Cognitive Function In School-age Children Research Articles

Prenatal and childhood exposure to ambient air pollution and cognitive function in school-age children: Examining sensitive windows and sex-specific associations

BackgroundCombined effect of both prenatal and early postnatal exposure to ambient air pollution on child cognition has rarely been investigated and periods of sensitivity are unknown. This study explores the temporal relationship between pre- and postnatal exposure to PM10, PM2.5, NO2 and child cognitive function. MethodsUsing validated spatiotemporally resolved exposure models, pre- and postnatal daily PM2.5, PM10 (satellite based, 1 km resolution) and NO2 (chemistry-transport model, 4 km resolution) concentrations at the mother's residence were estimated for 1271 mother-child pairs from the French EDEN and PELAGIE cohorts. Scores representative of children's General, Verbal and Non-Verbal abilities at 5–6 years were constructed based on subscale scores from the WPPSI-III, WISC-IV or NEPSY-II batteries, using confirmatory factor analysis (CFA). Associations of both prenatal (first 35 gestational weeks) and postnatal (60 months after birth) exposure to air pollutants with child cognition were explored using Distributed Lag Non-linear Models adjusted for confounders. ResultsIncreased maternal exposure to PM10, PM2.5 and NO2, during sensitive windows comprised between the 15th and the 33rd gestational weeks, was associated with lower males’ General and Non-verbal abilities. Higher postnatal exposure to PM2.5 between the 35th and 52nd month of life was associated with lower males’ General, Verbal and Non-verbal abilities. Some protective associations were punctually observed for the very first gestational weeks or months of life for both males and females and the different pollutants and cognitive scores. DiscussionThese results suggest poorer cognitive function at 5–6 years among males following increased maternal exposure to PM10, PM2.5 and NO2 during mid-pregnancy and child exposure to PM2.5 around 3-4 years. Apparent protective associations observed are unlikely to be causal and might be due to live birth selection bias, chance finding or residual confounding.

Hippocampal volume and cognitive performance in children with congenital heart disease

BackgroundCongenital heart disease (CHD) is associated with an increased risk of brain abnormalities. Studies indicate a particular vulnerability of the hippocampus to hypoxia and inflammation. Yet, information regarding the hippocampus and its relation to cognitive function in school-age children with CHD remains scarce.MethodsChildren who underwent cardiopulmonary bypass surgery for CHD (N = 17) and healthy controls (N = 14) at 10 years of age underwent neurodevelopmental assessment and cerebral magnetic resonance imaging to measure IQ, working memory performance and hippocampal volume.ResultsIQ was significantly lower in children with CHD compared to controls (98 vs 112, P = 0.02). Children with CHD showed worse working memory performance with significantly lower scores in the letter-number sequencing test (P = 0.02). After adjusting for total brain volume, hippocampal volume was smaller in children with CHD compared to controls (P < 0.01). Smaller hippocampal volume was associated with lower IQ (P = 0.04), and digit span scaled score (P = 0.03), but not with other working memory tests (P > 0.1).ConclusionThis study suggests that the hippocampus may be particularly susceptible in children with CHD thereby contributing to cognitive impairments. Further research is necessary to understand the contribution of the hippocampus to cognitive impairments in children with CHD.ImpactIQ is significantly lower in school-age children with congenital heart disease compared to controls.Working memory performance seems to be worse in children with congenital heart disease.Smaller hippocampal volume is associated with lower IQ and seems to be associated with lower working memory performance.The study adds knowledge on the etiology of cognitive impairments in school-age children with congenital heart disease.

Prenatal and postnatal exposure to ambient air pollution and cognitive function in school-age children in France

Prenatal and postnatal exposure to ambient air pollution and cognitive function in school-age children in France

Skin Carotenoids and Relations to Intellectual Abilities and Academic Achievement Among School-Aged Children

ObjectivesCarotenoids are pigments found abundantly in vegetables that accumulate in the human body (i.e., the skin and central nervous system) and can serve as biomarkers for higher diet quality. Skin carotenoids have been previously correlated with cognitive function in adults; however, the relation between skin carotenoids and cognition in children is unknown. This study aimed to assess the link between skin carotenoids and cognitive function in school-aged children. MethodsChildren ages 7–12 (N = 106) participated in a cross-sectional study. Skin carotenoids were measured using reflection spectroscopy. Intellectual abilities and academic achievement were measured using Woodcock-Johnson IV. Dietary carotenoid intake was assessed using the Block Food Frequency Questionnaire and body fat percentage was measured using dual energy x-ray absorptiometry. Following initial bivariate correlations, a partial spearman correlation was conducted assessing relationships between skin carotenoids and Woodcock-Johnson IV following adjustment of covariates. ResultsSkin carotenoids were inversely correlated to body fat percentage and positively associated with household income and dietary carotenoids. Additionally, bivariate correlations revealed that General Intellectual Ability and multiple subtests of achievement were positively related to skin carotenoid status. Following adjustment for body fat percentage, household income, and dietary carotenoids, only quantitate reasoning and broad math skills (applied problems, calculation, and math facts fluency) were positively related to skin carotenoids (rs = 0.24, P = 0.02; rs = 0.225, P = 0.027). ConclusionsSkin carotenoids were positively associated with quantitate reasoning, a form of fluid reasoning, and broad math skills in school-aged children. Although carotenoid status was positively associated with WCJ subsets, these relationships were partially accounted for by household income, child adiposity, and dietary intake. Skin carotenoids were positively related to several cognitive function measures in school-aged children. Funding SourcesThis study was funded by the Egg Nutrition Center.

Food Insecurity Is Not Related to Cognitive Function in School-Aged Children in Querétaro, Mexico

Abstract Objectives To evaluate the relationship between household food insecurity and food insecurity of the mothers during her childhood with cognitive function in school children in Querétaro. Methods A total of 153 children (6–10 y) of public elementary schools in the municipality of Querétaro participated in a cross-sectional study. Household food insecurity was measured using the ELCSA (Latin American and Caribbean Food Security Scale) and a validated questionnaire to measure food insecurity of the mother during her childhood. Anthropometric measurements (weight, height, waist circumference) were taken by standardized personnel and the WISC IV scale adapted to children for the determination of cognitive function was applied by trained psychologists. Statistical ANOVA tests were used to determine mean differences in cognitive function between children with and without food insecurity. A logistic regression was also calculated to determine the odds of having low cognitive function in the presence of food insecurity, both at the household level and of the mother during her childhood. All analyses were adjusted for maternal level of education as a confounder. Results The children had a combined prevalence of overweight and obesity of 39.9%. A total of 54.3% of the households had food insecurity and 80.4% of the mothers had food insecurity in their childhood. The prevalence of the average score of the Total Intelligence Quotient (TIQ) of the children was 52.3%, and 38.2% had TIQ below average. Children living in households with food insecurity and with mothers that had food insecurity in their past had lower TIQ (89.08 ± 8.23, and, 91.87 ± 11.18, respectively) compared with children in food secure households (95.39 ± 12.20) and with mothers that had food security in their childhood (96.87 ± 12.03). However, after adjusting for maternal level of education, no relationship was observed between food insecurity and TIQ. Similarly, the adjusted logistic regression model showed no relationship between food insecurity in the household and mother's food insecurity in the past with TIQ. Conclusions In the present study, food insecurity was not related to cognitive function of school-aged children in Querétaro, Mexico. Funding Sources Partially funded by CONACYT.

Air Pollution Exposure During Fetal Life, Brain Morphology, and Cognitive Function in School-Age Children

BackgroundAir pollution exposure during fetal life has been related to impaired child neurodevelopment, but it is unclear if brain structural alterations underlie this association. The authors assessed whether air pollution exposure during fetal life alters brain morphology and whether these alterations mediate the association between air pollution exposure during fetal life and cognitive function in school-age children. MethodsWe used data from a population-based birth cohort set up in Rotterdam, The Netherlands (2002–2006). Residential levels of air pollution during the entire fetal period were calculated using land-use regression models. Structural neuroimaging and cognitive function were performed at 6 to 10 years of age (n = 783). Models were adjusted for several socioeconomic and lifestyle characteristics. ResultsMean fine particle levels were 20.2 μg/m3 (range, 16.8–28.1 μg/m3). Children exposed to higher particulate matter levels during fetal life had thinner cortex in several brain regions of both hemispheres (e.g., cerebral cortex of the precuneus region in the right hemisphere was 0.045 mm thinner (95% confidence interval, 0.028–0.062) for each 5-μg/m3 increase in fine particles). The reduced cerebral cortex in precuneus and rostral middle frontal regions partially mediated the association between exposure to fine particles and impaired inhibitory control. Air pollution exposure was not associated with global brain volumes. ConclusionsExposure to fine particles during fetal life was related to child brain structural alterations of the cerebral cortex, and these alterations partially mediated the association between exposure to fine particles during fetal life and impaired child inhibitory control. Such cognitive impairment at early ages could have significant long-term consequences.

Developmental trajectories for attention and working memory in healthy Japanese school-aged children.

The aim of this study was to investigate the developmental trajectories of attention, short-term memory, and working memory in school-aged children using a 10 min test battery of cognitive function. Participants comprised 144 typically developing children (TDC) aged 7-12 years and 24 healthy adults, divided according to age into seven groups (12 males and 12 females for each age group). Participants were assessed using CogHealth, which is a computer-based measure composed of five tasks. We measured attention, short-term memory, and working memory (WM) with visual stimulation. Each task was analyzed for age-related differences in reaction time and accuracy rate. Attention tasks were faster in stages from the age of 7-10 years. Accuracy rate of short-term memory gradually increased from 12 years of age and suddenly increased and continued to increase at 22 years of age. Accuracy rate of working memory increased until 12 years of age. Correlations were found between the ages and reaction time, and between ages and accuracy rate of the tasks. These results indicate that there were rapid improvements in attention, short-term memory, and WM performance between 7 and 10 years of age followed by gradual improvement until 12 years of age. Increase in short-term memory continued until 22 years of age. In our experience CogHealth was an easy and useful measure for the evaluation of cognitive function in school-age children.

The moderating effect of self-efficacy on normal-weight, overweight, and obese children's math achievement: A longitudinal analysis

Increased body weight is associated with decreased cognitive function in school-aged children. The role of self-efficacy in shaping the connection between children's educational achievement and obesity-related comorbidities has not been examined to date. Evidence of the predictive ability of self-efficacy in children is demonstrated in cognitive tasks, including math achievement scores. This study examined the relationship between self-efficacy and math achievement in normal weight, overweight, and obese children. I hypothesized that overweight and obese children with higher self-efficacy will be less affected in math achievement than otherwise comparable children with lower self-efficacy. I tested this prediction with multilevel growth modeling techniques using the ECLS-K 1998–1999 survey data, a nationally representative sample of children. Increased self-efficacy moderates the link between body weight and children's math achievement by buffering the risks that increased weight status poses to children's cognitive function. My findings indicate that self-efficacy moderates math outcomes in overweight, but not obese, children.

THERAPY OF ENDOCRINE DISEASE: Impact of iodine supplementation in mild-to-moderate iodine deficiency: systematic review and meta-analysis

Although the detrimental effects of severe iodine deficiency are well recognised, the benefits of correcting mild-to-moderate iodine deficiency are uncertain. We undertook a systematic review of the impact of iodine supplementation in populations with mild-to-moderate iodine deficiency. We searched Medline and the Cochrane library for relevant articles published between January 1966 and April 2013, which investigated the effect of iodine supplementation on maternal and newborn thyroid function, infant neurodevelopment and cognitive performance in school-age children. The quality of studies was graded and eligible trials were evaluated in the meta-analysis. Nine randomised controlled trials (RCTs) and eight observational studies met the inclusion criteria. Controlled trials on infant neurodevelopment were lacking; gestational iodine supplementation reduced maternal thyroid volume and serum thyroglobulin and in some studies prevented a rise in serum thyroid-stimulating hormone. None of the intervention trials recorded an excess frequency of thyroid dysfunction in contrast to observational studies. A pooled analysis of two RCTs which measured cognitive function in school-age children showed modest benefits of iodine supplementation on perceptual reasoning (standardised mean difference (SMD) 0.55; 95% CI 0.05, 1.04; P=0.03) and global cognitive index (SMD 0.27; 95% CI 0.10, 0.44; P=0.002) with significant heterogeneity between studies. Iodine supplementation improves some maternal thyroid indices and may benefit aspects of cognitive function in school-age children, even in marginally iodine-deficient areas. Further large prospective controlled studies are urgently required to clarify these findings and quantify the risk/benefits of iodine supplementation in regions previously believed to be iodine sufficient such as the UK.

Acute Exercise Enhances Preschoolers’ Ability to Sustain Attention

A growing body of research has illuminated beneficial effects of a single bout of physical activity (i.e., acute exercise) on cognitive function in school-age children. However, the influence of acute exercise on preschoolers' cognitive function has not been reported. To address this shortcoming, the current study examined the effects of a 30-min bout of exercise on preschoolers' cognitive function. Preschoolers' cognitive function was assessed following a single bout of exercise and a single sedentary period. Results revealed that, after engaging in a bout of exercise, preschoolers exhibited markedly better ability to sustain attention, relative to after being sedentary (p = .006, partial eta square = .400). Based on these findings, providing exercise opportunities appears to enhance preschoolers' cognitive function.

Treatment for Schistosoma japonicum, Reduction of Intestinal Parasite Load, and Cognitive Test Score Improvements in School-Aged Children

BackgroundTo determine whether treatment of intestinal parasitic infections improves cognitive function in school-aged children, we examined changes in cognitive testscores over 18 months in relation to: (i) treatment-related Schistosoma japonicum intensity decline, (ii) spontaneous reduction of single soil-transmitted helminth (STH) species, and (iii) ≥2 STH infections among 253 S. japonicum-infected children.MethodologyHelminth infections were assessed at baseline and quarterly by the Kato-Katz method. S. japonicum infection was treated at baseline using praziquantel. An intensity-based indicator of lower vs. no change/higher infection was defined separately for each helminth species and joint intensity declines of ≥2 STH species. In addition, S. japonicum infection-free duration was defined in four categories based on time of schistosome re-infection: >18 (i.e. cured), >12 to ≤18, 6 to ≤12 and ≤6 (persistently infected) months. There was no baseline treatment for STHs but their intensity varied possibly due to spontaneous infection clearance/acquisition. Four cognitive tests were administered at baseline, 6, 12, and 18 months following S. japonicum treatment: learning and memory domains of Wide Range Assessment of Memory and Learning (WRAML), verbal fluency (VF), and Philippine nonverbal intelligence test (PNIT). Linear regression models were used to relate changes in respective infections to test performance with adjustment for sociodemographic confounders and coincident helminth infections.Principal FindingsChildren cured (β = 5.8; P = 0.02) and those schistosome-free for >12 months (β = 1.5; P = 0.03) scored higher in WRAML memory and VF tests compared to persistently infected children independent of STH infections. A decline vs. no change/increase of any individual STH species (β:11.5–14.5; all P<0.01) and the joint decline of ≥2 STH (β = 13.1; P = 0.01) species were associated with higher scores in WRAML learning test independent of schistosome infection. Hookworm and Trichuris trichiura declines were independently associated with improvements in WRAML memory scores as was the joint decline in ≥2 STH species. Baseline coinfection by ≥2 STH species was associated with low PNIT scores (β = −1.9; P = 0.04).Conclusion/SignificanceChildren cured/S. japonicum-free for >12 months post-treatment and those who experienced declines of ≥2 STH species scored higher in three of four cognitive tests. Our result suggests that sustained deworming and simultaneous control for schistosome and STH infections could improve children's ability to take advantage of educational opportunities in helminth-endemic regions.

Critical windows of exposure for arsenic-associated impairment of cognitive function in pre-school girls and boys: a population-based cohort study

Exposure to arsenic through drinking water has been associated with impaired cognitive function in school-aged children in a few cross-sectional studies; however, there is little information on critical windows of exposure. We conducted a population-based longitudinal study in rural Bangladesh. We assessed the association of arsenic exposure, based on urinary arsenic (U-As; twice during pregnancy and twice in childhood), with the development of about 1700 children at 5 years of age using Wechsler Pre-school and Primary Scale of Intelligence [intelligence quotient (IQ)]. Median maternal U-As in pregnancy was 80 µg/l (10-90 percentiles: 25-400 µg/l). Children's urine contained 35 (12-155) µg/l and 51 (20-238) µg/l at 1.5 and 5 years, respectively. Using multivariable-adjusted regression analyses, controlling for all potential confounders and loss to follow-up, we found that verbal IQ (VIQ) and full scale IQ (FSIQ) were negatively associated with (log) U-As in girls. The associations were consistent, but somewhat stronger with concurrent arsenic exposure [VIQ: B = -2.4, 95% confidence interval (CI) = -3.8 to -1.1; FSIQ: B = -1.4, 95% CI = -2.7 to -0.1, n = 817), compared with that at 1.5 years (VIQ: B = -0.85, 95% CI = -2.1 to 0.4; FSIQ: B = -0.74, 95% CI = -1.9 to 0.4, n = 902), late gestation (VIQ: B = -1.52, 95% CI = -2.6 to -0.4; FSIQ: B = -1.35, 95% CI = -2.4 to -0.3, n = 874) and early gestation (VIQ: B = -1.23, 95% CI = -2.4 to -0.06; FSIQ: B = -0.92, 95% CI = -2.0 to -0.2, n = 833). In boys, U-As showed consistently low and non-significant associations with all IQ measures. An effect size calculation indicated that 100 µg/l U-As was associated with a decrement of 1-3 points in both VIQ and FSIQ in girls. We found adverse effects of arsenic exposure on IQ in girls, but not boys, at 5 years of age.

Iron Deficiency in Childhood: Causes and Consequences for Child Development

The main causes of iron deficiency (ID) are briefly discussed, followed by the examination of studies of ID and child cognitive and motor development and behaviour for evidence of a causal link, classifying them by study design. Iron deficiency anaemia (IDA) is associated with many psychosocial and economic disadvantages that can affect child development and could explain the frequently demonstrated relationship between IDA and poor development and behavioural differences. There is evidence of changes to brain function in infants with IDA. Many treatment trials lack statistical power due to small samples, including children without ID in the sampling or iron treatment resulting in little or no differences in iron status between placebo and treated groups. In children with IDA under 3 years, randomized trials indicate that iron supplementation is usually beneficial to motor development, but the effect on mental development is inconsistent. Iron supplementation also has a beneficial effect on cognitive function in school-aged children with IDA. Evidence for a threshold level of ID at which child development is affected is inconsistent, but children with IDA are most likely to benefit from iron supplementation. Possible harmful effects of iron supplementation in iron-replete children on growth and morbidity have to be considered when developing programmes and policy.

Pre- and postnatal arsenic exposure and child development at 18 months of age: a cohort study in rural Bangladesh

Exposure to arsenic through drinking water has been associated with impaired cognitive function in school-aged children in cross-sectional studies; however, there are few longitudinal studies and little information on effects of exposure in early life when the brain is generally most vulnerable. A longitudinal cohort study beginning in early pregnancy was conducted in rural Bangladesh, where arsenic concentrations in well water vary considerably. We assessed the effects of pre- and postnatal arsenic exposure on development of 2112 children at 18 months of age with Bayley Scales of Infant Development-II (mental and psychomotor development indices), Wolke's Behavior Rating Scale and maternal report of language. We related the measures of child development to arsenic concentrations in maternal urine in gestational weeks 9 and 30 and child's urinary arsenic at 18 months of age. Details of socio-economic background, home stimulation and anthropometric measurements of mothers and children were also available. Median maternal urinary arsenic concentration averaged over early and late gestation was 96 µg/l, whereas children's urine contained 35 µg/l of arsenic. There was no significant effect of any of the arsenic exposure measures on any of the child development measures after controlling for social and economic confounders, child's age and sex. Contrary to expectations, we found no indications of adverse effects of pre- or postnatal arsenic exposure on child development at 18 months. It remains possible that duration of exposure is critical and that effects will become apparent later in childhood.

Absence of adverse effects of severe hypoglycemia on cognitive function in school-aged children with diabetes over 18 months.

Some children with type 1 diabetes may be at risk of cognitive impairments, but mechanisms of this effect have not been confirmed. The objective of this study was to determine whether severe hypoglycemia (SH) in children with type 1 diabetes is associated with cognitive decline over 18 months. A sample of 142 6- to 15-year-old children with type 1 diabetes (mean age 11.6 +/- 2.7 years) enrolled in a trial of intensive therapy (IT) or usual care (UC) were tested with the Das-Naglieri Cognitive Assessment System at baseline and after 9 and 18 months. Episodes of SH were recorded by parents and reported promptly for verification by study nurses. HbA(1c) was measured quarterly. Over 18 months, 58 of 142 patients (41%) experienced 111 SH episodes, with a RR of SH of 1.12 for IT over UC. Neither occurrence nor frequency of SH was associated with decline in full-scale intelligence quotient (IQ), standard scores for planning, attention, simultaneous processing, or successive processing, or scaled scores on any of eight subtests. The same findings emerged when only patients who had experienced hypoglycemic seizures or coma were included in the SH group for analyses. These effects persisted when the child's age, sex, type 1 diabetes duration, and age at diagnosis were controlled statistically. HbA(1c) during the trial was not associated with cognitive changes. SH did not induce adverse changes in the measures of cognitive function administered to 6- to 15-year-old children with type 1 diabetes in this study. Although SH should be avoided in all children with diabetes, these episodes did not have adverse effects on cognition in this age-group over 18 months.

Neurodevelopmental outcome and lifestyle assessment in school-aged and adolescent children with hypoplastic left heart syndrome.

The purposes of this study are to describe the quality of life and cognitive function in school-aged children who have undergone staged palliation for hypoplastic left heart syndrome (HLHS), and to identify factors that are predictive of neurodevelopmental outcome in this population. School-aged survivors with HLHS who had undergone palliative surgery at our institution were identified and mailed a questionnaire to assess subjectively quality of life, school performance, and incidence of medical complications. A subgroup of local patients underwent standardized testing of cognitive function and neurologic examination. These patients were compared with the larger (remote) group of questionnaire respondents to determine whether results may be generalizable to the entire HLHS population. Potential predictors of neurologic and cognitive outcome were tested for their association with test scores using multivariate regression analysis. Questionnaire results were obtained from 115 of 138 eligible children (83%; mean age: 9.0 +/- 2.0 years). Standardized testing was performed in 28 of 34 (82%) eligible local patients (mean age: 8.6 +/- 2.1 years). The majority of parents or guardians described their child's health as good (34%) or excellent (45%) and their academic performance as average (42%) or above average (42%). One third of the children, however, were receiving some form of special education. Chronic medication usage was common (64%); the incidence of medical complications was comparable to that previously reported in children with Fontan physiology. Cognitive testing of the local group demonstrated a median full scale IQ of 86 (range: 50-116). Mental retardation (IQ: <70) was noted in 18% of patients. In multivariate analysis, only the occurrence of preoperative seizures predicted lower full scale IQ. Although the majority of school-aged children with HLHS had IQ scores within the normal range, mean performance for this historical cohort of survivors was lower than that in the general population.

A healthy body and a healthy mind?: the relationship between ill-health and cognitive function in school-age children.

Health of school age children and the Partnership for Child DevelopmentUntil recently, health programmes in developing countries have focused on infant survival and on the health of adolescents and, consequently, the health concerns of children of school age, falling between the ages of infancy and adolescence, have been neglected. The World Bank Development Report of 1993, stated a need to move beyond the focus on survival and to capture the concept that community health depends on the quality of life and opportunities for development. In response, the Partnership for Child Development was set up in 1992 to address the problem of ill-health among school-age children in the developing world.