where possible, ix) using early weight gain as a predictor of further weight gain to inform the timing of intervention/switch options, and x) considering adding metformin or glucagon-like peptide-1 receptor agonists, or topiramate(second-line due to potential adverse cognitive effects) to antipsychotics, or aripiprazole to clozapine or olanzapine.

Phosphatidylserine: A comprehensive overview of synthesis, metabolism, and nutrition

Phosphatidylserine (PtdS) is classified as a glycerophospholipid and a primary anionic phospholipid and is particularly abundant in the inner leaflet of the plasma membrane in neural tissues. It is synthesized from phosphatidylcholine or phosphatidylethanolamine by exchanging the base head group with serine, and this reaction is catalyzed by PtdS synthase-1 and PtdS synthase-2 located in the endoplasmic reticulum. PtdS exposure on the outside surface of the cell is essential for eliminating apoptotic cells and initiating the blood clotting cascade. It is also a precursor of phosphatidylethanolamine, produced by PtdS decarboxylase in bacteria, yeast, and mammalian cells. Furthermore, PtdS acts as a cofactor for several necessary enzymes that participate in signaling pathways. Beyond these functions, several studies indicate that PtdS plays a role in various cerebral functions, including activating membrane signaling pathways, neuroinflammation, neurotransmission, and synaptic refinement associated with the central nervous system (CNS). This review discusses the occurrence of PtdS in nature and biosynthesis via enzymes and genes in plants, yeast, prokaryotes, mammalian cells, and the brain, and enzymatic synthesis through phospholipase D (PLD). Furthermore, we discuss metabolism, its role in the CNS, the fortification of foods, and supplementation for improving some memory functions, the results of which remain unclear. PtdS can be a potentially beneficial addition to foods for kids, seniors, athletes, and others, especially with the rising consumer trend favoring functional foods over conventional pills and capsules. Clinical studies have shown that PtdS is safe and well tolerated by patients.

The complex interplay between autism spectrum disorder and gut microbiota in children: A comprehensive review

Autism spectrum disorder (ASD) is characterized by defects in social communication and interaction along with restricted interests and/or repetitive behavior. Children with ASD often also experience gastrointestinal (GI) problems in fact incidence of GI problems in ASD is estimated up to 80 percent. Intestinal microbiota, which is a collection of trillions of microorganisms both beneficial and potentially harmful bacteria living inside the gut, has been considered one of the key elements of gut disorders. The goal of this review is to explore potential link between gut microbiota and ASD in children, based on the recently available data. This review discusses recent advances in this rapidly expanding area of neurodevelopmental disorders, which focuses on what is known about the changes in composition of gut bacteria in children with ASD, exploration of possible mechanisms via which gut microbiota might influence the brain and thus lead to appearance of ASD symptoms, as well as potential treatments that involve modulation of gut flora to improve symptoms in children with ASD, i.e., probiotics, postbiotics or changes in the diet. Of course, it's important to keep in mind inherent difficulties in proving of existence of causal relationships between gut bacteria and ASD. There are significant gaps in understanding of the mechanism of gut-brain axis and the mechanisms that underlie ASD. Standardized approaches for research in this area are needed. This review would provide an overview of this exciting emerging field of research.

Calcium Hexacyanoferrate (III) Nanocatalyst Enables Redox Homeostasis for Autism Spectrum Disorder Treatment

Autism spectrum disorder (ASD) is a multifaced neurodevelopmental disorder with considerable heterogeneity, in which over-generated reactive oxygen species (ROS) induce a cascade of pathological changes, including cellular apoptosis and inflammatory responses. Given the complex etiology of ASD, no effective treatment is available for ASD. In this work, a specific catalytic nanoenzyme, calcium hexacyanoferrate (III) nanocatalysts (CaH NCs), is designed and engineered for efficient ASD treatment. CaH NCs can mimic the activities of natural enzymes including superoxide dismutase, peroxidase, catalase, and glutathione peroxidase, which mitigates intracellular excessive ROS and regulates redox equilibrium. These CaH NCs modulate mitochondrial membrane potential, elevate B-cell lymphoma-2 levels, and suppress pro-apoptotic proteins, including Caspase-3 and B-cell lymphoma-2-associated X, thus effectively reducing cellular apoptosis. Importantly, CaH NCs alleviate inflammation by upregulating anti-inflammatory cytokine interleukin-10 and downregulating pro-inflammatory factors, resulting in attenuated activation of microglial and astrocytic and subsequent reduction in neuroinflammation. Subsequently, CaH NCs enhance social abilities, decrease anxiety levels, ameliorate repetitive behaviors, and improve learning and memory in ASD animal models through inflammation regulation and apoptosis inhibition. The CaH NCs in managing and preventing ASD represents a paradigm shift in autism treatment, paving the alternative but efficient way for clinical interventions in neurological conditions.

Risk factors for nephrolithiasis formation: an umbrella review

OBJECTIVE

Nephrolithiasis is prevalent and burdensome worldwide. At present, evidence on the risk factors for nephrolithiasis is unconsolidated and the associations remain uncertain. The authors systematically evaluate the robustness of the meta-analytic evidence and aid more reliable interpretations of the epidemiological relationships.

METHODS

The authors conducted a comprehensive review of the meta-analyses, screened the included studies with the aid of the AMSTAR 2 evaluation tool, and then used R (4.1.1) software to perform data analysis to evaluate the association between candidate risk factors and kidney stones, and evaluated the credibility of the evidence of the association between risk factors and kidney stones according to the GRADE classification, and finally obtained the strength and effectiveness of the association.

RESULTS

The authors finally included 17 meta-analyses regarding 46 risk factors, 34 of which (73.9%) showed statistically significant association with nephrolithiasis. Among the significant associations, the authors found that waist circumference, BMI, dietary intake and fructose intake were positively correlated with the occurrence and development of nephrolithiasis. Caffeine, dietary fiber and DASH-diet showed a tendency to reduce kidney stones. Interestingly, calcium supplementation, dietary calcium, and vitamin D, which are widely believed to be responsible for stone formation, made no difference or even reduced the risk of nephrolithiasis.

CONCLUSIONS

The authors' study demonstrates the suggestive causal (central obesity, type 2 diabetes, gout, dietary sodium, fructose intake and higher temperatures) risk factors of nephrolithiasis. The authors also demonstrate the suggestive causal (coffee/alcohol/beer intake, dietary calcium and DASH-diet) protective factors of nephrolithiasis. To provide epidemiological basis for the treatment and prevention of nephrolithiasis.

Environmental Risk Factors, Protective Factors, and Biomarkers for Hearing Loss: An Umbrella Review

OBJECTIVE

We aimed to investigate the potential environmental risk factors, protective factors, and biomarkers of hearing loss (HL), and establish a hierarchy of evidence.

DATA SOURCES

Embase, PubMed, Cochrane Library, and Web of Science electronic database from inception to June 1, 2023.

REVIEW METHODS

We included meta-analyses of observational studies of associations between HL and environmental risk factors, protective factors, or biomarkers. We calculated summary effect estimates, 95% confidence interval, heterogeneity I2 statistic, 95% prediction interval, small study effects, and excess significance biases.

RESULTS

Of the 9211 articles retrieved, 60 eligible articles were included. The 60 eligible articles identified 47 potential environmental risk and protective factors (N = 4,123,803) and 46 potential biomarkers (N = 173,701). Evidence of association was convincing (class I) for rheumatoid arthritis (RA) and every 1 cm increase in height. Evidence of association was highly suggestive (class II) for human immunodeficiency virus (HIV), diabetes, cumulative noise exposure (CNE), smoking, congenital cytomegalovirus (CMV) infection, combined exposure to organic solvents and noise, non-Gaussian noise exposure, each 1 kg increase in birth weight, noise exposure, and alopecia areata (AA).

CONCLUSION

In this umbrella review, RA, every 1 cm increase in height, HIV, diabetes, CNE, smoking, congenital CMV infection, combined exposure to organic solvents and noise, non-Gaussian noise exposure, each 1 kg increase in birth weight, noise exposure, and AA were strongly associated with HL.

Protocol for the development of a reporting guideline for umbrella reviews on epidemiological associations using cross-sectional, case-control and cohort studies: the Preferred Reporting Items for Umbrella Reviews of Cross-sectional, Case-control and Cohort studies (PRIUR-CCC)

INTRODUCTION

Observational studies are fraught with several biases including reverse causation and residual confounding. Overview of reviews of observational studies (ie, umbrella reviews) synthesise systematic reviews with or without meta-analyses of cross-sectional, case-control and cohort studies, and may also aid in the grading of the credibility of reported associations. The number of published umbrella reviews has been increasing. Recently, a reporting guideline for overviews of reviews of healthcare interventions (Preferred Reporting Items for Overviews of Reviews (PRIOR)) was published, but the field lacks reporting guidelines for umbrella reviews of observational studies. Our aim is to develop a reporting guideline for umbrella reviews on cross-sectional, case-control and cohort studies assessing epidemiological associations.

METHODS AND ANALYSIS

We will adhere to established guidance and prepare a PRIOR extension for systematic reviews of cross-sectional, case-control and cohort studies testing epidemiological associations between an exposure and an outcome, namely Preferred Reporting Items for Umbrella Reviews of Cross-sectional, Case-control and Cohort studies (PRIUR-CCC). Step 1 will be the project launch to identify stakeholders. Step 2 will be a literature review of available guidance to conduct umbrella reviews. Step 3 will be an online Delphi study sampling 100 participants among authors and editors of umbrella reviews. Step 4 will encompass the finalisation of PRIUR-CCC statement, including a checklist, a flow diagram, explanation and elaboration document. Deliverables will be (i) identifying stakeholders to involve according to relevant expertise and end-user groups, with an equity, diversity and inclusion lens; (ii) completing a narrative review of methodological guidance on how to conduct umbrella reviews, a narrative review of methodology and reporting in published umbrella reviews and preparing an initial PRIUR-CCC checklist for Delphi study round 1; (iii) preparing a PRIUR-CCC checklist with guidance after Delphi study; (iv) publishing and disseminating PRIUR-CCC statement.

ETHICS AND DISSEMINATION

PRIUR-CCC has been approved by The Ottawa Health Science Network Research Ethics Board and has obtained consent (20220639-01H). Participants to step 3 will give informed consent. PRIUR-CCC steps will be published in a peer-reviewed journal and will guide reporting of umbrella reviews on epidemiological associations.

Predicting autism spectrum disorder using maternal risk factors: A multi-center machine learning study

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with a complex environmental etiology involving maternal risk factors, which have been combined with machine learning to predict ASD. However, limited studies have considered the factors throughout preconception, perinatal, and postnatal periods, and even fewer have been conducted in multi-center. In this study, five predictive models were developed using 57 maternal risk factors from a cohort across ten cities (ASD:1232, typically developing[TD]: 1090). The extreme gradient boosting model performed best, achieving an accuracy of 66.2 % on the external cohort from three cities (ASD:266, TD:353). The most important risk factors were identified as unstable emotions and lack of multivitamin supplementation using Shapley values. ASD risk scores were calculated based on predicted probabilities from the optimal model and divided into low, medium, and high-risk groups. The logistic analysis indicated that the high-risk group had a significantly increased risk of ASD compared to the low-risk group. Our study demonstrated the potential of machine learning models in predicting the risk for ASD based on maternal factors. The developed model provided insights into the maternal emotion and nutrition factors associated with ASD and highlighted the potential clinical applicability of the developed model in identifying high-risk populations.

Neurodevelopmental Disruptions in Children of Preeclamptic Mothers: Pathophysiological Mechanisms and Consequences

Preeclampsia (PE) is a multisystem disorder characterized by elevated blood pressure in the mother, typically occurring after 20 weeks of gestation and posing risks to both maternal and fetal health. PE causes placental changes that can affect the fetus, particularly neurodevelopment. Its key pathophysiological mechanisms encompass hypoxia, vascular and angiogenic dysregulation, inflammation, neuronal and glial alterations, and disruptions in neuronal signaling. Animal models indicate that PE is correlated with neurodevelopmental alterations and cognitive dysfunctions in offspring and in humans, an association between PE and conditions such as cerebral palsy, autism spectrum disorder, attention deficit hyperactivity disorder, and sexual dimorphism has been observed. Considering the relevance for mothers and children, we conducted a narrative literature review to describe the relationships between the pathophysiological mechanisms behind neurodevelopmental alterations in the offspring of PE mothers, along with their potential consequences. Furthermore, we emphasize aspects pertinent to the prevention/treatment of PE in pregnant mothers and alterations observed in their offspring. The present narrative review offers a current, complete, and exhaustive analysis of (i) the pathophysiological mechanisms that can affect neurodevelopment in the children of PE mothers, (ii) the relationship between PE and neurological alterations in offspring, and (iii) the prevention/treatment of PE.

The spectrum of pre-mRNA splicing in autism

Disruptions in spatiotemporal gene expression can result in atypical brain function. Specifically, autism spectrum disorder (ASD) is characterized by abnormalities in pre-mRNA splicing. Abnormal splicing patterns have been identified in the brains of individuals with ASD, and mutations in splicing factors have been found to contribute to neurodevelopmental delays associated with ASD. Here we review studies that shed light on the importance of splicing observed in ASD and that explored the intricate relationship between splicing factors and ASD, revealing how disruptions in pre-mRNA splicing may underlie ASD pathogenesis. We provide an overview of the research regarding all splicing factors associated with ASD and place a special emphasis on five specific splicing factors-HNRNPH2, NOVA2, WBP4, SRRM2, and RBFOX1-known to impact the splicing of ASD-related genes. In the discussion of the molecular mechanisms influenced by these splicing factors, we lay the groundwork for a deeper understanding of ASD's complex etiology. Finally, we discuss the potential benefit of unraveling the connection between splicing and ASD for the development of more precise diagnostic tools and targeted therapeutic interventions. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Evolution and Genomics > RNA and Ribonucleoprotein Evolution RNA Evolution and Genomics > Computational Analyses of RNA RNA-Based Catalysis > RNA Catalysis in Splicing and Translation.

Association between interpregnancy interval and risk of autism spectrum disorder: a systematic review and Bayesian network meta-analysis

Although the risk of autism spectrum disorder (ASD) has been reported to be associated with interpregnancy intervals (IPIs), their association remains debatable due to inconsistent findings in existing studies. Therefore, the present study aimed to explore their association. PubMed, Embase, Web of Science, and the Cochrane Library were systematically retrieved up to May 25, 2022. An updated search was performed on May 25, 2023, to encompass recent studies. The quality of the included studies was assessed using the Newcastle-Ottawa Scale (NOS). Our primary outcome measures were expressed as adjusted odds ratios (ORs). Given various control measures for IPI and diverse IPI thresholds in the included studies, a Bayesian network meta-analysis was performed. Eight studies were included, involving 24,865 children with ASD and 2,890,289 children without ASD. Compared to an IPI of 24 to 35 months, various IPIs were significantly associated with a higher risk of ASD (IPIs < 6 months: OR = 1.63, 95% CI 1.53-1.74, n = 5; IPIs of 6-11 months: OR = 1.50, 95% CI 1.42-1.59, n = 4; IPIs of 12-23 months: OR = 1.19, 95% CI 1.12-1.23, n = 10; IPIs of 36-59 months: OR = 0.96, 95% CI 0.94-0.99, n = 2; IPIs of 60-119 months: OR = 1.15, 95% CI 1.10-1.20, n = 4; IPIs > 120 months: OR = 1.57, 95% CI 1.43-1.72, n = 4). After adjusting confounding variables, our analysis delineated a U-shaped restricted cubic spline curve, underscoring that both substantially short (< 24 months) and excessively long IPIs (> 72 months) are significantly correlated with an increased risk of ASD.  Conclusion: Our analysis indicates that both shorter and longer IPIs might predispose children to a higher risk of ASD. Optimal childbearing health and neurodevelopmental outcomes appear to be associated with a moderate IPI, specifically between 36 and 60 months. What is Known: • An association between autism spectrum disorder (ASD) and interpregnancy intervals (IPIs) has been speculated in some reports. • This association remains debatable due to inconsistent findings in available studies. What is New: • Our study delineated a U-shaped restricted cubic spline curve, suggesting that both shorter and longer IPIs predispose children to a higher risk of ASD. • Optimal childbearing health and neurodevelopmental outcomes appear to be associated with a moderate IPI, specifically between 36 and 60 months.

Management of Pregnant Women with Mental Disorders Requires Attention to Gestational Diabetes Mellitus

Background

Psychiatric interventions may be required during pregnancy. In the aspect of the management of psychiatric symptoms and the consideration of the need for pharmacotherapy, possibly to manage the effects on the fetus, pregnant women with mental disorders are considered high risk as other physical illnesses.

Objective

We investigated the characteristics of pregnant women with psychiatric disorders compared with high-risk pregnant women with physical illnesses at our university hospital and the effects of psychotropic drug use on pregnant women with mental disorders and their children.

Materials and Methods

In a multivariate analysis of 1282 pregnant women, excluding those with multiple pregnancies who gave birth at our hospital between January 2017 and the end of December 2019, we evaluated the effects of mental disorders and the use of psychotropic drugs throughout at least the third trimester up to the day of delivery on obstetric complications and infants. All data were collected retrospectively.

Results

Ninety-nine pregnant women had mental disorders and 62 took psychotropic drugs. Among multiple factors, pregnant women with mental disorders were associated with significantly higher rates of smoking and gestational diabetes mellitus (GDM) and significantly lower child abnormalities. The cause or effect was difficult to determine; however, the use of antipsychotics or antidepressants was also significantly associated with GDM, while psychotropic use was not related to any of the other factors investigated in this study.

Conclusions

Attention to GDM might be important in the management of pregnant women with mental disorders.

Percutaneous vertebroplasty versus percutaneous kyphoplasty for osteoporotic vertebral compression fractures: an umbrella review protocol of systematic reviews and meta-analyses

INTRODUCTION

Several systematic reviews and meta-analyses have confirmed that percutaneous vertebroplasty and percutaneous kyphoplasty showed safety and beneficial efficacy in patients with osteoporotic vertebral compression fractures. Whereas, there is wide variation among results, which are not conducive to the evaluation and use of clinicians. This study will investigate the efficacy and safety of percutaneous vertebroplasty and percutaneous kyphoplasty for the treatment of osteoporotic vertebral compression fractures, aiming to provide a more reliable evidence base for clinical practice in treating osteoporotic vertebral compression fractures.

METHODS AND ANALYSIS

We will retrieve the relevant articles using the five databases(PubMed, Scopus, EMBASE, Cochrane Library and Web of Science) from inception to March 2023 for systematic review and meta-analysis comparing the overall safety and efficacy of percutaneous vertebroplasty and percutaneous kyphoplasty in patients with osteoporotic vertebral compression fractures. Three reviewers will screen citation titles, abstracts and evaluate the full text of each relevant citation based on prespecified eligibility criteria. Any discrepancies in decisions between reviewers will be resolved through discussion. We will assess the methodological quality of the included studies according to A MeaSurement Tool to Assess systematic Reviews 2 checklist.

ETHICS AND DISSEMINATION

This umbrella review will inform clinical and policy decisions regarding the benefits and harms of percutaneous vertebroplasty versus percutaneous kyphoplasty for osteoporotic vertebral compression fractures. Neither primary data nor individual patient information will be collected, thus ethics approval is not required. Findings will be reported through a peer-reviewed publication, conference presentations and the popular press.

PROSPERO REGISTRATION NUMBER

CRD42021268141.

Development and validation of a risk score model for predicting autism based on pre- and perinatal factors

Background

The use of pre- and perinatal risk factors as predictive factors may lower the age limit for reliable autism prediction. The objective of this study was to develop a clinical model based on these risk factors to predict autism.

Methods

A stepwise logistic regression analysis was conducted to explore the relationships between 28 candidate risk factors and autism risk among 615 Han Chinese children with autism and 615 unrelated typically developing children. The significant factors were subsequently used to create a clinical risk score model. A chi-square automatic interaction detector (CHAID) decision tree was used to validate the selected predictors included in the model. The predictive performance of the model was evaluated by an independent cohort.

Results

Five factors (pregnancy influenza-like illness, pregnancy stressors, maternal allergic/autoimmune disease, cesarean section, and hypoxia) were found to be significantly associated with autism risk. A receiver operating characteristic (ROC) curve indicated that the risk score model had good discrimination ability for autism, with an area under the curve (AUC) of 0.711 (95% CI=0.679-0.744); in the external validation cohort, the model showed slightly worse but overall similar predictive performance. Further subgroup analysis indicated that a higher risk score was associated with more behavioral problems. The risk score also exhibited robustness in a subgroup analysis of patients with mild autism.

Conclusion

This risk score model could lower the age limit for autism prediction with good discrimination performance, and it has unique advantages in clinical application.

Serotonin modulates excitatory synapse maturation in the developing prefrontal cortex

Serotonin (5-HT) imbalances in the developing prefrontal cortex (PFC) are linked to long-term behavioral deficits. However, the synaptic mechanisms underlying 5-HT-mediated PFC development are unknown. We found that chemogenetic suppression and enhancement of 5-HT release in the PFC during the first two postnatal weeks decreased and increased the density and strength of excitatory spine synapses, respectively, on prefrontal layer 2/3 pyramidal neurons in mice. 5-HT release on single spines induced structural and functional long-term potentiation (LTP), requiring both 5-HT2A and 5-HT7 receptor signals, in a glutamatergic activity-independent manner. Notably, LTP-inducing 5-HT stimuli increased the long-term survival of newly formed spines ( ≥ 6 h) via 5-HT7 Gαs activation. Chronic treatment of mice with fluoxetine, a selective serotonin-reuptake inhibitor, during the first two weeks, but not the third week of postnatal development, increased the density and strength of excitatory synapses. The effect of fluoxetine on PFC synaptic alterations in vivo was abolished by 5-HT2A and 5-HT7 receptor antagonists. Our data describe a molecular basis of 5-HT-dependent excitatory synaptic plasticity at the level of single spines in the PFC during early postnatal development.

Severity of Autism Spectrum Disorder Symptoms Associated with de novo Variants and Pregnancy-Induced Hypertension

Genetic factors, particularly, de novo variants (DNV), and an environment factor, exposure to pregnancy-induced hypertension (PIH), were reported to be associated with risk of autism spectrum disorder (ASD); however, how they jointly affect the severity of ASD symptom is unclear. We assessed the severity of core ASD symptoms affected by functional de novo variants or PIH. We selected phenotype data from Simon's Simplex Collection database, used genotypes from previous studies, and created linear regression models. We found that ASD patients carrying DNV with PIH exposure had increased adaptive and cognitive ability, decreased social problems, and enhanced repetitive behaviors; however, there was no difference in patients without DNV between those with or without PIH exposure. In addition, the DNV genes carried by patients exposed to PIH were enriched in ubiquitin-dependent proteolytic processes, highlighting how candidate genes in pathways and environments interact. The results indicate the joint contribution of DNV and PIH to ASD.

Relationship between autism and brain cortex surface area: genetic correlation and a two-sample Mendelian randomization study

BACKGROUND

Alterations in surface area (SA) in specific regions of the cortex have been reported in many individuals with autism spectrum disorder (ASD), however, the genetic background between ASD and SA is still unclear. This study estimated the genetic correlation and causal effect of ASD and cortical SA.

METHODS

Summarized data of genome-wide association studies (GWAS) were separately downloaded from the Psychiatric Genomics Consortium (18,381 cases of ASD, and 27,969 controls) and the Enhancing Neuroimaging Genetics through Meta-Analysis Consortium (33,992 participants of Europeans). We used Linkage disequilibrium score regression (LDSC) and Heritability Estimation from Summary Statistics (HESS) to calculate the heritability of each trait. As for the genetic correlation between ASD and SA, LDSC was used for global correlation and HESS was used to examine the local genetic covariance further. We used three Mendelian randomization (MR) methods, Inverse-variance weighted, MR-Egger, and weighted median to estimate the causal relationship.

RESULTS

LDSC observed a nominal significant genetic correlation (rg = 0.1229, P-value = 0.0346) between ASD and SA of the rostral anterior cingulate gyrus whereas analysis through HESS did not reveal any significant loci having genetic covariance. Based on MR results, statistically meaningful estimations were found in the following areas, postcentral cortex (β (SE) = 21.82 (7.84) mm, 95% CI: 6.46 to 37.19 mm, PIVW = 5.38 × 10- 3, PFDR = 3.09 × 10- 2), posterior cingulate gyrus (β (SE) = 6.23 (2.69) mm, 95% CI: 0.96 to 11.49 mm, PIVW = 2.05 × 10- 2, PFDR = 4.26 × 10- 2), supramarginal gyrus (β (SE) = 19.25 (8.43) mm, 95% CI: 29.29 to 35.77 mm, PIVW = 2.24 × 10- 2, PFDR = 4.31 × 10- 2).

CONCLUSION

Our results provided genetic evidence to support the opinion that individuals with ASD tend to develop differences in cortical SA of special areas. The findings contributed to understanding the genetic relationship between ASD and cortical SA.

Reanalysis of Trio Whole-Genome Sequencing Data Doubles the Yield in Autism Spectrum Disorder: De Novo Variants Present in Half

Autism spectrum disorder (ASD) is a common condition with lifelong implications. The last decade has seen dramatic improvements in DNA sequencing and related bioinformatics and databases. We analyzed the raw DNA sequencing files on the Variantyx® bioinformatics platform for the last 50 ASD patients evaluated with trio whole-genome sequencing (trio-WGS). "Qualified" variants were defined as coding, rare, and evolutionarily conserved. Primary Diagnostic Variants (PDV), additionally, were present in genes directly linked to ASD and matched clinical correlation. A PDV was identified in 34/50 (68%) of cases, including 25 (50%) cases with heterozygous de novo and 10 (20%) with inherited variants. De novo variants in genes directly associated with ASD were far more likely to be Qualifying than non-Qualifying versus a control group of genes (p = 0.0002), validating that most are indeed disease related. Sequence reanalysis increased diagnostic yield from 28% to 68%, mostly through inclusion of de novo PDVs in genes not yet reported as ASD associated. Thirty-three subjects (66%) had treatment recommendation(s) based on DNA analyses. Our results demonstrate a high yield of trio-WGS for revealing molecular diagnoses in ASD, which is greatly enhanced by reanalyzing DNA sequencing files. In contrast to previous reports, de novo variants dominate the findings, mostly representing novel conditions. This has implications to the cause and rising prevalence of autism.

Examining associations of folic acid supplements administered to mothers during pre-conceptional and prenatal periods with autism spectrum disorders in their offspring: insights from a multi-center study in China

Objective

To investigate the relationship between maternal folic acid (FA) supplementation during the pre-conceptional and prenatal periods and the subsequent risk of autism spectrum disorder (ASD) in offspring.

Methods

A total of 6,049 toddlers aged 16-30 months were recruited from August 2016 to March 2017 for this cross-sectional study conducted in China. The parents of the enrolled toddlers provided information on maternal supplemental FA, socio-demographic information, and related covariates. Standard diagnostic procedures were implemented to identify toddlers with ASD.

Results

Among the 6,049 children included in the study, consisting of 3,364 boys with an average age of 22.7 ± 4.1 months, a total of 71 children (1.2%) were diagnosed with ASD. Mothers who did not consume FA supplements during the prenatal period were found to have a significantly increased risk of having offspring with ASD, in comparison to those who were exposed to FA supplements (odds ratio [OR] = 2.47). However, we did not find a similar association during the pre-conceptional period. Compared to mothers who consistently used FA supplements from pre-conception to the prenatal period, those who never used FA supplements were statistically significantly associated with a higher risk of ASD in their offspring (OR = 2.88).

Conclusion

This study indicated that providing continuous maternal FA supplementation during the pre-conceptional and prenatal periods may decrease the risk of ASD in offspring. The prenatal period is considered to be the most crucial time for intervention.

A comparison between children and adolescents with autism spectrum disorders and healthy controls in biomedical factors, trace elements, and microbiota biomarkers: a meta-analysis

INTRODUCTION

Autism spectrum disorder (ASD) is a multifaceted developmental condition that commonly appears during early childhood. The etiology of ASD remains multifactorial and not yet fully understood. The identification of biomarkers may provide insights into the underlying mechanisms and pathophysiology of the disorder. The present study aimed to explore the causes of ASD by investigating the key biomedical markers, trace elements, and microbiota factors between children with autism spectrum disorder (ASD) and control subjects.

METHODS

Medline, PubMed, ProQuest, EMBASE, Cochrane Library, PsycINFO, Web of Science, and EMBSCO databases have been searched for publications from 2012 to 2023 with no language restrictions using the population, intervention, control, and outcome (PICO) approach. Keywords including "autism spectrum disorder," "oxytocin," "GABA," "Serotonin," "CRP," "IL-6," "Fe," "Zn," "Cu," and "gut microbiota" were used for the search. The Joanna Briggs Institute (JBI) critical appraisal checklist was used to assess the article quality, and a random model was used to assess the mean difference and standardized difference between ASD and the control group in all biomedical markers, trace elements, and microbiota factors.

RESULTS

From 76,217 records, 43 studies met the inclusion and exclusion criteria and were included in this meta-analysis. The pooled analyses showed that children with ASD had significantly lower levels of oxytocin (mean differences, MD = -45.691, 95% confidence interval, CI: -61.667, -29.717), iron (MD = -3.203, 95% CI: -4.891, -1.514), and zinc (MD = -6.707, 95% CI: -12.691, -0.722), lower relative abundance of Bifidobacterium (MD = -1.321, 95% CI: -2.403, -0.238) and Parabacteroides (MD = -0.081, 95% CI: -0.148, -0.013), higher levels of c-reactive protein, CRP (MD = 0.401, 95% CI: 0.036, 0.772), and GABA (MD = 0.115, 95% CI: 0.045, 0.186), and higher relative abundance of Bacteroides (MD = 1.386, 95% CI: 0.717, 2.055) and Clostridium (MD = 0.281, 95% CI: 0.035, 0.526) when compared with controls. The results of the overall analyses were stable after performing the sensitivity analyses. Additionally, no substantial publication bias was observed among the studies.

INTERPRETATION

Children with ASD have significantly higher levels of CRP and GABA, lower levels of oxytocin, iron, and zinc, lower relative abundance of Bifidobacterium and Parabacteroides, and higher relative abundance of Faecalibacterium, Bacteroides, and Clostridium when compared with controls. These results suggest that these indicators may be a potential biomarker panel for the diagnosis or determining therapeutic targets of ASD. Furthermore, large, sample-based, and randomized controlled trials are needed to confirm these results.

Exposure to greenness during pregnancy and the first three years after birth and autism spectrum disorder: A matched case-control study in shanghai, China

Causes of autism spectrum disorder (ASD) have not been fully understood. Previous studies have linked environmental factors with ASD. However, evidence for the greenness-ASD association is limited, especially in China. To fill this gap, we conducted a matched case-control study to examine the association between greenness and ASD in China. Participants in this study were 84,934 children aged 3-12 years in Shanghai, China, selected using a multi-stage cluster sampling method. ASD cases were firstly screened by questionnaires completed by both children's parents and teachers, and were then confirmed by clinical examinations. Further, 10 healthy controls were randomly selected to match each ASD case by age and sex. The final analyses included 146 ASD cases and 1460 healthy controls. Participants' exposure to greenness before and after birth was assessed by normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI) from NASA's Earth Observing System according to their residential locations. We used conditional logistic regression to examine the ASD-greenness association. Per interquartile range (IQR) increase in EVI500m and NDVI500m during the year before birth were associated with lower risks of ASD with adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of 0.96 (95%CI: 0.946, 0.975, IQR = 0.074) and 0.937 (95%CI: 0.915, 0.959, IQR = 0.101). Exposure to greenness during the first 3 years after birth was also significantly associated with lower risk of ASD [IQR ORs for EVI500m and NDVI500m were 0.935 (95%CI: 0.91, 0.962, IQR = 0.06) and 0.897 (95%CI: 0.861, 0.935, IQR = 0.09), respectively]. Air pollution showed mediation effects on thegreenness-ASD association. Greenness was observed to have stronger beneficial effects on children without historical diseases and term birth. More greenness exposure before and after birth were significantly associated with lower risks of ASD in children. Our results highlight the importance of greenness in urban planning.

Associations of unintended pregnancy with autism spectrum disorders and the modification of folic acid supplements

There is limited evidence on the associations of unintended pregnancy with autism spectrum disorders (ASD). This study aimed to examine this relationship and the modification of pre-conceptional and prenatal folic acid supplements. Six thousand and five toddlers aged 16 to 30 months from seven cities of six provinces in China were eligible for participation. Information on unintended pregnancy and folic acid supplements was obtained via questionnaires from caregivers of toddlers. The diagnosis of ASD was based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) and the Chinese version of the Childhood Autism Rating Scale (CARS). Of the 6005 toddlers in the study (3337 boys and 2668 girls), 71 (1.18%) received the diagnosis of ASD. Generalized linear models with a logit link function showed unintended pregnancy was positively associated with ASD (odds ratios [OR] = 1.69, 95% confidence interval [CI], 1.05-2.79). Stratified estimates indicated that the association remained stable among toddlers of mothers without pre-conceptional and prenatal folic acid supplements (OR = 2.75, 95% CI, 1.04-7.27; n = 1243, 20.70%). Unintended pregnancy was associated with higher odds of ASD in 16-30 months of toddlers, and the association was consistent among toddlers of mothers without prenatal folic acid supplements. Our findings emphasize the need to raise awareness of the risk of unintended pregnancy and the benefits of folic acid supplements among Chinese women.

Diversity and Classification of Genetic Variations in Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a neurodevelopmental condition with symptoms that affect the whole personality and all aspects of life. Although there is a high degree of heterogeneity in both its etiology and its characteristic behavioral patterns, the disorder is well-captured along the autistic triad. Currently, ASD status can be confirmed following an assessment of behavioral features, but there is a growing emphasis on conceptualizing autism as a spectrum, which allows for establishing a diagnosis based on the level of support need, free of discrete categories. Since ASD has a high genetic predominance, the number of genetic variations identified in the background of the condition is increasing exponentially as genetic testing methods are rapidly evolving. However, due to the huge amount of data to be analyzed, grouping the different DNA variations is still challenging. Therefore, in the present review, a multidimensional classification scheme was developed to accommodate most of the currently known genetic variants associated with autism. Genetic variations have been grouped according to six criteria (extent, time of onset, information content, frequency, number of genes involved, inheritance pattern), which are themselves not discrete categories, but form a coherent continuum in line with the autism spectrum approach.

All-cause mortality and suicide mortality in autistic individuals: An entire population longitudinal study in Taiwan

LAY ABSTRACT

Our study was the first population-based study in an Asian country to investigate the mortality rates among autistic individuals. Among the entire Taiwanese population (N = 29,253,529), between 2003 and 2017, 45,398 autistic individuals were identified and 1:4 age-/sex-matched to 181,592 non-autistic individuals. We found that autistic individuals had increased risks of all-cause mortality, natural-cause mortality, and suicide mortality compared with non-autistic individuals. Furthermore, autistic males were more likely to die by suicide, and autistic females were more likely to die of accident compared with the non-autistic individuals.

Autism spectrum disorder prevalence in Italy: a nationwide study promoted by the Ministry of Health

BACKGROUND

This nationwide study aimed to estimate Autism Spectrum Disorder (ASD) prevalence in 7-9-year-old Italian children. Promoted by Italy's Ministry of Health and coordinated by the National Observatory for Autism at the National Institute of Health, it covered schools in northern (Lecco and Monza-Brianza), central (Rome and its province), and southern (Palermo and its province) regions from February 24, 2016, to February 23, 2018, using a multi-stage approach defined by the European Union's ASD network.

METHODS

Phase one identified ASD-diagnosed children in mainstream schools through local Ministry of Education (MoE) disability registries. Phase two had a subset of schools screen 7-9-year-olds using the Social Communication Questionnaire-Life version (SCQ-L). Those with SCQ-L scores of 15 + underwent clinical consultation for ASD symptoms, cognitive abilities, and life skills. To counter potential false negatives, 20% scoring 11-14 were randomly assessed via Autism Diagnostic Interview-Revised (ADI-R).

RESULTS

MoE data revealed 9.8 per 1000 certified ASD children in the north, 12.2 in the central, and 10.3 in the south. In phase two, 35,823 SCQ-L questionnaires were distributed across 198 schools (northern: 11,190 in 49 schools, central: 13,628 in 87 schools, southern: 11,005 in 62 schools). Of SCQ-L respondents, 2.4% (n = 390) scored above the 15 cutoff. Among these, 100 had ASD diagnoses, and 50 had other diagnoses. Among 115 families assessed, 16.5% (n = 19) received ASD diagnoses.

CONCLUSIONS

The estimated prevalence of ASD in Italy was 13.4 (11.3-16.0) per 1,000 children aged 7-9 years, with a male-to-female ratio of 4.4:1. It will guide national policies in enhancing services tailored to the specific needs of autistic children.

Gut microbiota and autism spectrum disorders: where do we stand?

BACKGROUND

Children with autism spectrum disorder (ASD) often have digestive problems and microbial imbalances in their guts, suggesting that these conditions may play a role in the development of the disorder. Scopus-based research on the gut microbiota and ASD was examined in this bibliometric analysis to shed light on the current state of research and identify potential hotspots for future work in this area.

METHODS

We searched documents from the Scopus database and reference citation analysis to collect published data on the gut microbiota and ASD from 2003 to 2022. The downloaded document records were exported to VOSviewer v.1.6.19 to examine and visualize the collaboration between countries and determine the research hotspots.

RESULTS

The search yielded 958 articles specifically dedicated to gut microbiota and ASD. The number of publications in this field increased rapidly after 2013, with a peak in 2022. The United States (n = 267; 27.87%) was the most active country, followed by China (n = 171; 17.85%) and Italy (n = 96; 10.02). International collaboration was observed, with the USA playing a central role. University College Cork, Ireland, was the most productive institution (n = 24; 2.51%). The National Natural Science Foundation of China was the most active funding agency (n = 76; 7.93%). Nutrients journal had the highest number of publications (n = 28; 2.92%). The articles related to gut microbiota and ASD were highly cited, with an h-index of 108. The research themes identified focused on the modulation of gut microbiota as a potential therapy for children with ASD and gut-brain axis dysfunction in ASD.

CONCLUSIONS

In recent years, the study of gut microbiota and its association with ASD has garnered considerable interest as an emergent field of study. The results of this study substantially enhance our current understanding of the knowledge landscape in this field and illuminate potential avenues for future research. It is essential to emphasize the significance of devoting more resources to the newest and most promising research areas, such as investigating the potential therapeutic benefits of modulating the intestinal microbiota in children with ASD. This research has enormous potential and merits intensified focus and investigation.

Environmental Risk Factors, Protective Factors, and Biomarkers for Allergic Rhinitis: A Systematic Umbrella Review of the Evidence

Many potential environmental risk factors, protective factors, and biomarkers of AR have been published, but so far, the strength and consistency of their evidence are unclear. We conducted a comprehensive review of environmental risk, protective factors, and biomarkers for AR to establish the evidence hierarchy. We systematically searched Embase, PubMed, Cochrane Library, and Web of Science electronic database from inception to December 31, 2022. We calculated summary effect estimate (odds ratio (OR), relative risk (RR), hazard ratio (HR), and standardized mean difference (SMD)), 95% confidence interval, random effects p value, I2 statistic, 95% prediction interval, small study effects, and excess significance biases, and stratification of the level of evidence. Methodological quality was assessed by AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews 2). We retrieved 4478 articles, of which 43 met the inclusion criteria. The 43 eligible articles identified 31 potential environmental risk factors (10,806,206 total population, two study not reported), 11 potential environmental protective factors (823,883 total population), and 34 potential biomarkers (158,716 total population) for meta-analyses. The credibility of evidence was convincing (class I) for tic disorders (OR = 2.89, 95% CI 2.11-3.95); and highly suggestive (class II) for early-life antibiotic use (OR = 3.73, 95% CI 3.06-4.55), exposure to indoor dampness (OR = 1.49, 95% CI 1.27-1.75), acetaminophen exposure (OR = 1.54, 95% CI 1.41-1.69), childhood acid suppressant use (OR = 1.40, 95% CI 1.23-1.59), exposure to indoor mold (OR = 1.66, 95% CI 1.26-2.18), coronavirus disease 2019 (OR = 0.11, 95% CI 0.06-0.22), and prolonged breastfeeding (OR = 0.72, 95% CI 0.65-0.79). This study is registered in PROSPERO (CRD42022384320).