Low Muscle Strength Thresholds for the Detection of Cardiometabolic Risk in Adolescents

Effect of Yoga or Physical Exercise on Muscle Function in Rural Indian Children: A Randomized Controlled Trial

BACKGROUND

Synergistic effects of yoga or physical exercise (PE) along with protein supplementation on children's muscle function in rural India have not been studied. Hence, we aimed to study the effect of yoga and PE along with protein supplementation on muscle function in healthy 6- to 11-year-old rural Indian children post 6 months of intervention.

METHODS

A randomized controlled trial on 232 children, recruited into 3 groups, each receiving 1 protein-rich ladoo (148 kcal, 7 g protein/40 g ladoo-an Indian sweet snack) daily and performing (1) yoga (n = 78) for 30 minutes 5 times per week, (2) PE (n = 76) for 30 minutes 5 times per week, or (3) control group (n = 78) no additional exercise. Maximum power, maximum voluntary force (Fmax), and grip strength (GS) were measured. Data were analyzed using paired t tests and a 2-way mixed analysis of variance with post hoc Bonferroni adjustment.

RESULTS

GS, maximum power, and Fmax within yoga group increased significantly (P < .05) from baseline to endline. GS and Fmax increased significantly within PE group postintervention (P < .001). In controls, GS increased (P < .05) at endline. No significant effect of the intervention was observed on the change in maximum power (P > .05) postintervention. The 2 exercise groups showed significant increase in Fmax compared with the control group (P < .05). Similarly, increase in GS was significantly higher in both the exercise groups compared with the control group (P < .05). No significant difference was observed in change in muscle function between the 2 exercise groups (P > .05).

CONCLUSIONS

Structured physical activity along with protein supplementation resulted in improved muscle function in children. Yoga and PE showed a comparable impact on muscle force.

Lifelong Fitness in Ambulatory Children and Adolescents with Cerebral Palsy I: Key Ingredients for Bone and Muscle Health

Physical activity of a sufficient amount and intensity is essential to health and the prevention of a sedentary lifestyle in all children as they transition into adolescence and adulthood. While fostering a fit lifestyle in all children can be challenging, it may be even more so for those with cerebral palsy (CP). Evidence suggests that bone and muscle health can improve with targeted exercise programs for children with CP. Yet, it is not clear how musculoskeletal improvements are sustained into adulthood. In this perspective, we introduce key ingredients and guidelines to promote bone and muscle health in ambulatory children with CP (GMFCS I-III), which could lay the foundation for sustained fitness and musculoskeletal health as they transition from childhood to adolescence and adulthood. First, one must consider crucial characteristics of the skeletal and muscular systems as well as key factors to augment bone and muscle integrity. Second, to build a better foundation, we must consider critical time periods and essential ingredients for programming. Finally, to foster the sustainability of a fit lifestyle, we must encourage commitment and self-initiated action while ensuring the attainment of skill acquisition and function. Thus, the overall objective of this perspective paper is to guide exercise programming and community implementation to truly alter lifelong fitness in persons with CP.

Assessment of Balance Parameters in Children with Weakened Axial Muscle Tone Undergoing Sensory Integration Therapy

Children with weakened axial muscle tone face various problems every day. One is maintaining a stable body posture, which limits their participation in activities and games with peers. The study aimed to assess balance parameters in children with weakened axial muscle tone who underwent sensory integration therapy (SI). The study group consisted of 21 children (divided into three age groups) referred by a doctor for therapy.

METHODS

The ZEBRIS platform was used to measure the balance parameters (MCoCx, MCoCy, SPL, WoE, HoE, and AoE). The study was conducted twice: before and after two months of sensory integration therapy. The results were compiled using the TIBICO^® Statistica software version 13.3.0.

RESULTS

After the SI program, statistically significant changes were observed in the values of MCoCy_oe, WoE_oe, AoE_oe in the group of four-year-olds, MCoCX_ce in the group of five-year-olds, and in SPL_ce and AoE_ce in six-year-olds. A statistically significant, highly positive correlation was observed between body height and changes in SPL_oe, HoE_oe, and AoE_oe in the group of six-year-olds, as well as in the case of changes in SPL_oe in the group of five-year-olds. In the group of four-year-olds, a statistically significant correlation occurred only between body height and the change in the MCoCx_oe value.

CONCLUSIONS

the sensory integration therapy used in the study group of 4-6-year-old children with reduced muscle tone gave positive results in the form of improved static balance and balance.

Muscle Wasting among Hospitalized Children: A Narrative Review of the Feasibility and Accuracy of Diagnostic Methods

Muscle wasting is associated with a worse quality of life and increased morbidity and mortality among hospitalized children, especially those with chronic diseases. This review was conducted to summarize the data available on the most feasible and accurate diagnostic methods for detecting muscle wasting among hospitalized children, especially to review the evidence of the accuracy and feasibility of conducting assessments using handgrip strength (HGS). Many diagnostic methods are used in hospital settings to assess muscle wasting, by evaluating either muscle mass or strength, with evidentiary support for assessing muscle mass provided using ultrasonography, magnetic resonance imaging, computed tomography, dual-energy X-ray, bioelectrical impedance analysis, and anthropometry measurements. Currently, the most common diagnostic method used to detect muscle strength loss is the handheld dynamometer. Studies support using HGS among healthy and hospitalized children to assess the overall nutritional status and especially muscle function. However, almost all of these studies have been conducted in hospital settings and recruited children with different chronic diseases using a small sample size. More longitudinal cohort studies with large sample sizes are needed to assess the accuracy and feasibility of using HGS among hospitalized children.

C-reactive protein, but not neutrophil-lymphocyte ratio, is inversely associated with muscle strength only in older men: NHANES 1999-2002

To evaluate the association of inflammation (C-reactive protein (CRP) and neutrophil-lymphocyte ratio (NLR) levels) with muscle strength in older adults. We also aimed to evaluate whether these associations are sex-specific. A cross-sectional study was performed with data from the National Health and Nutrition Examination Survey (NHANES) 1999-2000 and 2001-2002. A total of 2387 individuals over 50 years of both sexes were evaluated, according to the eligibility criteria for the strength test. Muscle strength was measured by Kinetic Communicator isokinetic dynamometer; while the NLR was obtained by the ratio of the total neutrophil for lymphocyte count and CRP was quantified by latex nephelometry. Linear regression analyses, crude and adjusted for confounders, were used to estimate the coefficients and 95 % confidence intervals for peak strength (muscle strength) by tertiles of NLR and CRP. There was no association between NLR and peak strength for both sexes. CRP levels were inversely associated with peak force in men [2nd tertile β = -3.33 (-15.92; 9.25); 3rd tertile β = -24.69 (-41.18; -8.20), p for trend = 0.005], but not in women [2nd tertile β = -3.22 (-15.00; 8.56); 3rd tertile β = -9.23 (-28.40; -9.94), p for trend = 0.332]. In conclusion, NLR levels were not associated with muscle strength in both sexes. CRP levels were inversely associated with muscle strength in older men, but not in women, suggesting that the association between inflammation and muscle strength in older adults can be sex-specific.

Physical Function of Japanese Preadolescents during the COVID-19 Pandemic

Children's exercise habits have changed during the COVID-19 pandemic. This study aimed to examine the physical function and physical activity of preadolescent children before and during the COVID-19 pandemic. This cross-sectional study compared time spent in moderate-to-vigorous physical activity (MVPA), grip strength, single-leg standing time, and two-step tests of healthy children aged 10 to 12 years, enrolled from January 2018 to January 2020 (pre-COVID-19 group, n = 177) and from January 2021 to September 2022 (during-COVID-19 group, n = 69). The during-COVID-19 group had weaker grip strength (median: 14.4 vs. 15.8 kg; p = 0.012), worse performance on the two-step test (mean: 1.56 vs. 1.60; p = 0.013), and less MVPA (median: 4 vs. 7 h per week; p = 0.004). Logistic regression showed that the during-COVID-19 group was significantly related to weaker grip strength (odds ratio: 0.904, 95% CI: 0.829-0.986; p = 0.022) and worse performance in the two-step test (odds ratio: 0.976, 95% CI: 0.955-0.997; p = 0.028). The COVID-19 pandemic decreased exercise opportunities for preadolescent children, which may have had a negative impact on muscle strength and balance. It is essential to increase the amount of MVPA among preadolescent children.

Exposure to mixture of heavy metals and muscle strength in children and adolescents: a population-based study

Human beings are exposed to heavy metals through various ways in daily life. However, the effect of heavy metal mixtures on muscle strength in children and adolescents remains unclear. We aimed to investigate the relationship of exposure to heavy metal mixtures (barium, cadmium, cobalt, manganese, molybdenum, lead, antimony, strontium, tin, thallium, tungsten, uranium, and cesium) with muscle strength in children and adolescents. A total of 1357 (boys, 50.8%) participants aged between 8 and 17 were extracted from the National Health and Nutrition Examination Surveys 2011-2014. Urine metals were measured by inductively coupled plasma-mass spectrometry. Muscle strength was measured through a grip test using a handgrip dynamometer. Weighted quantile sum regression was performed to estimate the mixture effect of urinary metals on muscle strength. After adjusting for potential confounders, comparing participants in the highest versus lowest quartiles of cobalt, molybdenum, lead, antimony, strontium, thallium, and cesium, the handgrip strength decreased by - 4.48 kg (95% CI: - 6.93, - 2.03), - 6.13 kg (- 8.76, - 3.51), - 2.26 kg (- 4.22, - 0.30), - 2.38 kg (- 4.68, - 0.08), - 2.29 kg (- 4.45, - 0.13), - 4.78 kg (- 7.13, - 2.44), and - 5.68 kg (- 9.20, - 2.17), respectively. Furthermore, exposure to a mixture of metals were also significantly associated with decreased muscle strength (β: - 2.62 kg; 95% CI: - 3.71, - 1.54). Findings from the present study suggest that higher heavy metal exposure and the exposure levels of a mixture of metals in urine are inversely related to handgrip strength, implying that children's grip strength is not entirely explained by energy intake or lack of exercise, but may be related to environmental pollutants.

Cross-sectional association between physical fitness and cardiometabolic risk in Chilean schoolchildren: the fat but fit paradox

BACKGROUND

Previous studies have examined the "fat but fit" paradox, revealing that greater levels of physical fitness may diminish the harmful consequences of excess weight on cardiometabolic risk. Despite the above, specific information about the "fat but fit" paradox in prepuberal population is scarce. The aim of this study was to determine the relationship between cardiometabolic risk across (individual and combined) physical fitness and excess weight status and whether the "fat but fit" paradox is met in the sample of schoolchildren analyzed.

METHODS

A cross-sectional study was conducted including 452 children (59.1% girls), aged 7-9 years from Santiago (Chile). Physical fitness was assessed as cardiorespiratory fitness and muscular fitness. Cardiorespiratory fitness was determined by the 6-minute-walk-test and muscle strength was assessed by the handgrip and standing long jump tests. Excess weight (overweight and obesity) was computed through body mass index (z-score). Cardiometabolic risk was established by summing the z-score of the serum glucose, triglycerides, high-density lipoprotein, insulin and waist-to-height ratio.

RESULTS

Schoolchildren with high physical fitness (individual or combined) showed the lowest cardiometabolic risk mean scores (P for trend <0.001 for all physical fitness groups). Conversely, schoolchildren with low physical fitness (individual or combined) showed the highest cardiometabolic risk mean scores (P for trend <0.001 for all categories). Additionally, schoolchildren without excess weight and with high individual or combined physical fitness status exhibits lower cardiometabolic risk mean scores compared to schoolchildren with excess weight and low physical fitness status (individual or combined) (P for trend <0.001 for all physical fitness groups). A lower odd of having high cardiometabolic risk was found in schoolchildren without excess weight and with both high physical fitness (both cardiorespiratory fitness and muscular fitness) [odds ratio (OR) =0.08; 95% confidence interval (CI): 0.04 to 0.16] in comparison to those with excess weight and low physical fitness.

CONCLUSIONS

Our results suggest that improvements in both fatness and aerobic fitness could be associated with lower cardiometabolic risk.

Isometric strength of upper limb muscles in youth using hand-held and hand-grip dynamometry

The present study aimed to determine the isometric strength profile of the upper limb muscles of children and adolescents between 7–15 years of age. Furthermore, to (a) identify the age at which differences in strength are observed between sexes; to (b) determine the age range at which significant progression of strength could be observed; and (c) identify the role of each muscle on the total upper limb strength. Cross-sectional study that evaluated the isometric strength of nine muscle groups of the upper limb of 243 Chilean children, split into 9 age groups, separated by 1-year intervals. For this, hand-held dynamometry and hand-grip dynamometry were used. A two-factor analysis of variance for the maximum isometric strength and a stepwise multiple linear regression analysis were performed. From 11 years of age, wrist flexors were the first muscle group that revealed a significant difference in isometric strength in favor of boys (P=0.0143). In boys, the narrowest and earliest age range in the progression of isometric strength was 10 to 12 years for wrist flexors (P=0.0392). Shoulder flexors was the main factor that explained the performance of the total upper limb strength (R²=0.742; P<0.001). The most progressive isometric strength development occurred from age 10 years in the ventral and distal muscles of the upper limb; and from this age the boys begin to present a greater isometric strength than girls. In addition, the isometric strength of shoulder flexors explained the higher total upper limb strength performance.

Is grip strength linked to body composition and cardiovascular risk markers in primary schoolchildren? Cross-sectional data from three African countries

OBJECTIVES

Muscular strength represents a specific component of health-related fitness. Hand grip strength (HGS) is used as an indicator for musculoskeletal fitness in children. HGS can also be used as a marker of cardiometabolic risk, but most available HGS data are derived from Western high-income countries. Therefore, this study examines whether HGS is associated with body composition and markers of cardiovascular risk in children from three sub-Saharan African countries.

DESIGN

Cross-sectional study.

SETTING

Public primary schools (grade 1-4) in Taabo (Côte d'Ivoire), Gqeberha (South Africa) and Ifakara (Tanzania).

PARTICIPANTS

Data from 467 children from Côte d'Ivoire (210 boys, 257 girls), 864 children from South Africa (429 boys, 435 girls) and 695 children from Tanzania (334 boys, 361 girls) were analysed.

PRIMARY AND SECONDARY OUTCOME MEASURES

Body composition (assessed via bioelectrical impedance analysis) was the primary outcome. Cardiovascular risk markers were considered as secondary outcome. Blood pressure was measured with an oscillometric monitor, and blood markers (cholesterol, triglycerides, glycated haemoglobin) via Afinion point-of-care testing. HGS (independent variable) was assessed with a hydraulic hand dynamometer. Inferential statistics are based on mixed linear regressions and analyses of covariance.

RESULTS

Across all study sites, higher HGS was associated with lower body fat, higher muscle mass and higher fat-free mass (p<0.001, 3.9%-10.0% explained variance), both in boys and girls. No consistent association was found between HGS and cardiovascular risk markers.

CONCLUSIONS

HGS assessment is popular due to its simplicity, feasibility, practical utility and high reliability of measurements. This is one of the first HGS studies with children from sub-Saharan Africa. There is a great need for further studies to examine whether our findings can be replicated, to develop reference values for African children, to establish links to other health outcomes, and to explore whether HGS is associated with later development of cardiovascular risk markers.

TRIAL REGISTRATION NUMBER

ISRCTN29534081.

Impact of critical illness and withholding of early parenteral nutrition in the pediatric intensive care unit on long-term physical performance of children: a 4-year follow-up of the PEPaNIC randomized controlled trial

Background

Many critically ill children face long-term developmental impairments. The PEPaNIC trial attributed part of the problems at the level of neurocognitive and emotional/behavioral development to early use of parenteral nutrition (early-PN) in the PICU, as compared with withholding it for 1 week (late-PN). Insight in long-term daily life physical functional capacity after critical illness is limited. Also, whether timing of initiating PN affects long-term physical function of these children remained unknown.

Methods

This preplanned follow-up study of the multicenter PEPaNIC randomized controlled trial subjected 521 former critically ill children (253 early-PN, 268 late-PN) to quantitative physical function tests 4 years after PICU admission in Leuven or Rotterdam, in comparison with 346 age- and sex-matched healthy children. Tests included handgrip strength measurement, timed up-and-go test, 6-min walk test, and evaluation of everyday overall physical activity with an accelerometer. We compared these functional measures for the former critically ill and healthy children and for former critically ill children randomized to late-PN versus early-PN, with multivariable linear or logistic regression analyses adjusting for risk factors.

Results

As compared with healthy children, former critically ill children showed less handgrip strength (p < 0.0001), completed the timed up-and-go test more slowly (p < 0.0001), walked a shorter distance in 6 min (p < 0.0001) during which they experienced a larger drop in peripheral oxygen saturation (p ≤ 0.026), showed a lower energy expenditure (p ≤ 0.024), performed more light and less moderate physical activity (p ≤ 0.047), and walked fewer steps per day (p = 0.0074). Late-PN as compared with early-PN did not significantly affect these outcomes.

Conclusions

Four years after PICU admission, former critically ill children showed worse physical performance as compared with healthy children, without impact of timing of supplemental PN in the PICU. This study provides further support for de-implementing the early use of PN in the PICU.

Trial registration ClinicalTrials.gov, NCT01536275; registered on February 22, 2012.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04010-3.

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.

The Different Effects of Skeletal Muscle and Fat Mass on Height Increment in Children and Adolescents Aged 6-11 Years: A Cohort Study From China

OBJECTIVE

This study aimed to investigate the contribution of body composition including skeletal muscle mass (SMM) and body fat mass (BFM) to longitudinal growth among children and adolescents aged 6-11 years old.

METHODS

This cohort study was conducted from the annual health examination between 2019 and 2020. Annual height gain and weight gain and changes in SMM and BFM were calculated and compared between sexes, different nutritional status, and growth curve shifting mode. Spearman analyses and multiple linear regression analysis were performed to identify the impact of SMM, BFM, or body mass index (BMI) on height gain.

RESULTS

Of the 584 subjects, the annual height gains of boys (4.76 cm in the 6-9-year group and 4.63 cm in the 10-11-year group) were significantly lower than those of girls (5.48 and 5.74 cm, respectively). Spearman analysis showed that SMM gain and height gain were positively and significantly correlated in each examination of all children (r = 0.535 for boys and 0.734 for girls, p < 0.001). Conversely, BFM and height gains were negatively (r = -0.5240 for boys and -0.232 for girls, p < 0.001) correlated. Multiple linear regression analysis identified SMM gain as an independent predictor (95% CI: 1.20,1.44) of height gain after adjusting for age, gender, BMI, BFM gain, and percentage of body fat (PBF).

CONCLUSION

SMM gains, rather than BFM gains, were associated with height gains in children and adolescents aged 6-11 years. Monitoring SMM changes in routine healthcare might motivate children and adolescents to achieve dietary and exercise recommendations, thereby growing taller without gaining excessive weight.

Association of the gut microbiota and fecal short-chain fatty acids with skeletal muscle mass and strength in children

We aimed to investigate whether the gut microbiota and fecal short-chain fatty acids (SCFAs) are associated with skeletal muscle mass and strength in healthy Chinese children aged 6-9 years. In this study, 412 children were enrolled. 16S rRNA gene sequencing was used to characterize the gut microbiota compositions. Fecal SCFAs were quantified using high-performance liquid chromatography. Dual X-ray absorptiometry was used to measure the total body lean soft tissue mass (TSM), total body fat mass (TBF), appendicular skeletal muscle mass (ASM), and appendicular fat mass (AFM). TSM/height² (TSMI), ASM/height² (ASMI), TSM/weight (TSMR), ASM/weight (ASMR), and the ratio of TSM/TBF and ASM/AFM were calculated. Handgrip strength (HGS) was measured using the Jamar® Plus+ Hand Dynamometer. A multiple regression analysis after adjustment for covariates and multiple test correction showed some operational taxonomic units in partial least squares models identified by Multivariate methods with Unbiased Variable selection analysis such as genera of Faecalibacterium, Lachnospira, Lachnospiraceae_ND3007_group, and Lachnospiraceae_UCG-004 were positively correlated with at least one measure of TSM, TSMI, ASM, ASMI, and ASMI Z-score (β: 0.103-0.143, p_FDR : .008-.032) but negatively correlated with at least one measure of TSMR, TSM/TBF, ASMR, ASM/AFM, and ASMR Z-score (β: -0.185 to 0.124, p_FDR  = .008-.045). Children with higher fecal butyric acid, acetic acid, and total SCFA levels exhibited higher TSM, ASM, TSMI, ASMI, and ASMI Z-score and lower TSM/TBF, ASM/AFM, TSMR, ASMR, and ASMR Z-score. However, after additional adjustment for TBF or body mass index, only the associations for Faecalitalea and Pyramidobacter still existed. Mediation analysis suggested that total body fat significantly mediated 66.3%-95.3% of the estimated association of microbiota and SCFAs with TSM, ASM, and ASMI Z-score. Our results suggest that the associations of gut microbiota and SCFAs with skeletal muscle quality in children may largely depend upon on total body fat content.

Handgrip strength cut-off points for early detection of cardiometabolic risk in Chilean children

The aim of this study was to determine whether handgrip strength is associated with cardiometabolic risk in children. The secondary aim was to establish sex-specific handgrip strength cut-off points for early detection of cardiometabolic risk. A total sample of 452 Chilean children (267 girls and 185 boys) aged 7-9 years old was analyzed. Muscle fitness was measured by an adjustable dynamometer and normalized by body mass (i.e., handgrip strength/body mass). Sex-specific cardiometabolic risk scores were computed as the sum of the waist-to-height ratio (Equation 1) or waist circumference (Equation 2) and insulin, triglycerides, high-density lipoproteins, and glycemia levels. Receiver operating curve (ROC) analyses were performed to identify those with cardiometabolic risk scores > 1 standard deviation above the mean. ROC analyses showed a significant discriminating accuracy of normalized handgrip strength in identifying cardiometabolic risk in boys (≤ 0.33) and girls (≤ 0.40) using both equations. The highest sensitivity was offered by Equation 2 for boys [46%; 95% CI (32-59%)] and for girls [71%; 95% CI (60-80)]. The greatest specificity was also offered by Equation 2 for boys [82%; 95% CI (74-88)] and girls [63%; 95% CI (55-70)]. Since the values obtained by ROC analyses are low (especially in boys), caution is warranted regarding the strength of the existing evidence base.Conclusion: These specific cut-off points according to sex for possible cardiometabolic risk could be used by Chilean health professionals and school staff as an initial assessment in the field setting. What is known • There is strong evidence for the importance of muscular fitness during childhood and adolescence for cardiometabolic risk. • There has been no research to establish minimum handgrip strength capacity levels to predict cardiometabolic risk among Chilean children. What is new • Cut-off points for handgrip strength relative to body mass to identify cardiometabolic risk in Chilean children are 0.33 in boys and 0.40 in girls. • The early use of these cut-off points and its appropriate identification could have benefits of preventive and diagnostic therapeutic intervention and as a starting point to define adequate levels of handgrip strength.

Using Body Composition Groups to Identify Children and Adolescents at Risk of Dyslipidemia

The impact of body composition on the early origin of chronic diseases is an increasingly appreciated phenomenon. Little is known about the characteristics of children with varying body composition. The aim of this study was to investigate serum lipid profiles and other characteristics in relation to body composition. The data of 1394 participants (aged 6 to <18 years) of the observational general population-based Austrian LEAD Study have been analyzed. Body composition groups were defined by appendicular lean mass (ALMI) and fat mass (FMI) indices assessed by DXA. Serum lipid profiles (triglycerides, LDL-c, HDL-c) and other characteristics (e.g., prematurity, smoke exposure, physical activity, nutrition) were investigated in these body composition groups. Different body composition groups, which are not distinguishable by BMI, exist. Children with high ALMI and high FMI showed higher triglycerides and LDL-c, but lower HDL-c levels. In contrast, levels did not differ between those with high FMI but low (or normal) ALMI, and other body composition groups. BMI should be interpreted cautiously, and body composition should be measured by more precise techniques. In particular, children and adolescents with high FMI who have concomitantly high ALMI should be followed closely in future studies to investigate whether they are at increased risk of cardiovascular problems.

Hypertension among South African children in disadvantaged areas and associations with physical activity, fitness, and cardiovascular risk markers: A cross-sectional study

Childhood hypertension drives hypertension in later life; hence, assessing blood pressure in children is an important measure to determine current and future cardiovascular health. There is, however, a paucity of childhood blood pressure data, particularly for sub-Saharan Africa. This study explores blood pressure and associations with age, sex, socioeconomic status, physical activity, fitness, and cardiovascular risk markers. In the 'Disease, Activity and Schoolchildren's Health' (DASH) study, a cross-sectional analysis was conducted in disadvantaged neighbourhoods in the Eastern Cape province of South Africa. Assessments included blood pressure, accelerometer-measured physical activity, physical fitness, and cardiovascular risk markers. The study consisted of 785 children (383 boys, 402 girls, M = 12.4±0.9 years). Overall, 18% of the children were classified as hypertensive, while 20% were either overweight/obese, and almost four out of ten children did not meet global daily physical activity recommendations. Hypertensive children were more likely to be overweight/obese, χ² (2,785) = 14.42, p < 0.01, but only if they did not meet physical activity recommendations, χ² (2,295) = 11.93, p < 0.01. Considering the moderating effect which sufficient activity has on the relationship between hypertension and body weight, more emphasis should be placed on early primary health intervention and education strategies.

Muscle weakness is a prognostic indicator of disability and chronic disease multimorbidity

BACKGROUND

The objective of this study was to use nationally-representative data on Americans greater than 50 years of age to determine the association between grip strength and inflammation as independent predictors of incident disability, chronic multimorbidity and dementia.

METHODS

Middle age and older adults (n = 12,618) from the 2006-2008 waves of the Health and Retirement Study with 8-years of follow-up were included. Longitudinal modeling was performed to examine the association between baseline grip strength (normalized to body mass: NGS) and high sensitivity C-reactive protein (hs-CRP) (≥3.0 mg/L) with incident physical disabilities (i.e., ≥2 limitations to activities of daily living), chronic multimorbidity (≥2 of chronic conditions), and dementia.

RESULTS

The odds of incident disability were 1.25 (95% CI: 1.20-1.30) and 1.31 (95% CI: 1.26-1.36) for men and women respectively, for each 0.05-unit lower NGS. The odds of incident chronic multimorbidity were 1.14 (95% CI: 1.08-1.20) and 1.14 (95% CI: 1.07-1.21) for men and women respectively for each 0.05-unit lower NGS. The odds of incident dementia were 1.10 for men (95% CI: 1.02-1.20) for each 0.05-unit lower NGS, but there was no significant association for women. Elevated hs-CRP was only associated with chronic multimorbidity among men (OR = 1.29; 95% CI: 1.00-1.73) and women (OR = 1.60; 95% CI: 1.26-2.02).

CONCLUSIONS

Our findings indicate a robust inverse association between NGS and disability and chronic, multimorbidity in older men and women, and dementia in men. Elevated hs-CRP was only associated with chronic multimorbidity in men and women. Healthcare providers should implement measures of grip strength in routine health assessments and discuss the potential dangers of weakness as well as interventions to improve strength with their patients.

Temporal Trends in the Standing Broad Jump Performance of 10,940,801 Children and Adolescents Between 1960 and 2017

BACKGROUND

The standing broad jump (SBJ) is an excellent functional measure of explosive lower-body strength that is significantly related to health among children and adolescents.

OBJECTIVES

The aim of this study was to estimate national (country-level) and international (pooled global data) temporal trends in SBJ performance for children and adolescents, and to examine the relationships between national trends in SBJ performance and national trends in health-related and socioeconomic/demographic indicators.

METHODS

Data were obtained from a systematic search of studies reporting temporal trends in SBJ performance for 9- to 17-year-olds, and by examining national fitness datasets. Sample-weighted regression models estimated trends at the study/dataset-country-sex-age level, with national and international trends estimated by a post-stratified population-weighting procedure. Pearson's correlations quantified relationships between national trends in SBJ performance and national trends in health-related and socioeconomic/demographic indicators.

RESULTS

Data from 34 studies/datasets were extracted to estimate trends for 10,940,801 children and adolescents from 24 high-, 4 upper-middle-, and 1 low-income countries between 1960 and 2017. Collectively, there was a negligible (per decade) improvement in SBJ performance of 1.73 cm (95% CI 1.71-1.75), 0.99% (95% CI 0.97-1.01) or a standardized effect size of 0.07 (0.07-0.07) over the entire period, with the rate of improvement steady from the 1960s to the 1980s, slowing in the 1990s, before declining. Sex- and age-related temporal differences were negligible. Trends differed between countries, with most countries experiencing declines. National trends in SBJ performance were not significantly related to national trends in health-related and socioeconomic/demographic indicators.

CONCLUSIONS

SBJ performance of children and adolescents has declined since 2000 (at least among most of the countries in this analysis) and is suggestive of a modern decline in functional explosive lower-body strength. Growing recognition of the importance of muscular fitness as a marker of population health highlights the need for continued tracking of temporal trends in SBJ, especially among low- and lower-middle-income countries for which temporal data are lacking.

PROSPERO REGISTRATION NUMBER

CRD42013003657.

A Systematic Analysis of Temporal Trends in the Handgrip Strength of 2,216,320 Children and Adolescents Between 1967 and 2017

OBJECTIVE

To estimate national and international temporal trends in handgrip strength for children and adolescents, and to examine relationships between trends in handgrip strength and trends in health-related and sociodemographic indicators.

METHODS

Data were obtained through a systematic search of studies reporting temporal trends in the handgrip strength for apparently healthy 9-17-year-olds, and by examining large national fitness datasets. Temporal trends at the country-sex-age level were estimated by sample-weighted regression models relating the year of testing to mean handgrip strength. International and national trends were estimated by a post-stratified population-weighting procedure. Pearson's correlations quantified relationships between national trends in handgrip strength and national trends in health-related/sociodemographic indicators.

RESULTS

2,216,320 children and adolescents from 13 high-, 5 upper-middle-, and 1 low-income countries/special administrative regions between 1967 and 2017 collectively showed a moderate improvement of 19.4% (95% CI 18.4-20.4) or 3.8% per decade (95% CI 3.6-4.0). The international rate of improvement progressively increased over time, with more recent values (post-2000) close to two times larger than those from the 1960s/1970s. Improvements were larger for children (9-12 years) compared to adolescents (13-17 years), and similar for boys and girls. Trends differed between countries, with relationships between national trends in handgrip strength and national trends in health-related/sociodemographic indicators negligible-to-weak and not statistically significant.

CONCLUSIONS

There has been a substantial improvement in absolute handgrip strength for children and adolescents since 1967. There is a need for improved international surveillance of handgrip strength, especially in low- and middle-income countries, to more confidently determine true international trends.

PROSPERO REGISTRATION NUMBER

CRD42013003657.

Better muscle strength with healthy eating

PURPOSE

Hand grip strength (HGS) can predict physical function in next year when it is positively associated with nutritional and health status. This study aimed to determine the relationship between the healthy eating index (HEI)-2015 and hand grip strength.

METHODS

This cross-sectional study was conducted on data from 4010 participants in the Ravansar non-communicable disease (RaNCD) cohort study. HGS was measured using a hand-held hydraulic hand grip dynamometer. HEI-2015 was calculated using data from the food frequency questionnaire.

RESULTS

The mean of total HEI-2015 score was significantly higher in participants with an optimal HGS than in participants with a weak HGS (P = 0.006). Higher adherence to healthy eating was associated with optimal muscle strength (OR 1.26; CI 95% 1.02-1.62). This association was remained after being adjusted for potential confounders (P = 0.01). Among the HEI-2015 components, we only found association between whole fruit, added sugar, and HGS (P = 0.01, 0.019).

CONCLUSIONS

Our findings indicated that adherence to HEI-2015 could promote muscle strength. Among the HEI-2015 components, higher intake of whole fruit and lower adherence to added sugar had significantly positive effects on HGS.

LEVEL OF EVIDENCE

Level V, descriptive cross-sectional study.

The longitudinal relationship between dietary intake, physical activity and muscle strength among adolescents

The longitudinal relationship between muscle strength, dietary intake and physical activity among adolescents is not well understood. We investigated the trend and longitudinal effects of dietary intakes and physical activity scores on muscle strength in adolescents. This prospective cohort study consisted of 436 adolescents (134 males; 302 females) aged 13 years at baseline (2012) who were followed up at the ages of 15 (2014) and 17 (2016) years, respectively. We measured muscle strength using a calibrated hand dynamometer, estimated dietary intake with a 7-d dietary history and physical activity scores with a validated physical activity questionnaire for older children. A generalised estimating equation was used to examine the effect of dietary intakes and physical activity on muscle strength changes. The analysis was performed separately by sex. The muscle strength for males and females had increased within the 5-year period. The dietary intakes (energy and macronutrients) also increased initially but plateaued after the age of 15 years for both sexes. Females recorded a significant declining trend in physical activity scores compared with males as they grew older. A significant positive longitudinal relationship was found between protein (β = 0·035; P = 0·016), carbohydrate intake (β = 0·002; P = 0·013) and muscle strength among males. However, no longitudinal relationship was found between dietary intake, physical activity and muscle strength among females. Higher protein and carbohydrate intake among males was associated with higher muscle strength but was not observed in females. Nutrition and physical activity focusing on strength building are required in early adolescence and need to be tailored to males and females accordingly.

Relationship of Handgrip Strength to Metabolic Syndrome Among Korean Adolescents 10-18 Years of Age: Results from the Korean National Health and Nutrition Examination Survey 2014-18

Introduction: Handgrip strength (HGS), a simple, convenient, and economic measurement of muscle strength, is known to be related to metabolic syndrome (MetS) in adults. This relationship in adolescents, however, has not been widely examined. this study investigated the relationship of MetS (as defined by the International Diabetes Federation [IDF]'s criteria) to HGS in Korean adolescents. Materials and Methods: This cross-sectional study analyzed data on 2802 adolescents 10-18 years of age from the Korean National Health and Nutrition Examination Survey (KNHANES) 2014-18, which had measured and recorded HGS, body mass index, and other parameters relevant to MetS. Normalized HGS was defined as the sum of the maximum HGS from both hands normalized per weight. Complex sample multivariate logistic regression analyses were performed to investigate the relationship between HGS and MetS. Results: The risk of MetS decreased with increasing sex-specific quartile of normalized HGS in both boys and girls after adjustment for age (P_trend < 0.001). Higher HGS was associated with lower odds of having MetS, such that for every 5% increase of normalized HGS, the odds were decreased by factors of 0.79 (0.73-0.85) and 0.67 (0.59-0.77) for boys and girls, respectively, after age adjustment. Conclusions: This population-based, nationally representative study suggests that higher HGS is associated with lower risk of MetS in Korean adolescents regardless of sex.

Handgrip Strength and Current Smoking Are Associated with Cardiometabolic Risk in Korean Adolescents: A Population-Based Study

This study aimed to identify the independent association of handgrip strength and current smoking with cardiometabolic risk in adolescents. Data of 1806 adolescents (12–18 years) from the Korea National Health and Nutrition Examination Surveys were analyzed by complex samples logistic regression analyses. Handgrip strength was normalized by body weight into relative handgrip strength. A cardiometabolic risk index score was calculated from the z-scores of the following components: waist circumference, triglycerides, high-density lipoprotein cholesterol, glucose, and blood pressure. Relative handgrip strength showed an inverse association with high cardiometabolic risk, with an adjusted odds ratio of 8.5 (95% confidence interval [CI], 3.7–19.3) for boys and 5.7 (95% CI, 2.9–11.2) for girls on comparing the lowest and the highest age-and sex-specific quartiles of relative handgrip strength. The adjusted odds ratios for high cardiometabolic risk on comparing the second quartile and the highest quartile of relative handgrip strength were 3.9 (95% CI, 1.7–8.9) in boys and 2.6 (95% CI, 1.3–5.3) in girls. Current smoking was independently associated with high cardiometabolic risk in boys aged 15–18 years. These findings suggest the need to increase muscle strength in adolescents and reduce smoking in older boys to promote cardiometabolic health.

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

Handgrip strength (HGS) is a well-established indicator of muscle strength and can help to identify risk of sarcopenic obesity in children. This study explores the relationship between adiposity and muscular strength in healthy Chilean adolescents. Adolescents (n = 491) aged 10–17 were selected from five schools in Santiago, Chile. HGS was determined by dynamometry. Anthropometry (weight, height, waist and mid arm circumference), physical activity and socioeconomic status were also measured. Relative HGS (RHGS) was calculated by dividing maximum HGS of the dominant hand by body-mass index (BMI) and low RHGS was categorized as <25^th percentile by sex. Logistic regression was used to determine the relationship between two markers of adiposity (abdominal obesity category by waist circumference and nutritional status measured by BMI category) and low RHGS, adjusting for possible confounding variables. Participants were on average 13.6y (2.4), 32.8% were overweight or obese and 37.5% were at risk of or had abdominal obesity. RHGS was 1.25 kg/kg/m² overall, with a significant difference by sex (1.51 for boys versus 1.14 for girls). In adjusted analyses, boys and girls with risk of abdominal obesity, had 3.3 (1.6–6.6) and 4.1 (1.8–9.3) increased odds of low RHGS, respectively, compared to boys and girls with normal waist circumference. Those with abdominal obesity compared to normal WC, had 8.5 (3.4–21.4) and 6.5 (2.0–21.3) increased odds of low RHGS for boys and girls, respectively. We observed similar associations for BMI category. In our sample of healthy adolescents, higher adiposity related to greater odds of low muscle strength measured by dynamometry. Considering the demographic shift from a young to an aging population in many countries, along with the increasing prevalence of obesity beginning in childhood, understanding how adiposity relates to low muscle strength is of growing importance.

Grip Strength Cut Points for Diabetes Risk Among Apparently Healthy U.S. Adults

INTRODUCTION

Early detection screening tools are needed to aid in preventing vascular complications associated with type 2 diabetes. As low muscular strength is linked to increased diabetes risk, the purpose of this study is to establish muscular strength cut points for determining diabetes risk using a large, nationally representative U.S.

METHODS

Using the 2011-2012 and 2013-2014 National Health and Nutrition Examination Survey data, 5,108 participants aged 20-80 years (68.6% aged 20-50 years; young male participants, n=1,813, mean age=33.43 years; young female participants, n=1,692, mean age=33.39 years; older male participants, n=813, mean age=59.92 years; older female participants, n=790, mean age=60.45 years) and free of common diabetes comorbidities were included. Muscular strength was assessed using a handgrip dynamometer and normalized by adjusting for body weight. A logistic regression for survey data controlling for covariates was used to determine normalized grip strength cut points. Diabetes risk was determined using American Diabetes Association diagnostic criteria. Analyses were conducted in the summer of 2019.

RESULTS

Normalized grip strength significantly predicted diabetes (p=0.0332), and the cut points for detecting diabetes risk included 0.78 (young male participants), 0.57 (young female participants), 0.68 (older male participants), and 0.49 (older female participants). The risk percentages for diabetes and estimated rates reported for all subgroups were comparable, and the risk percentages included 6.84 (95% CI=5.32, 8.36; younger male participants), 7.49 (95% CI=5.87, 9.10; younger female participants), 5.76 (95% CI=2.34, 9.19, older male participants), and 4.27 (95% CI=2.44, 6.10; older female participants).

CONCLUSIONS

Normalized grip strength using the cut points proposed in this paper may be a useful screening tool for diabetes risk in apparently healthy, normotensive adults.

Lower grip strength in youth with obesity identifies those with increased cardiometabolic risk

BACKGROUND

We examined whether grip strength differentiates youth with obesity with increased cardiometabolic risk.

METHODS

The sample comprised 43 youth with severe obesity (mean age 14.8, standard deviation 3.0 years) enrolled in the Childhood Overweight BioRepository of Australia. Grip strength was normalized to body mass and categorized as low and moderate/high.

RESULTS

Youth with low grip strength had higher systolic blood pressure (mean difference 13mmHg), low-density lipoprotein cholesterol (0.26mmol/l), continuous metabolic syndrome score (0.36), and carotid intima-media thickness (0.05mm) compared with those with moderate/high grip strength.

CONCLUSIONS

Low grip strength may differentiate youth with obesity with increased cardiometabolic risk.

Muscle strength cut-offs for the detection of metabolic syndrome in a nonrepresentative sample of collegiate students from Colombia

BACKGROUND

Evidence shows an association between grip strength and health; however, grip strength cut-offs for the detection of metabolic syndrome (MetS) in Latin American populations are scarce. The purpose of this study was to determine cut-offs of normalized grip strength (NGS) for the detection of MetS in a large nonrepresentative sample of a collegiate student population from Colombia.

METHODS

A total of 1795 volunteers (61.4% female; age = 20.68 ± 3.10 years, mean ± SD), ranging between 18 and 30 years of age participated in the study. Strength was estimated using a handheld dynamometer and normalized to body mass (handgrip strength (kg)/body mass (kg)). Anthropometrics, serum lipids indices, blood pressure, and fasting plasma glucose were measured. Body composition was measured by bioelectrical impedance analysis. MetS was defined as including ≥3 of the 5 metabolic abnormalities according to the International Diabetes Federation definition. A metabolic risk score was computed from the following components: waist circumference, triglycerides, high-density lipoprotein cholesterol, glucose, and systolic and diastolic blood pressure.

RESULTS

Receiver operating curve analysis showed significant discriminatory accuracy of NGS in identifying the thresholds and risk categories. Lower strength was associated with increased prevalence of MetS. In males, weak, intermediate, and strong NGS values at these points were <0.466, 0.466-0.615, >0.615, respectively. In females, these cut-off points were <0.332, 0.332-0.437, >0.437, respectively.

CONCLUSION

Our sex-specific cut-offs of NGS could be incorporated into a clinical setting for identifying college students at cardiometabolic disease risk.

Nonalcoholic Fatty Liver Disease Is Associated With Low Skeletal Muscle Mass in Overweight/Obese Youths

Background: Recent studies in adult non-elderly and elderly individuals have reported a link between nonalcoholic fatty liver disease (NAFLD) and sarcopenia. Nonetheless, whether this relationship would be found outside these populations it is still unknown. Hence, we evaluated the relationship between NAFLD and skeletal muscle mass in children and adolescents with overweight/obesity. Methods: Two-hundred and thirty-four overweight/obese youths were enrolled. NAFLD was diagnosed by ultrasononography, after exclusion of infectious and metabolic disorders. Forty of the patients with NAFLD had also liver biopsy. Total and regional lean body mass and total fat mass measurements were obtained by dual-energy X-ray absorptiometry. The relative muscle mass (RMM) was defined as the percent of muscle mass (kg) relative to the sum of muscle and fat (kg) mass. Appendicular skeletal muscle mass (ASM) was calculated by the sum of muscle masses of the four limbs (kg), and expressed as percent of body weight. Results: Subjects were stratified according to tertiles of RMM. The prevalence of abdominal obesity, dyslipidemia, insulin resistance, metabolic syndrome, NAFLD as well as biopsy-proven nonalcoholic steatohepatitis (NASH) was significantly increased in the lowest tertile of RMM. After controlling for age, sex and Tanner stage, children in the lowest tertile of RMM had an increased risk for NAFLD (OR= 2.80, 95% CI=1.57-5.02) compared to those in the other two tertiles. This association persisted after additional adjustments for clinical and metabolic variables. Similarly, the risk of NAFLD in the lowest tertile of ASM/weight index was significantly higher compared to those in the other two tertiles after adjustment for the above confounders. Conclusions: This is the first study to establish an independent association between low muscle mass and NAFLD/NASH in overweight/obese youths. Considering the worldwide increase of pediatric obesity, measurements of muscle mass may serve as useful method of identifying among obese children those at high metabolic risk who may need intensive lifestyle interventions to prevent NAFLD and its progression.

Secular trends in the grip strength and body mass index of sport university students between 1973 and 2016: J-Fit＋study

Background/Objective

Sport university students are a unique population because they usually have a strong sport background since early childhood. In this study, we aimed to examine secular trends in grip strength of male, first-year sport university students in comparison with the general population between 1973 and 2016.

Methods

Existing data on the grip strength of 6,308 sport university students aged 18 years were examined. The data were obtained from the Juntendo Fitness Plus Study, a study of the Department of Physical Education/Health and Sports Science of Juntendo University. For reference, age- and sex-matched data (18 years old, male) on the grip strength were obtained from a national database.

Results

Compared with the general population, the sport university students had greater body mass index and stronger grip strength at all times.

Conclusions

The grip strength of sport university students significantly declined between the 1980s and 1990s, and it has plateaued since 2000, albeit at low levels. Compared with the peak performance of sport university students in 1984, the grip strength of students in 2016 was significantly lower by 8.1 kg. The downward trends were also confirmed in the general population during the same periods. In conclusion, the grip strength of sport university students has significantly declined over the last few decades.

Low levels of cardiorespiratory fitness and abdominal resistance are associated with metabolic risk in schoolchildren

Background Low levels of physical fitness are associated with metabolic disorders in adults. However, this relationship has been little explored in children and adolescents. The aim of the present study was to investigate whether there is an association between physical fitness related to health and the presence of metabolic risk in schoolchildren. Methods The sample for this cross-sectional study was composed of 1251 schoolchildren of both genders between 7 and 17 years of age. Three indicators of physical fitness related to health were evaluated: cardiorespiratory fitness (CRF), flexibility and abdominal resistance. The continuous metabolic syndrome score (cMetS) was calculated by using the sum of the Z scores of the following indicators: body mass index (BMI), systolic blood pressure, glucose, total cholesterol, high- and low-density lipoprotein cholesterol (HDL-c and LDL-c) and triglycerides. Subsequently, the cMetS was dichotomized, considering the presence or absence of metabolic risk. The data were analyzed using prevalence ratio (PR) values and 95% confidence intervals (CI), using Poisson regression. Results A higher prevalence of metabolic risk was found among students with low levels of CRF (PR: 1.48; CI: 1.10-1.98) and abdominal resistance (PR: 1.45; CI: 1.08-1.95). No association with flexibility was found. Conclusions Low levels of CRF and abdominal resistance are associated with the presence of metabolic risk in schoolchildren.

Handgrip strength attenuates the adverse effects of overweight on cardiometabolic risk factors among collegiate students but not in individuals with higher fat levels

The aims of this study are to (i) examine a clustered metabolic syndrome composite score (MetScore) and fatness among college students across body mass index (BMI) categories, and (ii) determine whether fit individuals have lower MetScores, fewer individual metabolic syndrome components, and lower fatness than unfit individuals across BMI categories. A total of 1,795 participants aged  >18 years who participated in The FUPRECOL Study were selected for the present analyses. Handgrip strength was tested by a grip dynamometer and used to classify adults as fit or unfit. Among all participants, MetScore, percentage of body fat, and visceral adiposity increased linearly across the BMI categories among college students (all P < 0.001). Individuals who were overweight and fit had a lower MetScore (-0.6 SD; P = 0.02), body fat percentage (-2.6%; P < 0.001) and visceral adiposity (-0.2; P = 0.01) than unfit peers. Moderately fit obese individuals had significantly lower visceral fat levels than unfit obese peers (-3.0; P = 0.03). These results suggest that having adequate handgrip strength-a proxy of overall strength capacity-may attenuate obesity-related cardiometabolic risk. Moreover, weight loss should be recommended to all individuals with obesity, even among those who are currently considered fit.

Muscle strength field-based tests to identify European adolescents at risk of metabolic syndrome: The HELENA study

OBJECTIVES

To determine whether handgrip strength (HG) and/or standing long jump (SLJ) are capable of detecting risk of metabolic syndrome (MetS) in European adolescents, and to identify age- and sex-specific cut points for these tests.

DESIGN

Cross-sectional study.

METHODS

Participants included 969 (aged 12.5-17.5 years old) adolescents from 9 European countries (n = 520 girls). Absolute and relative HG and SLJ tests were used to assess upper and lower muscle strength, respectively. MetS status was determined using the age- and sex-specific cut points proposed by Jolliffe and Janssen´s, Additionally, we computed a continuous cardiometabolic risk index with the average z-score of four cardiometabolic risk factors: Wait circumference, mean arterial pressure, triglycerides/high-density lipoprotein cholesterol, and fasting insulin.

RESULTS

The prevalence of MetS was 3.1% in European adolescents. Relative HG and absolute SLJ were the best tests for detecting the presence of MetS (Area under the receiver operating characteristic (AUC) = 0.799, 95%CI:0.773-0.824; and AUC = 0.695 95%CI:0.665-0.724), respectively) and elevated cardiometabolic risk index (AUC = 0.873, 95%CI:0.838-0.902; and AUC = 0.728 95%CI:0.698-0.756), respectively) and, regardless of cardiorespiratory fitness. We provide age- and sex-specific cut points of upper and lower muscle strength for European adolescents to identify the presence of MetS and elevated cardiometabolic risk index.

CONCLUSIONS

The proposed health-related cut points could be used as a starting point to define health-related levels of upper and lower muscle strength in adolescents. Likewise, the diagnostic statistics provided herein can be used to offer feedback to adolescents, parents, and education and health professionals about what it means to meet or fail test standards.

Low muscle mass and strength in pediatrics patients: Why should we care?

Skeletal muscle plays major roles in metabolism and overall health across the lifecycle. Emerging evidence indicates that prenatal (maternal diet during pregnancy and genetic defects) and postnatal factors (physical activity, hormones, dietary protein, and obesity) influence muscle mass acquisition and strength early in life. As a consequence, low muscle mass and strength contributes to several adverse health outcomes during childhood. Specifically, studies demonstrated inverse associations of muscle mass and strength to single and clustered metabolic risk factors. The literature also consistently reports that low muscle mass and strength are associated with reduced bone parameters during growth, increasing the risk of osteoporosis in old age. Furthermore, muscle mass gains are associated with improved neurodevelopment in the first years of life. Given these negative implications of low muscle mass and strength on health, it is crucial to track muscle mass and strength development from childhood to adolescence. Several body composition techniques are currently available for estimation of muscle mass, all with unique advantages and disadvantages. The value of ultrasound as a technique to measure muscle mass is emerging in pediatric research with potential for translating the research findings to clinical settings. For the assessment of muscle strength, the handgrip strength test has been widely employed but without a standardized protocol. Although further research is needed to define normative data and cut points for the low muscle mass and strength phenotype, the use of such non-invasive medical monitoring is a promising strategy to identify early abnormalities and prevent low muscle mass in adulthood.

The Association Between Differing Grip Strength Measures and Mortality and Cerebrovascular Event in Older Adults: National Health and Aging Trends Study

The purpose of this study was to compare the predictive capacity of different post-processing methods of hand grip strength (GS) for mortality and incident cerebrovascular events in older adults. A sample of 4,143 participants aged 65 years and older was included from the National Health and Aging Trends Study (NHATS) and followed for 6 years. GS measures included baseline (i.e., round 1) (1) absolute GS, (2) GS divided by body mass (NGS_mass), and (3) GS divided by body mass index (NGS_BMI), as well as (4) change in absolute GS from round 1 to round 2 (GS_1-2). Cox proportional hazards regression models were used to examine the association between sex- and age group-specific tertiles of GS measures (weak, moderate-strength, strong) with mortality (n = 641) and incident cerebrovascular events (n = 329). Absolute GS (hazard ratio [HR] = 1.83; 95% confidence interval [CI] = 1.51–2.22), NGS_mass (HR = 1.46; 95% CI = 1.21–1.76), and NGS_BMI (HR = 1.50; 95% CI = 1.24–1.82) were each associated with mortality among weak participants, but not GS_1-2 (HR = 1.10; 95% CI = 0.99–1.46). NGS_mass (HR = 1.54; 95% CI = 1.19–2.01) and NGS_BMI (HR = 1.37; 95% CI = 1.06–1.79) were both associated with incident cerebrovascular event among weak participants, but not absolute GS (HR = 1.12; 95% CI = 0.86–1.47) or GS_1-2 (HR = 1.11; 95% CI = 0.85–1.44). Absolute GS, NGS_mass, and NGS_BMI were each associated with mortality, whereas only NGS_mass and NGS_BMI were associated with cerebrovascular event. These findings suggest that different post-processing methods of GS may have differing predictive capacity in the elderly depending on the outcome of interest; however, since NGS measures were associated with both mortality and cerebrovascular events, they may be considered advantageous for screening in older adults.

Grip Strength Is Associated with Longitudinal Health Maintenance and Improvement in Adolescents

OBJECTIVE

To assess the effects of muscle strength, as determined by grip strength, on changes in health status in adolescents.

STUDY DESIGN

Risk variables included excess body fat, elevated fasting glucose, high blood pressure, elevated serum triglycerides, and low high-density lipoprotein cholesterol. Multinomial logistic regression was used to quantify the odds of experiencing health maintenance (no risk factors identified at either time point) or health improvement (presence of ≥1 baseline risk factor and fewer or no risk factors at follow-up) over a 2-year period. The primary exposure variable was grip strength normalized by body mass (normalized grip strength [NGS]), and previous cut-offs were used to determine whether adolescents were weak or strong.

RESULTS

Adolescents who had low NGSs had a significantly greater prevalence of health decline or poor health persistence as compared with those who were strong (boys: 60.2% vs 15.3%; girls: 51% vs 21.9%; all P < .001). Moreover, adolescents who were strong had an increased adjusted odds for health maintenance (OR 3.54; 95% CI 1.80-6.97) and health improvement (OR 1.30; 95% CI 1.05-1.60), even after we adjusted for baseline fat-free mass index, cardiorespiratory fitness, and objectively measured physical activity.

CONCLUSIONS

Greater NGS is associated with longitudinal health maintenance and health improvements in adolescents. Low NGS could be used as a prognostic indicator of cardiometabolic risk and to identify adolescents who would benefit most from lifestyle interventions to improve muscular fitness.

Temporal trends in muscular fitness of English 10-year-olds 1998-2014: An allometric approach

OBJECTIVES

To identify temporal trends in muscular fitness of English children using allometric scaling for height and weight to adjust for the influence of body size.

DESIGN

Repeated cross-sectional study.

METHODS

We measured; height, weight, standing broad-jump, handgrip, sit-ups and bent-arm hang in 10-year-old boys and girls from Chelmsford, England in: 2014 (n=306), 2008 (n=304) and 1998 (n=310). Physical activity was (PAQ-C) was assessed in 2008 and 2014. Muscular fitness was allometrically scaled for height and weight. We assessed temporal trends using General Linear Models (fixed factors: wave and sex) and reported effect sizes using partial eta squared (η_P²). We compared percentage change per year 1998-2008 with 2008-2014.

RESULTS

Ten-year-olds in 2014 were taller and heavier than in 2008 and 1998 but there were no differences in BMI. Compared with 2008, physical activity was lower in boys (η_P²=0.012) and girls (η_P²=0.27) assessed in 2014. There were significant main effects of wave for handgrip (η_P²=0.060), sit-ups (η_P²=0.120) and bent-arm hang (η_P²=0.204). Pairwise comparisons showed muscular fitness of both sexes was significantly lower in 2014 than in 1998. From 2008 to 2014 percent change per year in handgrip (1.6%) and sit-ups (3.9%) were greater than for the preceding decade (handgrip 0.6%, sit-ups 2.6%).

CONCLUSIONS

Downward temporal trends in muscular fitness appear independent of secular changes in body size. We found a decrease in self-reported physical activity concurrent with the accelerated declines in fitness from 2008 to 2014. These findings suggest the declines in children are not engaging in physical activities which support development of muscular fitness.

Relationships among cardiorespiratory fitness, muscular fitness, and cardiometabolic risk factors in Japanese adolescents: Niigata screening for and preventing the development of non-communicable disease study-Agano (NICE EVIDENCE Study-Agano) 2

OBJECTIVE

To examine the independent and combined associations of cardiorespiratory fitness (CRF) and muscular fitness (MF) with cardiometabolic risk factors in Japanese adolescents.

METHODS

A cross-sectional study including 993 Japanese adolescents (aged 13-14 years) was undertaken. Height, body mass, blood pressure, lipid profile (non-fasting), and HbA1c were measured. The physical fitness (PF) test included measurements of CRF (20 m multistage shuttle run test), upper limb strength (hand grip strength), lower limb strength (standing long jump), and muscular endurance (sit-ups). The clustered cardiometabolic risk (CCMR) was estimated by summing standardized Z-scores of body mass index (BMI), mean arterial pressure (MAP), non-high-density lipoprotein cholesterol (non-HDL-C), and HbA1c.

RESULTS

Linear regression analysis showed that all PF factors except for muscular endurance were inversely correlated with CCMR (P < .001). Among metabolic risk components, HbA1c was unrelated to PF, while non-HDL-C was inversely associated with CRF (B = -2.40; P < .001), upper limb strength (B = -1.77; P < .05), and lower limb strength (B = -1.53; P < .05) after adjustment for lifestyle factors. Logistic regression showed that the probability of having high CCMR (≥1SD) was synergistically higher in those with the lowest tertiles of both CRF and upper limb strength (P for interaction = .001); however, a substantially lower likelihood of having high CCMR was observed among individuals with the lowest tertile of upper limb strength but moderate CRF.

CONCLUSIONS

Lower CRF and MF were significantly and synergistically associated with an unhealthier metabolic risk profile.

Youth Resistance Training: The Good, the Bad, and the Ugly-The Year That Was 2017

The good news is that a growing body of evidence recognizes resistance training as foundational to long-term physical development. Original research and reviews published in 2017 conclude that early exposure to developmentally appropriate resistance training can improve markers of health, increase muscular fitness, enhance physical literacy, and reduce the risk of injury in young athletes. Although the papers discussed in the commentary add to our understanding of the pleiotropic benefits of youth resistance training, they also raise concerns. As measures of muscular strength and power have been found to track from childhood to adulthood, the bad news is that youth with low levels of muscular fitness tend to become weak adults who are at increased risk for functional limitations and adverse health outcomes. Furthermore, global participation in youth resistance training is falling far short of public health recommendations, and these ugly trends will likely impact the health and well-being of future generations. A change in current attitudes and common practices is urgently needed to educate parents, practitioners, and clinicians about the potential benefits of resistance training for all children and adolescents, not only young athletes.

Handgrip strength cutoff for cardiometabolic risk index among Colombian children and adolescents: The FUPRECOL Study

Evidence shows an association between muscular strength (MS) and health among young people, however low muscular strength cut points for the detection of high metabolic risk in Latin-American populations are scarce. The aim of this study was twofold: to explore potential age- and sex-specific thresholds of MS, for optimal cardiometabolic risk categorization among Colombian children and adolescents; and to investigate whether cardiometabolic risk differed by MS group by applying the receiver operating characteristic curve (ROC) cut point. MS was estimated by using a handle dynamometer on 1,950 children and adolescents from Colombia, using MS relative to weight (handgrip strength/body mass). A metabolic risk score was computed from the following components: waist circumference, triglycerides, HDL-c, glucose, and systolic and diastolic blood pressure. ROC analysis showed a significant discriminatory accuracy of MS in identifying the low/high metabolic risk in children and adolescents and in both genders. In children, the handgrip strength/body mass levels for a low metabolic risk were 0.359 and 0.376 in girls and boys, respectively. In adolescents, these points were 0.440 and 0.447 in girls and boys, respectively. In conclusion, the results suggest an MS level relative to weight for having a low metabolic risk, which could be used to identify youths at risk.

Handgrip Strength and Ideal Cardiovascular Health among Colombian Children and Adolescents

OBJECTIVE

To evaluate the association between handgrip strength and ideal cardiovascular health (CVH) in Colombian children and adolescents.

STUDY DESIGN

During the 2014-2015 school years, we examined a cross-sectional component of the FUPRECOL (Association for Muscular Strength with Early Manifestation of Cardiovascular Disease Risk Factors among Colombian Children and Adolescents) study. Participants included 1199 (n = 627 boys) youths from Bogota (Colombia). Handgrip strength was measured with a standard adjustable hand held dynamometer and expressed relative to body mass (handgrip/body mass) and as absolute values in kilograms. Ideal CVH, as defined by the American Heart Association, was determined as meeting ideal levels of the following components: 4 behaviors (smoking status, body mass index, cardiorespiratory fitness, and diet) and 3 factors (total cholesterol, blood pressure, and glucose).

RESULTS

Higher levels of handgrip strength (both absolute and relative values) were associated with a higher frequency of ideal CVH metrics in both sexes (P for trend ≤ .001). Also, higher levels of handgrip strength were associated with a greater number of ideal health behaviors (P for trend < .001 in both boys and girls), and with a higher number of ideal health factors in boys (P for trend < .001). Finally, levels of handgrip strength were similar between ideal versus nonideal glucose or total cholesterol groups in girls.

CONCLUSIONS

Handgrip strength was strongly associated with ideal CVH in Colombian children and adolescents, and thus supports the relevance of early targeted interventions to promote strength adaptation and preservation as part of primordial prevention.

Salivary latent trait cortisol (LTC): Relation to lipids, blood pressure, and body composition in middle childhood

Adversity experienced early in life has the potential to influence physical health later in life. The stress-health relation may be partially explained by stress-related effects on cardiovascular risk factors. This study explored links between individual differences in trait-like variation in the activity of the hypothalamic-pituitary-adrenal (HPA) axis with cardiovascular risk factors in children. 474 children (M age=9.22years; 54% female; 83% Caucasian) were included in this study, in which cardiovascular risk was assessed using the following indices - triglycerides (TG), HDL-cholesterol (HDL-C), glucose (Glu); resting systolic and diastolic blood pressure, body mass index (BMI), waist-to-hip ratio, and % fat. Saliva samples were measured 3 times a day (waking, 30min post-waking and bedtime) over 3days (later assayed for cortisol). A latent trait cortisol (LTC) factor explained 43% of the variance in cortisol levels within and across days. Confirmatory factor analysis identified three cardiovascular risk factors: lipids (i.e., TG and HDL-C), blood pressure (i.e., systolic and diastolic), and body composition (i.e., BMI, Waist-to-hip ratio, and % fat). Lower salivary LTC was associated with higher lipids, higher blood pressure, and higher body composition. The findings further support the internal and external validity of the LTC construct, and may also advance our understanding of the link between interindividual differences in HPA axis activity and cardiovascular risk in middle childhood.

The P4 Health Spectrum - A Predictive, Preventive, Personalized and Participatory Continuum for Promoting Healthspan

Chronic diseases (i.e., noncommunicable diseases), mainly cardiovascular disease, cancer, respiratory diseases and type-2-diabetes, are now the leading cause of death, disability and diminished quality of life on the planet. Moreover, these diseases are also a major financial burden worldwide, significantly impacting the economy of many countries. Healthcare systems and medicine have progressively improved upon the ability to address infectious diseases and react to adverse health events through both surgical interventions and pharmacology; we have become efficient in delivering reactive care (i.e., initiating interventions once an individual is on the verge of or has actually suffered a negative health event). However, with slowly progressing and often 'silent' chronic diseases now being the main cause of illness, healthcare and medicine must evolve into a proactive system, moving away from a merely reactive approach to care. Minimal interactions among the specialists and limited information to the general practitioner and to the individual receiving care lead to a fragmented health approach, non-concerted prescriptions, a scattered follow-up and a suboptimal cost-effectiveness ratio. A new approach in medicine that is predictive, preventive, personalized and participatory, which we label here as "P4" holds great promise to reduce the burden of chronic diseases by harnessing technology and an increasingly better understanding of environment-biology interactions, evidence-based interventions and the underlying mechanisms of chronic diseases. In this concept paper, we propose a 'P4 Health Continuum' model as a framework to promote and facilitate multi-stakeholder collaboration with an orchestrated common language and an integrated care model to increase the healthspan.

Muscle Weakness Is Associated With Diabetes in Older Mexicans: The Mexican Health and Aging Study

BACKGROUND

The risk of cardiovascular problems due to diabetes mellitus is highest among older Mexicans, and yet what remains to be determined is the association between muscle weakness and diabetes in this population. Therefore, the purpose of this study was to determine the association between muscle strength and diabetes among Mexican adults greater than 50 years of age.

DESIGN

Cross-sectional.

SETTING

National sample of households in both urban and rural areas.

PARTICIPANTS

A subsample of 1841 individuals aged 50 years and older was included from the 2012 Mexican Health and Aging Study.

MEASUREMENTS

Strength was assessed using a hand-held dynamometer, and the single largest reading from either hand was normalized to body mass (normalized grip strength [NGS]). Conditional inference tree analyses were used to identify sex-specific NGS weakness thresholds. Linear regression was used to examine the association between NGS and HbA1c, and logistic regression was used to assess the association between weakness and risk of diabetes (HbA1c ≥ 6.5% [≥48 mmol/mol]), after controlling for age, sex, and waist circumference.

RESULTS

NGS was inversely associated with HbA1c (β = -1.56; P < .001). Optimal sex-specific NGS weakness thresholds to detect diabetes were ≤0.46 and ≤0.30 for men and women, respectively. Weakness was associated with significantly increased odds of diabetes (odds ratio, 1.69; 95% confidence interval, 1.37-2.10), even after adjusting for age, sex, and waist circumference.

CONCLUSIONS

NGS was robustly associated with diabetes and other cardiometabolic risk factors in older Mexicans. This simple screen may serve as a valuable tool to identify adults that are at risk for negative health consequences or early mortality and who might benefit from lifestyle interventions to reduce risk.