Early childhood obesity is associated with compromised cerebellar development

The cerebellum plays more than one role in the dysregulation of appetite: Review of structural evidence from typical and eating disorder populations

OBJECTIVE

Dysregulated appetite control is characteristic of anorexia nervosa (AN), bulimia nervosa (BN), and obesity (OB). Studies using a broad range of methods suggest the cerebellum plays an important role in aspects of weight and appetite control, and is implicated in both AN and OB by reports of aberrant gray matter volume (GMV) compared to nonclinical populations. As functions of the cerebellum are anatomically segregated, specific localization of aberrant anatomy may indicate the mechanisms of its relationship with weight and appetite in different states. We sought to determine if there were consistencies in regions of cerebellar GMV changes in AN/BN and OB, as well as across normative (NOR) variation.

METHOD

Systematic review and meta-analysis using GingerALE.

RESULTS

Twenty-six publications were identified as either case-control studies (nOB  = 277; nAN/BN  = 510) or regressed weight from NOR data against brain volume (total n = 3830). AN/BN and OB analyses both showed consistently decreased GMV within Crus I and Lobule VI, but volume reduction was bilateral for AN/BN and unilateral for OB. Analysis of the NOR data set identified a cluster in right posterior lobe that overlapped with AN/BN cerebellar reduction. Sensitivity analyses indicated robust repeatability for NOR and AN/BN cohorts, but found OB-specific heterogeneity.

DISCUSSION

Findings suggest that more than one area of the cerebellum is involved in control of eating behavior and may be differentially affected in normal variation and pathological conditions. Specifically, we hypothesize an association with sensorimotor and emotional learning via Lobule VI in AN/BN, and executive function via Crus I in OB.

Use of Physical Activity and Exercise to Reduce Inflammation in Children and Adolescents with Obesity

Childhood obesity is a leading public health problem worldwide, as it is increasingly prevalent and therefore responsible for serious obesity-related comorbidities, not only in childhood but also in adulthood. In addition to cardio-metabolic obesity-related disorders, recent evidence suggests that excess adipose tissue in turn is associated with immune cell infiltration, increased adipokine release, and the development of low-grade systemic inflammation obesity. Exercise is considered a non-pharmacological intervention that can delay obesity-related comorbidities, improving cardiovascular fitness and modulating the inflammatory processes. It has been reported that the anti-inflammatory effect of regular exercise may be mediated by a reduction in visceral fat mass, with a subsequent decrease in the release of adipokines from adipose tissue (AT) and/or by the induction of an anti-inflammatory environment. In this narrative review, we discuss the role of AT as an endocrine organ associated with chronic inflammation and its role in obesity-related complications, focusing on the effect of exercise in reducing inflammation in children and adolescents with obesity. Regular physical exercise must be considered as a natural part of a healthy lifestyle, and promoting physical activity starting from childhood is useful to limit the negative effects of obesity on health. The crucial role of the immune system in the development of obesity-induced inflammatory processes and the efficacy of exercise as an anti-inflammatory, non-pharmacological intervention may provide possible targets for the development of new treatments and early preventive strategies.

Of differing methods, disputed estimates and discordant interpretations: the meta-analytical multiverse of brain volume and IQ associations

Brain size and IQ are positively correlated. However, multiple meta-analyses have led to considerable differences in summary effect estimations, thus failing to provide a plausible effect estimate. Here we aim at resolving this issue by providing the largest meta-analysis and systematic review so far of the brain volume and IQ association (86 studies; 454 effect sizes from k = 194 independent samples; N = 26 000+) in three cognitive ability domains (full-scale, verbal, performance IQ). By means of competing meta-analytical approaches as well as combinatorial and specification curve analyses, we show that most reasonable estimates for the brain size and IQ link yield r-values in the mid-0.20s, with the most extreme specifications yielding rs of 0.10 and 0.37. Summary effects appeared to be somewhat inflated due to selective reporting, and cross-temporally decreasing effect sizes indicated a confounding decline effect, with three quarters of the summary effect estimations according to any reasonable specification not exceeding r = 0.26, thus contrasting effect sizes were observed in some prior related, but individual, meta-analytical specifications. Brain size and IQ associations yielded r = 0.24, with the strongest effects observed for more g-loaded tests and in healthy samples that generalize across participant sex and age bands.

One Year of Recombinant Human Growth Hormone Treatment in Adults with Prader-Willi Syndrome Improves Body Composition, Motor Skills and Brain Functional Activity in the Cerebellum

We compared body composition, biochemical parameters, motor function, and brain neural activation in 27 adults with Prader-Willi syndrome and growth-hormone deficiency versus age-and sex-matched controls and baseline versus posttreatment values of these parameters after one year of recombinant human growth hormone (rhGH) treatment. To study body composition, we analyzed percentage of fat mass, percentage of lean mass, and muscle-mass surrogate variables from dual X-ray absorptiometry. Biochemical parameters analyzed included IGF-I, glucose metabolism, and myokines (myostatin, irisin, and IL6). To explore muscle function, we used dynamometer-measured handgrip strength, the Timed Up and Go (TUG) test, and the Berg Balance Scale (BBS). To study brain activation, we acquired functional magnetic resonance images during three motor tasks of varying complexity. After one year of treatment, we observed an increase in lean mass and its surrogates, a decrease in fat mass, improvements in TUG test and BBS scores, and increased neural activation in certain cerebellar areas. The treatment did not significantly worsen glucose metabolism, and no side-effects were reported. Our findings support the benefits of rhGH treatment in adults with Prader-Willi syndrome and growth-hormone deficiency on body composition and suggest that it may also improve balance and brain neural activation.

Cerebellar Volumes Associate with Behavioral Phenotypes in Prader-Willi Syndrome

The objective of this study was to investigate lobule-specific cerebellar structural alterations relevant to clinical behavioral characteristics of Prader-Willi syndrome (PWS). We performed a case-control study of 21 Japanese individuals with PWS (age; median 21.0, range 13–50 years, 14 males, 7 females) and 40 age- and sex-matched healthy controls with typical development. Participants underwent 3-Tesla magnetic resonance imaging. Three-dimensional T₁-weighted images were assessed for cerebellar lobular volume and adjusted for total intracerebellar volume (TIV) using a spatially unbiased atlas template to give a relative volume ratio. A region of interest analysis included the deep cerebellar nuclei. A correlation analysis was performed between the volumetric data and the clinical behavioral scores derived from the standard questionnaires (hyperphagia, autism, obsession, and maladaptive index) for global intelligence assessment in paired subgroups. In individuals with PWS, TIV was significantly reduced compared with that of controls (p < 0.05, family-wise error corrected; mean [standard deviation], 1014.1 [93.0] mm³). Decreased relative lobular volume ratios were observed in posterior inferior lobules with age, sex, and TIV as covariates (Crus I, Crus II, lobules VIIb, VIIIa, VIIIb, and IX). However, increased ratios were found in the dentate nuclei bilaterally in individuals with PWS (p < 0.01); the mean (standard deviation) × 10⁻³ was as follows: left, 1.58 (0.26); right, 1.67 (0.30). The altered lobular volume ratios showed negative correlations with hyperphagic and autistic characteristics and positive correlations with obsessive and intellectual characteristics. This study provides the first objective evidence of topographic patterns of volume differences in cerebellar structures consistent with clinical behavioral characteristics in individuals with PWS and strongly suggests a cerebellar contribution to altered functional brain connectivity in PWS.

Cerebellar Dysfunction in Adults with Prader Willi Syndrome

Severe hypotonia during infancy is a hallmark feature of Prader Willi syndrome (PWS). Despite its transient expression, moto development is delayed and deficiencies in motor coordination are present at older ages, with no clear pathophysiological mechanism yet identified. The diverse motor coordination symptoms present in adult PWS patients could be, in part, the result of a common alteration(s) in basic motor control systems. We aimed to examine the motor system in PWS using functional MRI (fMRI) during motor challenge. Twenty-three adults with PWS and 22 matched healthy subjects participated in the study. fMRI testing involved three hand motor tasks of different complexity. Additional behavioral measurements of motor function were obtained by evaluating hand grip strength, functional mobility, and balance. Whole brain activation maps were compared between groups and correlated with behavioral measurements. Performance of the motor tasks in PWS engaged the neural elements typically involved in motor processing. While our data showed no group differences in the simplest task, increasing task demands evoked significantly weaker activation in patients in the cerebellum. Significant interaction between group and correlation pattern with measures of motor function were also observed. Our study provides novel insights into the neural substrates of motor control in PWS by demonstrating reduced cerebellar activation during movement coordination.

Identification of a brain fingerprint for overweight and obesity

The brain plays a central role in the pathophysiology of overweight and obesity. Connectome-based Predictive Modeling (CPM) is a newly developed, data-driven approach that exploits whole-brain functional connectivity to predict a behavior or trait that varies across individuals. We used CPM to determine whether brain "fingerprints" evoked during milkshake consumption could be isolated for common measures of adiposity in 67 adults with overweight and obesity. We found that CPM captures more variance in waist circumference than either percent body fat or BMI, the most frequently used measures to assess brain correlates of obesity. In a post-hoc analysis, we were also able to derive a largely separable functional connectivity network predicting fasting blood insulin. These findings suggest that, in individuals with overweight and obesity, brain network patterns may be more tightly coupled to waist circumference than BMI or percent body fat and that adiposity and glucose tolerance are associated with distinct maps, pointing to dissociable central pathophysiological phenotypes for obesity and diabetes.

Increased brain age in adults with Prader-Willi syndrome

Prader-Willi syndrome (PWS) is the most common genetic obesity syndrome, with associated learning difficulties, neuroendocrine deficits, and behavioural and psychiatric problems. As the life expectancy of individuals with PWS increases, there is concern that alterations in brain structure associated with the syndrome, as a direct result of absent expression of PWS genes, and its metabolic complications and hormonal deficits, might cause early onset of physiological and brain aging. In this study, a machine learning approach was used to predict brain age based on grey matter (GM) and white matter (WM) maps derived from structural neuroimaging data using T1-weighted magnetic resonance imaging (MRI) scans. Brain-predicted age difference (brain-PAD) scores, calculated as the difference between chronological age and brain-predicted age, are designed to reflect deviations from healthy brain aging, with higher brain-PAD scores indicating premature aging. Two separate adult cohorts underwent brain-predicted age calculation. The main cohort consisted of adults with PWS (n = 20; age mean 23.1 years, range 19.8-27.7; 70.0% male; body mass index (BMI) mean 30.1 kg/m2, 21.5-47.7; n = 19 paternal chromosome 15q11-13 deletion) and age- and sex-matched controls (n = 40; age 22.9 years, 19.6-29.0; 65.0% male; BMI 24.1 kg/m2, 19.2-34.2) adults (BMI PWS vs. control P = .002). Brain-PAD was significantly greater in PWS than controls (effect size mean ± SEM +7.24 ± 2.20 years [95% CI 2.83, 11.63], P = .002). Brain-PAD remained significantly greater in PWS than controls when restricting analysis to a sub-cohort matched for BMI consisting of n = 15 with PWS with BMI range 21.5-33.7 kg/m2, and n = 29 controls with BMI 21.7-34.2 kg/m2 (effect size +5.51 ± 2.56 years [95% CI 3.44, 10.38], P = .037). In the PWS group, brain-PAD scores were not associated with intelligence quotient (IQ), use of hormonal and psychotropic medications, nor severity of repetitive or disruptive behaviours. A 24.5 year old man (BMI 36.9 kg/m2) with PWS from a SNORD116 microdeletion also had increased brain PAD of 12.87 years, compared to 0.84 ± 6.52 years in a second control adult cohort (n = 95; age mean 34.0 years, range 19.9-55.5; 38.9% male; BMI 28.7 kg/m2, 19.1-43.1). This increase in brain-PAD in adults with PWS indicates abnormal brain structure that may reflect premature brain aging or abnormal brain development. The similar finding in a rare patient with a SNORD116 microdeletion implicates a potential causative role for this PWS region gene cluster in the structural brain abnormalities associated primarily with the syndrome and/or its complications. Further longitudinal neuroimaging studies are needed to clarify the natural history of this increase in brain age in PWS, its relationship with obesity, and whether similar findings are seen in those with PWS from maternal uniparental disomy.

Epidemic obesity in children and adolescents: risk factors and prevention

The prevalence of obesity among children and adolescents (aged 2-18 years) has increased rapidly, with more than 100 million affected in 2015. Moreover, the epidemic of obesity in this population has been an important public health problem in developed and developing countries for the following reasons. Childhood and adolescent obesity tracks adulthood obesity and has been implicated in many chronic diseases, including type 2 diabetes, hypertension, and cardiovascular disease. Furthermore, childhood and adolescent obesity is linked to adulthood mortality and premature death. Although an imbalance between caloric intake and physical activity is a principal cause of childhood and adolescent obesity, environmental factors are exclusively important for development of obesity among children and adolescents. In addition to genetic and biological factors, socioenvironmental factors, including family, school, community, and national policies, can play a crucial role. The complexity of risk factors for developing obesity among children and adolescents leads to difficulty in treatment for this population. Many interventional trials for childhood and adolescent obesity have been proven ineffective. Therefore, early identification and prevention is the key to control the global epidemic of obesity. Given that the proportion of overweight children and adolescents is far greater than that of obesity, an effective prevention strategy is to focus on overweight youth, who are at high risk for developing obesity. Multifaceted, comprehensive strategies involving behavioral, psychological, and environmental risk factors must also be developed to prevent obesity among children and adolescents.

A Narrative Review of Medical and Genetic Risk Factors among Children Age 5 and Younger with Severe Obesity

Severe obesity defined as an age- and gender-specific body mass index ≥120% of the 95th percentile in children younger than 5 years is well recognized as a significant challenge for prevention and treatment. This article provides an overview of the prevalence, classification of obesity severity, patterns of weight gain trajectory, medical and genetic risk factors, and comorbid disorders among young children with an emphasis on severe obesity. Studies suggest rapid weight gain trajectory in infancy, maternal smoking, maternal gestational diabetes, and genetic conditions are associated with an increased risk for severe obesity in early childhood. Among populations of young children with severe obesity seeking care, co-morbid conditions such as dyslipidemia and fatty liver disease are present and families report behavioral concerns and developmental delays. Children with severe obesity by age 5 represent a vulnerable population of children at high medical risk and need to be identified early and appropriately managed.

Study Time after School and Habitual Eating Are Associated with Risk for Obesity among Overweight Korean Children: A Prospective Study

OBJECTIVE

To investigate behavioral factors that contribute to the development of obesity among overweight children.

METHODS

Among a community sample of 884 children aged 9-13 years, 833 children completed a baseline and 1-year follow-up examination that included anthropometrics, physical fitness, and behavioral factors.

RESULTS

During the follow-up period, BMI for most children with normal weight or obesity did not change. However, among overweight children (n = 100), about one-third developed obesity (n = 26), while the others were categorized as normal weight (n = 32) or overweight (n = 42) after 1 year. Characteristics of overweight children at baseline and follow-up were analyzed. Those who developed obesity showed a notable increase in blood pressure as well as in BMI, waist circumference, and body fat over 1 year. At baseline, this group spent more time studying after school compared to overweight children who did not develop obesity, while there were no differences in time spent viewing television or engaging in vigorous physical activity. Eating outside the home, fast food consumption, and habitual eating in the absence of hunger were more common at baseline in those who did versus those who did not develop obesity. After adjusting for age, sex, and BMI, spending more time studying after school and habitual eating without hunger were associated with the development of obesity.

CONCLUSION

Among Korean overweight children, study time after school and habitual eating without hunger were associated with an increased risk for development of obesity.

Loss of the imprinted, non-coding Snord116 gene cluster in the interval deleted in the Prader Willi syndrome results in murine neuronal and endocrine pancreatic developmental phenotypes

Global neurodevelopmental delay is a prominent characteristic of individuals with Prader-Willi syndrome (PWS). The neuromolecular bases for these delays are unknown. We identified neuroanatomical changes in the brains of mice deficient for a gene in the minimal critical deletion region for PWS (Snord116p-/m+). In Snord116p-/m+ mice, reduced primary forebrain neuron cell body size is apparent in embryonic day 15.5 fetuses, and persists until postnatal day 30 in cerebellar Purkinje neurons. Snord116 is a snoRNA gene cluster of unknown function that can localize to the nucleolus. In cerebellar Purkinje neurons from postnatal day 30 Snord116p-/m+ mice the reduction in neuronal cell body size was associated with decreased neuronal nucleolar size. We also identified developmental changes in the endocrine pancreas of Snord116p-/m+ animals that persist into adulthood. Mice lacking Snord116 have smaller pancreatic islets; within the islet the percentage of δ-cells is increased, while the percentage of α-cells is reduced. The α-cell markers, Sst and Hhex, are upregulated in Snord116p-/m+ isolated islets while Ins1, Ins2, Pdx1, Nkx6-1, and Pax6 are downregulated. There is a 3-fold increase in the percentage of polyhormonal cells in the neonatal pancreata of Snord116p-/m+ mice, due primarily to an increase in cells co-positive with somatostatin. Snord116 may play a role in islet cell lineage specification. The Snord116 gene cluster is important for developmental processes in the brain as well as the endocrine pancreas.

High-fat diet feeding differentially affects the development of inflammation in the central nervous system

Background

Obesity and its associated disorders are becoming a major health issue in many countries. The resulting low-grade inflammation not only affects the periphery but also the central nervous system. We set out to study, in a time-dependent manner, the effects of a high-fat diet on different regions of the central nervous system with regard to the inflammatory tone.

Methods

We used a diet-induced obesity model and compared at several time-points (1, 2, 4, 6, 8, and 16 weeks) a group of mice fed a high-fat diet with its respective control group fed a standard diet. We also performed a large-scale analysis of lipids in the central nervous system using HPLC-MS, and we then tested the lipids of interest on a primary co-culture of astrocytes and microglial cells.

Results

We measured an increase in the inflammatory tone in the cerebellum at the different time-points. However, at week 16, we evidenced that the inflammatory tone displayed significant differences in two different regions of the central nervous system, specifically an increase in the cerebellum and no modification in the cortex for high-fat diet mice when compared with chow-fed mice. Our results clearly suggest region-dependent as well as time-dependent adaptations of the central nervous system to the high-fat diet. The differences in inflammatory tone between the two regions considered seem to involve astrocytes but not microglial cells. Furthermore, a large-scale lipid screening coupled to ex vivo testing enabled us to identify three classes of lipids—phosphatidylinositols, phosphatidylethanolamines, and lysophosphatidylcholines—as well as palmitoylethanolamide, as potentially responsible for the difference in inflammatory tone.

Conclusions

This study demonstrates that the inflammatory tone induced by a high-fat diet does not similarly affect distinct regions of the central nervous system. Moreover, the lipids identified and tested ex vivo showed interesting anti-inflammatory properties and could be further studied to better characterize their activity and their role in controlling inflammation in the central nervous system.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-016-0666-8) contains supplementary material, which is available to authorized users.

The relationship between physical activity and diet and young children's cognitive development: A systematic review

OBJECTIVE

Given the high prevalence of suboptimal nutrition and low activity levels in children, we systematically reviewed the literature on the relationship between physical activity and dietary patterns and cognitive development in early childhood (six months to five years).

METHODS

In February 2016, we conducted two different searches of MEDLINE, PsycINFO, and ERIC. Each search included either physical activity (including gross motor skills) or diet terms, and neurocognitive development outcome terms. Included studies were in English, published since 2005, and of any study design in which the physical activity or diet measure occurred prior to age five.

RESULTS

For physical activity, twelve studies (5 cross-sectional, 3 longitudinal and 4 experimental) were included. Eleven studies reported evidence suggesting that physical activity or gross motor skills are related to cognition or learning. Both acute bouts and longer term exposures showed benefit. For diet, eight studies were included consisting of secondary analyses from longitudinal cohort studies. A healthier dietary pattern was associated with better cognitive outcomes in all studies, although some of the reported associations were weak and the measures used varied across the studies.

CONCLUSIONS

Physical activity and healthy diets in early childhood are associated with better cognitive outcomes in young children. The paucity of literature and the variability in the type and quality of measures used highlight the need for more rigorous research. Given that the early childhood years are critical for both obesity prevention and neurocognitive development, evidence that the same healthy behaviors could promote both should inform future interventions.

Role of Educational Status in Explaining the Association between Body Mass Index and Cognitive Function

Preserving physical and cognitive function becomes an important issue as people age. A growing number of studies have found that the correlation between body mass index (BMI) and cognitive function changes in different age groups. It is obvious that higher educational status is linked to higher cognitive function in terms of numerous risk factors that influence cognitive function. This study aimed to investigate the interplay between obesity and cognitive function categorized by different educational status.This study included 5021 participants aged 20 to 59 years who completed 3 neurocognitive function tests, including a simple reaction time test (SRTT), a symbol digit substitution test (SDST), and a serial digit learning test (SDLT) as reported in the National Health and Nutrition Examination Survey (NHANES) III database. The associations between neurocognitive function and BMI were analyzed using multivariate linear regression while controlling for confounders.After adjusting for pertinent covariates in mode 3, the β coefficients in the female participants with more than 12 years of education (interpreted as change of 3 neurocognitive function tests for each increment in BMI) comparing obesity groups to those with normal BMI were 16.2 (P < 0.001 for SRTT), 0.14 (P < 0.05 for SDST), and 0.9 (P < 0.05 for SDLT). Male participants with more than 12 years of education and female participants with fewer than 12 years of education demonstrated increased impairment as their BMI increased. However, this association was not significant after adjustments.Obese individuals had worse neurocognitive function than those of normal weight or overweight, especially in women with a high educational level.

Puzzle Pieces: Neural Structure and Function in Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder of genomic imprinting, presenting with a behavioural phenotype encompassing hyperphagia, intellectual disability, social and behavioural difficulties, and propensity to psychiatric illness. Research has tended to focus on the cognitive and behavioural investigation of these features, and, with the exception of eating behaviour, the neural physiology is currently less well understood. A systematic review was undertaken to explore findings relating to neural structure and function in PWS, using search terms designed to encompass all published articles concerning both in vivo and post-mortem studies of neural structure and function in PWS. This supported the general paucity of research in this area, with many articles reporting case studies and qualitative descriptions or focusing solely on the overeating behaviour, although a number of systematic investigations were also identified. Research to date implicates a combination of subcortical and higher order structures in PWS, including those involved in processing reward, motivation, affect and higher order cognitive functions, with both anatomical and functional investigations indicating abnormalities. It appears likely that PWS involves aberrant activity across distributed neural networks. The characterisation of neural structure and function warrants both replication and further systematic study.

Meta-analysis of associations between human brain volume and intelligence differences: How strong are they and what do they mean?

Positive associations between human intelligence and brain size have been suspected for more than 150 years. Nowadays, modern non-invasive measures of in vivo brain volume (Magnetic Resonance Imaging) make it possible to reliably assess associations with IQ. By means of a systematic review of published studies and unpublished results obtained by personal communications with researchers, we identified 88 studies examining effect sizes of 148 healthy and clinical mixed-sex samples (>8000 individuals). Our results showed significant positive associations of brain volume and IQ (r=.24, R(2)=.06) that generalize over age (children vs. adults), IQ domain (full-scale, performance, and verbal IQ), and sex. Application of a number of methods for detection of publication bias indicates that strong and positive correlation coefficients have been reported frequently in the literature whilst small and non-significant associations appear to have been often omitted from reports. We show that the strength of the positive association of brain volume and IQ has been overestimated in the literature, but remains robust even when accounting for different types of dissemination bias, although reported effects have been declining over time. While it is tempting to interpret this association in the context of human cognitive evolution and species differences in brain size and cognitive ability, we show that it is not warranted to interpret brain size as an isomorphic proxy of human intelligence differences.

Body Mass Index Mediates the Effects of Low Income on Preschool Children's Executive Control, with Implications for Behavior and Academics

BACKGROUND

Children from low-income backgrounds are more likely to have cognitive impairments, academic problems, and obesity. Biological mechanisms for the relationship between adiposity and neurocognitive functioning have been suggested, but the direction of effects is unclear.

METHODS

The relations among income, BMI, and cognitive-behavioral functioning were modeled longitudinally. Children (n = 306) were assessed at 36-39 months (Time 1; T1) and 63-67 months (Time 4; T4) through anthropometry, measures of executive control (EC), delay ability (DA), and questionnaires on academic readiness, social competence, and behavioral adjustment.

RESULTS

Income was positively related to T1 EC and DA and negatively related to T1 BMI. T1 BMI was negatively related to T4 EC, after controlling for T1 EC, but was unrelated to changes in DA. Neither T1 EC nor DA was related to changes in BMI. T4 EC predicted greater academic readiness and social competence and lower adjustment problems at T4. T4 BMI was related to higher T4 adjustment problems. There was an indirect effect of income on T4 EC through T1 BMI. There were indirect effects of T1 BMI on academic readiness, social competence, and adjustment through T4 EC. Children who were obese at T1 had a 19% lower rate of growth of EC, compared to nonobese children.

CONCLUSIONS

BMI mediates the effect of income on children's EC and has negative implications for academic readiness, social competence, and behavioral adjustment. The dual impact of obesity and cognitive-behavioral problems underscores the importance of early identification of and intervention for overweight children which could have neurocognitive and social-emotional benefits. What's New: BMI mediates the effect of income on preschoolers' executive control (EC) and has negative implications for academic readiness and behavioral adjustment. EC and delay ability did not predict changes in BMI. Early identification of, and intervention for, overweight children may have neurocognitive and social-emotional benefits.

Brain gray and white matter differences in healthy normal weight and obese children

PURPOSE

To compare brain gray and white matter development in healthy normal weight and obese children.

METHODS

Twenty-four healthy 8- to 10-year-old children whose body mass index was either <75(th) percentile (normal weight) or >95(th) percentile (obese) completed an MRI examination which included T1-weighted three-dimensional structural imaging and diffusion tensor imaging (DTI). Voxel-based morphometry was used to compare the regional gray and white matter between the normal weight and obese children, and tract-based spatial statistics was used to compare the water diffusion parameters in the white matter between groups.

RESULTS

Compared with normal weight children, obese children had significant (P < 0.05, family wise error corrected) regional gray matter reduction in the right middle temporal gyrus, left and right thalami, left superior parietal gyrus, left pre/postcentral gyri, and left cerebellum. Obese children also had higher white matter (P < 0.05, corrected) in multiple regions in the brain and higher DTI measured fractional anisotropy (FA) values (P < 0.05, corrected) in part of the left brain association and projection fibers. There was no difference in mean diffusivity at P < 0.05, corrected. DTI eigenvalues suggested that the FA differences were likely from decreased radial diffusivity (P < 0.1, corrected) and there was no change in axial diffusivity (corrected P > 0.35 for all voxels).

CONCLUSION

Our results indicated that obese but otherwise healthy children have different regional gray and white matter development in the brain and differences in white matter microstructures compared with healthy normal weight children.

Does the brain shrink as the waist expands?

Recent studies suggest that being overweight or obese is related to worse cognitive performance, particularly executive function. Obesity may also increase the risk of Alzheimer's disease. Consequently, there has been increasing interest in whether adiposity is related to gray or white matter (GM, WM) atrophy. In this review, we identified and critically evaluated studies assessing obesity and GM or WM volumes either globally or in specific regions of interest (ROIs). Across all ages, higher adiposity was consistently associated with frontal GM atrophy, particularly in prefrontal cortex. In children and adults <40 years of age, most studies found no relationship between adiposity and occipital or parietal GM volumes, whereas findings for temporal lobe were mixed. In middle-aged and aged adults, a majority of studies found that higher adiposity is associated with parietal and temporal GM atrophy, whereas results for precuneus, posterior cingulate, and hippocampus were mixed. Higher adiposity had no clear association with global or regional WM in any age group. We conclude that higher adiposity may be associated with frontal GM atrophy across all ages and parietal and temporal GM atrophy in middle and old age.

Impact of obesity on cognitive outcome in children with sleep-disordered breathing

OBJECTIVES

The objective of this study was to evaluate the impact of obesity on cognitive impairment, in children with obstructive sleep apnoea (OSA), children with OSA and obesity, and in normal controls.

METHODS

Thirty-six children with OSA (group 1), 38 children with OSA and obesity (group 2) and 58 normal controls (group 3) were studied. The Total intelligence quotient (T-IQ), Verbal IQ (V-IQ) and the Performance IQ (P-IQ) scores were obtained using the Wechsler Intelligence Scale for Children - Third Edition Revised. All participants' parents filled out the questionnaire containing the attention deficit and hyperactive disorder rating scale to investigate symptoms of hyperactivity and attention deficit. Obese and non-obese children with sleep-disordered breathing (SDB) underwent polysomnography.

RESULTS

T-QI and P-QI scores were significantly lower in group 2 with higher performance impairment at the subtest compared to other groups. In obese children, V-IQ was significantly correlated with age of onset (r = 0.335, p = 0.05) and duration of SDB (r = -0.362, p = 0.02), while P-IQ and T-IQ were correlated with body mass index (BMI) percentile (r = -0.341, p = 0.03) and respiratory disturbance index (RDI) (r = -0.321, p = 0.05), respectively. RDI and BMI negatively influenced T-IQ in obese children with OSA. No correlation was found between sleep parameters and IQ scores or subtest scores in all groups.

CONCLUSIONS

Obese children with OSA showed higher cognitive impairment. Obesity has an additive and synergic action with that exerted by OSA, speeding up the onset of complications.

Neurocognitive functioning in overweight and obese patients with bipolar disorder: data from the Systematic Treatment Optimization Program for Early Mania (STOP-EM)

OBJECTIVE

Obesity is frequent in people with bipolar I disorder (BD I) and has a major impact on the course of the illness. Although obesity negatively influences cognitive function in patients with BD, its impact in the early phase of the disorder is unknown. We investigated the impact of overweight and obesity on cognitive functioning in clinically stable patients with BD recently recovered from their first manic episode.

METHOD

Sixty-five patients with BD (25 overweight or obese and 40 normal weight) recently remitted from a first episode of mania and 37 age- and sex-matched healthy control. subjects (9 overweight or obese and 28 normal weight) were included in this analysis from the Systematic Treatment Optimization Program for Early Mania (commonly referred to as STOP-EM). All subjects had their cognitive function assessed using a standard neurocognitive battery. We compared cognitive function between normal weight patients, overweight-obese patients, and normal weight healthy control subjects.

RESULTS

There was a negative affect of BD diagnosis on the domains of attention, verbal memory, nonverbal memory, working memory, and executive function, but we were unable to find an additional effect of weight on cognitive functioning in patients. There was a trend for a negative correlation between body mass index and nonverbal memory in the patient group.

CONCLUSIONS

These data suggest that overweight-obesity does not negatively influence cognitive function early in the course of BD. Given that there is evidence for a negative impact of obesity later in the course of illness, there may be an opportunity to address obesity early in the course of BD.

Genetic diseases: congenital central hypoventilation, Rett, and Prader-Willi syndromes

The present review summarizes current knowledge on three rare genetic disorders of respiratory control, congenital central hypoventilation syndrome (CCHS), Rett syndrome (RTT), and Prader-Willi syndrome (PWS). CCHS is characterized by lack of ventilatory chemosensitivity caused by PHOX2B gene abnormalities consisting mainly of alanine expansions. RTT is associated with episodes of tachypneic and irregular breathing intermixed with breathholds and apneas and is caused by mutations in the X-linked MECP2 gene encoding methyl-CpG-binding protein. PWS manifests as sleep-disordered breathing with apneas and episodes of hypoventilation and is caused by the loss of a group of paternally inherited genes on chromosome 15. CCHS is the most specific disorder of respiratory control, whereas the breathing disorders in RTT and PWS are components of a more general developmental disorder. The main clinical features of these three disorders are reviewed with special emphasis on the associated brain abnormalities. In all three syndromes, disease-causing genetic defects have been identified, allowing the development of genetically engineered mouse models. New directions for future therapies based on these models or, in some cases, on clinical experience are delineated. Studies of CCHS, RTT, and PWS extend our knowledge of the molecular and cellular aspects of respiratory rhythm generation and suggest possible pharmacological approaches to respiratory control disorders. This knowledge is relevant for the clinical management of many respiratory disorders that are far more prevalent than the rare diseases discussed here.

Association between childhood obesity, cognitive development, physical fitness and social-emotional wellbeing in a transitional economy

BACKGROUND

It has been suggested that obese children have lower cognitive function, demonstrate poorer physical performance and are more susceptible to social-emotional problems.

AIMS

To describe associations between human physical growth, cognitive development, physical fitness and social-emotional characteristics of obese and non-obese children and to verify the predictors of intellectual coefficient by socioeconomic status (SES).

SUBJECTS AND METHODS

A sample of 107 non-obese (N-Ob) children [-1 z-score body mass index (BMI) ≤1 z-score] and 108 obese (Ob) children [2 z-score ≤BMI ≤5 z-score] from a larger cohort was evaluated. Intellectual coefficient (IQ), social-emotional wellbeing (SEW), 6-minute walk test (6MWT) and SES (mid-low, low and very low) were assessed.

RESULTS

Ob children were taller, heavier and present more height for age and BMI than N-Ob children (p < 0.001). A significant correlation between IQ and SEW (r = 0.14), 6MWT and BMI z-score (r = -0.18) and 6MWT and SEW (r = 0.15) was found. Multiple regression analysis revealed that BMI z-score had a negative impact on IQ in the mid-low SES sub-group and that SEW had a positive effect on IQ in the very-low SES sub-group.

CONCLUSIONS

In Chilean pre-school children from low-income families cognitive ability varied according to SES.

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.

Obesity, functional mobility and quality of life

Obesity is a health condition that, through a complex interaction of biopsychosocial and environmental factors, is associated with mobility disability. The mobility disability experienced by persons with obesity is associated with reduced health related quality of life (HRQoL) compared to persons without obesity. This paper will review and discuss functional mobility and its relationship to HRQoL for persons living with obesity. This will be done by conducting a review of the literature in the area of obesity and functional mobility and it's association with HRQoL. Recommendations to address the known factors that contribute to mobility disability and reduced quality of life are outlined while suggestions for research to contribute to best practice to enable mobility for persons with obesity are made.

Association between Frequency of Breakfast Consumption and Academic Performance in Healthy Korean Adolescents

BACKGROUND

The purpose of this study was to examine whether the frequency of breakfast consumption was related to academic performance in healthy Korean adolescents.

METHODS

We analyzed data from the seventh Korea Youth Risk Behavior Web-based Survey conducted in 2011, in which 75,643 adolescents from school grades 7-12 participated. We assessed the association between the frequency of breakfast consumption (per week) and academic performance using multivariate logistic regression analysis after adjusting for covariates such as age, body mass index, frequency of smoking, frequency of drinking, parents' education level, family economic status, frequency of vigorous physical activity (PA), frequency of moderate PA, frequency of muscular strength exercises, and level of mental stress.

RESULTS

For male adolescents, the odds ratios (ORs) for achieving average or higher academic performance according to the breakfast frequency per week were once per week, 1.004 (P=0.945); twice per week, 0.915 (P=0.153); 3 days per week, 0.928 (P=0.237); 4 days per week, 1.087 (P=0.176); 5 days per week, 1.258 (P<0.001); 6 days per week, 1.473 (P<0.001); and every day, 1.700 (P<0.001), compared to no breakfast per week. For female adolescents, the ORs for achieving average or higher academic performance according to the breakfast frequency were once per week, 1.068 (P=0.320); twice per week, 1.140 (P=0.031); 3 days per week, 1.179 (P=0.004); 4 days per week, 1.339 (P<0.001); 5 days per week, 1.449 (P<0.001); 6 days per week, 1.768 (P<0.001); and every day, 1.922 (P<0.001), compared to no breakfast per week.

CONCLUSION

The frequency of breakfast consumption is positively correlated with academic performance in both male and female healthy adolescents in Korea.

Overweight and obesity are associated with neuronal injury in the human cerebellum and hippocampus in young adults: a combined MRI, serum marker and gene expression study

There is growing evidence that obesity represents a risk for enhanced gray matter (GM) density changes comparable to those demonstrated for mild cognitive impairment in the elderly. However, it is not clear what mechanisms underlie this apparent alteration in brain structure of overweight subjects and to what extent these changes can already occur in the adolescent human brain. In the present volumetric magnetic resonance imaging study, we investigated GM changes and serum levels of neuron-specific enolase (NSE), a marker for neuronal injury, in a set of overweight/obese subjects and controls. We report a negative correlation for overweight and obese subjects between serum NSE and GM density in hippocampal and cerebellar regions. To validate our neuroimaging findings, we complement these data with NSE gene expression information obtained from the Allen Brain atlas. GM density changes were localized in brain areas that mediate cognitive function-the hippocampus associated with memory performance, and the cognitive cerebellum (lateral posterior lobes) associated with executive, spatial and linguistic processing. The data of our present study highlight the importance of extending current research on cognitive function and brain plasticity in the elderly in the context of obesity to young adult subjects and include serum biomarkers to validate imaging findings generally.

Childhood obesity: a life-long health risk

Childhood obesity has become major health concern for physicians, parents, and health agencies around the world. Childhood obesity is associated with an increased risk for other diseases not only during youth but also later in life, including diabetes, arterial hypertension, coronary artery disease, and fatty liver disease. Importantly, obesity accelerates atherosclerosis progression already in children and young adults. With regard to pathophysiological changes in the vasculature, the striking similarities between physiological changes related to aging and obesity-related abnormalities are compatible with the concept that obesity causes "premature" vascular aging. This article reviews factors underlying the accelerated vascular disease development due to obesity. It also highlights the importance of recognizing childhood obesity as a disease condition and its permissive role in aggravating the development of other diseases. The importance of childhood obesity for disease susceptibility later in life, and the need for prevention and treatment are also discussed.

Childhood obesity: a life-long health risk

Childhood obesity has become major health concern for physicians, parents, and health agencies around the world. Childhood obesity is associated with an increased risk for other diseases not only during youth but also later in life, including diabetes, arterial hypertension, coronary artery disease, and fatty liver disease. Importantly, obesity accelerates atherosclerosis progression already in children and young adults. With regard to pathophysiological changes in the vasculature, the striking similarities between physiological changes related to aging and obesity-related abnormalities are compatible with the concept that obesity causes "premature" vascular aging. This article reviews factors underlying the accelerated vascular disease development due to obesity. It also highlights the importance of recognizing childhood obesity as a disease condition and its permissive role in aggravating the development of other diseases. The importance of childhood obesity for disease susceptibility later in life, and the need for prevention and treatment are also discussed.

Modulatory effects of theta burst stimulation on cerebellar nonsomatic functions

Clinical and functional imaging studies suggest that the cerebellar vermis is involved in the regulation of a range of nonsomatic functions including cardiovascular control, thirst, feeding behavior, and primal emotions. Cerebello-hypothalamic circuits have been postulated to be a potential neuroanatomical substrate underlying this modulation. We tested this putative relationship between the cerebellar vermis and nonsomatic functions by stimulating the cerebellum noninvasively via neuronavigated transcranial magnetic stimulation. In this randomized, counter-balanced, within-subject study, intermittent theta burst stimulation (TBS) was applied on three different days to the vermis and the right and left cerebellar hemispheres of 12 right-handed normal subjects with the aim of modulating activity in the targeted cerebellar structure. TBS-associated changes were investigated via cardiovascular monitoring, a series of emotionally arousing picture stimuli, subjective analog scales for primal emotions, and the Profile of Mood States test. All 36 sessions of cerebellar stimulation were tolerated well without serious adverse events. Cardiovascular monitoring pointed to a mild but significant decrease in heart rate subsequent to vermal stimulation; no changes were detected in systolic or diastolic blood pressure measurements. Subjective ratings detected a significant increase in Thirst and a trend toward increased Appetite following vermal stimulation. These observations are consistent with existing neurophysiological and neuroimaging data indicating a role for the cerebellum in the regulation of visceral responses. In conjunction with the modulatory function of the cerebellum, our results suggest a role for the vermis in somatovisceral integration likely through cerebello-hypothalamic pathways. Further research is warranted to elucidate the potential mechanisms underlying the cerebellar modulation of nonsomatic functions.