The Effects of Exercise on Abdominal Fat and Liver Enzymes in Pediatric Obesity: A Systematic Review and Meta-Analysis

Challenges in Promoting Physical Activity for Managing MASLD in Canadian Children: Insights and Barriers

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease in children, closely linked to the rise in pediatric obesity. Physical activity (PA) is critical for MASLD management, yet many children fail to meet PA guidelines due to various barriers. This study quantifies PA levels and identifies barriers in Canadian children with MASLD.

METHODS

This prospective cohort study included 25 pediatric MASLD patients (≤ 18 years) recruited from a tertiary care center between spring and fall 2023. Participants completed the Habitual Activity Estimation Scale (HAES) and a modified PA Barrier Survey. Clinical, demographic, and laboratory data were collected.

RESULTS

The median age was 13 years, with 64% male participants. While 96% recognized the importance of PA, only 56% met the WHO-recommended 60 min of daily moderate-to-vigorous PA. Barriers included fatigue (84%), discomfort (56%), fear of injury (32%), and ridicule (36%). Participants who met PA guidelines were more likely to feel supported by healthcare providers (79% vs. 45%). Moderate technology use (52% used activity trackers) suggests potential for greater integration to boost engagement.

CONCLUSION

Children with MASLD face significant barriers to PA despite high awareness of its benefits. Tailored strategies incorporating technology and healthcare support are essential to improving PA adherence. Future research should explore larger cohorts and the influence of socioeconomic and cultural factors on PA behaviors.

Pediatric MASLD: current understanding and practical approach

Metabolic dysfunction-associated steatotic liver disease (MASLD) is now the most prevalent chronic liver disease in children in industrialized countries mainly due to the rise in obesity and overweight. Besides risk of progressive liver damage, MASLD also carries an increased risk of extra-hepatic morbidity, most importantly type 2 diabetes mellitus and cardiovascular disease. Important challenges remain in the prevention, detection, and treatment of this prevalent disorder. This review outlines the epidemiology and risk factors of MASLD and provides an approach to screening, diagnosis, and treatment based on current best available evidence and expert opinion. What is known: • NAFLD/MASLD is a common disorder in children strongly related to obesity/overweight and insulin resistance. • This silent disorder is underdiagnosed due to lack of awareness and lack of simple diagnostic criteria. What is new: • New diagnostic criteria have transformed NAFLD/MASLD from a diagnosis of exclusion to a positive diagnosis with simple criteria. • Effective treatments are emerging for adults and will likely become available for children. • Identifying children with NAFLD/MASLD has become even more important due to this new treatment perspective.

Practice Recommendations for Metabolic Dysfunction-Associated Steatotic Liver Disease by the Indian Society of Pediatric Gastroenterology, Hepatology and Nutrition (ISPGHAN)

JUSTIFICATION

There has been an alarming increase in metabolic dysfunction-associated steatotic liver disease (MASLD) and it is now the most common chronic liver disease worldwide, in both adult and pediatric populations. The lack of regional guidelines has hampered the formulation of national policies for prevention and management of MASLD in children. Therefore, we formulated recommendations for steatotic liver disease in children.

OBJECTIVES

To review the existing literature on the burden and epidemiology of pediatric MASLD and formulate recommendations for diagnostic evaluation, prevention, and management strategies.

PROCESS

The Indian Society of Pediatric Gastroenterology, Hepatology, and Nutrition invited national and international stakeholders to participate in a consensus meeting held on April 20, 2024, in Mumbai, Maharashtra, India. Various aspects of pediatric steatotic liver disease were deliberated upon and a consensus document and recommendations were formulated after several rounds of discussion.

RECOMMENDATIONS

Metabolic dysfunction-associated steatotic liver disease (MASLD) should be used as the preferred term in place of non-alcoholic fatty liver disease (NAFLD). There is a high prevalence of steatotic liver disease (SLD) among Indian children and adolescents, especially those who are overweight or obese. This condition may be progressive in childhood and associated with increased morbidity and mortality in adulthood. Various lifestyle, dietary, and genetic factors may predispose individuals to MASLD, including an increased intake of calorie-dense processed foods, sweetened sugar beverages, excessive screen time, higher sedentary time and lack of moderate to vigorous physical activity. MASLD is usually asymptomatic or presents with mild, non-specific symptoms and therefore, a high degree of suspicion is required for early diagnosis. MASLD is usually associated with cardiometabolic factors (hypertension, insulin resistance/diabetes mellitus, and/or dyslipidemia) and secondary causes should be excluded in all cases, particularly in the presence of red flag signs. Screening for MASLD should be considered in all obese children (body mass index or BMI ≥95th percentile) and in all overweight children (BMI ≥ 85th and <95thpercentile) with additional risk factors, such as prediabetes/diabetes, dyslipidemia, positive family history of metabolic syndrome, obstructive sleep apnea, and hypopituitarism. Abdominal ultrasound in combination with alanine aminotransferase (ALT) levels should be used as a screening test for MASLD in Indian children as per the proposed algorithm. Diet (any hypocaloric diet) and exercise (aerobic, resistance, or a combination of both; moderate to high intensity; regular in frequency) remain the cornerstones of pediatric MASLD management. Pharmacotherapy and/or endoscopic/surgical techniques for obesity should be considered as adjuncts and should be considered only after a failed adequate trial of lifestyle modifications.

Exercise training improves diabetic renal injury by reducing fetuin-A, oxidative stress and inflammation in type 2 diabetic rats

Background

Diabetic kidney disease (DKD) stands as a primary contributor to end-stage renal disease, associated with heightened mortality in cardiovascular diseases. This study aimed to explore the impact of an eight-week high-intensity interval training (HIIT) on renal injury in diabetic rats.

Methods

Twenty-eight male Wistar rats were randomly allocated into four groups: healthy control (CTL), diabetic control (DC), exercise (EX), and diabetes-exercise (D + EX). Induction of diabetes in the DC and D + EX groups occurred through a two-month high-fat diet followed by a single dose of 35 mg/kg streptozotocin (STZ). Rats in the EX and D + EX groups underwent 4-10 intervals of HIIT (80-100% Vmax) over 8 weeks. Subsequently, pathological and biochemical parameters were assessed in the serum and kidney tissue of the experimental groups.

Results

In the DC group, diabetes led to elevated kidney damage, glomerulosclerosis, fasting blood glucose (FBG), Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) index, animal weight, kidney dysfunction, albuminuria, and glomerular filtration rate. Additionally, serum and kidney levels of fetuin-A increased, along with kidney levels of KIM-1. Mechanistically, diabetes induction resulted in kidney inflammation by elevating levels of tumor necrosis factor-alpha (TNF-α), transforming growth factor beta (TGF-β), and interleukin 6 (IL-6), while reducing IL-10 levels and increasing the IL-6/IL-10 ratio. Furthermore, diabetes triggered renal oxidative stress, evidenced by increased Malondialdehyde (MDA) levels and decreased levels of glutathione peroxidase (GPx), catalase, and superoxide dismutase (SOD). HIIT mitigated the adverse effects of diabetes in the D + EX group compared to the DC group.

Conclusion

Our findings suggest that HIIT ameliorates type 2 diabetes (T2D)-induced kidney damage by mitigating inflammation, lowering serum levels of fetuin-A, and bolstering antioxidant defenses. This study highlights the potential of HIIT as a time-efficient intervention for diabetic nephropathy.

A population-based study of children suggests blunted morning cortisol rhythms are associated with alterations of the systemic inflammatory state

BACKGROUND

In children, digital media, lifestyle, and the COVID pandemic have impacted sunlight exposure, exercise, and diet patterns - cues that entrain the circadian clock. We hypothesized that low morning cortisol reflects a weak circadian clock, impacting the pro-inflammatory state. The primary objective was to test relationships between diurnal cortisol fluctuations and the inflammatory state in children as a means of providing indirect support for this hypothesis.

METHODS

The Cardiovascular Health Intervention Program (CHIP) was a population-based cross-sectional and longitudinal study of circadian health in public elementary school children in Southern Maine, USA (recruitment period 2012-2017). Participants were 689 students in 4th grade (baseline; age=9.2 ± 0.4 years), and 647 students in 5th grade (age=10.5 ± 0.5 years). Nine salivary cortisol measures per child (2 awakening and 1 prior to bed for 3 sequential days) (n = 1336 child phenotype days; n = 7987 cortisol assays), 10 cytokines measured in morning and evening saliva samples (n = 202 child phenotype days), and lipids were measured. Clinical outcomes were blood pressure, weight and height (body mass index [BMI]; BMI = kg/m2), among others.

FINDINGS

Upon-waking cortisol levels were 0.28 ± 0.13 µg/dL, 30-minute post-waking 0.33 ± 0.15 µg/dL, and evening 0.08 ± 0.10 µg/dL. Salivary cytokine levels (n = 202) showed interleukins (IL) IL-1β and IL-8 were highest in early morning (upon awakening; AM), and IL-6 and tumor necrosis factor (TNF) TNF-α highest before bed (PM) (IL-1β AM > PM [-4.02 fold; p < 0.001]; IL-8 AM > PM [-1.36 fold; p < 0.001]; IL-6 AM < PM [+1.49 fold; p < 0.001]; TNF-α AM < PM [+1.73 fold; p = 0.03]. Regression modeling showed high morning cortisol was associated with high morning IL-1β (p = 3.82 ×10-6), but low evening IL-1β (p = 6.27 ×10-4). Regression modeling of BMI z-score as the response variable showed the expected significant relationships to high density lipoprotein (HDL) (negative; p < 0.001), mean arterial pressure (positive; p < 0.001), and morning cortisol (negative; p = 0.01) but only weak relationships to either evening cortisol (p = 0.1) or cytokine (positive; p = 0.02; from the model with smallest Rsquared) levels.

INTERPRETATION

We provide preliminary data on diurnal fluctuations of inflammatory cytokines in saliva in a population-based cohort of children. Correlation of morning and evening cortisol levels with inflammatory cytokines in the same saliva samples showed that high morning cortisol was associated with high morning IL-1β and low evening IL-1β. Future studies may test the hypothesis that strong diurnal cycling of IL-1β may serve as a homeostatic mechanism keeping the immune system in check, and that low morning cortisol (possible circadian misalignment) may lead to less stringent control of inflammatory networks.

Exercise in the Management of Metabolic-Associated Fatty Liver Disease (MAFLD) in Adults: A Position Statement from Exercise and Sport Science Australia

Metabolic-associated fatty liver disease (MAFLD) is the most prevalent chronic liver disease worldwide, affecting 25% of people globally and up to 80% of people with obesity. MAFLD is characterised by fat accumulation in the liver (hepatic steatosis) with varying degrees of inflammation and fibrosis. MAFLD is strongly linked with cardiometabolic disease and lifestyle-related cancers, in addition to heightened liver-related morbidity and mortality. This position statement examines evidence for exercise in the management of MAFLD and describes the role of the exercise professional in the context of the multi-disciplinary care team. The purpose of these guidelines is to equip the exercise professional with a broad understanding of the pathophysiological underpinnings of MAFLD, how it is diagnosed and managed in clinical practice, and to provide evidence- and consensus-based recommendations for exercise therapy in MAFLD management. The majority of research evidence indicates that 150-240 min per week of at least moderate-intensity aerobic exercise can reduce hepatic steatosis by ~ 2-4% (absolute reduction), but as little as 135 min/week has been shown to be effective. While emerging evidence shows that high-intensity interval training (HIIT) approaches may provide comparable benefit on hepatic steatosis, there does not appear to be an intensity-dependent benefit, as long as the recommended exercise volume is achieved. This dose of exercise is likely to also reduce central adiposity, increase cardiorespiratory fitness and improve cardiometabolic health, irrespective of weight loss. Resistance training should be considered in addition to, and not instead of, aerobic exercise targets. The information in this statement is relevant and appropriate for people living with the condition historically termed non-alcoholic fatty liver disease (NAFLD), regardless of terminology.

Lifestyle interventions in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a dynamic chronic liver disease that develops in close association with metabolic irregularities. Between 2016 and 2019, the global prevalence among adults was reported as 38% and among children and adolescents it was about 10%. NAFLD can be progressive and is associated with increased mortality from cardiovascular disease, extrahepatic cancers and liver complications. Despite these numerous adverse outcomes, no pharmacological treatments currently exist to treat nonalcoholic steatohepatitis, the progressive form of NAFLD. Therefore, the main treatment is the pursuit of a healthy lifestyle for both children and adults, which includes a diet rich in fruits, nuts, seeds, whole grains, fish and chicken and avoiding overconsumption of ultra-processed food, red meat, sugar-sweetened beverages and foods cooked at high heat. Physical activity at a level where one can talk but not sing is also recommended, including leisure-time activities and structured exercise. Avoidance of smoking and alcohol is also recommended. Policy-makers, community and school leaders need to work together to make their environments healthy by developing walkable and safe spaces with food stores stocked with culturally appropriate and healthy food items at affordable prices as well as providing age-appropriate and safe play areas in both schools and neighbourhoods.

Metabolic-Dysfunction-Associated Steatotic Liver Disease-Its Pathophysiology, Association with Atherosclerosis and Cardiovascular Disease, and Treatments

Metabolic-dysfunction-associated steatotic liver disease (MASLD) is a chronic liver disease that affects more than a quarter of the global population and whose prevalence is increasing worldwide due to the pandemic of obesity. Obesity, impaired glucose metabolism, high blood pressure and atherogenic dyslipidemia are risk factors for MASLD. Therefore, insulin resistance may be closely associated with the development and progression of MASLD. Hepatic entry of increased fatty acids released from adipose tissue, increase in fatty acid synthesis and reduced fatty acid oxidation in the liver and hepatic overproduction of triglyceride-rich lipoproteins may induce the development of MASLD. Since insulin resistance also induces atherosclerosis, the leading cause for death in MASLD patients is cardiovascular disease. Considering that the development of cardiovascular diseases determines the prognosis of MASLD patients, the therapeutic interventions for MASLD should reduce body weight and improve coronary risk factors, in addition to an improving in liver function. Lifestyle modifications, such as improved diet and increased exercise, and surgical interventions, such as bariatric surgery and intragastric balloons, have shown to improve MASLD by reducing body weight. Sodium glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1RAs) have been shown to improve coronary risk factors and to suppress the occurrence of cardiovascular diseases. Both SGLT2i and GLP-1 have been reported to improve liver enzymes, hepatic steatosis and fibrosis. We recently reported that the selective peroxisome proliferator-activated receptor-alpha (PPARα) modulator pemafibrate improved liver function. PPARα agonists have multiple anti-atherogenic properties. Here, we consider the pathophysiology of MASLD and the mechanisms of action of such drugs and whether such drugs and the combination therapy of such drugs could be the treatments for MASLD.

A healthy lifestyle during adolescence was inversely associated with fatty liver indices in early adulthood: findings from the DONALD cohort study

A healthy lifestyle during adolescence is associated with insulin sensitivity or liver enzyme levels and thus might contribute to the prevention of non-alcoholic fatty liver disease (NAFLD). Therefore, we examined the association between adherence to a hypothesis-based lifestyle score including dietary intake, physical activity, sedentary behaviour, sleep duration and BMI in adolescence and fatty liver indices in early adulthood. Overall, 240 participants of the DOrtmund Nutritional and Anthropometric Longitudinally Designed study completed repeated measurements of lifestyle score factors during adolescence (females: 8·5-15·5 years, males: 9·5-16·5 years). Multivariable linear regression models were used to investigate the association between adolescent lifestyle scores and NAFLD risk (hepatic steatosis index (HSI) and fatty liver index (FLI)) in early adulthood (18-30 years). Participants visited the study centre 4·9 times during adolescence and achieved on average 2·8 (min: 0·6, max: 5) out of five lifestyle score points. Inverse associations were observed between the lifestyle score and fatty liver indices (HSI: ß=-5·8 % (95 % CI -8·3, -3·1), P < 0·0001, FLI: ß=-32·4 % (95 % CI -42·9, -20·0), P < 0·0001) in the overall study population. Sex-stratified analysis confirmed these results in men, while inverse but non-significant associations were observed in women (P > 0·05). A higher lifestyle score was associated with lower HSI and FLI values, suggesting that a healthy lifestyle during adolescence might contribute to NAFLD prevention, predominantly in men. Our findings on repeatedly measured lifestyle scores in adolescents and their association with NAFLD risk in early adulthood warrant confirmation in larger study populations.

Recreational Physical Activity Improves Adherence and Dropout in a Non-Intensive Behavioral Intervention for Adolescents With Obesity

Purpose: The aim of this study was to compare adherence and dropout rates in adolescents with obesity participating in a behavioral-counseling intervention with or without recreational physical activity (PA). Material and methods: Seventy-four adolescents (13 to 18y, 40 girls and 34 boys) with obesity (body mass index [BMI] z-score ≥ 2.0) were randomized into a counseling group (CG; n = 37) and a counseling + recreational physical activity group (CPAG; n = 37). Adolescents from both groups received behavioral counseling once a week for 12 weeks and monthly for an additional 12 weeks. CPAG adolescents participated in supervised recreational physical activity sessions twice a week for 12 weeks. Body composition, body image dissatisfaction, symptoms of depression, binge eating, bulimia, anorexia and quality of life were assessed at baseline and after 24-weeks. Result: The dropout rate was 2.73 times higher in adolescents from CG compared to CPAG (χ² = 4.48; p = .034; R²_McF = 0.044). Girls were 2.56 times more likely to withdraw when compared to boys (χ² = 3.86; p = .049; R²_McF = 0.038). Binomial logistic regression which incorporated sex, intervention group, BMI z-score and BSQ score at baseline (R²_McF = 0.177) explained 75% of the dropout rate. Both interventions were effective in reducing waist circumference (p < .01) and improving quality of life, symptoms of depression, bulimia and binge eating (p < .01). Conclusion: Incorporating a recreational physical activity component to a non-intensive behavioral intervention may be a feasible strategy to reduce dropout rates in adolescents with obesity seeking treatment.

Obesity and Adipose Tissue Dysfunction: From Pediatrics to Adults

Obesity is a growing health problem that affects both children and adults. The increasing prevalence of childhood obesity is associated with comorbidities such as cardiovascular disease, type 2 diabetes and metabolic syndrome due to chronic low-grade inflammation present at early stages of the disease. In pediatric patients suffering from obesity, the role of epigenetics, the gut microbiome and intrauterine environment have emerged as causative factors Interestingly, pediatric obesity is strongly associated with low birth weight. Accelerated weight gain oftentimes occurs in these individuals during the post-natal period, which can lead to increased risk of adiposity and metabolic disease. The pathophysiology of obesity is complex and involves biological and physiological factors compounded by societal factors such as family and community. On a cellular level, adipocytes contained within adipose tissue become dysregulated and further contribute to development of comorbidities similar to those present in adults with obesity. This review provides an overview of the current understanding of adipose tissue immune, inflammatory and metabolic adaptation of the adipose tissue in obesity. Early cellular changes as well as the role of immune cells and inflammation on the progression of disease in pivotal pediatric clinical trials, adult studies and mouse models are emphasized. Understanding the initial molecular and cellular changes that occur during obesity can facilitate new and improved treatments aimed at early intervention and subsequent prevention of adulthood comorbidities.

Investigaciones realizadas en Colombia relacionadas con actividad física y obesidad 2010-2020

Introducción: La obesidad es un problema de salud pública mundial. La actividad física es una herramienta importante de promoción y prevención de este problema. Se desconoce las investigaciones realizadas en Colombia al respecto, lo cual es necesario para implementar políticas públicas eficientes. Objetivo: analizar las investigaciones colombianas encontradas en bases de datos científicas sobre la actividad física y obesidad. Metodología: revisión sistemática de artículos de investigación realizados en Colombia del año 2010 al 2020, en las bases de datos PubMed y SciELO.  Resultados: de 87 artículos encontrados, 23 cumplieron los criterios de inclusión. El 91,3 % publicados en revistas indexadas internacionalmente. 69,5% estudios observacionales, 17,4% ensayos clínicos y 8,7% revisiones sistemáticas. Conclusiones: poca producción en Colombia. La mayoría en revistas indexadas, tuvieron diseño observacional y encontraron asociación entre poca actividad física con sobrepeso/obesidad. Alta prevalencia de sobrepeso/obesidad. Pocos autores fueron profesionales en el área del deporte y el entrenamiento. Introduction: Obesity is a global public health problem. Physical activity and exercise are important tools for promoting and preventing. The research carried out in Colombia in this regard is unknown, which is necessary to implement efficient public policies. Objective: to analyze Colombian research found in scientific databases on physical activity or exercise in overweight and obesity. Methodology: literary review of research articles carried out in Colombia from 2010 to 2020, in the PubMed and SciELO databases. Results: Of 87 articles found, 23 met the inclusion criteria. 91.3% published in internationally indexed journals. 69.5% observational studies, 17.4% clinical trials and 8.7% systematic reviews. Conclusions: little production in Colombia. Most of the indexed journals had an observational design and found an association between little physical activity and overweight/obesity. High prevalence of overweight/obesity. Few authors were professionals in the area of training.

Benefits of Physical Exercise as Approach to Prevention and Reversion of Non-Alcoholic Fatty Liver Disease in Children and Adolescents with Obesity

Non-alcoholic fatty liver disease (NAFLD) is an important health concern during childhood; indeed, it is the most frequent cause of chronic liver diseases in obese children. No valid pharmacological therapies for children affected by this condition are available, and the recommended treatment is lifestyle modification, usually including nutrition and exercise interventions. In this narrative review, we summarized up-to-date information on the benefits of physical exercise on NAFLD in children and adolescents with obesity. The role of exercise as non-pharmacological treatment was emphasized in order to provide recent advances on this topic for clinicians not deeply involved in the field. Several studies on obese children and adults confirm the positive role of physical activity (PA) in the treatment of NAFLD, but to date, there are no pediatric randomized clinical trials on exercise versus usual care. Among the pathogenic mechanisms involved in the PA effects on NAFLD, the main players seem to be insulin resistance and related inflammation, oxidative stress, and gut dysbiosis, but further evaluations are necessary to deeply understand whether these factors are correlated and how they synergistically act. Thus, a deeper research on this theme is needed, and it would be extremely interesting.

The effect of a 6-month walking program on biochemical parameters in sedentary adults with type 2 diabetes mellitus

This study assessed the effect of a 6-month walking program on biochemical parameters in patients with type-2 diabetes mellitus. A group of 40 sedentary patients with type-2 diabetes volunteered to participate in this study. Plasma glucose, triglyceride, total cholesterol, low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase, urea, creatinine, uric acid, C-reactive protein (CRP), and erythrocyte sedimentation rate were measured. Differences in outcome measures between pre- and post-intervention were assessed using paired t-test or Wilcoxon signed-rank test, with effect sizes interpreted separately for normally (µ2: small 0.01-0.06, moderate 0.061-0.14, and large >0.14) and non-normally distributed data (r: small = 0.1-0.3, moderate = 0.3-0.5, and large >0.5). Significant (p < 0.001) large decrease between the initial and final measurements was observed for glucose (r = 0.62), total cholesterol (µ2 = 0.88), triglycerides (r = 0.62), LDL (r = 0.61), AST (µ2 = 0.82), ALT (µ2 = 0.79), gamma-glutamyl transferase (µ2 = 0.79), urea (µ2 = 0.92), creatinine (r = 0.62), uric acid (r = 0.62), CRP (µ2 = 0.80), and erythrocyte sedimentation rate (µ2 = 0.58). On the other hand, significant (p < 0.001) large increase between the initial and final measurements was observed for HDL (r = 0.62). Supervised 6-month aerobic walking program is an effective strategy in (1) reducing hyperglycemia; (2) increasing HDL and reducing LDL, and triglycerides; (3) reducing plasma biomarkers of liver dysfunction, kidney dysfunction, and inflammation in type-2 diabetic patients.

Influence of adipose tissue immune dysfunction on childhood obesity

In recent decades, a dramatic rise has been observed in the prevalence of obesity in childhood and adolescence, along with an increase in fetal microsomia rates. The increased risk of obesity during this key period in development negatively affects the health of the individual later in life. Immune cells residing and recruited to white adipose tissue have been highlighted as important factors contributing to the pathogenesis of childhood obesity. Immune dysfunction in the context of obesity begins early in childhood, which is different from the pathological characteristics and influencing factors of adipose immunity in adults. Here, we explore the current understanding of the roles of childhood and early life events that result in high risks for obesity by influencing adipose tissue immune dysfunction under the pathological condition of obesity. Such knowledge will help in determining the mechanisms of childhood and early life obesity in efforts to ameliorate chronic inflammation-related metabolic diseases.

Effects of Different Doses of Exercise on Inflammation Markers Among Adolescents With Overweight/Obesity: HEPAFIT Study

PROPOSE

Obesity-related metabolic risk factors in adolescents who are overweight/obese may be associated with systemic low-grade inflammation; therefore, we investigated whether 6 months of exercise training altered markers of inflammation.

METHODS

Secondary analyses of a randomized controlled exercise-based intervention trial (September 2017-December 2018). Adolescents aged 11 to 17 years (Tanner stage II-V), 70% girls, with a body mass index z-score at or above the 85th percentile, and/or with excess of adiposity (body fat ≥ 30%). The participants were randomly assigned to the following 4 groups for 6 months: (1) standard physical education lessons, as a control (CTRL); (2) high-intensity physical education class (HIPE); (3) low-to-moderate intensity physical education class (LIPE); (4) a combined group (PLUS). Inflammatory markers and immune molecules including chemokines, cytokines, and growth factors (n = 65 biomarkers) were determined by cytokine antibody array.

RESULTS

Of the 120 randomly assigned participants, 95 were included in the analysis. Considering these 22 proteins, the LIPE group shows statistical significance in 9 proteins with log-fold change (logFC) and P < 0.05 (in BLC, eotaxin, fibroblast growth factor-6 [FGF-6], GCP-2, I-309, IGFBP-4, MCP-4, NAP-2, and PARC), followed by the PLUS group in 9 proteins (BLC, pro-epidermal growth factor, eotaxin, FGF-6, MCP-4, NAP-2, osteopontin, PARC, and RANTES), the HIPE group in 7 proteins (FGF-4, FGF-7, GCP-2, IGF-1, IGFBP-1, IGFBP-4, and MIP-1 delta), and the CTRL group in 6 proteins (FGF-4, IP-10, Leptin, MCP-1, MIG, and MIP-1 delta). However, subanalysis performed to detect differentially expressed proteins at baseline and after intervention, with significance at an adjusted P value ≤ 0.05 and absolute log fold-change (logFC) ≥ 1.0, showed 3 downregulated proteins in the LIPE group (BLC(logFC) = 1.27, eotaxin(logFC) = 1.18, and MCP-4(logFC) = 1.14), and 4 proteins in the HIPE group (BLC(logFC) = 1.45, FGF-6(logFC) = 1.20, MCP-4(logFC) = 1.50, and PARC(logFC) = 1.33), supporting that the changes we observed in the exercise groups were not time-related changes but occurred in response to exercise.

CONCLUSIONS

Implementing a 6-month physical exercise program in overweight/obese adolescents, based on LIPE and PLUS groups, significantly change several circulating inflammatory levels. Interventions involving supervised physical exercise may reduce the associated effects of systemic low-grade inflammation, thus preventing the development of obesity-related metabolic diseases in adolescents with overweight/obesity.

Resistance training effectiveness on body composition and body weight outcomes in individuals with overweight and obesity across the lifespan: A systematic review and meta-analysis

To systematically review and analyze the effects of resistance-based exercise programs on body composition, regional adiposity, and body weight in individuals with overweight/obesity across the lifespan. Using PRISMA guidelines, randomized controlled trials were searched in nine electronic databases up to December 2020. Meta-analyses were performed using random-effects model. One-hundred sixteen articles describing 114 trials (n = 4184 participants) were included. Interventions involving resistance training and caloric restriction were the most effective for reducing body fat percentage (ES = -3.8%, 95% CI: -4.7 to -2.9%, p < 0.001) and whole-body fat mass (ES = -5.3 kg, 95% CI: -7.2 to -3.5 kg, p < 0.001) compared with groups without intervention. Significant results were also observed following combined resistance and aerobic exercise (ES = -2.3% and -1.4 kg, p < 0.001) and resistance training alone (ES = -1.6% and -1.0 kg, p < 0.001) compared with no training controls. Resistance training alone was the most effective for increasing lean mass compared with no training controls (ES = 0.8 kg, 95% CI: 0.6 to 1.0 kg, p < 0.001), whereas lean mass was maintained following interventions involving resistance training and caloric restriction (ES = ~ - 0.3 kg, p = 0.550-0.727). Results were consistently observed across age and sex groups (p = 0.001-0.011). Reductions in regional adiposity and body weight measures were also observed following combined resistance and aerobic exercise and programs including caloric restriction (p < 0.001). In conclusion, this study provides evidence that resistance-based exercise programs are effective and should be considered within any multicomponent therapy program when caloric restriction is utilized in individuals with overweight or obesity.

Exercise dose on hepatic fat and cardiovascular health in adolescents with excess of adiposity

OBJECTIVE

The HEPAFIT study was aimed at examining the impact of a 6-month physical education intervention, considering various levels of exercise intensity, on hepatic fat and cardiometabolic health outcomes in adolescents with excess adiposity.

METHODS

Adolescents (n = 120), 11-17 years with excess adiposity by body fat >30%, were randomly assigned to one of the following 4 groups for 6 months: (1) standard physical education lessons, control (CTRL); (2) high-intensity physical education (HIPE); (3) low-to-moderate intensity physical education (LIPE) and (4) combined HIPE and LIPE (PLUS). The primary outcome was hepatic fat content measured by vibration-controlled transient elastography (controlled attenuation parameter [CAP]). Secondary outcomes were traditional cardiovascular health markers (body composition, serum lipids, aminotransferases and health-related physical fitness components).

RESULTS

Adjusted mixed effects linear models revealed a significant decrease in CAP levels in HIPE (-20.02 dB/m, p < 0.0001) (p = 0.001 vs. CTRL group) and PLUS (-16.25 dB/m, p = 0.005) groups. Body fat decreased in the HIPE (-2.88%, p < 0.001) (p = 0.001 vs. CTRL group) and LIPE (-1.26%, p = 0.022) groups. The physical fitness components were increased in the HIPE and PLUS group relative to the baseline (p < 0.05), and the HIPE group showed a reduction in the total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels (p < 0.05).

CONCLUSIONS

Implementation of a 6-month physical education exercise program, particularly high-intensity or combined high and low-intensity, improves hepatic fat storage and significantly reduces cardiometabolic markers in adolescents with excess of adiposity. Interventions involving supervised physical exercise may help to improve metabolism and fat deposition at the hepatic level, thus preventing the development of non-alcoholic fatty liver disease in adolescents.

Low handgrip strength is associated with higher liver enzyme concentrations in US adolescents

BACKGROUND

Increasing evidence highlights the role of muscular strength as a protective factor for cardiometabolic health in adolescents. However, it is not known the relationship between liver enzyme concentrations, liver disease risk factors, and muscular strength among young populations. The aim of this study was to determine the association between muscle strength and liver enzymes and chronic liver disease risk among US adolescents.

METHODS

Data from the NHANES cross-sectional study (2011-2014) was used. A total of 1270 adolescents were included in the final analysis (12-17 years old). Absolute handgrip strength (kg) was normalized according to body composition parameters by body weight [NHSw], whole-body fat [NHSf], and trunk fat [NHSt]).

RESULTS

In boys, handgrip strength was inversely associated with higher values of aspartate aminotransferase (AST) and gamma glutamyl transpeptidase (GGT) for all estimations of muscle strength (NHSw, NHSf, and NHSt) (p < 0.050). Likewise, boys with high and intermediate NHSw, NHSf, and NHSt presented lower AST and GGT than their counterparts with low handgrip strength (p < 0.050).

CONCLUSIONS

Our findings highlight the importance of muscular strength during adolescence since they could help in developing better liver enzyme profiles among adolescent population.

IMPACT

Our research suggests that US adolescents with low handgrip strength have higher values of liver enzymes as well as a higher prevalence of chronic liver disease. These findings are clinically meaningful and highlight the importance of muscular strength during adolescence since they could help in developing better liver enzyme profiles among young populations.

Non-alcoholic fatty liver disease in obese children and adolescents: a role for nutrition?

Non-alcoholic fatty liver disease (NAFLD) has become the most common cause of chronic liver disease in children, paralleling the increasing prevalence of obesity worldwide. The pathogenesis of paediatric NAFLD is not fully understood, but it is known that obesity, nutrition, lifestyle variables, genetic and epigenetic factors may be causally involved in the development of this common metabolic liver disease. In particular, obesity and nutrition are among the strongest risk factors for paediatric NAFLD, which may exert their adverse hepatic effects already before birth. Excess energy intake induces hypertrophy and hyperplasia of adipose tissue with subsequent development of systemic insulin resistance, which is another important risk factor for NAFLD. Diet composition and in particular simple carbohydrate intake (especially high fructose intake) may promote the development of NAFLD, whereas non-digestible carbohydrates (dietary fiber), by affecting gut microbiota, may favour the integrity of gut wall and reduce inflammation, opposing this process. Saturated fat intake may also promote NAFLD development, whereas unsaturated fat intake has some beneficial effects. Protein intake does not seem to affect the development of NAFLD, but further investigation is needed. In conclusion, lifestyle modifications to induce weight loss, through diet and physical activity, remain the mainstay of treatment for paediatric NAFLD. The use of dietary supplements, such as omega-3 fatty acids and probiotics, needs further study before recommendation.

Metabolic Fatty Liver Disease in Children: A Growing Public Health Problem

Metabolic-associated fatty liver disease (MAFLD), previously called nonalcoholic fatty liver diseases (NAFLD), is one of the most important causes of chronic liver disease worldwide and will likely become the leading cause of end-stage liver disease in the decades ahead. MAFLD covers a continuum of liver diseases from fatty liver to nonalcoholic steatohepatitis (NASH), liver fibrosis/cirrhosis and hepatocellular cancer. Importantly, the growing incidence of overweight and obesity in childhood, 4% in 1975 to 18% in 2016, with persisting obesity complications into adulthood, is likely to be harmful by increasing the incidence of severe MAFLD at an earlier age. Currently, MAFLD is the leading form of chronic liver disease in children and adolescents, with a global prevalence of 3 to 10%, pointing out that early diagnosis is therefore crucial. In this review, we highlight the current knowledge concerning the epidemiology, risk factors and potential pathogenic mechanisms, as well as diagnostic and therapeutic approaches, of pediatric MAFLD.

Metabolic Associated Fatty Liver Disease in Children-From Atomistic to Holistic

Non-alcoholic fatty liver disease has become the most common chronic liver disease in children due to the alarmingly increasing incidence of pediatric obesity. It is well-documented that MAFLD prevalence is directly related to an incremental increase in BMI. The multiple hits theory was designed for providing insights regarding the pathogenesis of steatohepatitis and fibrosis in MAFLD. Recent evidence suggested that the microbiome is a crucial contributor in the pathogenesis of MAFLD. Aside from obesity, the most common risk factors for pediatric MAFLD include male gender, low-birth weight, family history of obesity, MAFLD, insulin resistance, type 2 diabetes mellitus, obstructive sleep apnea, and polycystic ovarium syndrome. Usually, pediatric patients with MAFLD have nonspecific symptoms consisting of fatigue, malaise, or diffuse abdominal pain. A wide spectrum of biomarkers was proposed for the diagnosis of MAFLD and NASH, as well as for quantifying the degree of fibrosis, but liver biopsy remains the key diagnostic and staging tool. Nevertheless, elastography-based methods present promising results in this age group as potential non-invasive replacers for liver biopsy. Despite the lack of current guidelines regarding MAFLD treatment in children, lifestyle intervention was proven to be crucial in the management of these patients.

Is an Exercise Intervention the only way to Reduce Visceral Fat without Reducing Fat-free Mass in Children and Adolescents?

Objectives: To maintain proper development, it is recommended that children/adolescents focus more on increasing physical activity than dietary restriction when treating obesity. In other words, adults are better able to tolerate the reductions in fat-free body mass that often occur when trying to lose fat mass. In contrast, children and adolescents should avoid losses in fat-free mass in order to ensure proper development. Therefore, when trying to reduce visceral fat in children via a negative energy balance (i.e., exercise with or without calorie restriction), it is necessary to set desirable conditions in order to minimize the loss of fat-free mass. To determine whether this is possible, we reviewed literature discussing the relationship between changes in visceral fat obtained by abdominal imaging and changes in total body fat and fat-free mass after exercise training with and without calorie restriction in children and adolescents.Methods: Literature review.Results and Conclusions: Previous work found no reduction in fat-free mass in the exercise interventions in which there was no dietary-induced calorie restriction. This supports the idea that reducing visceral fat by increasing physical activity is the preferred strategy over dietary restriction in children and adolescents. Although factors such as the type (e.g. aerobic and/or resistance) of exercise and the amount (i.e. energy expenditure) of exercise will likely have an effect on the magnitude of change in intra-abdominal visceral fat, the quantity of each that is needed without reducing fat-free mass is currently unknown.

Influence of Chronic Exposure to Exercise on Heart Rate Variability in Children and Adolescents Affected by Obesity: A Systematic Review and Meta-Analysis

Background: Sedentary lifestyles are increasingly common amongst children, and insufficient physical activity is a global epidemic estimated to contribute to future incapacities and potential deaths. Objective: We aimed to increase the amount of evidence concerning the effect of chronic exposure to exercise on heart rate variability in children and adolescents affected by obesity. Methods: A systematic review commenced following the PRISMA guidelines developed by Web of Science, Virtual Health Library, PubMed, Cochrane Library, Embase, Ovid, Medline Complete, and Scopus using keywords obtained from the Descriptors in Health Sciences and Medical Subject Headlines (MeSH) terms. We considered (1) Population: Pediatric individuals affected by obesity; (2) Intervention: Exercise; (3) Control: Pre-intervention and sedentary; (4) Outcomes: Clearly presented primary parameters; and (5) Studies: Clinical trials, case controls, case reports, and case series. Results: 11 articles were involved and predominantly included procedures observed during approximately 12 weeks with a distribution of three sessions per week, each session being 30–60 min of aerobic exercise; additionally, the exercise grades were typically completed at a percentage of subjects’ maximum heart rates. The meta-analyses displayed a significant effect on the domains of time (R-R interval, SDNN, rMSSD), frequency (HF ms², HF (n.u.), LF/HF), and the non-linear index (SD1). Conclusions: Chronic exposure to exercise influences heart rate variability in children and adolescents affected by obesity by elevating the variability and parasympathetic activity and improving the sympathetic-vagal balance. Exercises should be recommended for the improvement of cardiac autonomic modulation to prevent the likelihood of further chronic diseases.

Pain phenotypes among adults living with cerebral palsy and spina bifida

ABSTRACT

Chronic pain is the most commonly reported physical symptomology of cerebral palsy (CP) and spina bifida (SB) throughout the lifespan, and yet, pain is perhaps the least understood comorbidity in these populations. The objective of this study was to compare the prevalence and types of pain diagnosed among adults living with and without CP or SB. In this retrospective cohort study, we analyzed data from a nationwide commercial insurance claims database. Beneficiaries were included if they had an International Classification of Diseases, Ninth revision, Clinical Modification diagnosis code for CP or SB (n = 22,648). Adults without CP or SB were also included as controls (n = 931,623). Pain phenotypes (nociceptive, nociplastic, and neuropathic pain) and pain multimorbidity (≥2 conditions) were compared. We found that adults living with CP or SB had a higher prevalence of any pain disorders (55.9% vs 35.2%), nociceptive pain (44.0% vs 26.7%), nociplastic pain (26.1% vs 11.9%), neuropathic pain (9.6% vs 5.6%), and pain multimorbidity (21.1% vs 8.4%), as compared to adults without CP or SB, and differences were to a clinically meaningful extent. Adjusted odds ratios of nociceptive pain (odds ratio [OR]: 2.20; 95% confidence interval [CI]: 2.15-2.24), nociplastic pain (OR: 2.47; 95% CI: 2.41-2.53), neuropathic pain (OR: 2.71; 95% CI: 2.54-2.89), and other pain (OR: 3.92; 95% CI: 3.67-4.19) were significantly higher for adults living with CP or SB. In conclusion, adults with CP or SB have a significantly higher prevalence and odds of common peripheral, central, and neuropathic pain disorders and pain multimorbidity, as compared to adults without CP or SB.

Nonalcoholic fatty liver disease and sarcopenia: pathophysiological connections and therapeutic implications

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) is currently one of the most common liver diseases worldwide. Recent data suggest that loss of skeletal muscle mass and function (i.e. sarcopenia) is highly prevalent and frequently overlooked in NAFLD patients. Experimental and clinical data suggest that the relationship between NAFLD and sarcopenia is pathophysiologically complex and bi-directional and there is a growing interest in unveiling how sarcopenia could influence NAFLD development and progression.

AREAS COVERED

PubMed/MEDLINE was searched for articles related to concomitant occurrence of NAFLD and sarcopenia between January 2013 and April 2020. Areas covered in this review include: (1) updated sarcopenia diagnosis strategy, (2) discussion of current data on pathophysiological connections between NAFLD and sarcopenia, and (3) analysis of current and future therapeutic implications of this knowledge.

EXPERT OPINION

Clinical studies describe a consistent association between NAFLD and sarcopenia, although a cause-effect relation remains to be determined. Active implementation of current diagnosis algorithms and optimized treatment can prevent sarcopenia related complications in subjects with NAFLD. Pathogenic pathways implicated in this relation are multiple and complex, a better understanding of them can provide novel biomarkers and targeted therapies that will hopefully have an important impact in NAFLD management.

Effects of Dietary and Lifestyle Interventions on Liver, Clinical and Metabolic Parameters in Children and Adolescents with Non-Alcoholic Fatty Liver Disease: A Systematic Review

Non-alcoholic fatty liver disease (NAFLD) affects 5.5–10.3% of children worldwide, while in obese individuals, it increases to almost 34%. Pediatric NAFLD is consistently associated with metabolic syndrome and insulin resistance. As no pharmacological agents exist for the treatment of NAFLD, lifestyle modifications remain the only therapy. However, as not all overweight/obese children have NAFLD, high-quality data, focused exclusively on NAFLD population are needed. Therefore, the present systematic review assessed the efficacy of lifestyle (diet or exercise) based on randomized controlled clinical trials (RCTs) on liver, anthropometric, glucose, and lipid parameters in children, with imaging or biopsy-proven NAFLD. In general, the results were inconclusive and therefore no specific recommendations could be drawn. In most studies, differences were derived from within group comparisons, which are known to be highly misleading. However, both low-carbohydrate and low-fat diets could benefit liver outcomes, as long as weight loss is achieved, but not necessary glucose and lipid parameters. No RCTs were found on exercise alone, as compared to no intervention on pediatric NAFLD. Concerning diet plus exercise interventions, all studies led to improvements in liver outcomes accompanied with weight loss. Resolution of NAFLD was found in considerably high percentages, while improvements were also seen in glucose but were modest in lipid parameters.

Adipose Tissue Development and Expansion from the Womb to Adolescence: An Overview

Prevalence rates of pediatric obesity continue to rise worldwide. Adipose tissue (AT) development and expansion initiate in the fetus and extend throughout the lifespan. This paper presents an overview of the AT developmental trajectories from the intrauterine period to adolescence; factors determining adiposity expansion are also discussed. The greatest fetal increases in AT were observed in the third pregnancy trimester, with growing evidence suggesting that maternal health and nutrition, toxin exposure, and genetic defects impact AT development. From birth up to six months, healthy term newborns experience steep increases in AT; but a subsequent reduction in AT is observed during infancy. Important determinants of AT in infancy identified in this review included feeding practices and factors shaping the gut microbiome. Low AT accrual rates are maintained up to puberty onset, at which time, the pattern of adiposity expansion becomes sex dependent. As girls experience rapid increases and boys experience decreases in AT, sexual dimorphism in hormone secretion can be considered the main contributor for changes. Eating patterns/behaviors and interactions between dietary components, gut microbiome, and immune cells also influence AT expansion. Despite the plasticity of this tissue, substantial evidence supports that adiposity at birth and infancy highly influences its levels across subsequent life stages. Thus, a unique window of opportunity for the prevention and/or slowing down of the predisposition toward obesity, exists from pregnancy through childhood.

Multicomponent Exercise Training Combined with Nutritional Counselling Improves Physical Function, Biochemical and Anthropometric Profiles in Obese Children: A Pilot Study

Aerobics or strength exercise plus diet interventions have been shown to counteract childhood obesity. However, little is known with regard to periodized multicomponent exercise interventions combined with nutritional counselling, which might be less demanding but more enjoyable and respectful of children and adolescents’ nature. In order to analyze the impact of such a multimodal approach, 18 obese children (10.8 ± 1.6 years; 63% females; z Body Mass Index 3 ± 0.4) trained for 60 min, twice weekly and were measured for body composition, biochemical parameters and physical function. We found that 16 weeks of multimodal intervention (14 of training), based on fun-type skill-learning physical activities and physical conditioning with challenging circuits and games, together with nutritional counselling, led to an attendance > 80%, with significant overall health improvement. Body composition was enhanced (p < 0.01 for z BMI, mid-upper-arm-circumference, waist-to-height ratio, tricipital and subscapular skinfolds, body-fat % by Slaughter equation and Dual energy X-ray absorptiometry body fat% and trunk fat%), as well as metabolic profile (LDL cholesterol, gamma-glutamyl transferase , alanine aminotransferase ; p < 0.05), homeostatic model assessment of insulin resistance (HOMA-IR; p < 0.05) and inflammatory response (C-Reactive Protein; p < 0.05). Physical fitness was also improved (p < 0.01) through better cardiovascular test scores and fundamental movement patterns (Functional Movement Screen-7, FMS-4). Tailoring multimodal supervised strategies ensured attendance, active participation and enjoyment, compensating for the lack of strict caloric restrictions and the low volume and training frequency compared to the exercise prescription guidelines for obesity. Nutritional counselling reinforced exercise benefits and turned the intervention into a powerful educational strategy. Teamwork and professionals’ specificity may also be key factors.

Effects of physical training on anthropometrics, physical and physiological capacities in individuals with obesity: A systematic review

Increasing the amount of physical activity is an important strategy for weight loss. This systematic review summarizes recent findings on the effects of physical training on anthropometric characteristics, physical performances and physiological capacities in individuals with overweight and obesity. A systematic literature search strategy was conducted from inception until June 2019 using four electronic databases that identified 2,708 records. After screening for titles, abstracts and full texts, 116 studies were included in our final analysis. Both aerobic (e.g., endurance training) and anaerobic training (e.g., high-intensity training, resistance training) improved body composition and physical fitness indicators in adults, adolescents and children with obesity (effect size: 0.08 < d < 2.67, trivial to very large). This systematic review suggests that both low- and high-intensity training significantly reduced body weight and fat mass while increasing fat-free mass in individuals with obesity (effect size: 0.04 <d <3.2, trivial to very large). A significant increase in VO_2max also occurs in individuals with obesity in response to aerobic training or high-intensity interval training (effect size: 0.13 < d < 6.24, trivial to very large). Further studies are needed to define the optimal combination of training intensity and duration needed to produce the most efficacious results in individuals with obesity.

Association of Trunk/Leg Fat Mass Ratio with Low-Density Lipoproteins-Cholesterol and Triglycerides Concentration in Children and Adolescents: A Cross-Sectional, Retrospective Study

Background: Increased central (or abdominal) fat mass has been associated with cardiometabolic risk factors such as high low-density lipoproteins (LDL)-cholesterol or triglycerides (TG) concentration in children. Objectives: To generate pediatric reference centiles for trunk/leg fat mass ratio (T2L) (assessed by dual-energy X-ray absorptiometry [DXA]) and to evaluate the association of LDL-cholesterol and TG concentrations with T2L in children and adolescents. Methods: Data of the National Health and Nutrition Examination Survey (1999-2004) were used to determine total and regional fat mass by DXA of the participants (aged 8-19 years) who had also an examination of LDL-cholesterol and TG concentrations. Fat mass was assessed by DXA-determined fat mass index (FMI). Central fat mass was quantified by T2L. Results: The DXA results of 6538 children and adolescents (2629 females) were used to generate reference centiles for T2L. In girls, T2L was significantly associated with high LDL-cholesterol and TG concentration (odds ratio [OR] adjusted to FMI 1.69), (95% confidence interval [CI] 1.20-2.40), and 1.45 (95% CI 1.11-1.91, p = 0.003 and p = 0.008). In boys, T2L was significantly associated only with high TG concentration (OR adjusted to FMI 1.81 [95% CI 1.52-2.19, p < 0.001]). Conclusions: A central fat distribution seemed to be an independent risk factor for high TG concentrations in children and for high LDL-cholesterol only in girls. The first ethnicity-specific, pediatric reference centiles for T2L were presented.

Effects of Exercise Intervention on Health-Related Physical Fitness and Blood Pressure in Preschool Children: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

No previous systematic review has quantitatively examined the effect of physical exercise interventions on health-related physical fitness and blood pressure in children younger than 6 years old.

OBJECTIVE

To evaluate the effects of exercise interventions on health-related physical fitness (i.e., physical fitness components and body composition) and blood pressure in preschoolers.

METHODS

We searched four databases. Only randomized controlled trials (RCTs), evaluating the effectiveness of exercise intervention on weight-related outcomes, blood pressure, and physical fitness components in preschoolers (1-5.99 years old) were included. The effect sizes were reported as Hedges' g using random-effects models.

RESULTS

A total of 19 RCTs were included. Exercise interventions favored reductions in body mass index (g = - 0.17; 95% confidence interval [CI], - 0.31 to - 0.03), waist circumference (g = - 0.25; 95% CI - 0.47 to - 0.03), and body fat percentage (g = - 0.31; 95% CI - 0.60 to - 0.23); as well as improvement in cardiorespiratory fitness (g = 0.25; 95% CI 0.08-0.42), muscular strength (g = 0.25; 95% CI 0.09-0.40), and speed-agility (g = - 0.51; 95% CI - 0.78 to - 0.24). Blood pressure was not reduced. The subgroup analysis revealed that physical exercise alone favored larger reductions in body mass index and waist circumference compared with physical exercise combined with another intervention. Also, changes in cardiorespiratory fitness, lower-body muscular strength and speed-agility were associated with larger decreases in body composition.

CONCLUSION

Physical exercise whether combined or not with additional intervention has a small effect on both body weight and physical fitness in preschoolers. Also, it seems that interventions to prevent obesity should be directed towards improving physical fitness of preschoolers.

The Effect of Aerobic and Resistance Training and Combined Exercise Modalities on Subcutaneous Abdominal Fat: A Systematic Review and Meta-analysis of Randomized Clinical Trials

Subcutaneous abdominal adipose tissue (SAT), is the largest fat depot and major provider of free fatty acids to the liver. Abdominal fat is indirectly (via increased levels of low-grade inflammation) correlated with many of the adverse health effects of obesity. Although exercise is one of the most prominent components of obesity management, its effects on SAT are still unclear. The aim of this study was to investigate the independent effects of aerobic training (AT) and resistance training (RT) modalities and combined exercise modalities on SAT in adults. PubMed, SCOPUS, and Google Scholar were searched to find relevant publications up to November 2018. The effect sizes were represented as weighted mean difference (WMD) and 95% CIs. Between-study heterogeneity was examined using the I2 test. Overall, 43 identified trials that enrolled 3552 subjects (2684 women) were included. After removal of outliers, combining effect sizes indicated a significant effect of AT (WMD: -13.05 cm2; 95% CI: -18.52, -7.57; P < 0.001), RT (WMD: -5.39 cm2; 95% CI: -9.66, -1.12; P = 0.01), and combined exercise training (CExT; WMD: -28.82 cm2; 95% CI: -30.83, -26.81; P < 0.001) on SAT relative to control groups. Pooled effect sizes demonstrated a significant effect of AT on SAT compared with a CExT group (WMD: 11.07 cm2; 95% CI: 1.81, 20.33; P = 0.01). However, when comparing the AT and RT groups, no significant difference was seen in SAT (WMD: -0.73 cm2; 95% CI: -4.50, 3.04; P = 0.70). Meta-analysis of relevant trials indicated that AT, RT, and CExT lead to SAT reduction. Aerobic exercise was shown to produce greater efficacy in decreasing SAT.

Nonalcoholic Fatty Liver Disease in Children: Unique Considerations and Challenges

Nonalcoholic fatty liver disease (NAFLD) is increasing in prevalence in concert with the global epidemic of obesity and is being diagnosed at increasingly younger ages. The unique histologic features and early presentation of disease in pediatrics suggest that children and adults may differ with regard to etiopathogenesis, with children displaying a greater vulnerability to genetic and environmental factors. Of significant relevance to pediatrics, in utero and perinatal stressors may alter the lifelong health trajectory of a child, increasing the risk of NAFLD and other cardiometabolic diseases. The development and progression of disease in childhood is likely to carry increased risk of long-term morbidity. Novel biomarkers and therapeutic agents are needed to avoid the otherwise inevitable health and societal consequences of this rapidly expanding pediatric population.

Evaluations of Lifestyle, Dietary, and Pharmacologic Treatments for Pediatric Nonalcoholic Fatty Liver Disease: A Systematic Review

BACKGROUND & AIMS

There are no approved treatments for pediatric nonalcoholic fatty liver disease (NAFLD) and there is a lack of consensus on the best outcome measure for randomized controlled trials. We performed a systematic review of treatments tested for pediatric NAFLD, the degree of heterogeneity in trial design, and endpoints analyzed in these studies.

METHODS

We searched publication databases and clinical trial registries through January 7, 2018 for randomized controlled trials (published and underway) of children (<18 years) with NAFLD. We assessed improvements in histologic features, radiologic and biochemical markers of reduced fibrosis, metabolic syndrome parameters, and adverse events. The quality of the trials was assessed using a modified version of the Cochrane risk of bias tool.

RESULTS

Our final analysis included 21 randomized controlled trials, comprising 1307 participants (mean age, 12.6 years; 63% male; mean duration of intervention, 8 months). Most studies evaluated weight loss with lifestyle intervention (n=8), oral polyunsaturated fatty acid treatment (PUFAs, n=6), or oral antioxidant treatment (n=7). Biomarkers of NAFLD decreased with weight loss, but most studies did not include histologic data. Trials of antioxidants were heterogeneous; some reported reduced histologic features of steatohepatitis with no effect on triglycerides or insulin resistance. PUFAs and probiotics reduced radiologic markers of steatosis, insulin resistance, and levels of triglycerides. Only 38% of the trials had biopsy-proven NAFLD as an inclusion criterion. There was heterogeneity in trial primary endpoints; 10 studies (48%) used levels of aminotransferases or ultrasonography findings as a primary endpoint and only 3 trials (14%) used histologic features as the primary endpoint. We identified 13 randomized controlled trials that are underway in children with NAFLD. None of the protocols include collection of liver biopsies; 9 trials (69%) will use magnetic resonance imaging quantification of steatosis as a primary outcome.

CONCLUSIONS

In a systematic review of published and active randomized controlled trials of children with NAFLD, we found a large amount of heterogeneity in study endpoints and inclusion criteria. Few trials included histologic analyses. Antioxidants appear to reduce some features of steatohepatitis. Effects of treatment with lifestyle modification, PUFAs, or probiotics have not been validated with histologic analysis. Trials that are underway quantify steatosis magnetic resonance imaging-outcomes are anticipated.

Obesity and nonalcoholic fatty liver disease: From pathophysiology to therapeutics

The obesity epidemic is closely associated with the rising prevalence and severity of nonalcoholic fatty liver disease (NAFLD): obesity has been linked not only with simple steatosis (SS), but also with advanced disease, i.e., nonalcoholic steatohepatitis (NASH), NASH-related cirrhosis and hepatocellular carcinoma. As a consequence, apart from increasing all-cause mortality, obesity seems to increase liver-specific mortality in NAFLD patients. Given the lack of approved pharmacological interventions for NAFLD, targeting obesity is a rational option for its management. As the first step, lifestyle modification (diet and exercise) is recommended, although it is difficult to achieve and sustain. When the first step fails, adding pharmacotherapy is recommended. Several anti-obesity medications have been investigated in NAFLD (e.g., orlistat, glucagon-like peptide-1 analogs), other anti-obesity medications have not been investigated (e.g., lorcaserin, phentermine hydrochloric, phentermine/topiramate and naltrexone/bupropion), whereas some medications with weight-lowering efficacy have not been approved for obesity (e.g., sodium-glucose cotransporter-2 inhibitors, farnesoid X receptor ligands). If the combination of lifestyle modification and pharmacotherapy also fails, then bariatric surgery should be considered in selected morbidly obese individuals. This review summarizes best evidence linking obesity with NAFLD and presents related therapeutic options.

Update on pathogenesis, diagnostics and therapy of nonalcoholic fatty liver disease in children

Nonalcoholic fatty liver disease (NAFLD) represents the most common cause of chronic liver disease. Increasing prevalence of NAFLD in children may be the cause of unfavorable metabolic implications and development of end stage liver disease. NAFLD is a “multiple-hit” disease mediated by several metabolic, environmental, genetic and microbiological mechanisms. Additionally, lipotoxicity, oxidative stress and inflammation predispose to progressive liver damage. According to current guidelines, liver biopsy is an imperfect gold standard for NAFLD diagnosis, but due to its invasive character its use is limited in children and it should be performed only in children who need exclusion of coexisting diseases. Noninvasive methods should be preferred and current research is focused on serum markers and novel imaging or elastographic techniques. Therapeutic approaches for NAFLD are currently focused on lifestyle modification, insulin resistance, dyslipidemia, oxidative stress and the gut microbiome. However, a number of clinical studies on novel therapeutic molecules are ongoing.

Effects of exercise training on Fetuin-a in obese, type 2 diabetes and cardiovascular disease in adults and elderly: a systematic review and Meta-analysis

Background

Elevated levels of fetuin-A are associated with increased risks of metabolic syndrome, type 2 diabetes and nonalcoholic fatty liver disease. This meta-analysis investigated whether exercise interventions can reduce fetuin-A in adults.

Methods

We searched clinical trials that objectively assessed fetuin-A and included study arms with exercise intervention. The pre-intervention and post-intervention data were used for meta-analysis. The effect sizes were calculated as standardized mean differences or changes in fetuin-A and expressed as Hedges’ g using random-effects models.

Results

The overall Hedges’ g for fetuin-A in all included interventions was − 0.640 (95%CI − 1.129 to − 0.151; n = 9), but this effect was not observed in obese (g = − 0.096; 95%CI, − 0.328 to 0.135) and type 2 diabetes/dysglycemia (g = − 0.56; 95%CI, − 1.348 to 0.236) individuals. Additionally, the random-effects meta-regression analysis showed that there was not a greater decrease in fetuin-A in individuals who achieved greater body mass index reductions (regression coefficient = 0.065; 95%CI, − 0.185 to 0.315).

Conclusion

Supervised exercise is associated with reductions in fetuin-A levels in adults and elderly. However, the results of the present meta-analysis should be interpreted with caution because of the variety of type of exercises and individual obesity related-disorders involve. Therefore, additional high-quality randomized controlled trials describing the effect of supervised exercise interventions on fetuin-A in adults are still needed. 

Electronic supplementary material

The online version of this article (10.1186/s12944-019-0962-2) contains supplementary material, which is available to authorized users.

Greater Reduction in Abdominal Than in Upper Arms Subcutaneous Fat in 10- to 12-Year-Old Tennis Players: A Volumetric MRI Study

Background: Little is known about the impact of long term participation in sports and subcutaneous fat volume in children. This study aimed at determining whether tennis participation is associated with lower subcutaneous adipose tissue volume (SATv) in the abdominal and upper extremities in children. Methods: Magnetic resonance imaging (MRI) was used to determine the SATv stored in the abdominal region and upper arms in seven tennis players and seven inactive children matched by height and age (147 cm and 10.9 years). All participants were in Tanner stage 1 or 2. Results: Playing tennis was associated with 48% (P = 0.001) lower abdominal SATv and 17-18% (P > 0.05) lower upper arms SATv compared to controls. The ratio between abdominal/upper arms SATv was larger in the controls vs. tennis players (69% P = 0.001). The SATv was similar in the dominant and non-dominant arm within each group. Conclusion: Playing tennis during childhood is associated with reduced SATv in the abdominal region and a more favorable regional distribution of fat. Despite the large amount of contractile activity of the playing (dominant) arm, there was no indication of between-arms differences in SATv.

Grip Strength Moderates the Association between Anthropometric and Body Composition Indicators and Liver Fat in Youth with an Excess of Adiposity

Paediatric non-alcoholic fatty liver disease (NAFLD) is considered the most common early driver of chronic liver disease. The aim of this study was to examine whether grip strength moderates the association between anthropometric and body composition parameters and controlled attenuation parameter (CAP), an indicator of fat deposits in the liver, in children and adolescents with excess of adiposity. A total of 127 adolescents (67% girls) aged between 11 and 17, attending two public schools in Bogotá (Colombia), who had an axiological evaluation of obesity were included in this study. A grip strength test was assessed as an indicator of muscular strength, and cardiorespiratory fitness by maximal oxygen uptake was assessed using the 20 m shuttle-run test. Waist circumference (WC), waist-to-height ratio (WHtR), fat mass, and visceral adipose tissue (VAT) (cm³) were included as anthropometric and body composition measures. CAP was determined with a FibroScan^® 502 Touch device (Echosens, Paris, France). The anthropometric and body composition parameters including WC, WHtR, fat mass, and VAT were positively associated with the CAP (range β = 0.423 to 0.580), slightly reduced after being adjusted for handgrip strength/weight. The Johnson-Neyman technique revealed a significant inverse relationship between WC, WHtR, VAT, and CAP when grip strength normalized by body mass was above but not equal to or below 0.475 (8.1% of the sample), 0.469 (8.9% of the sample), and 0.470 (8.5% of the sample), respectively. In conclusion, grip strength adjusted by body mass, has a moderating effect on the association between anthropometric and body composition parameters (including WC, WHtR, and VAT) and CAP in in children and adolescents with excess of adiposity, suggesting the importance of promoting muscular strength during paediatric population in order to prevent NAFLD.

Effects of an exercise program on hepatic metabolism, hepatic fat, and cardiovascular health in overweight/obese adolescents from Bogotá, Colombia (the HEPAFIT study): study protocol for a randomized controlled trial

Background

A considerable proportion of contemporary youth have a high risk of obesity-related disorders such as cardiovascular disease, metabolic syndrome, or non-alcoholic fatty liver disease (NAFLD). Although there is consistent evidence for the positive effects of physical activity on several health aspects, most adolescents in Colombia are sedentary. It is, therefore, important to implement strategies that generate changes in lifestyle. The HEPAFIT study aims to examine whether a 6-month exercise program has benefits for hepatic fat content and cardiovascular health outcomes among overweight/obese adolescents from Bogotá, Colombia.

Methods/design

Altogether, 100 hundred overweight/obese, sedentary adolescents (aged 11–17 years) attending two public schools in Bogotá, Colombia, will be included in a parallel-group randomized controlled trial. Adolescents will be randomly assigned to an intervention group following one of four curricula: (1) the standard physical education curriculum (60 min per week of physical activity, n = 25) at low-to-moderate intensity; (2) a high-intensity physical education curriculum (HIPE, n = 25), consisting of endurance and resistance games and non-competitive activities, such as running, gymkhanas, lifting, pushing, wrestling, or hauling, for 60-min sessions, three times per week, with an energy expenditure goal of 300 to 500 kcal/session at 75–85% maximum heart rate (HRmax); (3) a low-to-moderate intensity physical education curriculum (LIPE, n = 25) consisting of endurance and resistance games and non-competitive activities (e.g., chasing, sprinting, dribbling, or hopping) for 60-min sessions, three times per week with an energy expenditure goal of 300 kcal/session at 55–75% HRmax; and (4) a combined HIPE and LIPE curriculum (n = 25). The HIPE, LIPE, and combined interventions were performed in addition to the standard physical education curriculum. The primary outcome for effectiveness is liver fat content, as measured by the controlled attenuation parameter 1 week after the end of the intervention program.

Discussion

The translational focus may be suitable for collecting new information in a school setting on the possible effects of physical activity interventions to reduce liver fat content and to improve metabolic profiles and the cardiometabolic health of overweight/obese adolescents. This may lead to the more efficient use of school physical education resources.

Trial registration

ClinicalTrials.gov, NCT02753231. Registered on 21 April 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2721-5) contains supplementary material, which is available to authorized users.

Evidence-Based Exercise Recommendations to Reduce Hepatic Fat Content in Youth- a Systematic Review and Meta-Analysis

The main purposes of this study were to elucidate the effects of supervised-exercise training (ET) interventions on hepatic fat content and on non-alcoholic fatty liver disease (NAFLD) prevalence in children and adolescents and to provide information about the optimal ET prescription (type, intensity, volume, and frequency) needed to reduce hepatic fat content in youths. Supervised-ET interventions performed in children and adolescents (6-19 years) that provided results of exercise effects on hepatic fat content or NAFLD prevalence were included. Supervised-exercise significantly reduced hepatic fat content compared to the control groups. Lifestyle interventions that included supervised-ET significantly reduced the prevalence of NAFLD. This systematic review and meta-analysis shows that supervised-ET could be an effective strategy in the management and prevention of NAFLD in children and adolescents. Both aerobic and resistance ET, at vigorous or moderate-to-vigorous intensities, with a volume ≥60 min/session and a frequency ≥3 sessions/week, aiming to improve cardiorespiratory fitness and muscular strength, had benefits on hepatic fat content reduction in youth. These data concur with the international recommendations of physical activity for health promotion in youth and may be useful when designing ET programs to improve and prevent hepatic steatosis in the pediatric population.

Prevention of Tamoxifen-related Nonalcoholic Fatty Liver Disease in Breast Cancer Patients

BACKGROUND

Tamoxifen is commonly used to prevent breast cancer recurrence. Studies have confirmed the association between tamoxifen and nonalcoholic fatty liver disease (NAFLD), with the results indicating the need for aggressive management of this side effect. We assessed the potential risk factors for and identified the possible protective factors of tamoxifen-related fatty liver.

MATERIALS AND METHODS

We enrolled patients with a history of breast cancer, aged 20 to 70 years, who had received with tamoxifen treatment within the past 5 years. We obtained the initial data and performed a follow-up blood test and ultrasound examination to compare the differences before and after tamoxifen treatment. The patients were divided into relatively normal and fatty liver groups.

RESULTS

Of the 266 enrolled tamoxifen-treated patients, 143 (53.8%) and 123 (46.2%) were in the relatively normal and fatty liver groups, respectively. The initial body weight (57.6 ± 9.3 kg vs. 60.9 ± 10.3 kg; P = .006) and body mass index (BMI; 23.4 ± 3.8 kg/m² vs. 25.0 ± 4.2 kg/m²; P < .001) were lower in the relatively normal group. An initial BMI of ≥ 22 kg/m² was a potential risk factor for tamoxifen-related NAFLD (hazard ratio [HR], 1.58; 95% confidence interval [CI], 1.00-2.48; P = .048). In contrast, a weekly exercise duration of ≥ 150 minutes reduced the risk (HR, 0.47; 95% CI, 0.31-0.69; P < .001).

CONCLUSION

The results from our study suggest that a BMI of ≥ 22 kg/m² is a potential risk factor for tamoxifen-related fatty liver and exercise is a possible protective factor.