Developmental characteristics and accuracy of autism screening among two-year-old toddlers in the ECHO program

BACKGROUND

The Modified Checklist for Autism in Toddlers (M-CHAT) is a common pediatric screening tool with mixed accuracy findings. Prior evidence supports M-CHAT screening for developmental concerns, especially in toddlers born preterm. This study examined M-CHAT accuracy in a large, nationwide sample.

METHODS

3393 participants from the Environmental influences on Child Health Outcomes (ECHO) program were included. Harmonized M-CHAT (M-CHAT-H) results were compared with parent-reported autism diagnosis and autism-related characteristics to assess accuracy for term and preterm children, together and separately. Generalized estimating equations, clustering for ECHO cohort and controlling for demographic covariates, were used to examine associations between developmental and behavioral characteristics with M-CHAT-H accuracy.

RESULTS

Sensitivity of the M-CHAT-H ranged from 36 to 60%; specificity ranged from 88 to 99%. Positive M-CHAT-H was associated with more developmental delays and behavior problems. Children with severe motor delays and more autism-related problems were more likely to have a false-negative M-CHAT-H. Children with fewer behavior problems and fewer autism-related concerns were more likely to have a false-positive screen.

CONCLUSION

The M-CHAT-H accurately detects children at low risk for autism and children at increased risk with moderate accuracy. These findings support use of the M-CHAT-H in assessing autism risk and developmental and behavioral concerns in children.

IMPACT

Previous literature regarding accuracy of the Modified Checklist for Autism in Toddlers (M-CHAT) is mixed but this study provides evidence that the M-CHAT performs well in detecting children at low risk for autism and consistently detects children with developmental delays and behavioral problems. The M-CHAT moderately detects children at increased risk for autism and remains a useful screening tool. This study examines M-CHAT accuracy in a large-scale, nationwide sample, examining associations between screening accuracy and developmental outcomes. These findings impact pediatric screening for autism, supporting continued use of the M-CHAT while further elucidating the factors associated with inaccurate screens.

Associations of Pre- and Postnatal Air Pollution Exposures with Child Behavioral Problems and Cognitive Performance: A U.S. Multi-Cohort Study

BACKGROUND

Population studies support the adverse associations of air pollution exposures with child behavioral functioning and cognitive performance, but few studies have used spatiotemporally resolved pollutant assessments.

OBJECTIVES

We investigated these associations using more refined exposure assessments in 1,967 mother-child dyads from three U.S. pregnancy cohorts in six cities in the ECHO-PATHWAYS Consortium.

METHODS

Pre- and postnatal nitrogen dioxide (NO2) and particulate matter (PM) ≤2.5μm in aerodynamic diameter (PM2.5) exposures were derived from an advanced spatiotemporal model. Child behavior was reported as Total Problems raw score using the Child Behavior Checklist at age 4-6 y. Child cognition was assessed using cohort-specific cognitive performance scales and quantified as the Full-Scale Intelligence Quotient (IQ). We fitted multivariate linear regression models that were adjusted for sociodemographic, behavioral, and psychological factors to estimate associations per 2-unit increase in pollutant in each exposure window and examined modification by child sex. Identified critical windows were further verified by distributed lag models (DLMs).

RESULTS

Mean NO2 and PM2.5 ranged from 8.4 to 9.0 ppb and 8.4 to 9.1 μg/m3, respectively, across pre- and postnatal windows. Average child Total Problems score and IQ were 22.7 [standard deviation (SD): 18.5] and 102.6 (SD: 15.3), respectively. Children with higher prenatal NO2 exposures were likely to have more behavioral problems [β: 1.24; 95% confidence interval (CI): 0.39, 2.08; per 2 ppb NO2], particularly NO2 in the first and second trimester. Each 2-μg/m3 increase in PM2.5 at age 2-4 y was associated with a 3.59 unit (95% CI: 0.35, 6.84) higher Total Problems score and a 2.63 point (95% CI: -5.08, -0.17) lower IQ. The associations between PM2.5 and Total Problems score were generally stronger in girls. Most predefined windows identified were not confirmed by DLMs.

DISCUSSION

Our study extends earlier findings that have raised concerns about impaired behavioral functioning and cognitive performance in children exposed to NO2 and PM2.5 in utero and in early life. https://doi.org/10.1289/EHP10248.

Executive functioning skills in early childhood children with autism, intellectual disability, and co-occurring autism and intellectual disability

BACKGROUND

Many children with autism and intellectual disability (ID) experience executive functioning (EF) difficulties. However, there is minimal research on EF skills in children with autism, ID, and co-occurring autism/ID in early childhood.

AIMS

To address this gap in the research, we evaluated EF profiles using the BRIEF-P among early childhood children (2-5 years of age) with autism, ID, and co-occurring autism/ID.

METHOD AND PROCEDURES

Participants in the current study were 87 children between the ages of 24 and 71 months (M = 46.8, SD = 12.7) diagnosed with autism (n = 24, 27.6 %), ID (n = 23, 26.4 %), or co-occurring autism/ID (n = 40, 46.0 %) that completed a comprehensive psychological evaluation at a university development center. We used a mixed Analysis of Variance (ANOVA) and between- and within-subjects ANOVAs as follow-up analyses.

OUTCOMES AND RESULTS

Results suggested that early childhood children with autism, ID, and autism/ID may have unique EF skill profiles. Children with ID exhibited the most significant EF impairments and children with autism had the least. Working memory was the most impaired EF domain across all diagnostic groups.

CONCLUSIONS AND IMPLICATIONS

Overall, our findings show that early childhood children with autism, ID, and autism/ID exhibit difficulties in EF skills. Children with ID exhibit the most significant EF impairments whereas children with autism show the least. However, regardless of diagnosis, working memory is the most impaired EF skill.

Maternal Plasma 25-Hydroxyvitamin D during Gestation Is Positively Associated with Neurocognitive Development in Offspring at Age 4-6 Years

BACKGROUND

Vitamin D is critical to embryonic neuronal differentiation and other developmental processes that may affect future neurocognitive function. However, observational studies have found inconsistent associations between gestational vitamin D and neurocognitive outcomes.

OBJECTIVES

We examined the association of gestational 25-hydroxyvitamin D [25(OH)D] with children's IQ at 4-6 y, and explored whether associations differed by race.

METHODS

This study used data from the CANDLE (Conditions Affecting Neurocognitive Development and Learning in Early Childhood) cohort. Between 2006 and 2011, CANDLE recruited 1503 women in their second trimester of healthy singleton pregnancies. Inclusion criteria for this analysis were gestation of ≥34 wk and availability of 25(OH)D and IQ data. Associations between second-trimester 25(OH)D plasma concentration and Stanford-Binet IQ scores in offspring at 4-6 y were examined using multivariable linear regression; interaction terms were used to explore possible effect modification by race.

RESULTS

Mean ± SD 25(OH)D concentration among 1019 eligible dyads was 21.6 ± 8.4 ng/mL, measured at a mean ± SD gestational age of 23.0 ± 3.0 wk. Vitamin D deficiency [25(OH)D < 20 ng/mL] was observed in 45.6%. Maternal 25(OH)D differed by race with a mean ± SD of 19.8 ± 7.2 ng/mL in Blacks sand 25.9 ± 9.3 ng/mL in Whites ( P  < 0.001). In adjusted models a 10-ng/mL increase in 25(OH)D was associated with a 1.17-point higher Full Scale IQ (95% CI: 0.27, 2.06 points), a 1.17-point higher Verbal IQ (95% CI: 0.19, 2.15 points), and a 1.03-point higher Nonverbal IQ (95% CI: 0.10, 1.95 points). We observed no evidence of effect modification by race.

CONCLUSIONS

Second-trimester maternal 25(OH)D was positively associated with IQ at 4-6 y, suggesting that gestational vitamin D status may be an important predictor of neurocognitive development. These findings may help inform prenatal nutrition recommendations and may be especially relevant for Black and other dark-skinned women at high risk of vitamin D deficiency.

Demographic and psychosocial factors associated with hair cortisol concentrations in preschool children

BACKGROUND

Early life stress has enduring effects on physical and mental health. Hair cortisol concentrations (HCCs) reflect exposures to contextual stressors in early life, but are understudied in preschool children.

METHODS

Hair samples from children (N = 693) during clinic visits (CVs) scheduled at 1-4 years (CV1-CV4) were measured using validated assay methods for HCC.

RESULTS

HCCs were highest at CV1 and decreased at CV2-CV4, with no sex differences. Black children had higher HCC than White/other children; these differences persisted even after adjusting for socioeconomic factors. Bivariable analyses showed significant effects on HCC for Black race, with specific demographic and psychosocial factors at different ages. Multivariable analyses showed that higher HCC at CV1 were associated with Black race and male sex; at CV2 with Black race, lower maternal self-esteem, socioeconomic adversity, and the child's risk for developmental delay; at CV3 with Black race; at CV4 with maternal depression and the child's prior HCC values.

CONCLUSIONS

HCCs were higher in Black children than White/other races; differences were related to maternal factors, socioeconomic adversity, and the child's risk for developmental delay. Public health measures to reduce disparities between Blacks and other races must also consider the long-term effects of chronic stress in early life.

Prospective Associations Between Infant Sleep at 12 Months and Autism Spectrum Disorder Screening Scores at 24 Months in a Community-Based Birth Cohort

BACKGROUND

Sleep problems have been associated with autism spectrum disorder (ASD) symptoms and diagnosis. However, past research has studied the simultaneous association of sleep problems with precursor ASD symptoms. Using data from a birth cohort, we estimate prospective associations between infant sleep characteristics at 12 months and later ASD screening scores at 24 months.

METHODS

We obtained data from children (N = 1,096) and their mothers as participants in the Conditions Affecting Neurocognitive Development and Learning in Early Childhood longitudinal birth cohort study. Mothers were enrolled between 2006 and 2011, when they were 16-26 weeks pregnant. Using linear regression, we examined the influence of infant sleep characteristics (nighttime and daytime sleep, night wakings, and sleep onset latency) at 12 months on ASD screening scores at 24 months while controlling for other psychosocial characteristics.

RESULTS

The number of night wakings was the only sleep characteristic at 12 months to be significantly associated with the development of early ASD symptoms at 24 months (B = 0.097, P = .021; 95% CI, 0.014 to 0.180). However, other competing risks, especially child socioemotional competence at 12 months (B = 0.573, P < .001; 95% CI, 0.361 to 0.785), showed stronger relative contributions in predicting ASD risk.

CONCLUSIONS

Infants with more sleep problems by 12 months, especially those waking more often during the night, showed an increased number of early ASD symptoms a year later. This study suggests that infant sleep characteristics could constitute one clinical sign of ASD risk, together with key psychosocial characteristics.

Socio-demographic, maternal, and child indicators of socioemotional problems in 2-year-old children: A cohort study

Throughout infancy and early childhood, stable and secure relationships with caregivers are needed to promote optimal socioemotional (SE) and cognitive development.The objective is to examine socio-demographic, maternal, and child indicators of SE problems in 2-year-olds living in an urban-suburban community in the southern United States.Mother-infant pairs enrolled in a prospective pregnancy cohort study.Shelby County (Memphis), Tennessee.One thousand five hundred three women were recruited during their second trimester and followed with their children through the child's age of 2 years.Child SE development was measured by the Brief Infant-Toddler Social Emotional Assessment at 2 years of age. Mothers reported their own behavioral and mental health, temperament, parenting stress, and potential for child abuse during gestation and/or when their child was 1 year of age. Examiners measured maternal IQ during data collection at the child's age of 1 year. Child communication, cognitive development, and risk for autism spectrum disorder were assessed at 1 and 2 years of age. Multivariable regression models were developed to predict mother-reported SE problems.In bivariate analyses, multiple maternal behavioral and mental health indicators and child cognitive skills were associated with reported child SE problems at 2 years of age. Regression analyses, controlling for socio-demographic, maternal, and child variables, showed the following factors were independently associated with mother-reported child SE problems: maternal education of high school or less, lower maternal IQ, higher maternal cyclothymic temperament score, greater parenting stress, greater maternal psychological distress, lower child expressive communication score, and child risk for autism spectrum disorder. Socio-demographic variables accounted for the variance often attributed to race.Since mothers in the study were medically low-risk, generalizing these findings to medically high-risk mothers is unwarranted. In addition, these SE outcomes in 2-year-old children do not reflect the trajectory of SE development throughout early childhood.Attention to independent indicators of future SE problems in children may help identify individual children and families needing intervention and target public prevention/treatment programs in communities.

Inattention and hyperactivity/impulsivity among children with attention-deficit/hyperactivity-disorder, autism spectrum disorder, and intellectual disability

BACKGROUND

Attention-Deficit/Hyperactivity Disorder (ADHD), Autism Spectrum Disorder (ASD), and Intellectual Disability (ID) are common co-occurring neurodevelopmental disorders; however, limited research exists regarding the presentation and severity of overlapping symptomology, particularly inattention and hyperactivity/impulsivity, when a child is diagnosed with one of more of these neurodevelopmental disorders.

AIMS

As difficulties with inattention and hyperactivity/impulsivity are symptoms frequently associated with these disorders, the current study aims to determine the differences in the severity of inattention and hyperactivity/impulsivity in children diagnosed with ADHD, ASD, ID, and co-occurring diagnosis of ADHD/ID, ASD/ADHD, and ASD/ID.

METHODS AND PROCEDURES

Participants in the current study included 113 children between the ages of 6 and 11 who were diagnosed with ADHD, ASD, ID, ADHD/ID, ASD/ADHD, or ASD/ID. Two MANOVA analyses were used to compare these groups witih respsect to symptom (i.e., inattention, hyperactivity/impulsivity) severity.

OUTCOMES AND RESULTS

Results indicated that the majority of diagnostic groups experienced elevated levels of both inattention and hyperactivity/impulsivity. However, results yielded differences in inattention and hyperactivity/impulsivity severity. In addition, differences in measure sensitivity across behavioral instruments was found.

CONCLUSIONS AND IMPLICATIONS

Children with neurodevelopmental disorders often exhibit inattention and hyperactivity/impulsivity, particularly those with ADHD, ASD, ASD/ADHD, and ADHD/ID; therefore, differential diagnosis may be complicated due to similarities in ADHD symptom severity. However, intellectual abilities may be an important consideration for practitioners in the differential diagnosis process as children with ID and ASD/ID exhibited significantly less inattention and hyperactive/impulsive behaviors. Additionally, the use of multiple behavior rating measures in conjunction with other assessment procedures may help practitioners determine the most appropriate diagnosis.

Gestational Vitamin 25(OH)D Status as a Risk Factor for Receptive Language Development: A 24-Month, Longitudinal, Observational Study

Emerging data suggest that vitamin D status during childhood and adolescence can affect neurocognitive development. The purpose of this study was to investigate whether gestational 25(OH)D status is associated with early childhood cognitive and receptive language development. The Conditions Affecting Neurocognitive Development and Learning in Early Childhood Study (CANDLE) study enrolled 1503 mother-child dyads during the second trimester of healthy singleton pregnancies from Shelby County TN. Among 1020 participants of the total CANDLE cohort for whom 25(OH)D levels were available, mean gestational 25(OH)D level during the second trimester was 22.3 ng/mL (range 5.9–68.4), with 41.7% of values <20 ng/dL. Cognitive and language scaled scores increased in a stair-step manner as gestational 25(OH)D levels in the second trimester rose from <20 ng/dL, through 20–29.99 ng/dL, to ≥30 ng/dL. When controlling for socioeconomic status, race, use of tobacco products, gestational age of the child at birth, and age at the 2-year assessment, the gestational 25(OH)D was positively related to receptive language development (p < 0.017), but not cognitive or expressive language.

The effect of nicotinamide on spontaneous and induced activity in smooth and skeletal muscle

BACKGROUND AND PURPOSE

Nicotinamide (NA) is currently undergoing clinical trials as a tumour radiosensitizer. The dose that can be administered is currently 80 mg/kg per day, but this may be restricted to 60 mg/kg per day by the high incidence of nausea and vomiting. To investigate some of NA's underlying mechanisms of action, we have used an ex vivo system to study the direct effect of this drug, over a wide range of concentrations, on isolated spontaneously active rat ileum. Effects on the gut were compared with the action of NA on skeletal and vascular smooth muscle.

MATERIALS AND METHODS

Isolated rat ileum rings were perfused with oxygenated Krebs' solution in an organ bath. NA (1 microM to 10 mM) was introduced to the perfusate and the change in amplitude of spontaneous peristaltic activity recorded. Dissected frog sartorius muscle was bathed in modified oxygenated Ringer's solution in an organ bath. The muscle was electrically stimulated to generate isometric contractions. Tension was then measured before and after the addition of a range of NA concentrations (8.2-24.6 mM) to the organ bath.

RESULTS

NA inhibited peristalsis in the ileum in a dose-dependent manner. At a drug concentration of 1 mM the amplitude of contractions was reduced to <50% of the initial control value. NA had no effect on the electrically induced contractions in the isolated frog sartorius muscle.

CONCLUSIONS

Gut smooth muscle is highly sensitive to the relaxant effect of NA producing 50% relaxation at a concentration approximately 10 fold lower than that required in rat arterial smooth muscle, while having no effect on non-mammalian skeletal smooth muscle. This may provide explanations for the occurrence of emesis in patients undergoing combined nicotinamide therapies and highlight possible alternatives available to counter this unwanted side-effect.

Estimate of the molecular weight of the sarcolemmal sodium channel using H2O-D2O centrifugation

The sodium channel saxitoxin binding component from rat sarcolemma was solubilized with NP-40 and centrifuged on sucrose gradients constructed in either D2O or H2O. When compared with a series of standard proteins the sedimentation behavior of the solubilized channel complex changed from an apparent S20,w of 9.1 in H2O to 6.1 in D2O. From these observations, a true partial specific volume of 0.83 ml/g was calculated for the complex. A Stokes radius of 8.6 nm was estimated from Sepharose 6-B chromatography in NP-40. The calculated protein molecular weight of the lipid-protein-detergent complex based on these data is 560,000. The complex contains about 56% protein, and the calculated molecular weight of this component is 314,000 if a v for the protein of 0.74 ml/g is assumed.

Size characteristics of the solubilized sodium channel saxitoxin binding site from mammalian sarcolemma

The sodium channel saxitoxin binding component from rat sarcolemma was solubilized with medium chain length non-ionic detergents including NP-40, Brij-96 and Lubrol-PX. Phospholipid was required for stability of the binding component. Specific saxitoxin binding was significantly temperature sensitive even with optimal levels of phospholipid present. The solubilized saxitoxin binding component chromatographed on Sepharose 6B at a position corresponding to that of a globular protein of 95--10 A Stokes radius, but had an apparent s20,w typical of a smaller molecule (s20,w = 9.2--10). Column behavior and s20,w were independent of the specific detergent used for solubilization. Anomalous column behavior may reflect molecular asymmetry, contribution from bound detergent or similar considerations.

Purification from rat sarcolemma of the saxitoxin-binding component of the excitable membrane sodium channel

The saxitoxin-binding component (SBC) of the excitable membrane sodium channel has been solubilized and purified from rat skeletal muscle sarcolemma. Phospholipid was required in mixed micelles with detergent for stability of the mammalian SBC. Even at optimal detergent-to-phospholipid ratio, the solubilized SBC showed significant temperature-dependent loss of specific toxin binding with time, necessitating maintenance of low temperatures during purification. Characteristics of saxitoxin binding to the solubilized material closely resembled those seen in intact membranes. A weak anion-exchange column was synthesized; it provided rapid 10- to 20-fold purification of the solubilized SBC. Additional necessary purification was obtained by chromatography on immobilized wheat germ agglutinin. Specific saxitoxin-binding activity of the purified material averaged approximately 1500 pmol of saxitoxin bound per mg of protein. Three bands were present in this material on sodium dodecyl sulfate/polyacrylamide gel electrophoresis. The purified material sedimented on a sucrose gradient with an apparent s20,w of 9.9 S.

Muscle surface membranes: preparative methods affect apparent chemical properties and neurotoxin binding

Considerable disagreement exists between results reported by various authors for lipid composition and enzyme activity in purified muscle membrane fractions presumed to be sarcolemma, although an explanation for these discrepancies has not been presented. We have prepared muscle light surface membrane fractions of comparable density (1.050--1.120) by a low-salt sucrose method and by an LiBr-KCl extraction procedure and compared them for density profile, total lipid and cholesterol content, protein composition and ATPase activity. In addition, sodium channels characteristic of excitable membranes have been quantitated in each preparation using [3H]saxitoxin binding assays, and the density of acetylcholine receptors determined in fractions from control and denervated muscle using alpha-[125I]bungarotoxin. Although both fractions contain predominantly surface membrane, the LiBr fraction consistently shows the higher specific activity of p-nitrophenylphosphatase, higher free cholesterol content, and higher density of sodium channels and acetylcholine receptors. The density distribution of sodium channels appears uniform throughout both fractions. Quantitative differences were seen between sodium dodecyl sulfate polyacrylamide gel electrophoresis patterns of membrane proteins from the two preparations although most bands are represented in both. A majority of the low-salt sucrose light membrane proteins were accessible in varying degrees to labelling with diazotized diiodosulfanylic acid in intact muscle. These results suggest that light surface membrane fractions may be mixtures of sarcolemma and T-tubular membranes. Using our preparative methods, the LiBr fraction may contain predominantly sarcolemma while low-salt sucrose light membranes may be enriched in T-tubular elements.