Body mass index and cognitive ability of young children

Growth trajectories for executive and social cognitive abilities in an Indian population sample: Impact of demographic and psychosocial determinants

Cognitive abilities are markers of brain development and psychopathology. Abilities, across executive, and social domains need better characterization over development, including factors that influence developmental change. This study is based on the cVEDA [Consortium on Vulnerability to Externalizing Disorders and Addictions] study, an Indian population based developmental cohort. Verbal working memory, visuo-spatial working memory, response inhibition, set-shifting, and social cognition (faux pas recognition and emotion recognition) were cross-sectionally assessed in > 8000 individuals over the ages 6-23 years. There was adequate representation across sex, urban-rural background, psychosocial risk (psychopathology, childhood adversity and wealth index, i.e. socio-economic status). Quantile regression was used to model developmental change. Age-based trajectories were generated, along with examination of the impact of determinants (sex, childhood adversity, and wealth index). Development in both executive and social cognitive abilities continued into adulthood. Maturation and stabilization occurred in increasing order of complexity, from working memory to inhibitory control to cognitive flexibility. Age related change was more pronounced for low quantiles in response inhibition (β∼4 versus  -1 versus -0.25 for lower quantiles). Wealth index had the largest influence on developmental change across cognitive abilities. Sex differences were prominent in response inhibition, set-shifting and emotion recognition. Childhood adversity had a negative influence on cognitive development. These findings add to the limited literature on patterns and determinants of cognitive development. They have implications for understanding developmental vulnerabilities in young persons, and the need for providing conducive socio-economic environments.

Association between nutritional status, physical fitness and executive functions in preadolescents: A person-centered approach

Objective

In the current study, a person-centered approach was adopted to investigate the relationship between nutritional status and physical fitness profiles and executive functions (EF) in preadolescents.

Methods

Participants (M age = 10.8 years; Male = 50.8%) were recruited from two primary schools in Hong Kong. Nutritional status [body mass index (BMI)], physical fitness including cardiorespiratory fitness (CRF, predicted VO2max, multi-stage fitness test) and speed-agility (20-m sprint) were measured on school days. EF performance was measured using the Flanker task (inhibition) and the Sternberg task (working memory).

Results

Data from 120 preadolescents were considered valid. Three distinct profiles were identified by a person-centered approach. Profile 1 was featured by high BMI (21.61 ± 3.38 kg/m2), poor VO2max (33.29 ± 23.96 ml/kg/min), and slow 20-m sprint (4.51 ± 0.13 s). Profile 2 was featured by low BMI (15.99 ± 3.38), fair VO2max (44.98 ± 23.96) and fast 20-m sprint (3.97 ± 0.13). Profile 3 was featured by low BMI (15.63 ± 3.38), poor VO2max (32.37 ± 23.96), and slow 20-m sprint (4.48 ± 0.13). Wald chi-square test revealed preadolescents in profile 1 and profile 2 performed better than profile 3 in accuracy of Flanker task (1 vs. 3: χ 2 = 12.23, P < 0.001; 2 vs. 3: χ 2 = 10.86, P = 0.001). That is, for normal weight preadolescents with poor CRF and speed-agility, those with superior nutritional status performed better in inhibition. For normal weight preadolescents with poor nutritional status, those with superior CRF and speed-agility had better inhibitory capacity.

Conclusion

Compared to the commonly used variable-centered approach, this person-centered approach is a valuable addition that expands the understanding of the association between nutritional status, physical fitness and EF in preadolescents. Results are discussed with regards to maximizing health behaviors and implications for educational policy.

Differences between Healthy-Weight and Overweight Serbian Preschool Children in Motor and Cognitive Abilities

The aim of this study was to determine the differences between healthy-weight and overweight 5-6-year-old preschool children in fine and gross motor skills and cognitive abilities. There were 91 subjects, preschool children (41 boys and 50 girls), who participated in this cross-sectional study. The body mass index (BMI) was calculated based on measures of body height and body mass, and WHO cutoff points were used for the assessment of the children's nutrition status. Fine motor abilities were determined using two Bruininks-Oseretsky (BOT-2) subtests, and gross motor skills are determined by the Test of Gross Motor Development (TGMD-2), while cognitive abilities were tested by the School Maturity Test (TZŠ+). Based on an independent-samples t-test, a difference in two out of three variables of gross motor skills was determined: manipulative skills and total gross motor skills between healthy-weight and overweight children, while in fine motor abilities and cognitive abilities there was no difference between these two groups. Although significant differences were found only in gross motor skills between healthy and overweight preschool children but not in fine motor skills and cognitive abilities, further longitudinal studies are required to understand the mechanisms of this, including the possible role of psychological factors.

Cardiovascular Risk Markers and Cognitive Performance in Children

Markers of cardiovascular risk and cognitive performance were assessed in 347 children. In contrast with body mass index and blood pressure, only retinal microcirculation explained a unique proportion of variance in inhibitory control and information processing, when dependencies between markers of cardiovascular risk were accounted for.

A Meta-Analysis of Stressors from the Total Environment Associated with Children's General Cognitive Ability

General cognitive ability, often referred to as ‘general intelligence’, comprises a variety of correlated abilities. Childhood general cognitive ability is a well-studied area of research and can be used to predict social outcomes and perceived success. Early life stage (e.g., prenatal, postnatal, toddler) exposures to stressors (i.e., chemical and non-chemical stressors from the total (built, natural, social) environment) can impact the development of childhood cognitive ability. Building from our systematic scoping review (Ruiz et al., 2016), we conducted a meta-analysis to evaluate more than 100 stressors related to cognitive development. Our meta-analysis identified 23 stressors with a significant increase in their likelihood to influence childhood cognitive ability by 10% or more, and 80 stressors were observed to have a statistically significant effect on cognitive ability. Stressors most impactful to cognition during the prenatal period were related to maternal health and the mother’s ability to access information relevant to a healthy pregnancy (e.g., diet, lifestyle). Stressors most impactful to cognition during the early childhood period were dietary nutrients (infancy), quality of social interaction (toddler), and exposure to toxic substances (throughout early childhood). In conducting this analysis, we examined the relative impact of real-world exposures on cognitive development to attempt to understand the inter-relationships between exposures to both chemical and non-chemical stressors and early developmental life stages. Our findings suggest that the stressors observed to be the most influential to childhood cognitive ability are not permanent and can be broadly categorized as activities/behaviors which can be modified to improve childhood cognition. This meta-analysis supports the idea that there are complex relationships between a child’s total environment and early cognitive development.

Impact of Early-Life Weight Status on Cognitive Abilities in Children

OBJECTIVE

Whether obesity is associated with childhood cognition is unknown. Given the sensitivity of the developing brain to environmental factors, this study examined whether early-life weight status was associated with children's cognition.

METHODS

Using data from mother-child pairs enrolled in the Health Outcomes and Measures of the Environment (HOME) Study (2003-2006), children's early-life weight status was assessed using weight-for-length/height standard deviation (SD) scores. A battery of neuropsychological tests was administered to assess cognition, executive function, and visual-spatial abilities at ages 5 and 8 years. Using linear mixed models, associations between early-life weight status and cognition were estimated.

RESULTS

Among 233 children, 167 were lean (≤1 SD) and 48 were nonlean (>1 SD). After covariate adjustment, the results suggest that full-scale intelligence quotient scores decreased with a 1-unit increase in weight-for-height SD score (β = -1.4, 95% CI: -3.0 to 0.1). For individual component scores, with a 1-unit increase in weight-for-height SD score, perceptual reasoning (β = -1.7, 95% CI: -3.3 to 0.0) and working memory (β: -2.4, CI: -4.4 to -0.4) scores decreased. Weight status was generally not associated with other cognition measures.

CONCLUSIONS

Within this cohort of typically developing children, early-life weight status was inversely associated with children's perceptual reasoning and working memory scores and possibly with full-scale intelligent quotient scores.

Overweight and obese infants present lower cognitive and motor development scores than normal-weight peers

AIMS

Compare the cognitive and motor development in overweight/obese infants versus normal-weight peers and investigate the correlation of body weight, body length and body mass index with cognitive and motor development.

METHODS

We conducted a cross-sectional study with 28 overweight/obese infants and 28 normal-weight peers between 6 and 24 months of age. Both groups were evaluated with cognitive and motor scales of the Bayley-III infant development test. The t-test for independent samples was performed to compare the groups, and the Spearman correlation was used to verify the association between variables.

RESULTS

Overweight/obese infants showed lower cognitive and motor composite scores than their normal-weight peers. A significant negative association was found of body weight and body length with cognitive development and of body mass index with motor development.

CONCLUSION

This is the first study that found an effect on both cognitive and motor development in overweight/obese infants when compared with normal-weight peers between 6 and 24 months of age.

Contributions of a Child's Built, Natural, and Social Environments to Their General Cognitive Ability: A Systematic Scoping Review

The etiology of a child’s cognitive ability is complex, with research suggesting that it is not attributed to a single determinant or even a defined period of exposure. Rather, cognitive development is the product of cumulative interactions with the environment, both negative and positive, over the life course. The aim of this systematic scoping review was to collate evidence associated with children’s cognitive health, including inherent factors as well as chemical and non-chemical stressors from the built, natural, and social environments. Three databases were used to identify recent epidemiological studies (2003–2013) that examined exposure factors associated with general cognitive ability in children. Over 100 factors were evaluated from 258 eligible studies. We found that recent literature mainly assessed the hypothesized negative effects of either inherent factors or chemical exposures present in the physical environment. Prenatal growth, sleep health, lead and water pollutants showed consistent negative effects. Of the few studies that examined social stressors, results consistently showed cognitive development to be influenced by both positive and negative social interactions at home, in school or the community. Among behavioral factors related to diet and lifestyle choices of the mother, breastfeeding was the most studied, showing consistent positive associations with cognitive ability. There were mostly inconsistent results for both chemical and non-chemical stressors. The majority of studies utilized traditional exposure assessments, evaluating chemical and non-chemical stressors separately. Collective evidence from a limited number of studies revealed that cumulative exposure assessment that incorporates multiple chemical and non-chemical stressors over the life course may unravel the variability in effect on cognitive development and help explain the inconsistencies across studies. Future research examining the interactions of multiple stressors within a child’s total environment, depicting a more real-world exposure, will aid in understanding the cumulative effects associated with a child’s ability to learn.

Associations between obesity and cognition in the pre-school years

OBJECTIVE

To test the hypothesis that obesity is associated with impaired cognitive outcomes in the pre-school years.

METHODS

Associations were examined between weight status at age 3-5 years and cognitive performance at age 5 years. Cognitive outcome measures were tests of pattern construction (visuospatial skills), naming vocabulary (expressive language skills), and picture similarity (reasoning skills). The sample was the UK Millennium Cohort Study (n = 12,349 participants).

RESULTS

Boys with obesity at 3 years had significantly lower performance in pattern construction at age 5 years compared to those of a healthy weight, even after controlling for confounders (β = -0.029, P = 0.03). Controlling for confounders, boys who developed obesity between the ages of 3 and 5 years had lower scores in pattern construction (β = -0.03, P = 0.03). "Growing out" of obesity had a positive association with picture similarity performance in girls (β = 0.03, P = 0.04).

CONCLUSIONS

Obesity in the pre-school years was associated with poorer outcomes for some cognitive measures in this study. Stronger relationships between obesity and cognition or educational attainment may emerge later in childhood.

Motor and Cognitive Performance of Overweight Preschool Children

Gross and fine motor skills and cognitive performance in obese and overweight children were compared to healthy weight children. Participants were 1,543 children (797 boys and 746 girls) ages 43 to 84 months, attending child-care centers in Munich, Germany. According to German Body Mass Index (BMI) standards for age and sex, 4.6% of the children were classified as obese (percentile greater or equal 97), 6.8% as overweight (percentile greater or equal 90 and less than 97), 5.9% as underweight (percentile less than 10), and 83.1% as being of healthy weight. Dependent variables were physical characteristics (height, weight, skinfold thickness), physical fitness (standing broad jump, shuttle run, hanging), body coordination (balancing forward, balancing backward, lateral jump, hopping), manual dexterity (right and left hand), and cognitive performance (intelligence, verbal ability, concentration). Higher proportions of children from lower socioeconomic and immigrant backgrounds were overweight. There was no association between weight and sex. Overweight children showed lower performance on gross motor skills (coordination and fitness), manual dexterity, and intelligence compared to healthy weight children, even after controlling for the effects of social class and immigration status.