Relative handgrip strength, nutritional status and abdominal obesity in Chilean adolescents

Examining the mediating role of muscle quantity in adolescents: associations with adiposity, cardiorespiratory fitness, muscular fitness, and cardiometabolic risk factors

The aim of this study was to evaluate the mediation role of muscle quantity in the relationship between physical fitness and cardiometabolic risk factors (CMRF) in adolescents. This cross-sectional study conducted with 120 adolescents of both sexes, aged between 10 and 17 years. Body mass, height, fat mass (FM), lean mass, blood pressure, high-density lipoprotein, low-density lipoprotein, triglycerides, glucose, insulin, cardiorespiratory fitness (CRF) and 1 repetition maximum strength (1-RM) with evaluation of the leg press 45° (RM-leg), bench press (RM-bench) and arm curl (RM-arm). Body mass index z-score, appendicular skeletal muscle mass, appendicular skeletal muscle mass index, lean mass index (LMI), muscle-to-fat ratio (MFR), age at peak height velocity, and CMRF z-score were calculated. The direct relation between FM and CMRF was mediated by the LMI (26%) and inverse relation between CRF and CMRF was mediated by the LMI (26%). For girls, the direct relation between FM and CMRF was mediated by the LMI (32%); the inverse relation between CRF, RM-leg, RM-arm and CMRF was mediated by the LMI (32%, 33%, and 32%, respective). For boys, the indirect effect was not significant, indicating that LMI is not a mediator in the relation between FM, CRF, 1-RM with CMRF. The direct relation between RM-leg and CMRF was mediated by the MRF (16%). This finding evidenced the importance of promoting a healthy lifestyle to improve physical fitness levels and the quantity of muscle mass in adolescents.

Predictive value of Global Leadership Initiative on Malnutrition criteria combined with handgrip strength for postoperative outcomes in overweight colorectal cancer patients

BACKGROUND AND AIM

The Global Leadership Initiative on Malnutrition (GLIM) criteria are increasingly used to assess the nutritional status of hospitalized patients and predict the prognosis of patients with malignant tumors; however, malnutrition is often overlooked in overweight individuals, such as colorectal cancer patients. This study aimed to investigate the predictive value of the GLIM criteria combined with handgrip strength (HGS) in overweight colorectal cancer patients.

METHODS

This retrospective study enrolled overweight patients who underwent radical resection for colorectal cancer at two centers between 2015 and 2021. Malnutrition was diagnosed based on the GLIM criteria. Skeletal muscle mass was assessed using the skeletal muscle index, and skeletal muscle function was assessed using the HGS test. The risk factors for complications and survival were also evaluated.

RESULTS

A total of 850 patients were enrolled in the study. The incidence of malnutrition in the GLIM and HGS-GLIM groups was 12.4% and 6.4%, respectively. The incidence of total complications in both the malnutrition groups was significantly higher than that in the control group. Patients in the HGS-GLIM-malnutrition group had worse overall survival and disease-free survival. HGS-GLIM was independently associated with postoperative complications (P = 0.046), overall survival (P = 0.037), and disease-free survival (P = 0.047).

CONCLUSION

The GLIM criteria combined with the HGS test is an effective tool for diagnosing malnutrition. Particularly, these modalities are applicable in overweight colorectal cancer patients. Compared with the standard GLIM criteria, this tool has a better predictive value for postoperative complications and long-term survival.

Higher handgrip strength is linked to higher salience ventral attention functional network segregation in older adults

Converging evidence suggests that handgrip strength is linked to cognition in older adults, and this may be subserved by shared age-related changes in brain function and structure. However, the interplay among handgrip strength, brain functional connectivity, and cognitive function remains poorly elucidated. Hence, our study sought to examine these relationships in 148 community-dwelling older adults. Specifically, we examined functional segregation, a measure of functional brain organization sensitive to ageing and cognitive decline, and its associations with handgrip strength and cognitive function. We showed that higher handgrip strength was related to better processing speed, attention, and global cognition. Further, higher handgrip strength was associated with higher segregation of the salience/ventral attention network, driven particularly by higher salience/ventral attention intra-network functional connectivity of the right anterior insula to the left posterior insula/frontal operculum and right midcingulate/medial parietal cortex. Importantly, these handgrip strength-related inter-individual differences in salience/ventral attention network functional connectivity were linked to cognitive function, as revealed by functional decoding and brain-cognition association analyses. Our findings thus highlight the importance of the salience/ventral attention network in handgrip strength and cognition, and suggest that inter-individual differences in salience/ventral attention network segregation and intra-network connectivity could underpin the handgrip strength-cognition relationship in older adults.

Differences in Physical Activity, Sedentary Behavior, Health-Related Physical Performance Indices and Academic Achievement: A Comparative Study of Normal-Weight and Obese Children in Qatar

Background: The relationship between physical activity (PA), health-related physical performance (PP), and academic achievement (AA) plays an important role in childhood. This study examined the differences in PA, sedentary behavior, health-related PP, maturity status, and AA between normal-weight and obese school children in Qatar. Methods: Eighty schoolchildren were recruited (age: 12.1 ± 0.6 years). Based on age-specific BMI percentiles, the children were classified as normal weight (n = 40) or obese (n = 40). Moore's equations were used to estimate their maturity status (PHV). The measurements encompassed anthropometric data as well as PP tests (medicine ball throw, postural stability, handgrip strength). AA was assessed by reviewing school records for grade point average in Mathematics, Science, and Arabic courses. The total amount of time spent participating in PA each week was calculated using the International Physical Activity Questionnaire Short Form. Results: Handgrip strength was the only parameter that showed a relevant group difference (p < 0.001, ηp2 = 0.15; normal weight: 19.7 ± 3.46 N; obese: 21.7 ± 2.80 N). We found only one moderate correlation between PHV and handgrip strength (r = 0.59). Conclusions: The findings suggest that obesity status alone might not serve as a sufficient predictor of AA in school or PA levels.

Health-related physical fitness, physical activity and its correlates among school going adolescents in hilly state in north India: a cross sectional survey

INTRODUCTION

Health-related physical fitness, which includes body composition, cardiorespiratory fitness, muscular endurance, flexibility, power, and strength are associated with risks of chronic diseases and promote good health and wellness. There have been reports of increasing levels of physical inactivity among children and adolescents, leading to increasing rates of obesity and decreased physical fitness. The present study was conducted among school going adolescents to estimate the levels and correlates of PF for timely intervention.

METHODOLOGY

School based cross-sectional study was done among students of class 8-11th in Government schools of Garhwal division of Uttarakhand. Multistage stratified random sampling was applied for recruitment of study participants. We recruited a final sample size of 634 students. Validated questionnaires and standard methods for assessment of physical fitness, physical activity levels and other variables such as waist circumference, hip circumference, BMI and hemoglobin estimation were done.

RESULTS

Average and above average cardiorespiratory fitness score as per Harvard step test among boys (54.3%) was significantly higher as compared to girls (21.3%) (χ2 = 88.93, p < 0.001). There was a significant association between gender and dominant handgrip strength (χ2 = 8.02, p = 0.01) as well as between gender and Shoulder stretch test (SST) of dominant (χ2 = 17.5, p < 0.05) as well as nondominant arm (χ2 = 13.5, p < 0.05). Sit and reach test results also showed a significant association with gender (χ2 = 27.17, p < 0.001). Gender, hemoglobin level, BMI and PAL scores significantly predicted cardiorespiratory fitness scores (R2 = 0.188, F value of the model = 37.69, p =< 0.001)).

CONCLUSION

Physical fitness of school going adolescents in Garhwal division of Uttarakhand was better than other parts of India, with significant gender differences. Physical activity levels (PAL) were poor and are also a significant predictor of physical fitness. More emphasis needs to be paid on the health and fitness of girl students. School based policies to increase PAL among students through innovation and rewards may go a long way in improving the long-term health of the students.

Bullying Victimization, Real and Perceived Physical Fitness, and Self-Perception Profiles in Middle-School Students with Overweight or Obesity

Bullying victimization has been associated with body weight and physical fitness. In order to compare the prevalence of victimization among adolescents with normal weight or overweight/obesity and to evaluate the association between real or perceived physical fitness and self-perception profiles, a sample of 128 middle-school youths (mean age: 12.2 ± 0.8 years, 61% males) was recruited. The body mass index (BMI) Z score was calculated. Physical fitness was assessed by hand grip strength (HGS), long jump (LJ), and a 3 min step test (3MST). Perceived physical fitness, self-perception profiles (social competence, athletic competence, and physical appearance), and experiences of victimization (teasing about physical appearance, verbal offenses, and exclusion from group activities) were explored using validated questionnaires. Eighty youths (62.5%) showed overweight/obesity. Compared to their counterparts, normal-weight subjects showed lower HGS and perceived muscular strength; higher LJ and 3MST performance; higher perceived overall fitness, speed and flexibility, and physical appearance. Teasing and verbal offences were more frequent among students with overweight/obesity. Being teased about physical aspects was positively related with the BMI Z score. Exclusion from groups was positively associated with LJ performance. All the types of victimization investigated were inversely related to perceived social competence. These findings suggest that self-perception may protect one from victimization, regardless of nutritional status.

Association of moderate and vigorous physical activity and relative muscle strength with neck circumference: a cross-sectional analysis of the Study of Health in Pomerode (SHIP-Brazil)

OBJECTIVE

Neck circumference is a simple anthropometric measurement that may be linked to chronic diseases, physical activity, and muscle strength. We sought to verify the association of moderate and vigorous physical activity levels and relative muscle strength with neck circumference in a community in southern Brazil.

METHODS

We cross-sectionally analyzed data from 2,488 participants (51% women), aged 20-79 years old from the Study of Health in Pomerode (SHIP-Brazil) conducted in Pomerode, Santa Catarina, Brazil. Increased neck circumference was defined with cutoff points of >39cm for men and >35cm for women. The independent variables were the level of moderate and vigorous physical activity using the short International Physical Activity Questionnaire, and relative muscle strength using the handgrip test and body mass. Univariate and multiple Poisson regression models were used to determine the association between variables (p≤0.05).

RESULTS

The prevalence of increased neck circumference was 48.2% (60.4% in men, 39.6% in women) and was associated with low relative muscle strength (PR=1.26, 95%CI: 1.17-1.35) in men, insufficient moderate and vigorous physical activity levels (PR=1.23, 95%CI: 1.14-1.32), and relative muscle strength (PR=1.73, 95%CI: 1.61-1.87) in women. After adjusting for covariates, no significant associations were observed between insufficient moderate and vigorous physical activity levels in men (PR=1.02, 95%CI: 0.95-1.07).

CONCLUSION

Increased neck circumference seems to be an important predictor of low moderate and vigorous physical activity and relative strength loss in adults, and more pronounced in women.

Muscle Quality Index in Morbidly Obesity Patients Related to Metabolic Syndrome Markers and Cardiorespiratory Fitness

BACKGROUND

Muscle quality index (MQI) is an emerging health indicator obtained by dividing handgrip strength by body mass index (BMI) that needs to be studied in morbidly obese patients (defined by BMI ≥ 35 kg/m²).

OBJECTIVE

To determine the association between MQI, metabolic syndrome (MetS) markers, and cardiorespiratory fitness (CRF), and as a second objective to determine the potential mediation role of MQI in the relationship between abdominal obesity and systolic blood pressure (SBP) in this sample.

METHODS

This cross-sectional study included 86 severely/morbidly obese patients (age = 41.1 ± 11.9 y, nine men). MQI, metabolic syndrome markers, CRF, and anthropometric parameters were measured. Two groups were developed according to MQI; High-MQI (n = 41) and Low-MQI (n = 45).

RESULTS

The Low-MQI group reported higher abdominal obesity (High-MQI: 0.7 ± 0.1 vs. Low-MQI: 0.8 ± 0.1 WC/height; p = 0.011), SBP (High-MQI: 133.0 ± 17.5 vs. Low-MQI: 140.1 ± 15.1 mmHg; p = 0.048), and lower CRF (High-MQI; 26.3 ± 5.9 vs. Low-MQI; 22.4 ± 6.1 mL/kg/min, p = 0.003) than the High-MQI group. Waist-to-height ratio (β: -0.07, p = 0.011), SBP (β: -18.47, p = 0.001), and CRF (β: 5.21, p = 0.011) were linked to MQI. In a mediation model, the indirect effect confirms that MQI is a partial mediator of the association between abdominal obesity with SBP.

CONCLUSIONS

MQI in morbidly obesity patients reported an inverse association with MetS markers and a positive association with CRF (VO2_max). It mediates the relationship between abdominal obesity and SBP.

Sarcopenia in youth

Recent research has revealed causes other than aging that may induce sarcopenia in young people, contrary to the long-studied age-dependent reduction in muscular mass and function. The risk of sarcopenia begins in early adulthood, resulting in exaggerated muscle dysfunction in later life. Despite its clinical significance, research on youth-onset sarcopenia is still in its infancy. Due to a paucity of epidemiologic data and standardized criteria for sarcopenia in youth, determining the prevalence of sarcopenia in the young population remains challenging. Based on the evidence, >1 in every 10 young adults of most ethnicities is estimated to have sarcopenia. This review summarizes the possible etiologies of sarcopenia in young populations, including metabolic syndrome, physical inactivity, inadequate nutrition, inherent and perinatal factors, vitamin D deficiency, endocrinopathy, an imbalance of gut microbiota, neuromuscular diseases, organ failure, malignancy, and other inflammatory disorders. This is the first review of the current knowledge on the importance, prevalence, diagnosis, and causes of sarcopenia in youth.

Physical Fitness Among Adolescents Who are Hispanic With Overweight or Obesity

PURPOSE

To describe cardiorespiratory, strength, muscular endurance, and flexibility fitness outcomes in a sample of adolescents who are Hispanic aged 11 to 15 years with overweight or obesity, stratified by age and sex.

METHODS

The sample included 280 adolescents (mean age: 13.0 ± 0.83 years, mean body mass index percentile: 94.6). Anthropometric measures included height, weight, body mass index percentile, and waist and hip circumference. Fitness measures included handgrip strength, sit-ups in 60 seconds, sit-and-reach test, and 6-minute walk test. We report mean scores for each fitness outcome measure and correlation coefficients with anthropometric measures.

RESULTS

Mean handgrip was 23.7 ± 6.48 kg, sit-and-reach test was 25.3 ± 8.13 cm, average sit-ups in 60 seconds were 19.4 ± 9.28, and 6-minute walk distance was 1960 ± 271 ft. Males outperformed females in all tests except sit-and-reach test.

DISCUSSION

Compared with published fitness values of healthy weight adolescents, our sample of adolescents who are Hispanic with overweight/obesity living in southern Florida is unconditioned in terms of cardiorespiratory fitness, strength, muscular endurance, and flexibility.

The Mediating Role of the Muscle Quality Index in the Relation of Screen Time and Abdominal Obesity with Health-Related Quality of Life in Chilean Schoolchildren

Screen time (ST) and abdominal obesity have a negative effect on health-related quality of life (HRQoL). However, there is little information regarding the mediating role of the muscle quality index (MQI) in these relationships. The aim of the present study was to investigate the association between HRQoL, physical status (i.e., anthropometrics and fitness), lifestyle (i.e., ST and physical activity), and the MQI, and then to determine the potential mediating role of the MQI in the relation of ST and abdominal obesity with HRQoL in Chilean schoolchildren. The cross-sectional study included 750 schoolchildren (girls, n = 332 and boys, n = 418) aged between 10 and 14 years (11.73 ± 1.08 y). MQI, lifestyle, fitness parameters, waist-to-height ratio (WtHR) and HRQoL were measured. HRQoL presented a significant correlation with WtHR (r: -0.19), VO2_max (r: 0.20), physical activity after school (r: 0.26), ST (r: -0.26) and MQI (r: 0.15). According to MQI, the high-MQI group reported higher HRQoL than the low-MQI group (low MQI: 36.10 ± 3.63 vs. high MQI: 37.43 ± 4.00, p < 0.001). In the mediation model, ST and abdominal obesity were negatively linked to HRQoL; the indirect effect confirmed that MQI is a partial mediator in the relation between ST and HRQoL (indirect effect = -0.04; SE = 0.02; 95% CI: -0.09, -0.01) and in the relation between abdominal obesity and HRQoL (indirect effect = -1.81; SE = 0.83; 95% CI: -3.41, -0.40). In conclusion, MQI is related to better HRQoL in schoolchildren, and the negative relation of ST and abdominal obesity with HRQoL is mediated by MQI.

Bioelectrical Impedance Analysis-Derived Phase Angle and Body Composition Are Predictors of Health-Related Fitness in Children and Adolescents with Obesity

There is little evidence in children and adolescents with obesity of the relationships between muscle strength/cardiorespiratory fitness (both components of health-related fitness = HRF) and body composition. Body composition and HRF were studied in 281 children and adolescents with obesity to explore their mutual relationship and to identify the predictors of HRF. By performing a bioelectrical impedance analysis (BIA), the fat-free mass (FFM) and percentage of body fat (%BF) were calculated, and the phase angle (PhA) was recorded. Handgrip strength (HGS), the standard broad jump (SBJ), and five broad jumps (FIVEBJ) were considered for the assessment of muscle strength, and the six-minute walking distance (SIXMWD) for cardiorespiratory fitness. The BMI Z-score was slightly higher in boys, and the %BF was higher in girls, with no difference in the FFM. HGS, the SBJ, and FIVEBJ were greater in the male sex. After controlling for sex, HGS was associated with the FFM, and with height, weight, and absolute BMI. On the contrary, the SBJ and FIVEBJ were negatively associated with adiposity, with a weak relationship with the FFM. The SIXMWD was only poorly related to height, the BMI Z-score, and the waist-to-height ratio. These results were confirmed with a multiple regression analysis. HGS, the SBJ, and FIVEBJ were higher in the first compared to the third tertile of the PhA in both sexes. The PhA also remained a consistent predictor of HGS, the SBJ, and FIVEBJ in a multiple regression analysis. In conclusion, the following predictors have been identified for HRF: the FFM for the isometric strength of the upper limbs and adiposity indicators for the SBJ and FIVEBJ. The PhA emerged as a proxy index of muscle strength.

Elevated Risk of Overweight/Obesity-Related Markers and Low Muscular Fitness in Children Attending Public Schools in Chile

In Chile, children of low socioeconomic status usually attend public schools and have few opportunities to engage in healthy behaviors. This may increase their risk of overweight/obesity and low muscular fitness. Therefore, we aimed to determine the association between the school type attended with overweight/obesity-related markers and the muscular fitness of children in Chile. We included 1410 children (6-13 years old) attending public, subsidized, or private schools. Overweight/obesity-related markers included BMI Z-scores, waist circumference, and body fat percentage. Muscular fitness assessment included handgrip strength and standing long jump. The odds ratios [95% CI] of overweight/obesity, elevated waist circumference, elevated body fat, low handgrip strength, and low standing long jump were compared between school types. Compared with boys attending public schools, those attending subsidized or private schools had lower odds ratios of low handgrip strength (0.63 [0.42-0.94] and 0.44 [0.25-0.78], respectively). Girls attending subsidized schools, compared with those in public schools, had lower odds of overweight/obesity (0.63 [0.44-0.90]) and of having low handgrip strength (0.51 [0.34-0.78]). Compared with girls in public schools, those attending private schools had lower odds (vs. public schools) of overweight/obesity (0.45 [0.28-0.74]), of having elevated body fat (0.53 [0.29-0.96]), and of having low standing long jump (0.41 [0.21-0.77]). The elevated risk of overweight/obesity-related markers and lower muscular fitness in children, particularly girls, attending public schools increase their current and future disease risk. This suggests that childhood socioeconomic status plays a central role in determining disease risk. Health-promoting interventions specifically focused on children from disadvantaged contexts are required.

The consumption of culinary preparations and ultra-processed food is associated with handgrip strength in teenagers

Background

A nutrient-poor and hypocaloric diet may be associated with lower handgrip strength (HGS), whereas a high-quality or balanced diet may be associated with higher HGS. However, no study has used the NOVA system for classifying food by their degree of processing.

Objective

To analyze the association between food consumption according to the degree of food processing and HGS in Brazilian teenagers.

Methods

This cross-sectional study included teenagers aged 18 and 19 years old from the 1997/98 São Luís’ birth cohort, Maranhão, Brazil. HGS (kilogram-force) was measured via a Jamar Plus + dynamometer. Food consumption was assessed using a semiquantitative food frequency questionnaire. The energy intake of culinary preparations (unprocessed or minimally processed food and processed culinary ingredients), processed, and ultra-processed foods was evaluated in percentages and categorized in tertiles. The associations between each food group intake and HGS was estimated via crude and adjusted linear regression models. A directed acyclic graph was used to identify confounding factors.

Results

We evaluated 2,433 teenagers, 52.1% of which were girls. For boys, adjusted analysis showed an association between the highest HGS and the 3^rd tertile of culinary preparation consumption (β: 1.95; 95%CI: 0.80; 3.10) and between the lowest HGS and the 3^rd tertile of ultra-processed food consumption (β: -2.25; 95%CI: -3.40; -1.10). Among girls, the consumption of culinary preparations in the 3^rd tertile was associated with higher HGS (β: 0.76; 95%CI: 0.05; 1.46).

Conclusions

Higher consumption of culinary preparations and lower consumption of ultra-processed foods can contribute to reduce the chance of lower HGS in adult life. Interventions to promote the development and preservation of muscle strength should include dietary recommendations.

Associations of muscle-strengthening exercise with overweight, obesity, and depressive symptoms in adolescents: Findings from 2019 Youth Risk Behavior Surveillance system

Background

Previous studies have focused on the opposite relation between muscle strength, obesity, and depression in adults. Moreover, the evidence has indicated that obesity and depression in adults might be significantly decreased with Muscle Strength Exercise (MSE) albeit it might be insufficient. Therefore, the current study aimed to investigate the association between MSE, adiposity, and depression among United States adolescents.

Materials and methods

This cross-sectional study used the Youth Risk Behavioral Survey (YRBS) data. In YRBS, a cluster sample was used, and the investigation was divided into three stages. The study surveyed 13,677 high school students and conducted self-reported questionnaires on sex, grade, race/ethnicity, MSE days, overweight, obesity, and depressive symptoms. The study got the nationally representative population of American students in Grade 9 to 12 (around 12–18 years).

Results

A total of 13,677 participants (female = 6,885, male = 6641) were included in the final analysis. The participants meeting the guidelines’ requirements seemed more likely to be obese than those not meeting (OR = 1.28, 95% CI = 1.06–1.55). There was no statistical significance in the relations between the MSE guidelines and overweight and depression (OR = 0.86, 95% CI = 0.73–1.01: OR = 0.94, 95% CI = 0.83–1.06). For all the participants, the prevalence of those conforming to MSE was 30.1%. One-fifth of the participants reported no MSE per week, 7.8% reported 3 days of MSE per week, and 7.7% reported 7 days.

Conclusion

The main finding of this study indicated a positive relationship between the normative MSE required in guidelines and low-level obesity. Beyond that, the evidence was insufficient to confirm the positive links between MSE and depression among American adolescents. Our study could offer evidence for future MSE interventions in adolescents.

Are Fat Mass and Lean Mass Associated with Grip Strength in Adolescents?

Background: The interaction between lean body mass (LBM) and fat mass index (FMI) with grip strength (GS) has not been explored in the same analysis model in adolescents. This study thus aims to analyze the association between FMI and LBM with GS. Methods: This cross-sectional study was conducted with data from the 2016 follow-up of the 1997/98 Birth Cohort of São Luís. Grip strength was assessed by the Jamar Plus + dynamometer. The LBM and FMI indexes were assessed [ratio of the mass (lean or fat-kg) to height (m2)]. The confounding variables identified for the relationship between FMI and LBM with GS in the same analysis model, by directed acyclic graph (DAG), were sex, age, race, work, alcohol consumption, smoking, physical activity, and consumption of ultra-processed foods and culinary preparations, used in the adjusted analysis. Results: A total of 2339 adolescents (52.5% girls) were analyzed. The boys have a higher GS than the girls. In the adjusted analysis, with each increase of 1 kg/m2 in the FMI, GS was reduced by 0.72 kgf for boys and 0.35 kgf for girls. At each increase of 1 kg/m2 in the LBM, GS increased by 2.18 kgf for boys and 1.26 kgf for girls. Conclusions: FMI was associated with lower GS regardless of the LBM. LBM was associated with higher GS regardless of the FMI.

Sarcopenic Obesity in Children and Adolescents: A Systematic Review

Sarcopenic obesity (SO) is defined as co-occurrence of increased fat mass and sarcopenia and may predict adverse health outcomes in the pediatric population. However, the prevalence of SO and its association with adverse health outcomes have not been well defined in children and adolescents. We systematically reviewed data on the SO definition, prevalence, and adverse outcomes in the pediatric population. A total of 18 articles retrieved from PubMed or Web of Science databases were included. Overall, there was a wide heterogeneity in the methods and thresholds used to define SO. The prevalence of SO ranged from 5.66% to 69.7% in girls, with a range between 7.2% and 81.3% in boys. Of the 8 studies that evaluated outcomes related to SO, all showed a significant association of SO with cardiometabolic outcomes, non-alcoholic fatty liver disease (NAFLD) severity, inflammation, and mental health. In conclusion, this review found that SO is highly prevalent in children and adolescents and is associated with various adverse health outcomes. Findings of this review highlight the need for the development of a consensus regarding definition, standardized evaluation methods, and age and gender thresholds for SO for different ethnicities in the pediatric population. Further studies are needed to understand the relationship between obesity and sarcopenia and SO impact on adverse health outcomes in children and adolescents.

Muscular Fitness and Cardiometabolic Variables in Children and Adolescents: A Systematic Review

BACKGROUND

The importance of muscular fitness (MF) in the performance of activities of daily living is unequivocal. Additionally, emerging evidence has shown MF can reduce cardiometabolic risk in children and adolescents.

OBJECTIVES

The purpose of this study was to examine and summarize the evidence regarding the relationship between MF phenotypes (i.e., maximum muscular strength/power, muscular endurance, and maximum muscular strength/power/endurance) and cardiometabolic variables (obesity, blood pressure, lipids, glucose homeostasis, inflammatory markers, and clustered cardiometabolic variables) in children and adolescents.

DESIGN

This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and was registered with PROSPERO, number CRD42020179273.

DATA SOURCES

A systematic review was performed on five databases (PubMed, EMBASE, SciELO, Scopus, and Web of Knowledge) from database inception to May 2020, with complementary searches in reference lists.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Eligibility criteria included (1) a study sample of youth aged ≤ 19 years, (2) an assessment of MF with individual or clustered cardiometabolic variables derived from adjusted models (regardless of test/measurement adopted or direction of reported association), and (3) a report of the association between both, using observational studies. Only original articles published in peer-reviewed journals in English, Portuguese, and Spanish languages were considered. The quality of the included studies was assessed by using the National Heart, Lung, and Blood Institute checklist. The percentage of results reporting a statistically significant inverse association between each MF phenotype and cardiometabolic variables was calculated.

RESULTS

Of the 23,686 articles initially identified, 96 were included (77 cross-sectional and 19 longitudinal), with data from children and adolescents from 35 countries. The score for the quality of evidence ranged from 0.33 to 0.92 (1.00 maximum). MF assessed by maximum muscular strength/power was inversely associated with lower obesity (64/113 total results (56.6%)) and reduction in clustered cardiometabolic risk (28/48 total results (58.3%)). When assessed by muscular endurance, an inverse association with obesity (30/44 total results (68.1%)) and cardiometabolic risk (5/8 total results (62.5%)) was identified. Most of the results for the relationship between MF phenotypes with blood pressure, lipids, glucose homeostasis, and inflammatory markers indicated a paucity of evidence for these interrelationships (percentage of results below 50.0%).

CONCLUSION

MF assessed by maximum muscular strength/power or muscular endurance is potentially associated with lower obesity and lower risk related to clustered cardiometabolic variables in children and adolescents. There is limited support for an inverse association between MF with blood pressure, lipids, glucose homeostasis biomarkers, and inflammatory markers in children and adolescents.

Health Risks of Sarcopenic Obesity in Overweight Children and Adolescents: Data from the CHILT III Programme (Cologne)

Sarcopenic obesity is increasingly found in youth, but its health consequences remain unclear. Therefore, we studied the prevalence of sarcopenia and its association with cardiometabolic risk factors as well as muscular and cardiorespiratory fitness using data from the German Children’s Health InterventionaL Trial (CHILT III) programme. In addition to anthropometric data and blood pressure, muscle and fat mass were determined with bioelectrical impedance analysis. Sarcopenia was classified via muscle-to-fat ratio. A fasting blood sample was taken, muscular fitness was determined using the standing long jump, and cardiorespiratory fitness was determined using bicycle ergometry. Of the 119 obese participants included in the analysis (47.1% female, mean age 12.2 years), 83 (69.7%) had sarcopenia. Affected individuals had higher gamma-glutamyl transferase, higher glutamate pyruvate transaminase, higher high-sensitivity C-reactive protein, higher diastolic blood pressure, and lower muscular and cardiorespiratory fitness (each p < 0.05) compared to participants who were ‘only’ obese. No differences were found in other parameters. In our study, sarcopenic obesity was associated with various disorders in children and adolescents. However, the clinical value must be tested with larger samples and reference populations to develop a unique definition and appropriate methods in terms of identification but also related preventive or therapeutic approaches.

Association between Relative Handgrip Strength and Chronic Lower Back Pain: A Nationwide Cross-Sectional Analysis of the Korea National Health and Nutrition Examination Survey

Lower back pain (LBP) is the most common musculoskeletal complaint and significantly reduces the quality of life. Muscle weakness is a major cause of LBP. Handgrip strength (HGS) is widely used to determine general muscle strength. Relative HGS (RHGS) incorporates body mass and provides a more accurate estimation of muscle strength and health status. We analyzed the data from Korea National Health and Nutrition Examination Survey to investigate the association between RHGS and chronic LBP. We identified 14,930 participants and excluded a total of 9553 participants with age < 50 years, with incomplete LBP information, and with incomplete HGS information. We analyzed the data of 5377 participants: 1086 (20.19%) with chronic LBP and 4291 (79.8%) without chronic LBP. Multivariate regression analysis with adjustment for covariates identified an association between weak RHGS and chronic LBP (odds ratio 1.31; CI 1.07-1.61; p = 0.01). This article demonstrated a significant association between RHGS and chronic LBP. Therefore, RHGS should be measured for patients with chronic LBP.

Muscular Strength of Upper and Lower Limbs and Self-Esteem in Chilean SchoolChildren: Independent Associations with Body Composition Indicators

The aim of this study was to analyze the relationship between muscular strength from upper and lower limbs with self-esteem among Chilean schoolchildren, drawing independent associations with body composition indicators. The sample consisted of 1078 schoolchildren. The muscular strength of the upper and lower limbs was evaluated using a digital dynamometer and long jump performance. The general strength index was calculated based on Z-score values. Rosenberg’s test was used to determine the level of self-esteem of participants. Body fat and body mass index were employed as body composition indicators. Boys had significantly more upper and lower strength, and a general strength index higher than girls (11.7 vs. 10.6; 109.7 vs. 97.4; 0.19 vs. −0.24, respectively). For boys and girls combined, there were no significant associations between all muscular strength variables and self-esteem. In boys, upper and lower limb strength was positively associated with self-esteem. In girls, no association between muscular strength and self-esteem was found. In both sexes, the general strength index was not associated with self-esteem. Strategies and programs that promote mental health and muscular strength among schoolchildren, specifically in boys, are needed.