Independent and combined associations of physical fitness components with inflammatory biomarkers in children and adolescents

Longitudinal associations of an exposome score with serum metabolites from childhood to adolescence

Environmental and lifestyle factors, including air pollution, impaired diet, and low physical activity, have been associated with cardiometabolic risk factors in childhood and adolescence. However, environmental and lifestyle exposures do not exert their physiological effects in isolation. This study investigated associations between an exposome score to measure the impact of multiple exposures, including diet, physical activity, sleep duration, air pollution, and socioeconomic status, and serum metabolites measured using LC-MS and NMR, compared to the individual components of the score. A general population of 504 children aged 6-9 years at baseline was followed up for eight years. Data were analysed with linear mixed-effects models using the R software. The exposome score was associated with 31 metabolites, of which 12 metabolites were not associated with any individual exposure category. These findings highlight the value of a composite score to predict metabolic changes associated with multiple environmental and lifestyle exposures since childhood.

Muscle Strength Indexes and Its Association With Cardiometabolic Risk Factors in Adolescents: An Allometric Approach

Background and aims: Muscle strength (MS) has been associated with better cardiometabolic health prognosis. However, the result for the beneficial relationship seems to be dependent on the influence of body size in determining MS levels. We investigate the association between allometric MS indexes and its association with cardiometabolic risk factors in adolescents. Methods: It was a cross-sectional study comprising 351 adolescents (male: 44.4%; age range 14-19 years) from Southern Brazil. MS was assessed by handgrip strength and three different allometric approaches were adopted: 1) MS index based on theoretical allometric exponent; 2) MS index including body mass and height; 3) MS index including fat-free mass and height. Obesity, high blood pressure, dyslipidemia, glucose imbalance and high-sensitivity C-reactive protein were investigated as individual factors or as combinations (either as combinations of components - presence of two adverse conditions, or number of components present in an individual - 0, 1, 2, 3+ cardiometabolic risk factors). Logistic and multinomial logistic regression analyses adjusted for confounding factors were used. The statistical significance adopted was 5%. Results: MS index based on theoretical allometric exponent was associated with lower likelihood (OR: 0.54; 95% CI: 0.28 - 0.89) for the presence of three or more cardiometabolic risk factors in the same individual. Conclusion: This study suggests that MS index based on the theoretical allometric exponent can be superior to allometric MS indexes that included body mass and height, or fat-free mass and height in representing the presence of high number of cardiometabolic risk factors in adolescents.

Cross-sectional associations between physical fitness and biomarkers of inflammation in children-The PANIC study

BACKGROUND

Systemic low-grade inflammation has been proposed as an underlying pathophysiological mechanism for cardiometabolic diseases. We investigated the associations of physical fitness with a systemic low-grade inflammatory state in a population sample of children.

METHODS

Altogether 391 children aged 6-9 years were examined. Cardiorespiratory fitness (maximal power output, W_max ) was assessed by a maximal cycle ergometer test and neuromuscular fitness by hand grip strength, sit-up, standing long jump, 50-meter shuttle run, static balance, sit-and-reach, and box and block tests. Body fat percentage (BF%) and lean mass (LM) were assessed by dual-energy X-ray absorptiometry (DXA). High sensitivity C-reactive protein (hs-CRP), leptin, leptin receptor, high molecular weight adiponectin (HMW-adiponectin), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and glycoprotein acetyls (GlycA) were assessed from fasting blood samples. The modified inflammatory score (IS) was calculated using the population-specific z-scores and formula (^z hs-CRP + ^z leptin + ^z IL-6 + ^z TNF-α + ^z GlycA)-^z leptin receptor-^z HMW-adiponectin. The data were analyzed using linear regression analyses.

RESULTS

Higher W_max /kg of body mass (β = -0.416, 95% CI = -0.514 to -0.318), higher number of completed sit-ups (β = -0.147, 95% CI = -0.244 to -0.049), a longer distance jumped in the standing long jump test (β = -0.270, 95% CI = -0.371 to -0.169), and a shorter time in the 50-meter shuttle run test (β = 0.123, 95% CI = 0.022 to 0.223) were associated with lower IS. None of these associations remained statistically significant after adjustment for BF%.

CONCLUSIONS

Higher physical fitness is associated with a more favorable inflammatory biomarker profile in children. However, the associations were explained by BF%.

A genetic correlation and bivariate genome-wide association study of grip strength and depression

Grip strength is an important biomarker reflecting muscle strength, and depression is a psychiatric disorder all over the world. Several studies found a significant inverse association between grip strength and depression, and there is also evidence for common physiological mechanisms between them. We used twin data from Qingdao, China to calculate genetic correlations, and we performed a bivariate GWAS to explore potential SNPs, genes, and pathways in common between grip strength and depression. 139 pairs of Dizygotic twins were used for bivariate GWAS. VEAGSE2 and PASCAL software were used for gene-based analysis and pathway enrichment analysis, respectively. And the resulting SNPs were subjected to eQTL analysis and pleiotropy analysis. The genetic correlation coefficient between grip strength and depression was -0.41 (-0.96, -0.15). In SNP-based analysis, 7 SNPs exceeded the genome-wide significance level (P<5×10-8) and a total of 336 SNPs reached the level of suggestive significance (P<1×10-5). Gene-based analysis and pathway-based analysis identified genes and pathways related to muscle strength and the nervous system. The results of eQTL analysis were mainly enriched in tissues such as the brain, thyroid, and skeletal muscle. Pleiotropy analysis shows that 9 of the 15 top SNPs were associated with both grip strength and depression. In conclusion, this bivariate GWAS identified potentially common pleiotropic SNPs, genes, and pathways in grip strength and depression.

Physical fitness and disordered eating among adolescents: Results from the EHDLA study

The aim of this study was to examine the association between a comprehensive spectrum of physical fitness components and disordered eating symptoms in a sample of Spanish adolescents. This cross-sectional study analysed a representative sample of 741 adolescents (55.1% girls) from the Eating Healthy and Daily Life Activities (EHDLA) study (Valle de Ricote, Region of Murcia, Spain). Objective physical fitness (i.e., cardiorespiratory fitness, upper body strength, lower body strength, speed-agility, and flexibility) was assesed by the ALPHA-FIT Test Battery for a young population. Disordered eating symptoms were assessed with the Sick, Control, One, Fat, Food (SCOFF) questionnaire. An incremental inverse association was found in participants with low cardiorespiratory fitness (OR = 2.33; 95% CI: 1.56-3.50), low handgrip strength (OR = 1.99; 95% CI: 1.33-2.97), low lower body strength (OR = 1.91; 95% CI: 1.28-2.86), low speed-agility (OR = 1.75; 95% CI: 1.17-2.62), and low global physical fitness (OR = 2.03; 95% CI: 1.37-3.01) and disordered eating symptoms, compared to participants with a high level of each of these physical fitness components. Our study provides evidence that, in Spanish adolescents, disordered eating symptoms are inversely associated with a comprehensive set of physical fitness components. Hence, it could be relevant to promote physical fitness, e.g., by a multifactorial approach, since it seems to be related to lower disordered eating symptoms in adolescents.

Leptin levels were negatively associated with lumbar spine bone mineral content in children with overweight or obesity

AIM

Adipokines seem to play a role in bone morphogenesis, although this also depends on the mechanical forces applied to the skeleton. The aim was to assess the relationships of resting leptin and adiponectin with bone parameters and whether high muscular fitness levels affect these relationships in children with overweight or obesity.

METHODS

This cross-sectional study took part from 2014 to 2016 in Granada, Spain. Participants were recruited from University Hospitals, and we also used advertisements in local media and school contacts in the city. Adipokines were analysed in plasma. Muscular fitness was assessed by 1 repetition maximum in bench and leg press tests. Dual-energy X-ray absorptiometry was used to measure bone parameters.

RESULTS

We included 84 children (10.0±1.2y; 63% boys) in this analysis. Leptin was negatively associated with lumbar spine bone mineral content (β=-0.162, p=0.053). No significant interaction was found for muscular fitness. Simple slope estimates suggested that children performing more than 133.3kg in leg press test ameliorated the negative association between leptin and lumbar spine bone mineral content.

CONCLUSION

Leptin levels were negatively associated with lumbar spine bone mineral content in children with overweight or obesity. A high muscular fitness at the lower body could counteract this association.

Changes in Specific Biomarkers Indicate Cardiac Adaptive and Anti-inflammatory Response of Repeated Recreational SCUBA Diving

Objective

Recreational SCUBA (rSCUBA) diving has become a highly popular and widespread sport. Yet, information on molecular events underlying (patho)physiological events that follow exposure to the specific environmental conditions (hyperbaric conditions, coldness, immersion, and elevated breathing pressure), in which rSCUBA diving is performed, remain largely unknown. Our previous study suggested that repeated rSCUBA diving triggers an adaptive response of cardiovascular and immune system. To elucidate further molecular events underlying cardiac and immune system adaptation and to exclude possible adverse effects we measured blood levels of specific cardiac and inflammation markers.

Methods

This longitudinal intervention study included fourteen recreational divers who performed five dives, one per week, on the depth 20–30 m that lasted 30 min, after the non-dive period of 5 months. Blood samples were taken immediately before and after the first, third, and fifth dives. Copeptin, immunoglobulins A, G and M, complement components C3 and C4, and differential blood count parameters, including neutrophil-to-lymphocyte ratio (NLR) were determined using standard laboratory methods. Cell-free DNA was measured by qPCR analysis and N-glycans released from IgG and total plasma proteins (TPP), were analyzed by hydrophilic interaction ultra-performance liquid chromatography.

Results

Copeptin level increased after the first dive but decreased after the third and fifth dive. Increases in immunoglobulins level after every dive and during whole studied period were observed, but no changes in C3, C4, and cfDNA level were detected. NLR increased only after the first dive. IgG and TPP N-glycosylation alterations toward anti-inflammatory status over whole studied period were manifested as an increase in monogalyctosylated and core-fucosylated IgG N-glycans and decrease in agalactosylated TPP N-glycans.

Conclusion

rSCUBA diving practiced on a regular basis promotes anti-inflammatory status thus contributing cardioprotection and conferring multiple health benefits.

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.

Muscle strength and its association with cardiometabolic variables in adolescents: does the expression of muscle strength values matter?

BACKGROUND

We investigate the association between different muscle strength (MS) indices with cardiometabolic variables in adolescents.

METHODS

Cross-sectional study comprising 351 adolescents (male 44.4%, age 16.6 ± 1.0 years) from Brazil. MS was assessed by handgrip strength and analyzed in five different ways: absolute MS and MS normalized for body weight, body mass index (BMI), height, and fat mass, respectively. Cardiometabolic variables investigated as outcomes were systolic and diastolic blood pressure (DBP), waist circumference (WC), high-sensitive C-reactive protein (hs-CRP), lipid and glucose metabolism markers. Multiple linear regression models adjusted for confounding factors were used.

RESULTS

Absolute MS and/or MS normalized for height was directly associated with WC [up to 32.8 cm, standard error (SE) = 4.7] and DBP (up to 8.8 mmHg, SE = 0.8), and inversely associated with high-density lipoprotein cholesterol (up to -8.0 mg/dL, SE = 14.1). MS normalized for body weight, BMI or fat mass was inversely associated with WC (up to -17.5 cm, SE = 2.2). According to sex, MS normalized for fat mass was inversely associated with triglycerides (male: 0.02 times lower, SE = 0.01; female: 0.05 times lower, SE = 0.01) and homeostatic model assessment for insulin resistance (male: 0.02 times lower, SE = 0.01; female: 0.06 times lower, SE = 0.01), and inversely associated with hs-CRP only among male (0.03 times lower, SE = 0.01).

CONCLUSION

When normalized for body weight, BMI or fat mass, MS was superior to absolute MS or MS normalized for height in representing adequately cardiometabolic variables among adolescents.

Association Between Changes in Muscle Strength and Risk of Depressive Symptoms Among Chinese Female College Students: A Prospective Cohort Study

Muscle strength can be a predictor of depressive symptoms among the elderly. We conducted a prospective study aiming to examine the association between change of handgrip strength and the incidence risk of depressive symptoms among Chinese female college students. Handgrip strength was used as a representative indicator of skeletal muscle strength, and a handheld digital smedley dynamometer was applied to measure handgrip strength. We also used the 20-item Zung self-rating depression scale to evaluate depressive status, and a score of ≥50 indicated moderate-to-severe depressive symptoms. During a 1-year follow-up period, the incidence of depressive symptoms is 10.7%. Multivariate logistic regressions analysis revealed that the multivariable-adjusted ORs (95% CI) of depressive symptoms for the categories of handgrip strength change was 1.00 (reference) for group 1, 0.57 (0.28, 1.19) for group 2, 0.41 (0.19, 0.89) for group 3 and 0.33 (0.11, 0.99) for group 4 (p = 0.018). This study indicated that change of handgrip strength level over one-year period is negatively associated with risk of depressive symptoms among Chinese female college students.

Mediating effect of fitness and fatness on the association between lifestyle and body dissatisfaction in Spanish youth

BACKGROUND

Previous studies have identified sedentary behaviour, physical activity and eating habits as variables that define a healthy lifestyle. The aims of this investigation were to determine the association between lifestyle and body dissatisfaction, as well as to test the mediating effect of fatness and fitness in this relationship in adolescents.

METHODS

The sample comprised 2216 adolescents aged 13.1 ± 0.90 years, of whom 980 were girls (age 13.1 ± 0.86) and 1236 were boys (age 13.1 ± 0.92). Body composition was measured by body mass index, neck circumference, waist to height ratio and body fat percentage, whereas physical activity, sedentary time, body dissatisfaction and eating habits were self-reported. Physical fitness was evaluated through the ALPHA-Fitness Battery.

RESULTS

The results showed that lifestyle was negatively related with body dissatisfaction. Moreover, physical fitness (β = -0.062; SE = 0.022; 95% IC [-0.106, -0.017]) and fatness (β = -0.052; SE = 0.011; 95% IC [-0.075, -0.032]) showed a significant mediation effect on the relationship between lifestyle and body dissatisfaction. The bootstrapped confidence intervals for the indirect effect were statistically significant, suggesting the mediation effect of fatness (percentage of the total effect of 51.0%) and fitness (percentage of the total effect of 21.3%) on the relationship between healthy lifestyle and body dissatisfaction.

CONCLUSION

The study suggests that adolescents with a healthy lifestyle may have less body dissatisfaction. Fatness and physical fitness can positively affect this relationship, decreasing young people's body dissatisfaction. Therefore, this study highlights the importance of a healthy lifestyle on physical and psychological health in adolescence.

Meeting the Physical Activity Recommendations and Its Relationship with Obesity-Related Parameters, Physical Fitness, Screen Time, and Mediterranean Diet in Schoolchildren

The up-to-date scientific evidence suggests that adequate levels of physical activity provide essential health benefits for children and adolescents and help to maintain a healthy body weight. In this sense, children and adolescents should at least accumulate 60 min of moderate-to-vigorous physical activity in a daily basis to achieve these benefits and be considered active. Likewise, some lifestyle-related elements may interact with each other in an antagonistic or synergistic way to modify physical activity status. Thus, a better understanding of how meeting physical activity recommendations influences these potentially modifiable lifestyle factors (obesity-related parameters, physical fitness, dietary habits, or sedentary behaviour) would significantly reinforce the importance of complying with those recommendations from a health perspective and support the establishment of strategies for the promotion of diminishing the lower trends of physical activity among the young population. This study seeks to verify the association of meeting physical activity international recommendations with obesity-related parameters, global physical fitness, screen time, and Mediterranean diet in Spanish schoolchildren aged 8 to 13. A cross-sectional study was performed including 250 schoolchildren (41.2% girls) aged 8-13 (9.7 ± 1.2) from six primary schools in the Region of Murcia (Spain). Results: A higher proportion of children who complying with physical activity recommendations shows normal weight, no abdominal obesity, and low adiposity in comparison to other with different obesity-related parameters categories. Higher values in global physical fitness score were found in those who meet the physical activity international recommendations in both sexes. These higher values were also shown for adherence to the Mediterranean diet in both sexes; not being so in the case of screen time. Notwithstanding, none of these mean differences were statistically significant. To conclude, the proportion of schoolchildren meeting the physical activity recommendations in our study is low. A higher proportion of children who meet with physical activity recommendations present normal weight, no abdominal obesity and low adiposity in comparison to other obesity-related parameters categories in both sexes. Likewise, those considered as active children seem to have higher global physical fitness score and adherence to the Mediterranean diet than children who do not meet the recommendations.

Effect of Aerobic and Anaerobic Exercise on the Complement System of Proteins in Healthy Young Males

This study was aimed at examining the impact of common types of physical efforts used to determine the aerobic and anaerobic performance of the participants on the complement system in their peripheral blood. Fifty-one physically active young males aged 16 years old (range 15–21 years) were divided into two age groups (younger, 15–17 years old and older, 18–21 years old) and performed two types of intensive efforts: aerobic (endurance; 20-m shuttle run test; Beep) and anaerobic (speed; repeated speed ability test; RSA). Venous blood samples were collected before and after each exercise (5 and 60 min) to profile the complement system components, namely the levels of C2, C3, C3a, iC3b, and C4. The endurance effort caused a decrease in the post-test C3 (p < 0.001 for both age groups) and increase in post-test C3a (p < 0.001 and p < 0.01 for the younger and older group, respectively), recovery iC3b (p < 0.001 and p < 0.05 for younger and older group, respectively), recovery C2 (p < 0.01 for both age groups), and post-test C4 (p < 0.05 and p < 0.01 for the younger and older group, respectively) levels, while the speed effort caused a decrease only in the post-test C2 (p < 0.05 for younger participants) and post-test C4 levels (p < 0.001 and p < 0.01 for the younger and older group, respectively) and an increase in the recovery C3a level (p < 0.05). Our study provides evidence that different types of physical effort promote different immune responses in physically active young men. Aerobic exercise induced the activation of an alternative pathway of the complement system, whilst the anaerobic effort had little influence. A better understanding of the post-exercise immune response provides a framework to prescribe physical activity to achieve different health outcomes.