Association between Exercise-Induced Changes in Cardiorespiratory Fitness and Adiposity among Overweight and Obese Youth: A Meta-Analysis and Meta-Regression Analysis

Cardiorespiratory and Muscular Fitness in Children and Adolescents with Obesity

PURPOSE OF REVIEW

Examine the current state of literature related to the impact of obesity in children and adolescents on health-related physical fitness and the resultant cardiometabolic disease risk.

RECENT FINDINGS

Cardiorespiratory fitness of children and adolescents has declined over the past few decades which corresponds with an increase in obesity rates. Children with obesity are more likely to have low cardiorespiratory fitness which is associated with higher cardiometabolic disease risk and poorer mental health. The impact of obesity on muscular fitness in children and adolescents is more difficult to ascertain, but in general measures of physical function are lower in children with obesity which has also been associated with higher cardiometabolic disease risk. Components of health-related physical fitness are trending negatively in children and adolescents and appear to be related to the increase in prevalence of obesity. The resultant cardiometabolic disease risk has also risen which suggests a greater disease burden in the future. These disparaging findings highlight the need for aggressive interventions to improve physical fitness in children and adolescents.

Cardiorespiratory fitness and targeted proteomics involved in brain and cardiovascular health in children with overweight/obesity

Cardiorespiratory fitness (CRF) is inversely associated with cardiovascular disease (CVD) risk factors and brain health impairments. However, the molecular mechanisms linking CRF to health in children are poorly understood. We aimed to examine protein levels related to brain health and CVD in plasma of fit compared to unfit children with overweight/obesity (OW/OB). Eighty-seven children with OW/OB (10.08 ± 1.1 years, 59% boys) from the ActiveBrains project were included. CRF was measured by performing a treadmill test, and children were categorized into fit or unfit. Targeted proteomics in plasma was performed using Olink's proximity extension assay technology of Neurology panel in the whole sample and of Cardiovascular panel in a subsample. Sixteen proteins (PLXNB3, sFRP3, CLEC1B, RSPO1, Gal8, CLEC10A, GCP5, MDGA1, CTSC, LAT, IL4RA, PRSS27, CXCL1, Gal9, MERTK, and GT) were differentially expressed between fit and unfit children with OW/OB after adjusting for sex, maturational status, and body mass index. However, statistically significant differences disappeared after applying FDR correction. Potential candidate proteins related to CRF levels in children with OW/OB were detected, being involved in several biological processes such as neurogenesis, immune/inflammatory response, signal transduction, platelet activation. Nevertheless, these preliminary findings should be confirmed or contrasted in future studies using larger sample sizes, longitudinal and experimental designs.HighlightsThe molecular mechanisms underlying the link of cardiorespiratory fitness (CRF) with cardiovascular and brain health in children with overweight/obesity (OW/OB) are poorly understood.Targeted proteomic analysis revealed differentially expressed proteins (PLXNB3, sFRP3, CLEC1B, RSPO1, Gal8, CLEC10A, GCP5, MDGA1, CTSC, LAT, IL4RA, PRSS27, CXCL1, Gal9, MERTK, and GT) in plasma of "Fit" compared to "Unfit" children with OW/OB. These proteins are involved in several biological processes such as immune/inflammatory response, neurogenesis, signal transduction, and cellular metabolic process.Longitudinal and experimental studies are warranted to reveal how improvements in CRF are related to changes in circulating levels of the abovementioned proteins and how they might reduce cardiovascular diseases risk factors and brain health impairments later in life.

Perceived Difficulties in Physical Tasks and Physical Fitness in Treatment- and Non-Treatment-Seeking Youths with Obesity

Youths with obesity are more likely to experience physical and psychosocial distress which strongly limits physical activity, with consequences on the quality of life. Most evidence of lower physical fitness and physical activity levels has been reported in treatment-seeking samples, while few data are available in community samples. Our aim was to assess whether perceived difficulties in physical tasks and physical fitness performance differed between treatment- and non-treatment-seeking youths with obesity, enrolled from a hospital (H) and a school (S). Three hundred fifty-one youths (269 from H and 82 from S) were enrolled. Sports participation, sedentary habits and perceived difficulties in physical tasks were assessed by interview. Six-minute walk test (SMWD) and long jump (LJ) were performed. BMI Z-score, sedentary time and perceived difficulties were higher in H vs. S. In addition, youths from H scored worse in SMWD and LJ. For the same BMI Z-score, the perceived difficulties and physical fitness were poorer in the H compared to the S group. The setting (H) was the stronger predictor of perceived difficulties and lower performance. Our findings underline that physical aspects imposed by obesity are more evident in treatment-seeking youths. Counseling related to perceived difficulties in physical tasks and performance is useful to treat youth with obesity with appropriate and personalized modalities.

What is the role of cardiorespiratory fitness and sedentary behavior in relationship between the genetic predisposition to obesity and cardiometabolic risk score?

Background

Genetic factors along with inadequate lifestyle habits are associated with the development of cardiometabolic alterations. Thus, the present study aimed to examine the role of sedentary behavior on the relationship between rs9939609 polymorphism (fat mass and obesity-associated gene-FTO) and cardiometabolic risk score according to cardiorespiratory fitness (CRF) levels in children and adolescents.

Methods

A cross-sectional study with 1215 children and adolescents (692 girls), aged between 6 and 17 years. Screen time as a marker of sedentary behavior was evaluated through a self-reported questionnaire and CRF was estimated using the 6-min walking and running test. The genotyping of the FTO rs9939609 polymorphism was performed using a real-time polymerase chain reaction. Clustered cardiometabolic risk score (cMetS) was calculated by summing z-scores of total cholesterol/high-density lipoprotein cholesterol ratio, triglycerides, glucose, systolic blood pressure, and waist circumference, and dividing it by five. Moderation analyses were tested using multiple linear regression models.

Results

The coefficient of the interaction term of FTO (rs9939609) and screen time indicated that screen time was a significant moderator on the relationship between FTO rs9939609 polymorphism and cMetS (p = 0.047) in children and adolescents classified with low CRF (β = 0.001; 95% CI = 0.001; 0.002). It was observed a significant association between genotype risk (AA) of FTO polymorphism and cMetS, in participants that spent more than 378 min a day in front of screen-based devices (β = 0.203; 95% CI = 0.000; 0.405). No interaction term was found for those with high CRF.

Conclusions

High sedentary behavior seems to influence the relationship between genetic predisposition to obesity and cardiometabolic risk factors in children and adolescents with low CRF.

Growth, Somatic Maturation, and Their Impact on Physical Health and Sports Performance: An Editorial

Over time, complex interactions and a nonlinear progression among a wide range of variables contribute to the improvement of physical health and of the elite level achievement in youth sport practitioners [...].

The Effect of an Intervention with Active Video Games Combined with Multicomponent Exercise on Cardiorespiratory fitness in Children with Overweight and Obesity: A Randomized Controlled Trial. (Preprint)

Background

Childhood overweight and obesity have become major global health problems and are negatively related with the cardiorespiratory fitness (CRF) level in school children and adolescents. Exercise, specifically multicomponent training, is effective for CRF improvement, but the main challenge is to ensure adherence to exercise in children with overweight and obesity. Therefore, new ways of exercising that are more attractive and motivational for this population are needed and playing or training with active video games (AVGs) has been proposed as an effective alternative because they require full-body movement and therefore increase energy expenditure.

Objective

The main aim of this study was to investigate the effects of an AVG intervention combined with multicomponent training on CRF at maximal and submaximal intensities in children with overweight or obesity.

Methods

We recruited 28 children (13 girls and 15 boys) aged 9 to 11 years with overweight or obesity from medical centers and divided them into 2 groups, an intervention group (n=20) that participated in a 5-month supervised AVG exercise program combined with multicomponent exercise, and a control group (n=8) that continued daily activities without modification. A maximal stress test to measure CRF using a walking-graded protocol with respiratory gas exchange was performed by the participants.

Results

The AVG group showed a significant decrease in heart rate and oxygen uptake for the same intensities in the submaximal stages of the maximal treadmill test, as well as a lower oxygen uptake percentage according to the individual maximal oxygen uptake, whereas the control group did not show overall changes. No change in the peak oxygen uptake (VO_2peak) was found.

Conclusions

A 5-month AVG intervention combined with multicomponent exercise had positive effects on CRF at submaximal intensity, showing a lower heart rate and oxygen uptake at the same intensities and displaying a lower oxygen uptake percentage according to the individual (VO_2peak). Greater benefits were found in children with the highest fat percentage.

Trial Registration

ClinicalTrials.gov NCT04418713; https://clinicaltrials.gov/show/NCT04418713