Exercise effects on arterial stiffness and heart health in children with excess weight: The SMART RCT

The effects of exercise training on inflammatory markers in children and adolescents: A systematic review and meta-analysis

INTRODUCTION AND AIM

Exercise training is effective for improving cardiometabolic health in children and adolescents, but less is known about its impact on inflammatory markers. We therefore, undertook a systematic review and meta-analysis to investigate the role of exercise training on pro-inflammatory cytokines including interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP) in children and adolescents.

METHOD

A comprehensive search was conducted in three electronic databases including PubMed, Web of Science, and Scopus, from inception to December 2023 to identify exercise trials with and without control groups, involving participants with mean ages ranging from ≥ 6 to < 18 years, of age with measurements of at least one of the following pro-inflammatory cytokines IL-6, TNF-α, or CRP. Standardized mean differences (SMD) and 95 % confidence interval (ICs) were calculated using random effects models.

RESULTS

Thirty-eight studies involving 2043 children and adolescents were included. The results show that exercise training resulted in significant reductions in IL-6 [SMD: -0.44; 95 % CI: -0.68, -0.21; P = 0.001] and CRP [SMD: -0.28; 95 % CI: -0.41, -0.16; P = 0.001], but not TNF-α [SMD: -0.15; 95 % CI: -0.38, -0.07; P = 0.19]. Subgroup analyses showed that IL-6 and CRP were reduced with aerobic training in adolescents, as was CRP with high-intensity interval training.

CONCLUSION

These results provide evidence that exercise training is effective for reducing IL-6 and CRP in adolescents, but not in children, and any benefits may be modulated by the type of exercise performed.

Mediating effect of fat mass, lean mass, blood pressure and insulin resistance on the associations of accelerometer-based sedentary time and physical activity with arterial stiffness, carotid IMT and carotid elasticity in 1574 adolescents

This study examined the mediating effect of total body fat mass, lean mass, blood pressure (BP) and insulin resistance on the associations of sedentary time (ST), light physical activity (LPA) and moderate-to-vigorous PA (MVPA) with carotid-femoral pulse wave velocity (cfPWV), carotid intima-media thickness (cIMT) and carotid elasticity in 1574 adolescents from the Avon Longitudinal Study of Parents and Children birth cohort, UK. ST, LPA and MVPA were assessed with ActiGraph accelerometer. ST and LPA were sex-categorised in tertiles as low (reference), moderate and high, while MVPA was categorised as <40 min/day (reference), 40-<60 min/day and ≥60 min/day. cfPWV, cIMT and carotid elasticity were measured with Vicorder and ultrasound. Fat mass and lean mass were assessed with dual-energy X-ray absorptiometry and homeostatic model assessment of insulin resistance (HOMA-IR) was computed. Mediation analyses structural equation models and linear mixed-effect models adjusted for cardiometabolic and lifestyle factors were conducted. Among 1574 adolescents [56.2% female; mean (SD) age 15.4 (0.24) years], 41% males and 17% females accumulated ≥60 min/day of MVPA. Higher ST was associated with lower cIMT partly mediated by lean mass. Higher LPA (standardized β = -0.057; [95% CI -0.101 to -0.013; p = 0.014]) and the highest LPA tertile were associated with lower cfPWV. BP had no significant mediating effect movement behaviour relations with vascular indices. Lean mass partially mediated associations of higher MVPA with higher cIMT (0.012; [0.007-0.002; p = 0.001], 25.5% mediation) and higher carotid elasticity (0.025; [0.014-0.039; p = 0.001], 28.1% mediation). HOMA-IR mediated the associations of higher MVPA with higher carotid elasticity (7.7% mediation). Engaging in ≥60 min/day of MVPA was associated with higher carotid elasticity. In conclusion, higher LPA was associated with lower arterial stiffness, but higher MVPA was associated with thicker carotid wall explained by higher lean mass.

Exercise and Insulin Resistance Markers in Children and Adolescents With Excess Weight: A Systematic Review and Network Meta-Analysis

Importance

Although benefits have been reported for most exercise modalities, the most effective exercise approaches for reducing insulin resistance in children and adolescents with excess weight and the optimal exercise dose remain unknown.

Objective

To compare exercise training modalities and their association with changes in insulin resistance markers among children and adolescents with excess weight and to establish the optimal exercise dose.

Data Sources

For this systematic review and network meta-analysis, 6 electronic databases (PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Scopus, Web of Science, and CINAHL) were searched for studies from inception to April 1, 2023.

Study Selection

Randomized clinical trials (ie, randomized controlled trials and randomized trials without a control group) were included if they reported outcomes associated with aerobic training, resistance training, high-intensity interval training (HIIT), or a combination of these interventions.

Data Extraction and Synthesis

Data extraction for this systematic review was conducted following a network meta-analysis extension of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guideline. Effect sizes were calculated as the mean difference (MD) with 95% CI using random-effects inverse-variance models with the Hartung-Knapp-Sidik-Jonkman method. The hierarchy of competing interventions was defined using the surface under the cumulative ranking curve. The Cochrane Risk-of-Bias tool, version 2 (RoB2), was used to independently assess the risk of bias of the included studies. The certainty of evidence in consistent networks was assessed using the Grading of Recommendation, Assessment, Development and Evaluation approach. The study protocol was prospectively registered with PROSPERO. Data analyses were conducted between May and June 2023.

Main Outcomes and Measures

The primary outcomes were fasting glucose, insulin, and homeostatic model assessment for insulin resistance (HOMA-IR).

Results

This analysis included 55 studies with a total of 3051 children and adolescents (mean [SD] age, 13.5 [2.3] years; 1537 girls [50.4%] and 1514 boys [49.6%]). Exercise was associated with reductions in fasting insulin (MD, -4.38 μU/mL [95% CI, -5.94 to -2.82 μU/mL]) and HOMA-IR (MD, -0.87 [95% CI, -1.20 to -0.53]). A nonlinear association in both markers was observed, with a required minimal exercise dosage of approximately 900 to 1200 metabolic equivalent of task minutes per week, especially in children and adolescents with insulin resistance at baseline. Combination HIIT and resistance training and concurrent training were the most effective approaches for reducing insulin resistance markers. On average, the certainty of evidence varied from low to moderate.

Conclusions and Relevance

These findings underscore the role of exercise interventions in enhancing insulin resistance markers among children and adolescents with overweight and obesity. It is advisable to include resistance exercises alongside aerobic and HIIT programs for a minimum of two to three 60-minute sessions per week.

Physical activity interventions for cardiopulmonary fitness in obese children and adolescents: a systematic review and meta-analysis

PURPOSE

This study [PROSPERO CRD42023416272] systematically analysed the effects of a physical activity intervention on cardiorespiratory fitness in obese children and adolescents and elucidated the factors that influenced those effects.

METHODS

A systematic review of the literature on physical activity interventions for improving cardiopulmonary fitness in obese children and adolescents from January 1, 2011, to March 1, 2023, was conducted. The search was performed on the Web of Science and PubMed databases, and the selected literature was first screened and then assessed for quality. Finally, a systematic review was conducted.

RESULTS

Out of the initially identified 1424 search records, 28 studies were eventually included in the systematic review. These studies encompassed a total of 2724 participants aged 5 to 18 years, with the publication dates of the literature primarily ranging from 2011 to 2023. Physical activity was found to effectively improve the following parameters in obese children and adolescents: weight [mean difference (MD), -2.03 (95% confidence interval, -2.59 to -1.47), p < 0.00001], maximal oxygen consumption [MD, -1.95 (95% CI, -1.06 to -2.84), p < 0.0001], heart rate [MD, -2.77 (95% CI, -4.88 to -0.67), p = 0.010], systolic blood pressure [MD, -8.11 (95% CI, -11.41 to -4.81), p < 0.00001], and diastolic blood pressure [MD, -4.18 (95% CI, -5.32 to -3.03), p < 0.00001]. High-intensity exercise was found to yield greater improvements than low- to moderate-intensity exercise in maximal oxygen consumption [MD, 1.43 (95% CI, 0.04 to 2.82), p = 0.04] and diastolic blood pressure [MD, -6.94 (95% CI, -10.61 to -3.26), p = 0.0002] in obese children and adolescents.

CONCLUSION

Physical activity can effectively improve the body weight, maximal oxygen consumption, heart rate, systolic blood pressure, and diastolic blood pressure of obese children and adolescents. The type of physical activity directly influences the participation interest of obese children and adolescents, with moderate- to high-intensity physical activity showing the most significant impact on intervention outcomes. High-frequency, long-term interventions yield better results than short-term interventions.

Preventative interventions that target cardiovascular dysfunction in children and young people: a systematic review of their effectiveness and an investigation of sexual dimorphism

Given that cardiovascular diseases remain a primary cause of mortality and morbidity, there is a need to consider preventative strategies to improve vascular function from early in life. The aims of this study were therefore to investigate which interventions may improve endothelial function, intima media thickness and arterial stiffness in children and young people and to assess whether these interventions differ in boys and girls. A systematic literature search of Science Direct, Pubmed, Google Scholar and the Cochrane Library by two independent reviewers was performed to source articles. Inclusion criteria were any studies including any child ≤18 years of age receiving an intervention, which measured vascular function other than blood pressure. Exclusion criteria were studies assessing children with chronic medical conditions. A total of 72 studies were identified, which met the inclusion criteria. A measurable change in outcome was more likely to be reported in studies investigating endothelial function (p = 0.03). Interventions which improved vascular function included physical activity and dietary programmes. Under 10% of studies considered sex differences. In conclusion, school-based physical activity interventions are most likely to result in improvements in vascular function. Endothelial function may be the first variable of vascular function to change secondary to an intervention. Standardisation of reporting of differences between the sexes is essential to be able to ensure interventions are equally effective for boys and girls.

Effects of an Exercise Program on Cardiometabolic and Mental Health in Children With Overweight or Obesity: A Secondary Analysis of a Randomized Clinical Trial

Importance

Childhood obesity is a risk factor associated with type 2 diabetes, cardiovascular disease, and mental disorders later in life. Investigation of the parallel effects of a defined exercise program on cardiometabolic and mental health in children with overweight or obesity may provide new insights on the potential benefits of exercise on overall health.

Objective

To investigate the effects of a 20-week exercise program on cardiometabolic and mental health in children with overweight or obesity.

Design, Setting, and Participants

This secondary analysis of a parallel-group randomized clinical trial was conducted in Granada, Spain, from November 1, 2014, to June 30, 2016. Data analyses were performed between February 1, 2020, and July 14, 2022. Children with overweight or obesity aged 8 to 11 years were eligible, and the study was performed in an out-of-school context.

Intervention

The exercise program included 3 to 5 sessions/wk (90 min/session) of aerobic plus resistance training for 20 weeks. The wait-list control group continued with their usual routines.

Main Outcomes and Measures

Cardiometabolic outcomes as specified in the trial protocol included body composition (fat mass, fat-free mass, and visceral adipose tissue), physical fitness (cardiorespiratory, speed-agility, and muscular), and traditional risk factors (waist circumference, blood lipid levels, glucose levels, insulin levels, and blood pressure). Cardiometabolic risk score (z score) was calculated based on age and sex reference values for levels of triglycerides, inverted high-density lipoprotein cholesterol, and glucose, the mean of systolic and diastolic blood pressure, and waist circumference. An additional cardiometabolic risk score also included cardiorespiratory fitness. Mental health outcomes included an array of psychological well-being and ill-being indicators.

Results

The 92 participants included in the per-protocol analyses (36 girls [39%] and 56 boys [61%]) had a mean (SD) age of 10.0 (1.1) years. The exercise program reduced the cardiometabolic risk score by approximately 0.38 (95% CI, -0.74 to -0.02) SDs; decreased low-density lipoprotein cholesterol level by -7.00 (95% CI, -14.27 to 0.37) mg/dL (to convert to mmol/L, multiply by 0.0259), body mass index (calculated as weight in kilograms divided by height in meters squared) by -0.59 (95% CI, -1.06 to -0.12), fat mass index by -0.67 (95% CI, -1.01 to -0.33), and visceral adipose tissue by -31.44 (95% CI, -58.99 to -3.90) g; and improved cardiorespiratory fitness by 2.75 (95% CI, 0.22-5.28) laps in the exercise group compared with the control group. No effects were observed on mental health outcomes.

Conclusions and Relevance

In this secondary analysis of a randomized clinical trial, an aerobic plus resistance exercise program improved cardiometabolic health in children with overweight or obesity but had no effect on mental health.

Trial Registration

ClinicalTrials.gov Identifier: NCT02295072.

School-Based Exercise Programs for Promoting Cardiorespiratory Fitness in Overweight and Obese Children Aged 6 to 10

The aim of this study was to conduct a systematic review of the school-based exercise programs for promoting cardiorespiratory fitness in overweight and obese children aged 6 to 10. Electronic databases (Web of Science and PubMed) were used as searching tools for collecting adequate studies published in the past 20 years. A total of 13 studies met the criteria for inclusion in this review, with a total of 2810 participants, both male and female. According to the results of this systematic review, overweight and obese children aged 6 to 10 who underwent certain interventions had their CRF improved. Furthermore, evidence suggested that interventions carried out during a longer period of time suggested led to greater improvement of cardiorespiratory fitness than a shorter one, but the level of cardiorespiratory fitness gradually decreases after the intervention.

Arterial stiffness precedes hypertension and metabolic risks in youth: a review

Arterial stiffness is a strong predictor of cardiovascular events and all-cause mortality in middle-aged and old adults. Arterial stiffness has been limited to being an intermediate marker of atherosclerotic cardiovascular events in adolescents and young adult studies. The paucity of normative longitudinal data and repeated gold-standard assessments of arterial stiffness among the young population has occasioned a huge knowledge gap in its clinical utility. This review summarizes recent longitudinal evidence in a large adolescent population, supporting the value of arterial stiffness as a novel risk factor for hypertension, overweight/obesity and insulin resistance. Preventing or decreasing arterial stiffness during adolescence may confer cardiometabolic health benefits in later life, but further pathological and mechanistic research is needed. The review also offers suggestions for incorporating arterial stiffness measures into routine paediatric and young adult clinical practice.

Effect of exercise training on arterial stiffness in obese and overweight children: a meta-analysis

The aim of this study was to investigate the effect of exercise training on arterial stiffness in obese and overweight children. Three databases were searched up to July 2021 for papers about exercise training and arterial stiffness in obese and overweight children. The quality of each identified study was evaluated. Effect sizes were estimated in terms of the standardized mean difference. Egger's test and sensitivity analysis were used to assess publication bias. In total, 26 studies by 19 researchers were included in the meta-analysis. Flow-mediated dilatation (FMD), pulse wave velocity (PWV), and intima-media thickness (IMT) were improved after exercise training in obese and overweight children. Subgroup analysis showed that exercise only reduced the PWV and IMT in individuals with a BMI < 30. FMD, PWV, and IMT were improved by exercise training in participants aged below 14 years, but only FMD was increased by exercise in participants aged 14 years and above. All types of training significantly improved FMD. Aerobic exercise (AE) and high-intensity intermittent training (HIIT) reduced the PWV of the participants, but were less effective than resistance training (RT) and aerobic plus resistance training. Only HIIT significantly reduced the IMT.   Conclusions: Exercise training improved vascular endothelial function and vascular sclerosis in overweight and obese children, especially in those with a BMI < 30 and younger than 14 years. AE had a more favorable effect on arterial stiffness. What is Known: • Exercise training was a good way to lose weight and subsequently promoted vascular function in overweight and obese children. What is New: • Exercise training was more effective on the vascular endothelial function and vascular sclerosis in overweight and obese children with a BMI<30. • Aerobic exercise had a more favorable effect on arterial stiffness, while the improvement was not effective after resistance training and combined training mode.

Effect of Exercise Training on Arterial Stiffness in Overweight or Obese Populations

The purpose was to analyze the effects of exercise training (ET) on arterial stiffness in all-age overweight or obese individuals. Sixty-one trials were included with ET improving flow-mediated dilation (FMD), pulse wave velocity (PWV), and intima-media thickness (IMT). In the subgroup analysis: (i) ET improved FMD in overweight or obese children and adolescents with a large effect size (SMD=0.83, 95% CI 0.42–1.25). PWV was decreased after ET regardless of age. IMT was decreased by ET in participants younger than 60, (ii) ET improved FMD, PWV, and IMT in participants whose BMI were smaller than 30 kg/m ² , but ET only improved PWV of participants whose BMI were larger than 30 kg/m ² . (iii) AE improved FMD, PWV, and IMT. High-intensity interval training (HIIT) decreased IMT. (iv) The increase of FMD only happened when training duration was longer than eight weeks. However, ET decreased PWV when the training duration was no longer than 12 weeks. IMT was decreased when the training duration was longer than eight weeks. ET instigated an improvement in endothelial function and arterial stiffness in overweight or obese populations, but depending on the different characteristics of exercise intervention and participants’ demographics.

Using compositional analysis to explore the relationship between physical activity and cardiovascular health in children and adolescents with and without type 1 diabetes

OBJECTIVE

The aim of this study was to use a compositional analysis approach to account for the inherent co-dependencies between behaviors and to explore how daily movement behaviors influence cardiovascular health in children with and without T1D.

RESEARCH DESIGN AND METHODS

Augmentation index, pulse wave velocity (PWV) and heart rate variability were measured in 20 children with (11.9 ± 1.6 years) and 17 children without T1D (11.6 ± 2.2 years). Subsequently, physical activity and sleep were assessed at 20 Hz for 28 consecutive days using a wrist-worn accelerometer. Compositional analyses were utilized to explore the relative effects of each movement behavior and the overall movement complex on cardiovascular parameters, with predictive modeling used to explore the effects of reallocating 20 min between behaviors.

RESULTS

Arterial stiffness markers were most influenced by the total movement composition, whereas autonomic function was most influenced by sedentary time and sleep relative to all other behaviors. Reallocation of time from moderate-to-vigorous physical activity (MVPA) to any other behavior was predicted to negatively affect all cardiovascular measures, independent of disease status, whereas reallocating time to MVPA was consistently predicted to improve all outcome measures. Additionally, the same intensity of physical activity appeared to be more potent for cardiovascular health in T1D children compared to nondiabetic peers.

CONCLUSIONS

Intensity, rather than volume, of physical activity may be key in reducing risk of premature adverse changes in cardiovascular health, whereas increasing time in MVPA could potentially the slow progression of cardiovascular aging in children with diabetes.

Effects of L-Citrulline Supplementation and Aerobic Training on Vascular Function in Individuals with Obesity across the Lifespan

Children with obesity are at higher risk for developing cardiometabolic diseases that once were considered health conditions of adults. Obesity is commonly associated with cardiometabolic risk factors such as dyslipidemia, hyperglycemia, hyperinsulinemia and hypertension that contribute to the development of endothelial dysfunction. Endothelial dysfunction, characterized by reduced nitric oxide (NO) production, precedes vascular abnormalities including atherosclerosis and arterial stiffness. Thus, early detection and treatment of cardiometabolic risk factors are necessary to prevent deleterious vascular consequences of obesity at an early age. Non-pharmacological interventions including L-Citrulline (L-Cit) supplementation and aerobic training stimulate endothelial NO mediated vasodilation, leading to improvements in organ perfusion, blood pressure, arterial stiffness, atherosclerosis and metabolic health (glucose control and lipid profile). Few studies suggest that the combination of L-Cit supplementation and exercise training can be an effective strategy to counteract the adverse effects of obesity on vascular function in older adults. Therefore, this review examined the efficacy of L-Cit supplementation and aerobic training interventions on vascular and metabolic parameters in obese individuals.

Vascular Ageing in Youth: A Call to Action

Extensive evidence shows that risk factors for cardiovascular disease (CVD) begin to develop early in life. Childhood obesity and elevated blood pressure (BP) have become overwhelmingly challenging, with 57% of today's children predicted to be obese by the age of 35 years, and global rates of hypertension in children and adolescents increasing by 75% from 2000 to 2015. Thus, there is an urgent need for tools that can assess early CVD risk in youth, which may lead to better risk stratification, preventative intervention, and personalised medicine. Vascular ageing (the deterioration in vascular structure and function) is a pivotal progenitor of health degeneration associated with elevated BP. Exposure to adverse environmental and genetic factors from fetal life promotes the development and accumulation of subclinical vascular changes that direct an individual towards a trajectory of early vascular ageing (EVA)-an independent predictor of target organ damage in the heart, brain, and kidneys. Therefore, characterising vascular ageing from youth may provide a window into cardiovascular risk later in life. However, vascular ageing measurements only have value when techniques are accurate/validated and when reliable thresholds are available for defining normal ranges and ranges that signal increased risk of disease. The aim of this paper is to summarise current evidence on the importance of vascular ageing assessment in youth and the impact of interventions to prevent or delay EVA, to highlight the need for standardisation and validation of measurement techniques in children and adolescents, and the importance of establishing reference values for vascular ageing measures in this population.

Cardiovascular Effects of Aerobic Exercise With Self-Selected or Predetermined Intensity in Adolescents With Obesity

This study compared the effects of self-selected exercise intensity (SEI) versus predetermined exercise intensity (PEI) on blood pressure (BP) and arterial stiffness in adolescents with obesity. A total of 37 adolescents, 14.7 (1.6) years old, body mass index ≥95th percentile were randomly allocated into SEI (n = 18; 12 boys) or PEI (n = 19; 13 boys). Both groups exercised for 35 minutes on a treadmill, 3 times per week, for 12 weeks. The SEI could set the speed at the beginning of the sessions and make changes every 5 minutes. The PEI adolescents were trained at an intensity set at 60% to 70% of heart rate reserve. Brachial and central BP, pulse pressure, augmentation index, and carotid-femoral pulse wave were determined at baseline and after 12 weeks. Both groups reduced brachial systolic BP (SEI, Δ = -9 mm Hg; PEI, Δ = -4 mm Hg; P < .01), central systolic BP (SEI, Δ = -4 mm Hg; PEI, Δ = -4 mm Hg; P = .01), and central pulse pressure (SEI, Δ = -4 mm Hg; PEI, Δ = -3 mm Hg; P = .02) without differences between groups. No changes in the augmentation index and carotid-femoral pulse wave were observed in either group. The SEI induced similar changes in various cardiovascular outcomes compared with PEI in adolescents with obesity.

Diffusion of scientific concepts on obesity in the global context: a historical review

ABSTRACT This article aimed to carry out a historical analysis of the dissemination of the scientific concepts on obesity, overweight and excess weight in the field of nutritional epidemiology in the world. The methodological procedures comprised: (1) Systematic search in the PubMed® database using single keywords and without date filter; (2) Documentary analysis of normative instruments on the websites of the World Health Organization, the Centers for Disease Control and Prevention and the World Obesity Federation; and (3) Analysis of the scientific production of scientists participating in the obesity classification of the International Obesity Task Force. The historical analysis showed that, considering the volume of publications on obesity, it appears that in the 1940-1949 decade the problem of obesity emerged on the world scenario. From the number of publications issued in the last 20 years, which corresponds to 85% of the investigated period, we can deduct that scientists’ concern to investigate the subject as a phenomenon coincides with the World Health Organization declaration of obesity as a global epidemic issued in the year 2000. In accordance with normative procedures established by international organizations, there has been a hegemonic use of the concepts of obesity and overweight, in this order of priority, by scientists worldwide. The concept of excess weight has experienced a relative rise since the year 2000, but its use has been very restricted, expressing dissonance in face of the recommendations of international standardization organizations, a fact that suggests discussion and review of its use by the world scientific community.