Improved insulin sensitivity and adiponectin level after exercise training in obese Korean youth

Roux-en-Y gastric bypass surgery in youth with severe obesity: 1-year longitudinal changes in spexin

BACKGROUND

Spexin is a novel peptide predominantly produced in human white adipose tissue and has recently been implicated as a potential signal in the regulation of body weight, energy homeostasis, and satiety. The effect of bariatric surgery on spexin is unknown.

OBJECTIVES

To study the effect of Roux-en-Y gastric bypass (RYGB) surgery on endogenous spexin concentration and various risk factors of type 2 diabetes and cardiovascular disease in youth with severe obesity.

SETTING

University hospital, United States METHODS: Spexin, body mass index (BMI), insulin, glucose, total and high molecular weight adiponectin, leptin, and high sensitivity C- reactive protein were measured longitudinally (baseline, 6 mo, and 12 mo) after RYGB surgery in girls with severe obesity (n = 12; age = 16.7 ± 1.5 years; BMI = 51.6 ± 2.9 kg/m²).

RESULTS

Serum spexin concentration increased (P = .01) at 6 months after surgery and stabilized afterward. Spexin level correlated negatively with homeostatic model assessment insulin resistance, HOMA-IR (Spearman correlation r = -.796, P < .001) and positively with high molecular weight adiponectin (Spearman correlation r = .691, P = .011). The change in spexin concentration, from baseline to 6 months after surgery, was inversely correlated with the corresponding change in BMI (Spearman correlation r = -.573, P = .051). Furthermore, the 6-month changes in spexin and HOMA-IR were inversely correlated (slope [standard error, SE] = -.0084 (.0019), P = .001)], even after adjusting for the change in BMI.

CONCLUSIONS

The enhancement of circulating spexin concentration in response to RYGB and correlations with beneficial postoperative changes in various adipokines in youth are novel findings that require further validation.

Effects of Physical Exercise on Adiponectin, Leptin, and Inflammatory Markers in Childhood Obesity: Systematic Review and Meta-Analysis

BACKGROUND

New findings on adipose tissue physiology and obesity-associated inflammation status suggest that modification of the adipokine level can be relevant for the long-term prevention of obesity-associated chronic disease.

OBJECTIVES

The scope of the present study was to investigate the effectiveness of physical exercise in reducing the systemic inflammation related to obesity in children.

METHODS

We conducted a systematic review with meta-analysis of controlled randomized trials, identified through electronic database search, which investigated the effect of physical exercise, without concomitant dietary intervention, on adiponectin, leptin, and/or other inflammatory markers in children up to age 18 years with a body mass index greater than the 95th percentile for age and sex.

RESULTS

Seven trials were included in the meta-analysis, with a total of 250 participants. Compared with the control group without any lifestyle modification, the physical exercise resulted in a reduction in leptin [standardized mean difference (SMD) -1.13; 95% confidence interval (95%CI): -1.89 to -0.37; I² = 79.9%] and interleukin-6 (SMD -0.84; 95%CI: -1.45 to -0.23, I² = 0.9%) and an increase in adiponectin plasma concentration (SMD 0.69; 95%CI: 0.02-1.35; I² = 74.3%).

CONCLUSIONS

These results indicate that physical exercise improved the inflammatory state in children with obesity. It is unclear whether this effect can reduce the risk of cardiovascular and metabolic disease in adulthood. Clinical trials with a uniform intervention protocol and outcome measurements are required to put our knowledge on adipose tissue biology into a clinical perspective.

Efficacy of Exercise Intervention for Weight Loss in Overweight and Obese Adolescents: Meta-Analysis and Implications

BACKGROUND

The global rise in obesity prevalence among children and adolescents has been linked to modifiable lifestyle factors, including lack of physical activity. However, no known meta-analysis has been conducted on the effects of exercise intervention on body composition and cardiometabolic risk factors in overweight and obese adolescents.

OBJECTIVES

The aim of this study was to (1) estimate whether exercise intervention meaningfully improves body composition and cardiometabolic risk factors in overweight and obese adolescents; and (2) discuss the implications of the findings in terms of primary healthcare provision and public health policy, using New Zealand as an exemplar context.

DATA SOURCES

Electronic databases (PubMed, Web of Science, SPORTDiscus, Google Scholar) from inception to May 2015. The reference lists of eligible articles and relevant reviews were also checked.

STUDY SELECTION

Inclusion criteria were (1) randomized controlled trial; (2) structured exercise intervention, alone or combined with any other kind of intervention; (3) control group received no structured exercise or behavioural modification designed to increase physical activity; (4) participants overweight or obese (body mass index [BMI] ≥85th percentile); and (5) participants aged between 10 and 19 years.

APPRAISAL AND SYNTHESIS METHODS

Initially, 1667 articles were identified. After evaluation of study characteristics, quality and validity, data from 13 articles (15 trials) involving 556 participants (176 male, 193 female, 187 unknown) were extracted for meta-analysis. Meta-analyses were completed on five body composition parameters and ten cardiometabolic parameters. Effect sizes (ESs) were calculated as mean differences, as well as standardized mean differences in order to determine effect magnitude.

RESULTS

Exercise intervention reduced BMI (mean 2.0 kg/m², 95 % CI 1.5-2.5; ES moderate), body weight (mean 3.7 kg, 95 % CI 1.7-5.8; ES small), body fat percentage (3.1 %, 95 % CI 2.2-4.1; ES small), waist circumference (3.0 cm, 95 % CI 1.3-4.8; ES small), but the increase (improvement) in lean mass was trivial (mean 1.6 kg, 95 % CI 0.5-2.6). The response to an oral glucose tolerance test following exercise intervention was for a decrease in the area under the curve for insulin (mean 162 μU/μl, 95 % CI 93-231; ES large) and blood glucose (mean 39 mg/dl, 95 % CI 9.4-69; ES moderate). Improvements in the homeostatic model assessment were also noted (mean 1.0, 95 % CI 0.7-1.4; ES moderate) and systolic blood pressure (mean 7.1 mmHg, 95 % CI 3.5-10.7; ES moderate). The effects of exercise on total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, fasting insulin and fasting blood glucose were inconclusive.

LIMITATIONS

Most of the included trials were short term (6-36 weeks) and 13 had methodological limitations. Additionally, the meta-analyses for some of the secondary outcomes had a small number of participants or substantial statistical heterogeneity.

CONCLUSIONS

The current evidence suggests that exercise intervention in overweight and obese adolescents improves body composition, particularly by lowering body fat. The limited available evidence further indicates that exercise intervention may improve some cardiometabolic risk factors.

The Impact of Physical Activity on Serum Inflammatory Markers in Overweight Pubertal Boys: 24-Month Follow-Up Study

PURPOSE

To investigate the differences in the pattern of changes in serum inflammatory cytokines measured annually over a 24-month period, between less active and more active overweight boys.

PARTICIPANTS/METHODS

In total, 25 pubertal overweight boys were divided by their moderate to vigorous physical activity (MVPA) levels into 2 groups: less active group (LAG; n = 10; MVPA < 60 min/d) and more active group (MAG; n = 15; MVPA > 60 min/d). Physical activity was measured by 7-day accelerometry. Serum concentration of 13 inflammatory cytokines [interleukin (IL)-2, IL-4, IL-6, IL-8, IL-10, IL-1α, IL-1β, vascular endothelial growth factor, interferon-γ, tumor necrosis factor-α, monocyte chemotactic protein-1, epidermal growth factor, and C-reactive protein] was measured at baseline (T0), after 12 months (T1), and after 24 months (T2) from fasting blood samples.

RESULTS

Serum IL-6 level was significantly higher [LAG: 1.27 (0.86, 1.98) pg/mL; MAG: 0.80 (0.52, 0.84) pg/mL] at T0 and IL-8 level [LAG: 10.26 (8.80, 11.64) pg/mL; MAG: 7.42 (6.10, 9.54) pg/mL] at T2 in LAG compared with MAG. The changes over the study period varied between different inflammatory markers. None of the slopes of any measured markers were statistically different between the LAG and MAG, although the slopes of interferon-γ and IL-10 tended to be different between the groups.

CONCLUSIONS

The pattern of changes over the study period varied between different inflammatory markers, but these changes were not different between the MVPA groups. More longitudinal studies are needed to investigate whether IL-6, IL-8, IL-10, and interferon-γ would be the choice of inflammatory markers to study the associations between obesity and physical activity in future.

Polyphenol-rich green tea extract improves adipose tissue metabolism by down-regulating miR-335 expression and mitigating insulin resistance and inflammation

Obesity leads to changes in miRNA expression in adipose tissue, and this modulation is linked to the pathophysiology of the disease. Green tea (GT) is a natural source of polyphenols that have been shown to confer health benefits, particularly preventing metabolic diseases. Here, we investigated if the beneficial effects of GT in obesity results from changes in the miRNA profile in white adipose tissue. GT treatment [500 mg/body weight (BW)/12 weeks] increased energy expenditure of high-fat diet-fed mice (16 weeks), leading to reduced weight gain, decreased adiposity, reduced inflammation and improved insulin sensitivity. These phenotypes were associated with a decrease in the expression of miR-335 in the adipose tissue. miR-335 was up-regulated by TNF-α in adipocytes and, in turn, down-regulated genes involved in insulin signaling and lipid metabolism. On the other hand, GT inhibited TNF-α effect. In conclusion, miR-335 serves as a link between inflammation and impaired metabolism in adipose tissue, providing an important mechanistic insight into the molecular basis underlying GT action during obesity.

Physical exercise promotes memory capability by enhancing hippocampal mitochondrial functions and inhibiting apoptosis in obesity-induced insulin resistance by high fat diet

A high-fat diet induces obesity in mice, leading to insulin resistance, decreased mitochondrial function, and increased apoptosis in the hippocampus, which eventually result in memory loss. The present study investigated the effect of physical exercise on memory, hippocampal mitochondrial function, and apoptosis in mice with in insulin resistance caused by obesity due to high-fat diet. Mice were randomly divided into four groups: control (CON), control and exercise (CON + EX), high fat diet (HFD), and high fat diet and exercise (HFD + EX). After receiving a high-fat (60%) diet for 20 weeks to induce obesity, the animals were subjected to an exercise routine 6 times per week, for 12 weeks. The exercise duration and intensity gradually increased over 4-week intervals. Hippocampal memory was examined using the step-down avoidance task. Mitochondrial function and apoptosis were also examined in the hippocampus and dentate gyrus. We found that obesity owing to a high-fat diet induced insulin resistance and caused a decrease in memory function. Insulin resistance also caused a decrease in mitochondrial function in the hippocampus by reducing Ca²⁺ retention and O_2, respiration, increasing the levels of H₂O₂, and Cyp-D, and mPTP opening. In addition, apoptosis in the hippocampus increased owing to decreased expression of Bcl-2 and increased expression of Bax, cytochrome c, and caspase-3 and TUNEL-positive cells. In contrast, physical exercise led to reduced insulin resistance, improved mitochondrial function, and reduced apoptosis in the hippocampus. The results suggest that physiological stimulations such as exercise improve hippocampal function and suppress apoptosis, potentially preventing the memory loss associated with obesity-induced insulin resistance.

The effects of physical activity on chronic subclinical systemic inflammation

Chronic subclinical systemic inflammation (CSSI) is a pathogenic event and a common risk factor for many noncommunicable diseases like atherosclerosis, metabolic syndrome, cardiovascular disease, insulin resistance and type 2 diabetes, cancer, and obstructive lung disease. On the other hand, regular physical activity has been found to reduce this risk. Many studies of different design were conducted to assess the association between inflammatory mediators as markers of CSSI and regular physical activity. The aim of this review was to present the current level of evidence and understanding of potential mechanisms by which physical activity reduces inflammatory mediators involved in CSSI and the types of physical activity required for the expected effect. We have found that observational studies consistently report a positive association between regular physical activity and lower CSSI, but the design of these studies does not allow to infer a causal relationship. Interventional studies, in contrast, were not consistent about the causal relationship between regular physical activity and lower CSSI. The problem in interpreting these results lies in significant differences between these interventional studies in their design, sample size, study population, and intervention itself (intensity and extent, follow up, weight loss). We can conclude that the scientific community has to invest a significant effort into high-quality interventional trials focused on finding the type, intensity, and extent of physical activity that would produce the most favourable effect on CSSI.

Adiponectin: A potential therapeutic target for metabolic syndrome

Adiponectin is an important adipocytokine secreted chiefly by fat containing adipocytes, and plays a crucial role in glucose and lipid metabolism, inflammation and oxidative stress. Alterations in adiponectin levels have been shown to directly affect lipid and glucose metabolism that further increase the synthesis of lipids, free fatty acids and inflammatory cytokines. Changes in adiponectin levels also contribute to insulin resistance, obesity, cardiovascular diseases and type 2 diabetes. In the present review, we provide a comprehensive evaluation of the role of adiponectin and its molecular mechanisms in metabolic syndrome. Clinical improvement in adiponectin levels have been shown to positively modulate lipid and glucose metabolism, thus further substantiating its role in regulation of lipid and glucose metabolism. Currently adiponectin is being investigated as a potential therapeutic target for metabolic syndrome, although more research is required to understand the underlying mechanisms controlling adiponectin levels, including dietary and lifestyle interventions, that may target adiponectin as a therapeutic intervention in metabolic syndrome.

Pre- and post-diagnosis physical activity is associated with survival benefits of colorectal cancer patients: a systematic review and meta-analysis

OBJECTIVE

Physical activity is associated with reduced risk of colorectal cancer. However, whether physical activity could impart cancer patients' survival benefits remains uncertain. The aim of this study is to systematically evaluate the relationship between physical activity and colorectal cancer mortality.

RESULTS

Our meta-analysis included 11 studies involving 17,295 patients with a follow-up period ranging from 3.8 to 11.9 years. Results indicated that physical activity was inversely associated with overall (RR = 0.81, 95% CI = 0.72-0.91) and colorectal cancer-specific mortality (RR = 0.79, 95% CI = 0.71-0.89) before the diagnosis of cancer, respectively. For physical activity after diagnosis, the pooled RRs of colorectal cancer-specific and total mortality were 0.77 (95% CI, 0.63-0.94) and 0.71 (95% CI, 0.63-0.81), respectively. Similar inverse associations between exercise and prognosis were found among colorectal cancer survivors who had high-level exercise compared with those who had low-level exercise or were inactive. There was no obvious evidence for publication bias among studies.

MATERIALS AND METHODS

We performed a systematic data search in PubMed, Cochrane Library databases and Web of Science for relevant articles before Jan 2016. We adopted adjusted estimates to calculate pooled relative risks (RRs) with 95% confidence intervals (CI) by the random-effects model. The publication bias was assessed by Begg's test.

CONCLUSIONS

Our meta-analysis provides comprehensive evidence that physical activity, whether before or after the diagnosis of colorectal cancer, is related to reduced overall and cancer-specific mortality. Our findings may have significant public health implications and more prospective randomized clinical trials should be warranted to certify this protective association.

Exercise and adiposity in overweight and obese children and adolescents: protocol for a systematic review and network meta-analysis of randomised trials

INTRODUCTION

Overweight and obesity is a worldwide public health problem among children and adolescents. However, the magnitude of effect, as well as hierarchy of exercise interventions (aerobic, strength training or both), on selected measures of adiposity is not well established despite numerous trials on this issue. The primary purposes of this study are to use the network meta-analytical approach to determine the effects and hierarchy of exercise interventions on selected measures of adiposity in overweight and obese children and adolescents.

METHODS AND ANALYSIS

Randomised exercise intervention trials >4 weeks, available in any language up to 31 August 2017 and which include direct and/or indirect evidence, will be included. Studies will be located by searching seven electronic databases, cross-referencing and expert review. Dual selection and abstraction of data will occur. The primary outcomes will be changes in body mass index (in kg/m²), fat mass and percent body fat. Risk of bias will be assessed using the Cochrane Risk of Bias assessment instrument while confidence in the cumulative evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation instrument for network meta-analysis. Network meta-analysis will be performed using multivariate random-effects meta-regression models. The surface under the cumulative ranking curve will be used to provide a hierarchy of exercise treatments (aerobic, strength or both).

ETHICS AND DISSEMINATION

This study does not require ethics approval. Findings will be presented at a professional conference and published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD 42017073103 .

Effect of home-based exercise intervention on fasting insulin and Adipocytokines in colorectal cancer survivors: a randomized controlled trial

BACKGROUND AND AIMS

Elevated circulating insulin is associated with increased risk of recurrence and cancer mortality in early-stage colorectal cancer (CRC). We conducted a randomized controlled trial to determine the effect of a 12-week home-based exercise program on fasting insulin, adipocytokines, and physical function in CRC survivors.

METHODS

One hundred and twenty-three stage II-III CRC patients were randomly assigned to either a home-based exercise (n=62) or standard care control group (n=61) for 12weeks. Home-based exercise consisted of aerobic and resistance training, with a goal of obtaining ≥18 metabolic equivalent task (MET)-h/wk. Participants in the exercise group were instructed to participate in >18MET-h/wk. of aerobic and resistance exercise while the participants in the control group were asked to maintain their usual daily activity. The primary outcome was fasting insulin levels. Secondary outcomes were adiponectin, TNF-α levels and 6min walk distance from baseline to post-intervention.

RESULTS

After the 12-weeks, moderate-vigorous physical activity participation increased from 9.1±14.7MET-h/wk. to 26.6±21.7MET-h/wk. in the exercise group, with no change in the control group (p<0.01 for group and time interaction). Circulating insulin level decreased by 1μU/ml (6.0±3.9 vs. 5.0±3.5, p=0.009) in the exercise group with no change in the control group (p=0.022 for group and time interaction). A similar trend was observed in TNF-α (p=0.030 for group and time interaction). Six minute walk distance increased by 25.2m in the exercise group with no change in the control group (p=0.061 for group and time interaction).

CONCLUSIONS

The 12week home-based exercise program increased level of physical activity and decreased circulating insulin levels in CRC survivors.

Exercise and BMI z-score in Overweight and Obese Children and Adolescents: A Systematic Review and Network Meta-Analysis of Randomized Trials

AIM

Examine the effects of selected types of exercise (aerobic, strength training, both) on BMI z-score in overweight and obese children and adolescents.

METHODS

Randomized exercise intervention trials ≥ 4 weeks were included. Studies were retrieved by searching six electronic databases, cross-referencing and expert review. Dual selection and abstraction occurred. Risk of bias and confidence in cumulative evidence were assessed. Network meta-analysis was performed using multivariate random-effects meta-regression models while surface under the cumulative ranking curves were used to calculate a hierarchy of exercise treatments. The number needed to treat (NNT) and percentile improvement (U₃ ) were also calculated.

RESULTS

Thirty-four studies representing 2,239 participants were included. Median exercise occurred 3 times per week, 50 minutes per session over a 12-week period. Statistically significant reductions in BMI z-score were found for aerobic exercise and combined aerobic and strength exercise, but not strength training alone (M±SD, 95% CI: aerobic, -0.10, -0.15 to -0.05; aerobic and strength, -0.11, -0.19 to -0.03; strength, 0.04, -0.07 to 0.15). Combined aerobic and strength training was ranked best, followed by aerobic exercise and strength training. The NNT was 2 for both aerobic exercise and combined aerobic exercise and strength training. Percentile improvements were 28.8% for aerobic exercise and 31.5% for combined aerobic exercise and strength training. Confidence in effect estimates was ranked as low for aerobic exercise and very low for combined aerobic and strength training as well as strength training.

CONCLUSIONS

Aerobic exercise and combined aerobic exercise and strength training are associated with reductions in BMI z-score.

Exercise, adipokines and pediatric obesity: a meta-analysis of randomized controlled trials

BACKGROUND/OBJECTIVE

Adipokines are involved in the etiology of diabetes, insulin resistance, and the development of atherosclerosis and other latent-onset complications. The objective of this meta-analysis was to determine the effectiveness of exercise interventions on adipokines in pediatric obesity.

SUBJECTS/METHODS

A computerized search was made using three databases. The analysis was restricted to studies that examined the effect of exercise interventions on adipokines (adiponectin, leptin, resistin and visfatin) in pediatric obesity (6-18 years old). Fourteen randomized controlled trials (347 youths) were included. Weighted mean difference (WMD) and 95% confidence intervals were calculated.

RESULTS

Exercise was associated with a significant increase in adiponectin (WMD=0.882 μg ml-1, 95% CI, 0.271-1.493) but did not alter leptin and resistin level. Likewise, exercise intensity and change in body fat; as well as total exercise program duration, duration of the sessions, and change in body fat all significantly influenced the effect of exercise on adiponectin and leptin, respectively.

CONCLUSIONS

Exercise seems to increase adiponectin levels in childhood obesity. Our results also suggested that exercise on its own, without the concomitant presence of changes in body composition levels, does not affect leptin levels.

Obesity-related insulin resistance in adolescents: a systematic review and meta-analysis of observational studies

Insulin resistance is common among obese adolescents; however, the extent of this problem is not clear. We conducted a systematic review of PubMed-Medline, CINAHL, The Web of Science, EMBASE and Scopus for observational studies evaluating components defining insulin resistance (insulin, C-peptide and homeostatic model assessment-insulin resistance [HOMA-IR]) in obese adolescents (12-18 years) versus non-obese adolescents. Our systematic review and meta-analysis followed the PRISMA guidelines. Data were combined using a random-effects model and summary statistics were calculated using the mean differences (MDs). 31 studies were included (n = 8655). In 26 studies, fasting insulin levels were higher in obese adolescents when compared to non-obese adolescents (MD = 64.11 pmol/L, 95%CI 49.48-78.75, p < 0.00001). In three studies, fasting C-peptide levels were higher in obese adolescents when compared to non-obese adolescents (MD = 0.29 nmol/L, 95%CI 0.22-0.36, p < 0.00001). In 24 studies, HOMA-IR values were higher in obese adolescents when compared to non-obese adolescents (MD = 2.22, 95%CI 1.78-2.67, p < 0.00001). Heterogeneity of effects among studies was moderate to high. Subgroup analyses showed similar results to the main analyses. Circulating insulin and C-peptide levels and HOMA-IR values were significantly higher in obese adolescents compared to those non-obese.

Effect of lifelong football training on the expression of muscle molecular markers involved in healthy longevity

PURPOSE

We investigated whether lifelong football training affects the expression of healthy longevity-related muscle molecular markers.

METHODS

Biopsies were collected from the vastus lateralis muscle of 10 lifelong football-trained men (68.2 ± 3.0 years) and of 10 active untrained healthy men (66.7 ± 1.3 years). Gene and protein expression was measured by RTqPCR on RNA and by western blotting on protein extracts from muscle biopsies, respectively.

RESULTS

The expression of AMPKα1/α2, NAMPT, TFAM and PGC1α, which are markers of oxidative metabolism, and MyHC β isoform expression was higher in the muscle of football-trained men vs untrained men. Also citrate synthase activity was higher in trained than in untrained men (109.3 ± 9.2 vs 75.1 ± 9.2 mU/mg). These findings were associated with a healthier body composition in trained than in untrained men [body weight: 78.2 ± 6.5 vs 91.2 ± 11.2 kg; body mass index BMI: 24.4 ± 1.6 vs 28.8 ± 4.0 kg m^-2; fat%: 22.6 ± 8.0 vs 31.4 ± 5.0%)] and with a higher maximal oxygen uptake (VO₂max: 34.7 ± 3.8 vs 27.3 ± 4.0 ml/min/kg). Also the expression of proteins involved in DNA repair and in senescence suppression (Erk1/2, Akt and FoxM1) was higher in trained than in untrained men. At BMI- and age-adjusted multiple linear regression analysis, fat percentage was independently associated with Akt protein expression, and VO₂max was independently associated with TFAM mRNA and with Erk1/2 protein expression.

CONCLUSIONS

Lifelong football training increases the expression of key markers involved in muscle oxidative metabolism, and in the DNA repair and senescence suppression pathways, thus providing the molecular basis for healthy longevity.

Epidemiology of Childhood Obesity in Korea

Over the past several decades, the prevalence of obesity has increased dramatically worldwide and is increasing not only in developed countries, but also in developing countries. This increase may lead to an increase in the incidence of chronic diseases throughout the lifespan. In Korean children and adolescents, the prevalence of obesity increased from 6.8% in 1998 to 10.0% in 2013. Obesity is a state that more commonly influences children and adolescents of lower socioeconomic status (SES) than those with a higher SES. However, the prevalence of metabolic syndrome in a nationally representative sample of Korean adolescents decreased from 1998 to 2012. According to the Diabetes Fact Sheet of the Korean Diabetes Association, the prevalence of type 2 diabetes among children aged 18 years or younger was 153.5 per 100,000 in 2006 and 205.0 per 100,000 in 2013. Obesity is a complex disease influenced by many interacting factors, such as adipocytokines, lipopolysaccharide-binding protein, adenovirus 36 infection, birth weight, lifestyle, and endocrine-disrupting chemicals. Obesity in youth can adversely impact practically every organ system and lead to serious consequences, such as metabolic, gastrointestinal, pulmonary, cardiovascular, and psychosocial complications. Therefore, coordinated efforts by governments, organizations, communities, and individuals are needed to prevent and treat childhood obesity. In particular, a long-term policy to improve the social environment will also be necessary.

Physical Activity and Gastric Cancer Risk: A Systematic Review and Meta-Analysis

OBJECTIVE

Physical activity represents a well-established way to prolong the life span; yet, it remains an unfulfilled goal for a great part of the population. In parallel, the burden of gastric cancer is considerable throughout the globe. In that context, the present meta-analysis aims to shed light on the association between physical activity and gastric cancer risk.

DATA SOURCES

Eligible observational studies were sought in PubMed up to June 01, 2015. In addition, a snowball procedure was conducted and contact with authors was implemented. Separate analyses were performed by type of physical activity (total; occupational; recreational), study design, published/provided data, anatomical site, and study location, along with stratification by gender.

MAIN RESULTS

Ten cohort studies (7551 incident cases in a total cohort size of 1 541 208 subjects) and 12 case-control studies (5803 cases and 73 629 controls) were eligible. "Any" type of physical activity was associated with lower risk of gastric cancer [pooled relative risk (RR) = 0.81; 95% CI: 0.73 to 0.89], which was reproducible in men (pooled RR = 0.87; 95% CI: 0.77-0.99). The protective effect was significant in the subgroup analyses of published data, noncardia cancer (pooled RR = 0.62; 95% CI: 0.52-0.75), and studies stemming from Asia (pooled RR = 0.82; 95% CI: 0.74-0.90).

CONCLUSIONS

This meta-analysis suggests a protective effect of physical activity regarding gastric cancer risk, especially in Asian populations.

Effect of exercise training on C reactive protein: a systematic review and meta-analysis of randomised and non-randomised controlled trials

PURPOSE

C-reactive protein (CRP) is a marker of chronic systemic inflammation frequently used in cardiovascular disease risk assessment. The purpose of this meta-analysis was to provide a quantitative estimate of the magnitude of change in CRP following participation in physical exercise interventions.

METHODS

All studies included in the meta-analysis were peer reviewed and published in English. Human participants were assigned to a non-exercise comparison group or exercise training group, with the intervention lasting ≥2 weeks. CRP levels were measured at baseline, during and/or after completion of the exercise training programme. Random-effects models were used to aggregate a mean effect size (ES), 95% CIs and potential moderators.

RESULTS

83 randomised and non-randomised controlled trials met the inclusion criteria and resulted in 143 effects (n=3769). The mean ES of 0.26 (95% CI 0.18 to 0.34, p<0.001) indicated a decrease in CRP following exercise training. A decrease in body mass index (BMI; β=1.20, SE=0.25, p<0.0001) and %Fat (β=0.76, SE=0.21, p=0.0002) were associated with a decrease in CRP, independently accounting for 11.1% and 6.6% of the variation in response, respectively. Exercise training led to a greater reduction in CRP when accompanied by a decrease in BMI (ES=0.38, 95% CI 0.26 to 0.50); however, a significant improvement in CRP occurred in the absence of weight loss (ES=0.19, 95% CI 0.10 to 0.28; both p<0.001).

CONCLUSIONS

These results suggest that engaging in exercise training is associated with a decrease in CRP levels regardless of the age or sex of the individual; however, greater improvements in CRP level occur with a decrease in BMI or %Fat.

The feasibility of progressive resistance training in women with polycystic ovary syndrome: a pilot randomized controlled trial

BACKGROUND

To evaluate the feasibility of executing a randomized controlled trial of progressive resistance training (PRT) in women with polycystic ovary syndrome (PCOS).

METHODS

Women with PCOS were randomized to an experimental (PRT) group or a no-exercise (usual care) control group. The PRT group was prescribed two supervised and two unsupervised (home-based) training sessions per week for 12 weeks. Feasibility outcomes included recruitment and attrition, adherence, adverse events, and completion of assessments. Secondary outcomes, collected pre and post intervention, included a range of pertinent physiological, functional and psychological measures.

RESULTS

Fifteen participants were randomised into the PRT group (n = 8) or control group (n = 7); five women (n = 2 in PRT group and n = 3 in control group) withdrew from the study. The most successful recruitment sources were Facebook (40 %) and online advertisement (27 %), while least successful methods were referrals by clinicians, colleagues and flyers. In the PRT group, attendance to supervised sessions was higher (95 %; standard deviation ±6 %) compared to unsupervised sessions (51 %; standard deviation ±28 %). No adverse events were attributed to PRT. Change in menstrual cycle status was not significantly different between groups over time (p = 0.503). However, the PRT group significantly increased body weight (p = 0.01), BMI (p = 0.04), lean mass (p = 0.01), fat-free mass (p = 0.005) and lower body strength (p = 0.03), while reducing waist circumference (p = 0.03) and HbA1c (p = 0.033) versus the control group. The PRT group also significantly improved across several domains of disease-specific and general health-related quality of life, depression, anxiety and exercise self-efficacy.

CONCLUSION

A randomized controlled trial of PRT in PCOS would be feasible, and this mode of exercise may elicit a therapeutic effect on clinically important outcomes in this cohort. The success of a large-scale trial required to confirm these findings would be contingent on addressing the feasibility hurdles identified in this study with respect to recruitment, attrition, compliance, and collection of standardized clinical data.

TRIAL REGISTRATION

Australia New Zealand Clinical Trials Registry; ACTRN12614000517673 Registered 15 May 2014.

Effects of Moderate Aerobic Exercise on Cognitive Abilities and Redox State Biomarkers in Older Adults

We used a moderate aerobic exercise program for 24 weeks to measure the positive impact of physical activity on oxidative stress and inflammatory markers and its association with cognitive performance in healthy older adults. A total of 100 healthy subjects (65–95 Yrs) were randomly classified into two groups: control group (n = 50) and exercise group (n = 50). Cognitive functioning, physical activity score, MDA, 8-OHdG, TAC, and hs-CRP were assessed using LOTCA battery, prevalidated PA questionnaire, and immunoassay techniques. LOTCA 7-set scores of cognitive performance showed a significant correlation with physical activity status and the regulation of both oxidative stress free radicals and inflammatory markers in all older subjects following 24 weeks of moderate exercise. Physically active persons showed a higher cognitive performance along with reduction in the levels of MDA, 8-OHdG, and hs-CRP and increase in TAC activity compared with sedentary participants. Cognitive performance correlated positively with the increase in TAC activity and physical fitness scores and negatively with MDA, 8-OHdG, and hs-CRP, respectively. There was a significant improvement in motor praxis, vasomotor organization, thinking operations, and attention and concentration among older adults. In conclusion, moderate aerobic training for 24 weeks has a positive significant effect in improving cognitive functions via modulating redox and inflammatory status of older adults.

Exercise-based interventions and C-reactive protein in overweight and obese youths: a meta-analysis of randomized controlled trials

BACKGROUND

One of the most commonly measured markers of inflammation in clinical settings is C-reactive protein (CRP). The purpose of this meta-analysis was to examine the evidence for the effectiveness of physical exercise interventions on modifying the levels of serum CRP in children and adolescents with excess of weight.

METHODS

Two independent reviewers assessed articles from seven databases. Studies were limited to physical exercise interventions in children and adolescents diagnosed as overweight or obese, and including a comparison control group. Weighted mean difference (WMD) was calculated using random-effects model and potential moderators were explored (i.e., weight status, ages, duration of study, frequency of exercise per week, and duration of session). The heterogeneity of the studies was estimated using Cochran's Q-statistic and I(2).

RESULTS

Nine randomized controlled trials met the inclusion criteria (n = 427 youths). Overall, results suggest a nonsignificant trend toward a reduction CRP levels (WMD = -0.72 mg/l; 95% confidence interval: -1.52 to 0.08; P = 0.077). Also, there were not significant moderators of exercise effects on CRP.

CONCLUSION

These results suggest that exercise programs in children and adolescents not mitigate the inflammatory effects of excess weight, although there was a trend toward reduction.

Cardiopulmonary fitness, adiponectin, chemerin associated fasting insulin level in colorectal cancer patients

PURPOSE

Since circulating level of insulin is associated with colorectal cancer prognosis, it is important to identify factors contributing to fasting insulin level in colorectal cancer patients. The purpose of the current study is to investigate the association of physical fitness, adiponectin, and chemerin levels with circulating level of insulin in colorectal cancer patients.

METHODS

A total of 123 stage II-III colorectal cancer patients who completed standard cancer treatment were recruited. Anthropometric characteristics, fitness measurements, fasting insulin level, homeostasis model assessment of insulin resistance, lipid profiles, and adiponectin and chemerin levels were analyzed.

RESULT

Cardiopulmonary fitness level inversely associated with fasting insulin levels (the least fit (1st tertile): 8.11 ± 0.64, moderately fit (2nd tertile): 6.02 ± 0.63, and highly fit (3rd tertile): 5.58 ± 0.66 μU/ml, unfit vs. moderately fit, p < 0.01; unfit vs. highly fit, p < 0.05) after adjustment for gender, age, stage, and BMI. In addition, fasting adiponectin and chemerin levels were associated with fasting insulin levels after adjustment for gender, age, stage, and BMI. In our combined analyses, participants with high adiponectin and low chemerin levels showed significantly lower fasting insulin levels (4.92 ± 0.75 vs. 8.07 ± 0.80 μU/ml, p < 0.01) compared with participants with low adiponectin and high chemerin levels. Multiple linear regression analysis confirmed that cardiopulmonary fitness and adiponectin levels (β = -0.299, p = 0.002; β = -0.201, p = 0.033) were independently associated with fasting insulin level.

CONCLUSION

Our results suggest that physical fitness and adiponectin and chemerin levels may contribute to circulating levels of insulin. These results suggest that exercise may influence the prognosis of colorectal cancer patients by influencing physical fitness level, circulating levels of adiponectin and chemerin.

Changes of Serum Adiponectin and Testosterone Concentrations Following Twelve Weeks Resistance Training in Obese Young Men

Background:

Circulating levels of adiponectin and testosterone decrease in obese men and this increases risks of cardiovascular disease and diabetes.

Objectives:

The purpose of this study was to survey changes of serum adiponectin and testosterone concentrations following twelve weeks resistance training in obese young men.

Patients and Methods:

In a semi-experimental study, twenty one obese young men were randomly placed in two groups: resistance training (26.5 ± 2.8 years) and control (27.4 ± 2.9 years). General characteristics of subjects and serum levels of adiponectin and testosterone were assessed before and after training. Resistance training protocol consisted of twelve weeks weight training (3 sessions per week, 10 exercises, 3 sets of 8 - 12 repetitions in each exercise, intensity 60% - 80% of one repetition maximum, rest between sets 1 minute and between exercises 2 minutes, duration of main training 20 - 40 minutes per each session).

Results:

Resistance training had no significant effect on body weight and body mass index (P > 0.05), whereas it decreased body fat percent (P = 0.017). Also, serum adiponectin (8.1 ± 1.8 vs. 10.5 ± 2.3 μg/mL) and testosterone concentrations (6.9 ± 2.4 vs. 8.2 ± 1.7 ng/mL) were increased after resistance training (P = 0.033, P = 0.018 respectively), while there were no significant changes in serum levels of these hormones in control group (P > 0.05).

Conclusions:

Twelve weeks of resistance training increased serum concentrations of adiponectin and testosterone in obese young men. With respect to inverse associations between changes of adiponectin and testosterone with BFP and insulin level variations after resistance training, it is recommended that obese young men do resistance training to benefit useful decreasing/preventive effects of this type of training against the risks of cardiovascular diseases and diabetes.

Exercise and BMI in Overweight and Obese Children and Adolescents: A Systematic Review and Trial Sequential Meta-Analysis

OBJECTIVE

Determine the effects of exercise on body mass index (BMI in kg · m(-2)) among overweight and obese children and adolescents.

METHODS

Trial sequential meta-analysis of randomized controlled exercise intervention trials ≥ 4 weeks and published up to November 11, 2014.

RESULTS

Of the 5,436 citations screened, 20 studies representing 971 boys and girls were included. Average length, frequency, and duration of training were 13 weeks, 3 times per week, for 46 minutes per session. Overall, random-effects models showed that exercise decreased BMI by 3.6% (mean: -1.08; 95% CI: -0.52 to -1.64; Q = 231.4; p < 0.001; I (2) = 90.9%; 95% CI: 87.6% to 93.4%; D (2) = 91.5%). Trial sequential meta-analysis showed that changes in BMI crossed the monitoring boundary for a type 1 error in 2010, remaining stable thereafter. The number needed to treat was 5 while the percentile improvement was 26.9. It was estimated that approximately 2.5 million overweight and obese children in the US and 22.0 million overweight and obese children worldwide could reduce their BMI by participating in a regular exercise program. Overall quality of evidence was rated as moderate.

CONCLUSIONS

Exercise is associated with improvements in BMI among overweight and obese children and adolescents. This trial is registered with PROSPERO Trial Registration #CRD42015017586.

The dose-response effect of physical activity on cancer mortality: findings from 71 prospective cohort studies

BACKGROUND

The WHO recommends moderate physical activity to combat the increasing risk of death from chronic diseases. We conducted a meta-analysis to assess the association between physical activity and cancer mortality and the WHO recommendations to reduce the latter.

METHODS

MEDLINE and EMBASE were searched up until May 2014 for cohort studies examining physical activity and cancer mortality in the general population and cancer survivors. Combined HRs were estimated using fixed-effect or random-effect meta-analysis of binary analysis. Associated HRs with defined increments and recommended levels of recreational physical activity were estimated by two-stage random-effects dose-response meta-analysis.

RESULTS

A total of 71 cohort studies met the inclusion criteria and were analysed. Binary analyses determined that individuals who participated in the most physical activity had an HR of 0.83 (95% CI 0.79 to 0.87) and 0.78 (95% CI 0.74 to 0.84) for cancer mortality in the general population and among cancer survivors, respectively. There was an inverse non-linear dose-response between the effects of physical activity and cancer mortality. In the general population, a minimum of 2.5 h/week of moderate-intensity activity led to a significant 13% reduction in cancer mortality. Cancer survivors who completed 15 metabolic equivalents of task (MET)-h/week of physical activity had a 27% lower risk of cancer mortality. A greater protective effect occurred in cancer survivors undertaking physical activity postdiagnosis versus prediagnosis, where 15 MET-h/week decreased the risk by 35% and 21%, respectively.

CONCLUSIONS

Our meta-analysis supports that current physical activity recommendations from WHO reduce cancer mortality in both the general population and cancer survivors. We infer that physical activity after a cancer diagnosis may result in significant protection among cancer survivors.

The effect of exercise on lipid profiles and inflammatory markers in lean male adolescents: a prospective interventional study

BACKGROUND

Physical activity improves body composition and inflammatory markers in obese individuals, but little is known about the nonobese population.

OBJECTIVE

The aim of this study was to investigate associations between exercise and inflammatory cytokines in lean male adolescents in Taiwan.

METHODS

This interventional study enrolled a total of 79 normal body weight male adolescents [mean age, 16.8 (1.0) years] from the Army Academy of Taiwan. Body composition and inflammatory markers were measured at baseline and upon completion of a 12-week exercise intervention program.

RESULTS

Subjects' postintervention anthropometric measures, including waist circumference [74.6 (5.2)→72.6 (5.2) cm], hip circumference [92.3 (4.1)→89.9 (5.0) cm], body fat mass [10.2 (3.2)→8.2 (3.2) kg], and body fat percentage [15.8% (4.2)→12.6 (4.5)%] declined significantly compared to preintervention (all P<0.001), as did systolic blood pressure (P=0.002) and mean blood pressure (P = 0.020). Postintervention body height and free fat mass increased significantly (both P<0.001). Subjects' postintervention lipids including total cholesterol, low-density lipoprotein, high-density lipoprotein, and triglycerides increased significantly (all P<0.001). Inflammatory markers including adiponectin [14.32 (6.68)→31.31 (30.53) μg/mL, P<0.001], interleukin 6 [2.15 (4.81)→2.86 (6.37) pg/mL, P=0.005], and C-reactive protein [1.00 (2.57)→2.30 (4.17) μg/mL, P<0.001] increased significantly postintervention, but not leptin.

CONCLUSIONS

Exercise training significantly improves body composition and anti-inflammatory adiponectin levels in lean male adolescents.

Health markers in obese adolescents improved by a 12-week recreational soccer program: a randomised controlled trial

The effects of a recreational soccer program (RSP) upon body composition, heart rate variability (HRV), biochemical markers, cardio-respiratory fitness, and endothelial function in obese adolescents were investigated. A randomised controlled clinical trial was conducted with 30 adolescents aged 12-17 years and body mass index (BMI) >2 standard deviations of WHO reference values, which were assigned to RSP (n = 10, 2 girls) and obese control (n = 10, 4 girls) groups. The 12-week RSP included 60-min sessions performed 3 times/week. BMI, waist circumference, blood pressure, blood glucose, lipid profile, insulin, C-reactive protein, HRV, and maximal oxygen consumption (VO2peak) were evaluated following standardised procedures. Body composition was determined by dual-energy X-ray absorptiometry and endothelial function by venous occlusion plethysmography. After intervention, RSP exhibited significant reductions in BMI (-0.7 ± 0.2 kg · m(-2)), waist circumference (-8.2 ± 1.4 cm), %body fat (-2.2 ± 0.4%), systolic blood pressure (-5.0 ± 2.3 mmHg), total cholesterol (-16.2 ± 5.8 mg · dL(-1)), triglycerides (-20.5 ± 12.9 mg · dL(-1)), C-reactive protein (-0.06 ± 0.01 mg · dL(-1)), insulin resistance (HOMA-IR, -1.4 ± 0.6), and sympathetic activity (LF, -13.9 ± 6.6 un) vs. controls (P < 0.05). Significant increase was observed in parasympathetic activity (HF, 13.9 ± 6.6 un), VO2peak (7.9 ± 2.8 ml · kg(-1) · min(-1)), and high-density lipoprotein cholesterol (11.0 ± 6.3 mg · dL(-1)) (P < 0.05). Vascular conductance (19.5 ± 8.1 ml · min(-1) · 100 ml, P = 0.005) increased and vascular resistance (-5.9 ± 2.4 ml · min(-1) · 100 ml, P = 0.041) decreased in RSP, but not in controls. A 12-week recreational soccer intervention was effective to improve biochemical, cardiovascular, and fitness health markers in obese adolescents.

Effects of aerobic and resistance training on abdominal fat, apolipoproteins and high-sensitivity C-reactive protein in adolescents with obesity: the HEARTY randomized clinical trial

OBJECTIVES

To investigate the effects of aerobic training, resistance training, or both on abdominal subcutaneous fat (subcutaneous adipose tissue (SAT)) (deep and superficial), visceral fat (visceral adipose tissue (VAT)), apolipoproteins A-1 and B (ApoA-1, ApoB), ApoB/ApoA-1 ratio and high-sensitivity C-reactive protein (HSCRP) in post-pubertal adolescents with obesity.

PARTICIPANTS

After a 4-week supervised moderate-intensity exercise run-in period, 304 postpubertal adolescents with overweight (body mass index (BMI) ⩾85th percentile for age and sex+diabetes risk factor) or obesity (⩾95th BMI percentile) aged 14-18 years were randomized to four groups for 22 weeks (5 months): aerobic training, resistance training, combined training or a non-exercising control.

METHODS

This study used a randomized controlled design. All groups received dietary counseling designed to promote healthy eating with a maximum daily energy deficit of 250 kcal. Abdominal fat (SAT and VAT) at the level of the fourth and fifth lumbar vertebrae (L4-L5) was measured by magnetic resonance imaging and ApoA-1, ApoB and HSCRP were measured after a 12-h fast at baseline and after 6 months.

RESULTS

Changes in SAT at L4-L5 were -16.2 cm(2) in aerobic (P=0.04 vs control), -22.7 cm(2) in resistance (P=0.009 vs control) and -18.7 cm(2) in combined (P=0.02 vs control). Combined training reduced ApoB levels from 0.81±0.02 to 0.78±0.02 g l(-1) (P=0.04 vs control) and ApoB/ApoA-1 ratio from 0.67±0.02 to 0.64±0.02 (P=0.02 vs control and P=0.04 vs aerobic). There were no significant differences in VAT, ApoA-1 or HSCRP levels between groups.

CONCLUSIONS

Aerobic and resistance training and their combination decreased abdominal SAT in adolescents with obesity. Combined training caused greater improvements in ApoB/ApoA-1 ratio compared with aerobic training alone.

Supplementation with a blend of krill and salmon oil is associated with increased metabolic risk in overweight men

BACKGROUND

Krill is an increasingly popular source of marine n-3 (ω-3) PUFA that is seen as a premium product. However, to our knowledge, the effect of krill-oil supplementation on insulin sensitivity in humans has not been reported.

OBJECTIVE

We assessed whether supplementation with a blend of krill and salmon (KS) oil [which is rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] affects insulin sensitivity in overweight men.

DESIGN

The design was a randomized, double-blind, controlled crossover trial. A total of 47 men with a mean ± SD age of 46.5 ± 5.1 y, who were overweight [body mass index (in kg/m(2)) from 25 to 30] but otherwise healthy, received 5 1-g capsules of KS oil or a control (canola oil) for 8 wk and crossed over to another treatment after an 8-wk washout period. The primary outcome was insulin sensitivity assessed by using the Matsuda method from an oral-glucose-tolerance test. Secondary outcomes included lipid profiles, inflammatory markers, 24-h ambulatory blood pressure, and carotid artery intimamedia thickness.

RESULTS

Unexpectedly, insulin sensitivity (per the Matsuda index) was 14% lower with the KS oil than with the control oil (P = 0.049). A mediation analysis showed that, after controlling for the likely positive effects of blood EPA and DHA (i.e., the omega-3 index), the reduction in insulin sensitivity after KS-oil supplementation was more marked [27% lower than with the control oil (P = 0.009)].

CONCLUSIONS

Supplementation with a blend of KS oil is associated with decreased insulin sensitivity. Thus, krill-oil supplementation in overweight adults could exacerbate risk of diabetes and cardiovascular disease. This trial was prospectively registered at the Australian New Zealand Clinical Trials Registry as ACTRN12611000602921.

Effects of regular exercise on obesity and type 2 diabete mellitus in Korean children: improvements glycemic control and serum adipokines level

[Purpose] The aim of the study was to clarify the effects of regular exercise on lipid profiles and serum adipokines in Korean children. [Subjects and Methods] Subjects were divided into controls (n=10), children who were obese (n=10), and children with type 2 diabetes mellitus (n=10). Maximal oxygen uptake (VO₂max), body composition, lipid profiles, glucagon, insulin and adipokines (leptin, resistin, visfatin and retinol binding protein 4) were measured before to and after a 12-week exercise program. [Results] Body weight, body mass index, and percentage body fat were significantly higher in the obese and diabetes groups compared with the control group. Total cholesterol, triglycerides, low-density lipoprotein cholesterol and glycemic control levels were significantly decreased after the exercise program in the obese and diabetes groups, while high-density lipoprotein cholesterol levels were significantly increased. Adipokines were higher in the obese and diabetes groups compared with the control group prior to the exercise program, and were significantly lower following completion. [Conclusion] These results suggest that regular exercise has positive effects on obesity and type 2 diabetes mellitus in Korean children by improving glycemic control and reducing body weight, thereby lowering cardiovascular risk factors and adipokine levels.

Targeting skeletal muscle mitochondria to prevent type 2 diabetes in youth

The prevalence of type 2 diabetes (T2D) has increased dramatically over the past two decades, not only among adults but also among adolescents. T2D is a systemic disorder affecting every organ system and is especially damaging to the cardiovascular system, predisposing individuals to severe cardiac and vascular complications. The precise mechanisms that cause T2D are an area of active research. Most current theories suggest that the process begins with peripheral insulin resistance that precedes failure of the pancreatic β-cells to secrete sufficient insulin to maintain normoglycemia. A growing body of literature has highlighted multiple aspects of mitochondrial function, including oxidative phosphorylation, lipid homeostasis, and mitochondrial quality control in the regulation of peripheral insulin sensitivity. Whether the cellular mechanisms of insulin resistance in adults are comparable to that in adolescents remains unclear. This review will summarize both clinical and basic studies that shed light on how alterations in skeletal muscle mitochondrial function contribute to whole body insulin resistance and will discuss the evidence supporting high-intensity exercise training as a therapy to circumvent skeletal muscle mitochondrial dysfunction to restore insulin sensitivity in both adults and adolescents.

Physical activity in overweight and obese adolescents: systematic review of the effects on physical fitness components and cardiovascular risk factors

BACKGROUND

The increasing prevalence of obesity in the pediatric age range has become a major concern. Studies have investigated the role of physical activity (PA) to prevent obesity in this population. However, previous reviews did not focus on the effects of PA in overweight/obese adolescents on physical fitness and risk factors for cardiovascular disease altogether.

OBJECTIVE

The present systematic review analyzed trials investigating the effect of PA on aerobic capacity, muscle strength, body composition, hemodynamic variables, biochemical markers, and endothelial function in obese/overweight adolescents.

METHODS

PubMed, LILACS, Web of Science, Scopus (including Embase), and SPORTDiscus databases were searched for relevant reports without time limits. Inclusion criteria included studies published in English, with overweight and obese adolescents aged 12-17 years. The review was registered (Number CRD42013004632) on PROSPERO, the International Prospective Register of Systematic Reviews.

RESULTS

The results indicated that PA is associated with significant and beneficial changes in fat percentage, waist circumference, systolic blood pressure, insulin, low-density lipoprotein cholesterol, and total cholesterol, as well as with small non-significant changes in diastolic blood pressure, glucose, and high-density lipoprotein cholesterol.

CONCLUSION

Although limited, results from controlled trials suggest that PA intervention may improve physical fitness and risk factors for cardiovascular disease in adolescents who are overweight or obese.

Higher omega-3 index is associated with increased insulin sensitivity and more favourable metabolic profile in middle-aged overweight men

We assessed whether omega-3 index (red blood cell concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)) was associated with insulin sensitivity and other metabolic outcomes in 47 overweight men aged 46.5 ± 5.1 years. Participants were assessed twice, 16 weeks apart. Insulin sensitivity was assessed by the Matsuda method from an oral glucose tolerance test. Linear associations were examined; stratified analyses were carried out with participants separated according to the omega-3 index: lower tertiles (LOI; n = 31) and highest tertile (HOI; n = 16). Increasing omega-3 index was correlated with higher insulin sensitivity (r = 0.23; p = 0.025), higher disposition index (r = 0.20; p = 0.054), and lower CRP concentrations (r = −0.39; p < 0.0001). Insulin sensitivity was 43% higher in HOI than in LOI men (Matsuda index 6.83 vs 4.78; p = 0.009). Similarly, HOI men had disposition index that was 70% higher (p = 0.013) and fasting insulin concentrations 25% lower (p = 0.038). HOI men displayed lower nocturnal systolic blood pressure (−6.0 mmHg; p = 0.025) and greater systolic blood pressure dip (14.7 vs 10.8%; p = 0.039). Men in the HOI group also had lower concentrations of CRP (41% lower; p = 0.033) and free fatty acids (21% lower, p = 0.024). In conclusion, higher omega-3 index is associated with increased insulin sensitivity and a more favourable metabolic profile in middle-aged overweight men.

Association of Inflammatory Cytokines with Traditional and Nontraditional Cardiovascular Risk Factors in Indians with known Coronary Artery Disease

BACKGROUND

Inflammatory processes are implicated in the etiology of cardiovascular disease (CVD). Data on the association of inflammatory markers with cardiovascular risk factors in Indian patients with CVD are limited.

AIM

This study was conducted with the aim to evaluate the association of inflammatory markers with traditional and nontraditional cardiovascular risk factors in angiographically proven coronary artery disease (CAD) patients.

SUBJECTS AND METHODS

We studied the association of serum highly sensitive C-reactive protein (hsCRP) (0.1-37.9 mg/l), interleukin-6 (IL-6) (2-253.2 pg/ml) and tumor necrosis factor-alpha (TNF-α) (8-525.8 pg/ml) with cardiovascular risk factors in 300 (M: 216, F: 84; mean age: 60.9 (12.4) years) CAD patients. All patients were evaluated for anthropometry and cardiovascular risk factors, and blood samples were collected for biochemical and inflammatory markers. Statistical analysis was carried out using SPSS Version 20.

RESULTS

Mean hsCRP, IL-6 and TNF-α in study population were 11.7 (9.7) mg/l, 64.5 (75.2) pg/ml, and 25.3 (40.9) pg/ml respectively. A total of 73.6% (221/300) patients had hsCRP levels >3.0 mg/l. All inflammatory markers were significantly higher and showed a positive correlation with dyslipidemia, diabetes mellitus, and/or hypertension (HTN). TNF-α had a negative correlation with age and positive correlation with smoking. Only IL-6 and hsCRP had a positive correlation with insulin resistance and negative correlation with insulin secretion. Among lipid parameters, triglyceride had a positive correlation, and high density lipoprotein had a negative correlation with all inflammatory markers. There was a progressive increase in the percentage of subjects with diabetes, HTN, and dyslipidemia with increasing levels of inflammatory markers.

CONCLUSIONS

Indian patients with CAD had significantly high levels of inflammatory markers, which were related to cardiovascular risk factors.

Endocrinology and Adolescence: aerobic exercise reduces insulin resistance markers in obese youth: a meta-analysis of randomized controlled trials

OBJECTIVE

The purpose of this meta-analysis was to examine the evidence for the effectiveness of aerobic exercise interventions on reducing insulin resistance markers in obese children and/or adolescents. A secondary outcome was change in percentage of body fat.

METHODS

A computerized search was made from seven databases: CINAHL, Cochrane Central Register of Controlled Trials, EMBASE, ERIC, MEDLINE, PsycINFO, and Science Citation Index. The analysis was restricted to randomized controlled trials that examined the effect of aerobic exercise on insulin resistance markers in obese youth. Two independent reviewers screened studies and extracted data. Effect sizes (ES) and 95% confidence interval (CI) were calculated, and the heterogeneity of the studies was estimated using Cochran's Q-statistic.

RESULTS

Nine studies were selected for meta-analysis as they fulfilled the inclusion criteria (n=367). Aerobic exercise interventions resulted in decreases in fasting glucose (ES=-0.39; low heterogeneity) and insulin (ES=-0.40; low heterogeneity) and in percentage of body fat (ES=-0.35; low heterogeneity). These improvements were specifically accentuated in adolescents (only in fasting insulin), or through programs lasting more than 12 weeks, three sessions per week, and over 60 min of aerobic exercise per session.

CONCLUSIONS

This meta-analysis provides insights into the effectiveness of aerobic exercise interventions on insulin resistance markers in the obese youth population.

Effect of exercise on serum adiponectin and lipoprotein levels in male rat

The effect of exercise and recovery period on adiponectin level is not still cleared. The aim of this study was to evaluate the effect of different intensities of running on serum adiponectin and lipoproteins levels in male rats. In this experimental study, one hundred and sixty rats aged 2 months years old (250 +/- 5 g) were randomly assigned into four groups including the control and the 3 groups running at the speeds of 18, 24 and 30 m min(-1) for 30 min. Serum adiponectin, Low Density Lipoprotein (LDL) and High Density Lipoprotein (HDL) levels were evaluated in four stages: Before running, immediately, 30 min and 5 h after the running finished. In different stages, 10 rats of each group were anesthetized and blood were collected from abdominal aorta. Serum adiponectin concentrations increased immediately after running in the rats ran with the speeds of 18, 24 and 30 m min(-1) in 30 min (p < 0.05). Thirty minute after running, serum adiponectin concentrations did not change only in the rats ran with the speed of 18 m min(-1) (p = 0.46). Five hours after running, serum adiponectin concentrations approximately reached into the before running levels in the rats ran with the speeds of 18, 24 and 30 m min(-1) (p < 0.05). There was no significant difference in serum LDL and HDL concentrations between and within rat groups (p > 0.05). Serum adiponectin concentrations rose when the running intensities in one exercise session increased in male rats. During recovery period, serum adiponectin concentrations decreased with the same pattern in different exercise intensities.

What is the effect of resistance training on the strength, body composition and psychosocial status of overweight and obese children and adolescents? A Systematic review and meta-analysis

BACKGROUND

Overweight and obese children and adolescents face many physical and psychosocial hardships. Resistance training is a modality of exercise which allows this at-risk group to excel and therefore has the potential to positively affect not only their physical but also psychosocial health.

OBJECTIVE

To systematically review and meta-analyse the peer-reviewed literature to determine the effect of resistance training on the strength, body composition and psychosocial status of overweight and/or obese children and/or adolescents.

DATA SOURCES

Relevant databases (MEDLINE, Embase, Scopus, Web of Science, SPORTDiscus, CINAHL, PsycINFO, Cochrane library, ProQuest) were searched up to and including 30 January 2013.

STUDY SELECTION

Included studies (n = 40, from the 2,247 identified) were randomised controlled trials (RCTs), non-randomised controlled trials (NRCTs) and uncontrolled trials (UCTs) which had run an exercise intervention, with a resistance training component, for overweight and/or obese children and/or adolescents, and which had examined the effect of resistance training on either strength, body composition or psychosocial outcomes.

STUDY APPRAISAL AND SYNTHESIS METHODS

Studies were initially critically appraised for risk of bias by the lead author, following which both co-authors critically appraised five randomly selected studies to assess reliability.

RESULTS

Randomised controlled trials and NRCTs were analysed separately from UCTs. To determine the overall intervention effect for each outcome variable for each study design group, standardised mean differences were calculated with each individual study/data set weighted by the inverse of the pooled variance. The overall intervention effect reported for RCTs and NRCTs was relative to the control group whereas the effect reported for UCTs shows an overall post-intervention effect. Subgroup analyses, which determined whether the overall intervention effect was influenced by intervention type, training volume, age, sex, risk of bias or study design (for RCT/NRCT group only), were run using the same summary measure. Typically, resistance training had very small to small effects on body composition and moderate to large effects on strength in favour of the intervention. However, the magnitude and direction of the effect of resistance training on psychological outcomes are still unclear given the limited number of studies which looked at psychosocial outcomes and the inconclusive results shown by this review. Uncontrolled trials typically showed larger intervention effects than RCTs and NRCTs; however, these results may be greatly influenced by maturational changes rather than the intervention itself.

LIMITATIONS

The included studies employed a number of different exercise intervention types (e.g. resistance training, resistance plus aerobic training etc.) that ranged from 6 to 52 weeks in duration. Studies also employed a number of different methodologies to assess similar outcome measures (e.g. dual energy X-ray absorptiometry versus skinfolds to assess body composition; one-repetition maximum testing versus hand grip strength to assess strength). However, by completing subgroup analyses and using a standardised summary measure these limitations have been accounted for.

CONCLUSION

While the effect of resistance training on the body composition and strength of overweight and obese children and adolescents is clear, given the paucity of conclusive data more studies are needed to fully understand the effect of resistance training on the psychosocial status of this population.

[Effect of a hypocaloric diet in the oxidative stress in obese subjects without prescription of exercise and antioxidants]

BACKGROUND AND OBJECTIVE

Obesity is characterized by a generalized increase of adipose tissue, high production of adipocytokines and presence of oxidative systemic stress. The objective of this study was to evaluate the changes generated in the oxidative stress and anthropometric parameters in obese subjects by the prescription of a hypocaloric diet in combination with moderate aerobic exercise and supplementation with antioxidants.

PATIENTS AND METHODS

Oxidative damage was determined in the plasma from 30 normal weight and 30 obese subjects. Three groups of treatment were established: Hypocaloric diet (HD), HD plus moderate aerobic exercise (HDE) and HDE plus antioxidants (DHEA). Biomarkers of oxidative stress (thiobarbituric acid reactive substances [TBARS], carbonyl groups, dityrosine) and anthropometric parameters were determined.

RESULTS

Higher values of biomarkers of oxidative damage were observed in obese (TBARS 13.74 ± 1.2 μM; carbonyl groups 0.89 ± 0.04 nmol of osazone/mg of protein; dityrosine 478.9 ± 27.4 RFU/mg of protein) in comparison to normal weight subjects (TBARS 7.08 ± 0.8 μM; carbonyl groups 0.65 ± 0.04 nmol of osazone/mg of protein; dityrosine 126.3 ± 12.6 RFU/mg of protein), thus showing the presence of an oxidative damage. The prescription of HD decreased the oxidative damage and anthropometric parameters in the obese subjects. We did not observe additional benefit effects on these determinations with HDE or HDEA treatments.

CONCLUSIONS

We demonstrated that an HD decreases the oxidative damage in obese subjects. Oxidative stress is an important factor in the development of comorbidity in obesity. Therefore, the prescription of a HD could be a key issue in the treatment of the disease.

Physical activity and risks of esophageal and gastric cancers: a meta-analysis

BACKGROUND

The incidence of esophageal and gastric cancer has been increasing rapidly worldwide in recent years, although the reason for this increase is unclear. Here, a statistical synthesis of studies that evaluated the association between physical activity, a well-known protecting factor against death and other chronic diseases, and the risk of esophageal and gastric cancer was performed.

METHODS

Potentially suitable studies were identified using Medline and Embase. The reference lists of all included articles and those of several recent reviews were searched manually. Studies were included if they (1) were published as case-control or cohort studies evaluating the association between physical activity and risk of esophageal or gastric cancer; and (2) reported point estimates (i.e., risk ratios, odds ratios) and measures of variability (i.e., 95% confidence intervals [CIs]) for physical activity and risk of esophageal or gastric cancer.

RESULTS

Fifteen studies were identified (7 cohorts, 8 case-controls; 984 esophageal and 7,087 gastric cancers). Collectively, they indicated that the risk of gastric cancer was 13% lower among the most physically active people than among the least active people (RR = 0.87, 95% confidence interval [CI] = 0.78 to 0.97) and that of esophageal cancer was 27% lower (RR = 0.73, 95% CI = 0.56 to 0.97).

CONCLUSIONS

Pooled results from observational studies support a protective effect of physical activity against both esophageal and gastric cancer.

Circulating interleukin-1β concentrations are independently-positively associated with γ-glutamyltransferase activity within the normal range in middle-aged apparently healthy Japanese women

We previously demonstrated that the circulating concentrations of interleukin (IL)-1β, which is known to induce the development and progression of type 2 diabetes and its complications, were positively associated with γ-glutamyltransferase (γ-GTP) activity in middle-aged apparently healthy Japanese men. It was still unknown if the association between IL-1β concentrations and γ-GTP activity is within the normal range in apparently healthy Japanese women. In this study, we conducted a cross-sectional study of 824 apparently healthy women aged 40-64 y [mean±standard deviation age, 53.1±7.1 y; body mass index (BMI), 22.0±3.1 kg/m(2)] who participated in health checkups in Japan, and whose γ-GTP activity was within the normal range (<38 U/L). Associations of γ-GTP with IL-1β and other clinical or lifestyle factors were determined using analysis of variance (ANOVA) and one-way analysis of covariance (ANCOVA) followed by Tukey's multiple-range test. Multivariate logistic regression analyses (MLRA) were performed with γ-GTP activity as the dependent variable; independent variables included IL-1β plus clinical and lifestyle factors. ANOVA and ANCOVA indicated that IL-1β concentrations were positively associated with γ-GTP activity. MLRA showed that γ-GTP activity showed trends for higher IL-1β concentrations after adjusting for age, BMI, energy intake, alcohol intake, and smoking status. Together, IL-1β concentrations are positively associated with γ-GTP activity within the normal range in middle-aged apparently healthy Japanese women. Our results suggest that γ-GTP activity would be useful for assessing inflammation from the healthy state in Japanese women.

Exercise and insulin resistance in youth: a meta-analysis

BACKGROUND AND OBJECTIVES

The prevalence of obesity and diabetes is increasing among children, adolescents, and adults. Although estimates of the efficacy of exercise training on fasting insulin and insulin resistance have been provided, for adults similar estimates have not been provided for youth. This systematic review and meta-analysis provides a quantitative estimate of the effectiveness of exercise training on fasting insulin and insulin resistance in children and adolescents.

METHODS

Potential sources were limited to peer-reviewed articles published before June 25, 2013, and gathered from the PubMed, SPORTDiscus, Physical Education Index, and Web of Science online databases. Analysis was limited to randomized controlled trials by using combinations of the terms adolescent, child, pediatric, youth, exercise training, physical activity, diabetes, insulin, randomized trial, and randomized controlled trial. The authors assessed 546 sources, of which 4.4% (24 studies) were eligible for inclusion. Thirty-two effects were used to estimate the effect of exercise training on fasting insulin, with 15 effects measuring the effect on insulin resistance. Estimated effects were independently calculated by multiple authors, and conflicts were resolved before calculating the overall effect.

RESULTS

Based on the cumulative results from these studies, a small to moderate effect was found for exercise training on fasting insulin and improving insulin resistance in youth (Hedges' d effect size = 0.48 [95% confidence interval: 0.22-0.74], P < .001 and 0.31 [95% confidence interval: 0.06-0.56], P < .05, respectively).

CONCLUSIONS

These results support the use of exercise training in the prevention and treatment of type 2 diabetes.

Inhibition of postprandial hyperglycemia by either an insulin-dependent or -independent drug reduces the expression of genes related to inflammation in peripheral leukocytes of OLETF rats

Treatment with the dipeptidyl peptidase-4 inhibitor, anagliptin, or with the α-glucosidase inhibitor, miglitol, reduced the oral sucrose load-inducible expression of interleukin (IL)-1β, IL-18, tumor necrosis factor-α, S100a8, S100a9, S100a11, IL-1R2, IL-1Rn and tumor necrosis factor receptor 2 genes in peripheral leukocytes of Otsuka Long-Evans Tokushima fatty (OLETF) rats at the stage of impaired glucose tolerance. Inhibiting postprandial hyperglycemia reduced the expression of genes related to inflammation in peripheral leukocytes of OLETF rats.

Can resistance training change the strength, body composition and self-concept of overweight and obese adolescent males? A randomised controlled trial

BACKGROUND/AIM

Resistance training is an exercise modality at which overweight and obese adolescents can excel and which can therefore positively affect their psychological well-being. The aim of this study was to determine the effect of a 6-month resistance training intervention on the self-concept strength and body composition of overweight and obese adolescent males.

METHODS

56 overweight and obese males aged 13-17 years were randomly allocated to an Intervention (n=30) or Control (n=26) group. Primary (psychological) and secondary (strength and body composition) outcomes were assessed at baseline as well as at 3 (halfway through the intervention), 6 (immediately postintervention) and 12 months follow-up. Random effects mixed modelling was used to determine the effects of the intervention.

RESULTS

Statistically significant differences between the Intervention and Control groups were observed at 3-month and 6-month assessments for exercise self-efficacy, resistance training confidence and self-esteem. Large increases in strength for the Intervention group, relative to Controls, were also observed with no substantial changes in body composition shown for either group. Values for all variables returned to baseline following completion of the programme.

CONCLUSIONS

A 6-month resistance training intervention can positively affect the self-concept and strength of overweight and obese adolescent boys.

Association between physical activity and mortality in colorectal cancer: a meta-analysis of prospective cohort studies

Several prospective cohort studies have examined the association between prediagnosis and/or postdiagnosis physical activity (PA) on colorectal cancer outcomes and reported conflicting results. To quantitatively assess this association, we have conducted a meta-analysis of prospective studies. Databases and reference lists of relevant studies were searched using MEDLINE and EMBASE up to January 2013. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated using random-effects models. For this meta-analysis, a total of seven prospective cohort studies were included. The analysis included 5,299 patients for prediagnosis PA and 6,348 patients for postdiagnosis PA, followed up over a period ranging from 3.8 to 11.9 years. The analyses showed that patients who participated in any amount of PA before diagnosis had a RR of 0.75 (95% CI: 0.65-0.87, p < 0.001) for colorectal cancer-specific mortality compared to patients who did not participate in any PA. Those who participated in high PA before diagnosis (vs. low PA) had a RR of 0.70 (95% CI: 0.56-0.87, p = 0.002). Similarly, patients who participated in any PA after diagnosis had a RR of 0.74 (95% CI: 0.58-0.95, p = 0.02) for colorectal cancer-specific mortality compared to patients who did not participate in any PA. Those who participated in high PA after diagnosis (vs. low PA) had a RR of 0.65 (95% CI: 0.47-0.92, p = 0.01). Similar inverse associations of prediagnosis or postdiagnosis PA were found for all-cause mortality. In conclusion, both prediagnosis and postdiagnosis PA were associated with reduced colorectal cancer-specific mortality and all-cause mortality.

Effects of a 12-week home-based exercise program on the level of physical activity, insulin, and cytokines in colorectal cancer survivors: a pilot study

PURPOSE

The purposes of this study are to examine (1) the feasibility and efficacy of two different home-based exercise protocols on the level of physical activity (PA), and (2) the effect of increased PA via home-based exercise program on biomarkers of colorectal cancer.

METHODS

Seventeen patients (age 55.18 ± 13.3 years) with stage II-III colorectal cancer completed the 12-week home-based exercise program. Subjects were randomized into either casually intervened home-based exercise group (CIHE) or intensely intervened home-based exercise group (IIHE). The primary outcome was the level of PA. Furthermore, insulin, homeostasis model assessment of insulin resistance, insulin-like growth factor axis, and adipocytokines were measured.

RESULTS

Both CIHE and IIHE program significantly increased the level of PA at 12 weeks compared to its level at baseline (CIHE, 10.00 ± 8.49 vs. 46.07 ± 45.59; IIHE, 12.08 ± 11.04 vs. 35.42 ± 27.42 MET hours per week). Since there was no difference in PA change between groups (p = 0.511), the data was combined in analyzing the effects of increased PA on biomarkers. Increase in PA significantly reduced insulin (6.66 ± 4.58 vs. 4.86 ± 3.48 μU/ml, p = 0.006), HOMA-IR (1.66 ± 1.23 vs. 1.25 ± 1.04, p = 0.017), and tumor necrosis alpha-α (TNF-α 4.85 ± 7.88 vs. 2.95 ± 5.38 pg/ml, p = 0.004), and significantly increased IGF-1 (135.39 ± 60.15 vs. 159.53 ng/ml, p = 0.007), IGF binding protein (IGFBP)-3 (2.67 ± 1.48 vs. 3.48 ± 1.00 ng/ml, p = 0.013), and adiponectin (6.73 ± 3.07 vs. 7.54 ± 3.96 μg/ml, p = 0.015).

CONCLUSION

CIHE program was as effective as IIHE program in increasing the level of PA, and the increase in PA resulted in significant change in HOMA-IR, IGF-1 axis, TNF-α, and adiponectin levels in stage II-III colorectal cancer survivors.

A review of randomized controlled trials of aerobic exercise training on fitness and cardiometabolic risk factors in obese adolescents

Aerobic training is the most prescribed exercise modality for the management of pediatric obesity. There is strong evidence that it decreases waist circumference, percent body fat and visceral fat, increases cardiorespiratory fitness, and decreases blood pressure in obese adolescents. However, the independent effects of aerobic exercise training on other cardiometabolic risk factors (ie, insulin resistance markers, plasma lipid levels, and inflammatory markers) are limited and yield inconsistent findings. Our article reviews randomized controlled trials evaluating the effects of aerobic exercise training on body composition, fitness, lipid levels, and insulin resistance in obese adolescents (aged 13-18 years) and outlines future research directions for this population.