Paediatric obesity: a neurodevelopmental perspective

Family screening for neurodevelopmental problems and its associations with child cognitive function enable tailored treatment for childhood obesity

AIM

To identify neurodevelopmental disorders in children with obesity, and investigate associations to cognitive functions as well as parents' self-reported neurodevelopmental problems.

METHODS

Eighty children were included at two outpatient obesity clinics in Sweden 2018-2019. Of these, 50 children without previously diagnosed neurodevelopmental disorders were screened, and so were their parents. Children who screened positive for neurodevelopmental problems were referred to a specialised psychiatry unit for further diagnosis. Test results of cognitive functioning were compared with the norm and between study groups by neurodevelopmental diagnoses.

RESULTS

Of the screened families, 17/50 children were diagnosed by the psychiatric unit with attention deficit-hyperactivity disorder (ADHD) and 15/82 parents screened positive for neurodevelopmental problems. Having a mother who screened positive for neurodevelopmental problems was associated with child ADHD (p < 0.05). The children's full-scale intelligence quotient (92.86 ± 12.01, p < 0.001) and working memory index (90.62 ± 12.17, p < 0.001) were lower than the norm. Working memory index was lower in children with ADHD compared to without ADHD: 84.76 ± 9.58 versus 94.09 ± 12.29 (p ≤ 0.01). Executive constraints were associated with verbal deviances.

CONCLUSION

Increased awareness is needed about the overlap between neurodevelopmental problems and obesity in obesity clinics.

Physical activity on prescription for children with obesity: a focus group study exploring experiences in paediatric healthcare

Background

Insufficient physical activity is a growing public health concern and is closely linked to obesity in both adults and children. Swedish physical activity on prescription (PAP) is effective in increasing physical activity levels in adults, but knowledge about how PAP is used in paediatric healthcare is lacking. Therefore, this study aimed to explore experiences of working with PAP for children with obesity amongst paediatric staff and managers.

Methods

Seven focus group discussions with 26 participants from paediatric outpatient clinics in western Sweden were conducted. Data were analysed both inductively and deductively, framed by the Normalization Process Theory's four core constructs: coherence, cognitive participation, collective action, and reflexive monitoring.

Results

The PAP work for children with obesity was experienced to be about helping children to become physically active, and less about losing weight. Identified barriers for using PAP were the non-uniform nature of the work and a perceived lack of guidelines. Collaboration with physiotherapists and physical activity organisers outside the organisation was identified as an important facilitator. An important contextual factor for implementing PAP is the collaboration between paediatric clinics and physical activity organisers. In the transition between these stakeholders, maintaining a family-centred approach when working with PAP was experienced as challenging.

Conclusions

PAP is a well-known intervention that is inconsistently used for children with obesity. The intervention should include a family-centred approach for this patient group. It also needs to align better with existing collaborations with other healthcare units as well as with new forms of collaboration with physical activity organisers in the community.

Associations between waist circumference and executive function among Chinese Tibetan adolescents living at high altitude

Background

Associations between body composition and execution function (EF) were currently studied in low altitude (LA) areas. However, the research on the correlation between waist circumference (WC) and EF among adolescents living at high altitude (HA) was limited.

Objective

We sought to explore the association between WC and EF in Chinese Tibetan adolescents aged 13-18 years in HA areas.

Methods

After excluding invalid data and extreme values, 1,228 participants (583 boys and 645 girls) were eventually included. The areas of Lhasa (average elevation of 3650 m), Nagqu (4500 m), Qamdo (3500 m), and Nyingchi (3100 m) in China were chosen as study sites. Participants completed tasks to measure inhibitory control, working memory, and cognitive flexibility. The predictive association between WC and EF was explored by One-way ANOVA, Pearson correlation, and linear regression analysis.

Results

After controlling for concomitant variables, the reaction time (RT) of responding to inhibitory control (difference incongruent and congruent), working memory (1-back, 2-back), and cognitive flexibility (heterogeneous, difference in heterogeneous and homogeneous) stimuli in subjects with WC ≥ 85th percentile was longer than that in those with WC of the 15th percentile or below [by 1.785 ms (95% CI: 0.078, 3.491), 208.734 ms (95% CI: 96.886, 320.582), 106.679 ms (95% CI: 16.485, 196.873), 82.307 ms (95% CI: 19.171, 145.442), and 58.397 ms (95% CI: 0.343,116.452), respectively], (P < 0.05).

Conclusion

After adjustment for concomitant variables, WC was significantly positively associated with the RT of inhibitory control, working memory, and cognitive flexibility among Chinese Tibetan adolescents in HA areas.

Orexin/Hypocretin System Dysfunction in ESSENCE (Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations)

Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations (ESSENCE) is an umbrella term covering a wide range of neurodevelopmental difficulties and disorders. Thus, ESSENCE includes attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and other neurodevelopmental disorders (NDDs) and difficulties, with a variety of symptoms in cognitive, motor, sensory, social, arousal, regulatory, emotional, and behavioral developmental domains, frequently co-occurring and likely having partly common neurobiological substrates. The ESSENCE concept is a clinical paradigm that promotes organizing NDDs in everyday clinical practice according to their coexistence, symptom dimensions overlapping, and treatment possibilities. Despite increased knowledge regarding NDDs, the neurobiological mechanisms that underlie them and other ESSENCE-related problems, are not well understood. With its wide range of neural circuits and interactions with numerous neurotransmitters, the orexin/hypocretin system (Orx-S) is possibly associated with a variety of neurocognitive, psychobiological, neuroendocrine, and physiological functions and behaviors. Dysfunction of Orx-S has been implicated in various psychiatric and neurological disorders. This article provides an overview of Orx-S dysfunctions' possible involvement in the development, presentation, and maintenance of ESSENCE. We provide a focused review of current research evidence linking orexin neuropeptides with specific clinical NDDs symptoms, mostly in ADHD and ASD, within the Research Domain Criteria (RDoC) framework. We propose that Orx-S dysfunction might have an important role in some of these neurodevelopmental symptom domains, such as arousal, wakefulness, sleep, motor and sensory processing, mood and emotional regulation, fear processing, reward, feeding, attention, executive functions, and sociability. Our perspective is presented from a clinical point of view. Further, more thorough systematic reviews are needed as well as planning of extensive new research into the Orx-S's role in ESSENCE, especially considering RDoC elements.

Sex-specific epigenetic development in the mouse hypothalamic arcuate nucleus pinpoints human genomic regions associated with body mass index

Recent genome-wide association studies corroborate classical research on developmental programming indicating that obesity is primarily a neurodevelopmental disease strongly influenced by nutrition during critical ontogenic windows. Epigenetic mechanisms regulate neurodevelopment; however, little is known about their role in establishing and maintaining the brain's energy balance circuitry. We generated neuron and glia methylomes and transcriptomes from male and female mouse hypothalamic arcuate nucleus, a key site for energy balance regulation, at time points spanning the closure of an established critical window for developmental programming of obesity risk. We find that postnatal epigenetic maturation is markedly cell type and sex specific and occurs in genomic regions enriched for heritability of body mass index in humans. Our results offer a potential explanation for both the limited ontogenic windows for and sex differences in sensitivity to developmental programming of obesity and provide a rich resource for epigenetic analyses of developmental programming of energy balance.

Is earlier obesity associated with poorer executive functioning later in childhood? Findings from the Millennium Cohort Study

BACKGROUND

Children affected with overweight or obesity have been associated with having lower educational achievement compared to peers who are non-overweight/obese. One of the drivers of this association could be a link between obesity and poorer executive function. Evidence is limited to small, cross-sectional studies which lack adjustment for important common causes.

OBJECTIVE

We investigate the association between weight status and executive function longitudinally in mid-childhood, accounting for potential common causes.

METHODS

Linear regression analyses were conducted to examine associations between weight status between 5 and 7 years and executive functioning at 11 years in members of the Millennium Cohort Study (n = 7739), accounting for a wide range of potential common causes. Age- and sex-specific International Obesity Taskforce cut-points for body mass index (BMI) were used. Executive function, including decision-making, impulsivity and spatial working memory, was assessed using the Cambridge Neuropsychological Test Automated Battery.

RESULTS

There were no unadjusted associations between weight status and decision-making or impulsivity. After adjustment for all potential common causes, there was a lack of consistent evidence to support an association between persistent obesity (including overweight) between 5 and 7 years and spatial working memory task at 11 years.

CONCLUSIONS

We found little evidence that poorer spatial working memory contributes to the association of children with obesity having lower educational achievement.

Memory and Executive Function in Adolescent and Young Adult Females with Moderate to Severe Obesity Before and After Weight Loss Surgery

There is a global increase in the prevalence of severe obesity in females during adolescence, which is a critical period for neurocognitive development. An increasing number of adolescents and young adults are now undergoing weight loss surgery as a treatment strategy for obesity. In addition to metabolic complications, obesity has been linked to neurocognitive comorbidity, and studies exploring cognitive performance in adolescents with severe obesity and the impact of bariatric surgery on cognitive abilities are limited. Verbal memory and executive function were assessed cross-sectionally in 69 females with moderate to severe obesity and 24 females without obesity, 13-24 years old. In an exploratory analysis, cognitive changes were also assessed longitudinally over 12 months in a subset of 35 females with moderate to severe obesity following weight loss surgery (n = 21) or following usual care without surgery (n = 14). In cross-sectional analysis, females with moderate to severe obesity showed lower scores for short-term and long-term recall (verbal memory) and response inhibition and cognitive flexibility (executive function) than the comparison group, when adjusted for age and baseline intelligence. Females with moderate to severe obesity who underwent surgery showed significant weight loss but no improvement in verbal memory and executive function scores over 12 months compared with those who did not have surgery. Females with moderate to severe obesity demonstrate worse performance in tests of verbal memory and executive function than the comparison group without obesity. In addition, exploratory analyses provide no indication that weight loss surgery improves these observed cognitive decrements over a period of 12 months. Further studies are necessary to comprehensively evaluate changes in cognitive function following bariatric surgery.

Consequences of early life overfeeding for microglia - Perspectives from rodent models

The early life period is crucially important to how the individual develops, and environmental and lifestyle challenges during this time can lead to lasting programming effects on the brain and immune system. In particular, poor diet in early development can lead to long-term negative metabolic and cognitive outcomes, with those who over-eat in early development being at risk of obesity and poor learning and memory throughout their adult lives. Current research has identified a neuroinflammatory component to this metabolic and cognitive programming that can potentially be manipulated to restore a healthy phenotype. Thus, early life over-feeding in a rat model leads to microglial priming and an exacerbated microglial response to immune challenge when the rats reach adulthood. Microglial responses to a learning task are also impaired. To specifically investigate the role of microglia in these programming effects our group has developed a novel transgenic rat with a diphtheria toxin receptor insertion in the promoter region for the Cx3cr1 gene, expressed on microglia and monocytes; allowing us to conditionally ablate microglia throughout the brain. With this model we reveal that microglia have a direct role in regulating feeding behavior and modifying cognition, but are not likely to be the sole mechanism by which early life overfeeding confers lasting neuroimmune and cognitive effects. Additional work implicates changes to the hypothalamic-pituitary-adrenal axis in this. Together these data highlight the importance of dietary choices in early life and the potential for positive interventions targeting the neuroimmune and neuroendocrine stress systems to reverse such programming damage.

Changes in Motor Skill Proficiency After Equine-Assisted Activities and Brain-Building Tasks in Youth With Neurodevelopmental Disorders

There is a lack of current research to support the efficacy of a combination of equine-assisted activities (EAA) and brain building activities to influence motor skill competencies in youth with neurodevelopmental disorders (ND). The primary objective of this study was to quantify changes in motor skill proficiency before and after 8 weeks of EAA and brain-building activities in youth with ND. A secondary objective was to quantify changes in motor skill proficiency before and after 1 year of EAA and brain-building activities in youth with ND. Twenty-five youth completed the same 32-week protocol that was separated into 4, 8-week blocks, in the following order: (1) control; (2) EAA-only; (3) washout; (4) GaitWay block (EAA and brain building activities). Before and after each block, motor skills were assessed using the Short Form of the Bruininks-Oseretsky Test of Motor Proficiency-Version 2 (BOT-2). Seven youth continued with the GaitWay intervention for one additional year, and the BOT-2 Short Form was also administered following this intervention. A repeated-measures analysis-of-variance was performed to compare BOT-2 subtest and overall scores between interventions with a significance of 0.05. Manual dexterity was higher at Post-Washout [3.3 (2.4)] vs. Pre-Control [2.2 (2.1); p = 0.018] and Post-Control [2.6 (2.0); p = 0.024], and at Post-GaitWay vs. Pre-Control [3.2 (2.4) vs. 2.2 (2.1); p = 0.037]. Upper-limb coordination was higher at Post-GaitWay vs. Post-Control [6.0 (4.1) vs. 3.9 (3.8); p = 0.050]. When compared to Pre-Control [3.2 (3.0)], strength was higher at Post-EAA [4.9 (3.5); p = 0.028] and at Post-GaitWay [5.2 (2.9); p = 0.015]. Overall scores were higher at Post-GaitWay [39.1 (22.2)] when compared to Pre-Control [32.4 (21.6); p = 0.003] and Post-Control [32.5 (21.9); p = 0.009]. Additionally, motor skills were maintained for 1 year following the Post-GaitWay testing session among seven participants. This is the first known study to include and demonstrate the short-term and long-term effects of a combination of EAA and brain building activities with motor proficiency in youth with ND.

Clinical Trial Registration: Motor Skill Proficiency After Equine-Assisted Activities and Brain-building Tasks; www.ClinicalTrials.gov, identifier: NCT04158960.

Altered neural correlates of episodic memory in adolescents with severe obesity

Negative effects of obesity on memory and associated medial temporal circuitry have been noted in animal models, but the status in humans, particularly children, is not well established. Our study is the first to examine neural correlates of successful memory encoding of visual scenes and their associated context in adolescents with severe obesity (age 14-18 years, 43% male). Despite similar subsequent memory as adolescents without obesity (BMI for age and sex <95th percentile), those with severe obesity (BMI for age and sex 120% above the 95th percentile) showed reduced hippocampal, parahippocampal, frontal, and parietal engagement during encoding of remembered visual scenes and greater lateral temporal engagement during encoding of their associated context. Standardized testing revealed a trend level group difference in memory performance, with a larger magnitude of obesity-related difference in recollection-related memory that was mediated by individual differences in lateral temporal activation during contextual encoding. The observed widespread functional alterations are concerning in light of the importance of mnemonic processing for academic achievement and feeding behavior and underscore the need for prevention and intervention initiatives for pediatric obesity.

A Review of Childhood Behavioral Problems and Disorders in the Development of Obesity: Attention Deficit/Hyperactivity Disorder, Autism Spectrum Disorder, and Beyond

PURPOSE OF REVIEW

Given the high rates of pediatric and adult obesity, it is imperative to identify early risk factors that might contribute to excess weight gain. This review aims to investigate the relationship between childhood behavioral problems with the development and persistence of obesity. Specifically, this review highlights the association of obesity with (1) neurocognitive constructs, such as executive functioning and inhibition/impulsivity, and (2) disorders commonly diagnosed in childhood, including attention deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD).

RECENT FINDINGS

Consistent evidence supports a relationship between childhood behavioral problems, executive functioning, inhibition/impulsivity, ADHD, and ASD with obesity across the lifespan. Longitudinal studies suggest behavior problems, neurocognitive functioning deficits, and ADHD symptoms in childhood predict weight gain over time. Identifying risk factors in childhood that promote obesity may help develop targeted intervention and prevention programs. Additional research should elucidate mechanisms that account for these relationships.

Neurodevelopmental disorders are highly over-represented in children with obesity: A cross-sectional study

OBJECTIVE

To investigate prevalence of neurodevelopmental disorders in children with obesity and to compare body mass index (BMI) and metabolic profile in the children.

METHODS

Seventy-six children (37 girls, 39 boys) were consecutively recruited from a university outpatient clinic specialized in severe obesity. Neurodevelopmental disorders including attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and developmental coordination disorder (DCD) were assessed using interviews and questionnaires. Neurodevelopmental diagnoses were collected retrospectively in medical records.

RESULTS

BMI ranged between 1.9 and 5.9 SDS and age between 5.1 and 16.5 years. In 13.2% and 18.4% ASD and ADHD was assigned, respectively. In addition, 25% screened positive for DCD, 31.6% had at least one neurodevelopmental disorder, and 18.4% had a parent who screened positive for adult ADHD. Girls with ASD/ADHD had higher BMI SDS than girls without neurodevelopmental disorder (P = 0.006).

CONCLUSIONS

One third of children with obesity referred to specialist centers have a neurodevelopmental disorder including deviant motor skills, and these problems may deteriorate weight status. One fifth of the parents exhibit ADHD symptomatology which could partly explain the poor adherence by some families in obesity units. Future obesity therapy could benefit from incorporating a neurodevelopmental treatment approach.

Obesity and neuroinflammation: a pathway to cognitive impairment

Obesity is a growing problem worldwide and is associated with a range of comorbidities, including cognitive dysfunction. In this review we will address the evidence that obesity and high fat feeding can lead to cognitive dysfunction. We will also examine the idea that obesity-associated systemic inflammation leads to inflammation within the brain, particularly the hypothalamus, and that this is partially responsible for these negative cognitive outcomes. Thus, obesity, and high fat feeding, lead to systemic inflammation and excess circulating free fatty acids. Circulating cytokines, free fatty acids and immune cells reach the brain at the level of the hypothalamus and initiate local inflammation, including microglial proliferation. This local inflammation likely causes synaptic remodeling and neurodegeneration within the hypothalamus, altering internal hypothalamic circuitry and hypothalamic outputs to other brain regions. The result is disruption to cognitive function mediated by regions such as hippocampus, amygdala, and reward-processing centers. Central inflammation is also likely to affect these regions directly. Thus, central inflammation in obesity leads not just to disruption of hypothalamic satiety signals and perpetuation of overeating, but also to negative outcomes on cognition.

Neurocognitive correlates of obesity and obesity-related behaviors in children and adolescents

Childhood obesity rates have risen dramatically over the past few decades. Although obesity has been linked to poorer neurocognitive functioning in adults, much less is known about this relationship in children and adolescents. Therefore, we conducted a systematic review to examine the relationship between obesity and obesity-related behaviors with neurocognitive functioning in youth. We reviewed articles from 1976 to 2013 using PsycInfo, PubMed, Medline and Google Scholar. Search terms included cognitive function, neurocognitive function/performance, executive function, impulsivity, self-regulation, effortful control, cognitive control, inhibition, delayed gratification, memory, attention, language, motor, visuo-spatial, academic achievement, obesity, overweight, body mass index, waist-hip ratio, adiposity and body fat. Articles were excluded if participants had health problems known to affect cognitive functioning, the study used imaging as the only outcome measure, they were non-peer-reviewed dissertations, theses, review papers, commentaries, or they were non-English articles. Sixty-seven studies met inclusion criteria for this review. Overall, we found data that support a negative relationship between obesity and various aspects of neurocognitive functioning, such as executive functioning, attention, visuo-spatial performance, and motor skill. The existing literature is mixed on the effects among obesity, general cognitive functioning, language, learning, memory, and academic achievement. Executive dysfunction is associated with obesity-related behaviors, such as increased intake, disinhibited eating, and less physical activity. Physical activity is positively linked with motor skill. More longitudinal research is needed to determine the directionality of such relationships, to point towards crucial intervention time periods in the development of children, and to inform effective treatment programs.

Cognitive profile, parental education and BMI in children: reflections on common neuroendrocrinobiological roots

Overweight and obesity may be associated with cognitive problems and both may share "neuroendocrinobiological roots" in common cerebral areas. We investigated intellectual performances and a possible "specific cognitive profile" in overweight/obese children. A cross-sectional study was conducted on 898 school children (6 to 13 years) attending primary schools. Wechsler Intelligence Scale for Children-revised (WISC-R) revealed significant differences in performance intelligence quotient (PIQ) scores between body mass index (BMI) subgroups (p < 0.01). Regression analysis identified BMI as the only variable significantly related to PIQ (p < 0.05). Gender (p < 0.05) and parental educational score (p < 0.001) were significantly related to verbal intelligence quotient (VIQ). Parental educational score was the only factor significantly related to total intelligence quotient (TIQ) (p < 0.05). Parental education seems to play a major role in TIQ and VIQ; a lower PIQ score is clearly related to a higher BMI. A routine neurocognitive assessment in overweight/obese children is recommended. Finally, we have added some reflections on common neuroendocrinobiological roots.