Nonpharmacological interventions on glycated haemoglobin in youth with type 1 diabetes: a Bayesian network meta-analysis.

The available evidence on the impact of specific non-pharmacological interventions on glycaemic control is currently limited. Consequently, there is a need to determine which interventions could provide the most significant benefits for the metabolic health of young individuals with type 1 diabetes mellitus. The aim of this study was to identify optimal nonpharmacological interventions on glycaemic control, measured by glycated haemoglobin (HbA1c), in children and adolescents with type 1 diabetes. Systematic searches were conducted in PubMed, Web of Science, Scopus, and SPORTDiscus from inception to July 1, 2023. Randomised clinical trials (RCT) investigating nonpharmacological interventions (e.g., physical activity, nutrition, and behavioural therapies) were included. Primary outcome was change in HbA1c levels. Secondary outcome was change in daily insulin dose requirement. Seventy-four RCT with 6,815 participants (49.43% girls) involving 20 interventions were analysed using a network meta-analysis. Most interventions showed greater efficacy than standard care. However, multicomponent exercise, which includes aerobic and strength training (n = 214, standardised mean difference [SMD] =- 0.63, 95% credible interval [95% CrI] - 1.09 to - 0.16) and nutritional supplements (n = 146, SMD =- 0.49, - 0 .92 to - 0.07) demonstrated the greatest HbA1c reductions. These interventions also led to the larger decreases in daily insulin needs (n = 119, SMD =- 0.79, 95% CrI -  1.19 to - 0.34) and (n = 57, SMD =- 0.62, 95% CrI -  1.18 to - 0.12, respectively). The current study underscores non-pharmacological options such as multicomponent exercise and nutritional supplements, showcasing their potential to significantly improve HbA1c in youth with type 1 diabetes. Although additional research to confirm their efficacy is required, these approaches could be considered as potential adjuvant therapeutic options in the management of type 1 diabetes among children and adolescents.

Incidence of type 1 diabetes mellitus in children and adolescents under 20 years of age across 55 countries from 2000 to 2022: A systematic review with meta-analysis.

AIMS: The aim of this study was to determine the global incidence of type 1 diabetes mellitus (T1DM) in children and adolescents under 20 years of age from 2000 to 2022. MATERIALS AND METHODS: Two reviewers searched three electronic databases (PubMed, Web of Science, and CINAHL) for studies published between January 2000 and November 2022. Pooled estimates of T1DM incidence with a 95% confidence interval (CI) per 100,000 person-years were calculated by country/region, sex, age, and COVID-19 pandemic period (pre-COVID-19 and pandemic). RESULTS: The study included 126 studies from 55 countries and 18 regions. The incidence rate (IR) of T1DM from 2000 to 2022 was 14.07 (95%CI, 12.15-16.29) per 100,000 person-years. Finland and high-income North America had the highest IR, with 56.81 (95%CI, 55.91-57.73) and 28.77 (95%CI, 26.59-31.13) per 100,000 person-years, respectively. The IR was 13.37 (95%CI, 10.60-16.88) per 100,000 person-years in boys and 13.87 (95%CI, 11.51-16.70) per 100,000 person-years in girls. There were statistically significant differences among different age ranges: 0-4 versus 5-9 and 10-14 years old (p < 0.001); 5-9 versus 15-19 (p < 0.001) and 10-14 versus 15-19 years old (p = 0.003). Finally, during the pandemic period (2020-2022), the IR was 24.84 (95%CI, 17.16-35.96) per 100,000 person-years, which was higher but not significant compared with the prepandemic period (2017-2019) of 13.56 (95%CI, 7.49-24.56) per 100,000 person-years (p = 0.090). CONCLUSIONS: The IR of T1DM in children and adolescents under 20 years of age is substantial, especially during the pandemic period, although it varies across regions. More reliable data from additional countries are needed to determine the worldwide incidence of T1DM.

Reference values and associated factors of controlled attenuation parameter and liver stiffness in adults: A cross-sectional study.

BACKGROUND & AIMS: The utilization of non-invasive techniques for liver fibrosis and steatosis assessment has gained acceptance as a viable substitute for liver biopsy in clinical practice. This study aimed to establish normative data for the controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) by age and gender, as well as to explore the relationship between anthropometric measures, clinical status, and biochemical profile according to the 90th percentile cut-off values for CAP/LSM in a U.S. adult population. METHODS AND RESULTS: In this cross-sectional analysis, 7.522 US adults aged 20-80 years from the National Health and Nutrition Examination Survey (NHANES 2017-2020) were included. CAP and LSM were quantified using the FibroScan® 502-v2 device. A comprehensive range of data was collected, including sociodemographic, anthropometric, biochemical, lifestyle, and clinical conditions. Participants were segmented by sex and age. The median ± standard deviation (SD) for CAP was significantly lower in women (258.27 ± 61.02 dB/m) than in men (273.43 ± 63.56 dB/m), as was the median ± SD for LSM (women: 5.50 ± 4.12 kPa, men: 6.36 ± 5.63 kPa). Although median CAP and LSM values displayed an upward trend with age, statistical significance was not achieved. Notably, higher liver CAP values (above the 90th percentile) correlated with more pronounced clinical and biochemical profile differences compared to lower CAP values (below the 90th percentile) (p < 0.001). CONCLUSIONS: Our study provides age- and sex-stratified standard values for CAP and LSM in a sizeable, nationally representative cohort of adults. The evidence of sex-specific variations in TE test results from our study sets the stage for future research to further corroborate these findings.

Combined aerobic and muscle-strengthening activity guidelines and their association with obesity in US adolescents.

Most of the evidence on physical activity for maintaining a healthy weight in adolescents is based solely on aerobic physical activity alone, with little attention given to the muscle strength component. This study aimed to investigate the associations between aerobic activities and muscle-strengthening activities (MSA) and overweight/obesity among a representative sample of adolescents. Data from the United States-based Youth Risk Behavior Surveillance System for the 2011-2019 cycle were used in this cross-sectional study. Adolescents self-reported their adherence to aerobic and MSA guidelines, as well as their height and weight. Overweight and obesity were defined using the age- and sex-specific criteria of the Centers for Disease Control and Prevention, with a body mass index (BMI) ≥85th and ≥95th percentiles, respectively. We examined the associations between adherence to physical activity guidelines (reference: not meeting either of the physical activity guidelines) and overweight/obesity or obesity using binary logistic regressions. These analyses were adjusted for race/ethnicity, sex, age, screen time, sleep duration, tobacco, alcohol, fruit, vegetables, and soda consumption. A total of 42 829 adolescents (48.98% girls) were included in the study. Of these, 22.23% met both guidelines for physical activity, 30.47% had overweight/obesity, and 14.51% had obesity. Compared with meeting neither guideline, meeting both aerobic and MSA guidelines was associated with lower odds of having overweight/obesity (odds ratio [OR] = 0.64, 95% confidence interval [CI], 0.60 to 0.68) and obesity (OR = 0.52, 95% CI 0.48 to 0.56). These results were consistent across years of assessment, sex, and race/ethnicity. In conclusion, our results highlight the importance of MSA, which is often overlooked in physical activity recommendations in many studies, in combating childhood obesity in the United States.

Physical performance changes in season are associated with GPS data in soccer players.

This study investigated the associations between preseason and in-season performance with external workload in professional soccer players. Twenty-one players completed hamstring strength, countermovement jump (CMJ), 20-m sprint, and Yo-Yo intermittent recovery tests before (preseason) and after 8 weeks (in-season). External workload (total distance, high-intensity running distance, number of sprints, and power plays) was quantified during this period, and used to divide the average above and below subgroups outcome by outcome for further analyses. Significance was accepted when P≤0.05. Hamstring strength declined from pre- to in-season [-6%; p=0.014; effect size (ES): -0.41], while Yo-Yo performance improved (46%; p=0.001; ES: 1.31). When divided by high-intensity running distance, only the below-average subgroup improved CMJ performance (5%; p=0.030). For minutes played, the above-average subgroup improved Yo-Yo performance (41%; p<0.001), but not the below-average subgroup. Furthermore, playing time correlated with improved Yo-Yo performance (p=0.040; r=0.534). Improved 20-m sprint performance associated with more sprints performed (p=0.045; r=-0.453). Physical capabilities changed over a competitive season and were related to, and differentiated by, external workload. Because hamstring strength decreased and CMJ only improved in players exposed to less high-intensity external load, practitioners should individualize approaches to counteract these conditions when high external workload is performed over the season.

Factor structure of the 10-item CES-D Scale among patients with persistent COVID-19.

The presence of persistent coronavirus disease 2019 (COVID-19) might be associated with significant levels of psychological distress that would meet the threshold for clinical relevance. The Center for Epidemiologic Studies Depression Scale (CES-D) version 10 has been widely used in assessing psychological distress among general and clinical populations from different cultural backgrounds. To our knowledge, however, researchers have not yet validated these findings among patients with persistent COVID-19. A cross-sectional validation study was conducted with 100 patients from the EXER-COVID project (69.8% women; mean (±standard deviation) ages: 47.4 ± 9.5 years). Confirmatory factor analyses (CFAs) were performed on the 10-item CES-D to test four model fits: (a) unidimensional model, (b) two-factor correlated model, (c) three-factor correlated model, and (d) second-order factor model. The diagonal-weighted least-squares estimator was used, as it is commonly applied to latent variable models with ordered categorical variables. The reliability indices of the 10-item CES-D in patients with persistent COVID-19 were as follows: depressive affect factor ( α Ord = 0 . 82 ${\alpha }_{\mathrm{Ord}}=0.82$ ; ω u - cat = 0 . 78 ${\omega }_{{\rm{u}}-\mathrm{cat}}=0.78$ ), somatic retardation factor ( α Ord = 0 . 78 ${\alpha }_{\mathrm{Ord}}=0.78$ ; ω u - cat = 0 . 56 ${\omega }_{{\rm{u}}-\mathrm{cat}}=0.56$ ), and positive affect factor ( α Ord = 0 . 56 ${\alpha }_{\mathrm{Ord}}=0.56$ ; ω u - cat = 0 . 55 ${\omega }_{{\rm{u}}-\mathrm{cat}}=0.55$ ). The second-order model fit showed good Omega reliability ( ω ho = 0 . 87 ${\omega }_{\mathrm{ho}}=0.87$ ). Regarding CFAs, the unidimensional-factor model shows poor goodness of fit, especially residuals analysis (root mean square error of approximation [RMSEA] = 0.081 [95% confidence interval, CI = 0.040-0.119]; standardized root mean square residual [SRMR] = 0.101). The two-factor correlated model, three-factor correlated model, and second-order factor model showed adequate goodness of fit, and the χ2 difference test ( ∆ X 2 $\unicode{x02206}{X}^{2}$ ) did not show significant differences between the goodness of fit for these models ( ∆ X 2 = 4.1128 $\unicode{x02206}{X}^{2}=4.1128$ ; p = 0.127). Several indices showed a good fit with the three-factor correlated model: goodness-of-fit index = 0.974, comparative fit index = 0.990, relative noncentrality index = 0.990, and incremental fit index = 0.990, which were all above 0.95, the traditional cut-off establishing adequate fit. On the other hand, RMSEA = 0.049 (95% CI = 0.000-0.095), where an RMSEA < 0.06-0.08 indicates an adequate fit. Item loadings on the factors were statistically significant ( λ j ≥ 0.449 ${\lambda }_{j}\ge 0.449$ ; p's < 0.001), indicating that the items loaded correctly on the corresponding factors and the relationship between factors ( ϕ ≥ 0.382 $\phi \ge 0.382$ ; p's ≤ 0.001. To our knowledge, this is the first study to provide validity and reliability to 10-item CES-D in a persistent COVID-19 Spanish patient sample. The validation and reliability of this short screening tool allow us to increase the chance of obtaining complete data in a particular patient profile with increased fatigue and brain fog that limit patients' capacity to complete questionnaires.

Twenty-four-hour movement guidelines during adolescence and its association with obesity at adulthood: results from a nationally representative study.

To determine the association between adherence to the 24-h movement guidelines during adolescence with obesity at adulthood 14 years later in a nationally representative cohort. We analyzed data from 6984 individuals who participated in Waves I (1994-1995) and IV (2008-2009) of the National Longitudinal Study of Adolescent Health (Add Health) in the USA. Obesity was defined by the International Obesity Task Force cut-off points at Wave I and adult cut-points at Wave IV (body mass index [BMI]≥30 kg/m2 and waist circumference [WC]≥102 cm in male and 88 cm in female). Physical activity, screen time and sleep duration were self-reported. Adolescents who met screen time recommendation alone (ß = -1.62 cm, 95%CI -2.68 cm to -0.56), jointly with physical activity (ß = -2.25 cm, 95%CI -3.75 cm to -0.75 cm), and those who met all three recommendations (ß = -1.92 cm, 95%CI -3.81 cm to -0.02 cm) obtained lower WC at Wave IV than those who did not meet any of these recommendations. Our results also show that meeting with screen time recommendations (IRR [incidence rate ratio] = 0.84, 95%CI 0.76 to 0.92) separately and jointly with physical activity recommendations (IRR = 0.86, 95%CI 0.67 to 0.97) during adolescence is associated with lower risk of abdominal obesity at adulthood. In addition, adolescents who met all 24-h movement recommendations had lower risk of abdominal obesity later in life (IRR = 0.76, 95%CI 0.60 to 0.97). CONCLUSION: Promoting the adherence to the 24-h movement guidelines from adolescence, especially physical activity and screen time, seems to be related with lower risk of abdominal obesity later in life, but not for BMI. WHAT IS KNOWN: • Some studies have shown a relationship between adherence to 24-h movement guidelines and adiposity or obesity markers in youth. However, most of these studies have a cross-sectional design or a short follow-up. WHAT IS NEW: • This is the first study which determined the association between adherence to the 24-h movement guidelines during adolescence with obesity at adulthood 14 years later in a nationally representative US cohort. • Meeting the 24-h movement guidelines from adolescence seems to be related with lower risk of abdominal obesity later in life, but not for body mass index.

Effect of immunology biomarkers associated with hip fracture and fracture risk in older adults.

Osteoporosis is a skeletal disease that can increase the risk of fractures, leading to adverse health and socioeconomic consequences. However, current clinical methods have limitations in accurately estimating fracture risk, particularly in older adults. Thus, new technologies are necessary to improve the accuracy of fracture risk estimation. In this observational study, we aimed to explore the association between serum cytokines and hip fracture status in older adults, and their associations with fracture risk using the FRAX reference tool. We investigated the use of a proximity extension assay (PEA) with Olink. We compared the characteristics of the population, functional status and detailed body composition (determined using densitometry) between groups. We enrolled 40 participants, including 20 with hip fracture and 20 without fracture, and studied 46 cytokines in their serum. After conducting a score plot and two unpaired t-tests using the Benjamini-Hochberg method, we found that Interleukin 6 (IL-6), Lymphotoxin-alpha (LT-α), Fms-related tyrosine kinase 3 ligand (FLT3LG), Colony stimulating factor 1 (CSF1), and Chemokine (C-C motif) ligand 7 (CCL7) were significantly different between fracture and non-fracture patients (p < 0.05). IL-6 had a moderate correlation with FRAX (R2 = 0.409, p < 0.001), while CSF1 and CCL7 had weak correlations with FRAX. LT-α and FLT3LG exhibited a negative correlation with the risk of fracture. Our results suggest that targeted proteomic tools have the capability to identify differentially regulated proteins and may serve as potential markers for estimating fracture risk. However, longitudinal studies will be necessary to validate these results and determine the temporal patterns of changes in cytokine profiles.

Is fear of hypoglycemia a major barrier to an active lifestyle in children and adolescents with type 1 diabetes? The Diactive-1 Study.

Studies on fear of hypoglycemia as a barrier to physical activity among youth with type 1 diabetes (T1D) have been limited and controversial, most of which used self-reported assessment. The aim of the study was to evaluate the relationship between fear of hypoglycemia and physical activity and glycemic metrics in children and adolescents with T1D. Seventy-four participants (6-18 years of age; 44.6% females) with T1D were included in the study. Physical activity was assessed through accelerometry on nine consecutive days, and blood glucose metrics were simultaneously tracked using continuous glucose monitoring (time-in-range and hypoglycemic events). A closed question was used to evaluate the avoidance of physical activity due to fear of hypoglycemia. Fifteen participants (20%) reported avoiding physical activity due to fear of hypoglycemia. The group reporting no fear of hypoglycemia showed lower total physical activity (-35.33 min/day, 95% confidence interval [CI] (-77.57 to -1.47)) and light physical activity (-29.81 min/day, 95% CI -64.01 to -2.75) and higher sedentary time (77.95 min/day, 95% CI 26.46-136.87) per day compared with those with fear of hypoglycemia. No difference was found between those patients with fear of hypoglycemia in terms of meeting the recommendations of glycated hemoglobin, glucose coefficient of variation, and time-in-range when compared to those with no fear of hypoglycemia. In conclusion, children and adolescents with fear of hypoglycemia were more active, less sedentary, and had similar glycemic metrics to those without fear. Our results therefore suggest that fear of hypoglycemia may be less of a barrier to an active lifestyle than previously believed.

Prevalence of meeting all three 24-h movement guidelines and its correlates among preschool-aged children.

The aim of the present study was twofold: first, to determine the meeting all three 24-h movement guidelines in Colombian preschool-aged children, and second, to explore the associations between different socio-ecological correlates and the meeting of these guidelines. This was a cross-sectional study with data from the Encuesta Nacional de Situación Nutricional (ENSIN-2015) in Colombia, 2015-2016. The sample comprised 3002 low-income preschoolers (3-4 years old, 50.7% boys). Data on physical activity, screen time, and sleep time were collected using the Cuestionario para la Medición de Actividad Física y Comportamiento Sedentario, reported by their parents. In total, 18 potential correlates (individual, interpersonal, organizational, and community level) were analyzed. Backward binary logistic regression analysis was performed with the potential correlates as independent variables and meeting all three 24-h movement guidelines as dependent variables. The prevalence of preschoolers meeting all three 24-h movement guidelines or none was 4.8% and 16.6%, respectively. In the final model, boys (odds ratio [OR] = 1.87, 95% confidence interval [CI] 1.00-3.50) and those who do not have television in their bedroom (OR = 2.09, 95%CI 1.05-4.14) were more likely to meet all three 24-h movement guidelines compared to with girls and those who have television, respectively. In conclusion, strategies to promote adherence to all 24-h movement guidelines among low-income preschoolers are warranted, and should focus on actions considering the importance of sex and home environment changes to support these movement behaviors.

A descriptive ranking of blood pressure and physical fitness of Latin-American ethnic schoolchildren.

BACKGROUND: There is a general lack of information about how insufficient physical activity impacts blood pressure and physical fitness in Latin-American ethnic minorities. AIMS: To describe the interactions between insufficient physical activity, blood pressure, and physical fitness outcomes in Latin-American schoolchildren of different ethnicity. METHODS: This was a prospective, international, multi-center, and cross-sectional study of three Latin-American countries involving schoolchildren from seven ethnic groups of Colombia (Tikuna, Nasa, Embera), Brazil (African, Mulato), and Chile (Mapuche), and also European schoolchildren from Brazil and Chile. Data were categorized based on whether participants were physically active (PA) or insufficient physical activity (iPA) using the WHO physical activity recommendations. The main outcomes were systolic (SBP), diastolic (DBP), and mean arterial (MAP) blood pressure, and scores for physical and cardiorespiratory fitness (CRF, by estimated V˙O2max), handgrip muscle strength (HGS), and standing long jump (SLJ). Secondary outcomes were anthropometric measures (weight, height, body mass index [BMI], waist circumference [WC], waist-to-height ratio), and body fat percentage (BF%, limited data by country). Primary and secondary outcomes were ranked. RESULTS: For both PA and iPA categories, significant interactions between ethnic groups were found concerning SBP/DBP (F(37.7), ES 0.08; F(51.5), ES 0.08), V˙O2max (F(37.7), ES 0.08; F(51.5), ES 0.08), HGS (F(33.8), ES 0.07; F(5.03), ES 0.04), and SLJ (F(64.3), ES 0.14; F(64.3), 0.14). In the iPA category, Mapuche schoolchildren were classified 1st (119.5; 81.5) with highest SBP/DBP and highest MAP (94.6 mmHg); Embera schoolchildren were classified 1st with lowest V˙O2max (33.7 mL/kg/min); and European schoolchildren were classified 1st (19.9 kg) with lowest HGS and SLJ (121.4 m) physical fitness. CONCLUSIONS: Under conditions of insufficient physical activity conditions, Mapuche schoolchildren had the most detrimental blood pressure, whereas Embera, Tikuna, and European schoolchildren had the lowest levels of physical fitness. These results serve to highlight the need for the early and appropriate promotion of physical activity based on ethnic differences in Latin-American schools.

Adherence to aerobic and muscle-strengthening activities guidelines: a systematic review and meta-analysis of 3.3 million participants across 32 countries.

OBJECTIVE: To estimate the global prevalence of meeting the WHO guidelines for both aerobic and muscle-strengthening activities (MSA) in populations aged ≥5 years, and whenever possible to explore this prevalence according to sociodemographic and lifestyle factors. DESIGN: A systematic review and meta-analysis. DATA SOURCES: Five databases were systematically searched for studies published from inception to September 2022. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Articles with representative samples aged ≥5 years reporting the prevalence of meeting both aerobic and MSA guidelines were included. RESULTS: Twenty-one studies comprising 3 390 001 individuals from 32 countries were included. Overall adherence to the aerobic and MSA guidelines was 17.12% (95% CI 15.42% to 18.88%) in adults ≥18 years (n=3 346 723). Among adolescents aged 12-17 years, adherence to both guidelines was 19.74% (95% CI 14.72% to 25.31%) (n=43 278). No studies reported data for children aged 5-11 years. Women, older age, low/medium education levels, underweight or obesity, and poor and moderate self-rated health were associated with lower adherence to the physical activity guidelines (p<0.001) among adults, although the prevalence remained very low in all cases. Subgroup analyses were not conducted with children and adolescents due to a lack of studies. CONCLUSIONS: Only one out of five adolescents and adults met the recommended combined aerobic and MSA guidelines. Large-scale public health interventions promoting both types of exercise are needed to reduce the associated burden of non-communicable diseases. PROSPERO REGISTRATION NUMBER: CRD42022338422.

Mechanical Determinants of Sprinting and Change of Direction in Elite Female Field Hockey Players.

Profile determination in field hockey is critical to determining athletes' physical strengths and weaknesses, and is key in planning, programming, and monitoring training. This study pursued two primary objectives: (i) to provide descriptive data on sprinting, deceleration, and change of direction (COD) abilities and (ii) to elucidate the mechanical variables that influence sprint and COD performance in elite female field hockey players. Using radar and time-gate technology, we assessed performance and mechanical data from 30 m sprinting, deceleration, and COD tests for 26 elite female hockey players. A machine learning approach identified mechanical variables related to sprint and COD performance. Our findings offer a framework for athlete categorization and the design of performance-enhancing training strategies at the international level. Two pivotal mechanical variables-relative maximum horizontal force (F0) and maximum velocity (Vmax)-predominantly influence the times across all tested distances. However, the force-velocity profile (FVP) and horizontal deceleration do not influence the variance in the COD test outcomes. These insights can guide the design, adjustment, and monitoring of training programs, assisting coaches in decision making to optimize performance and mitigate injury risks for female hockey players.

Effects of Moderate-to-Heavy Sled Training Using Different Magnitudes of Velocity Loss in Professional Soccer Players.

ABSTRACT: Grazioli, R, Loturco, I, Lopez, P, Setuain, I, Goulart, J, Veeck, F, Inácio, M, Izquierdo, M, Pinto, RS, and Cadore, EL. Effects of moderate-to-heavy sled training using different magnitudes of velocity loss in professional soccer players. J Strength Cond Res 37(3): 629-635, 2023-This study investigated the effects of a 11-week moderate-to-heavy sled training intervention with different magnitudes of velocity loss on sprint and jump performance, mechanical muscle function, and body composition in professional soccer players. Seventeen players (age 25.8 ± 4.3 years; height 180.0 ± 8.6 cm; mass 77.7 ± 9.7 kg) were randomly allocated into 2 groups, based on different magnitudes of velocity loss: 10% of velocity decrease (G10, n = 8) and 20% of velocity decrease (G20, n = 9). The velocity-based sled training consisted of 20-m resisted sprints with a progressive loading increase from 45 to 65% of body-mass throughout the intervention. Pre-intervention and postintervention sprint and jump performance, hamstring and quadriceps peak torque and isometric rate of torque development, and lower-limb lean mass measured by dual X-ray absorptiometry were assessed and compared. Two-way repeated measures analysis of variance revealed a significant time-effect for decreases in 10- and 20-m sprint times ( p = 0.018 and p = 0.033, respectively), but without a time-group interaction. The G10 showed greater beneficial effects than G20 for both 10-m (-5.5 ± 3.3%, magnitude-based inference [MBI]: possibly vs. -1.7 ± 5.9%, MBI: possibly trivial) and 20-m (-2.5 ± 2.1%, MBI: possibly vs. -1.4 ± 3.7%, MBI: likely trivial) sprint times. Moreover, there was a significant time effect for countermovement jump height and quadriceps isometric peak torque, which decreased significantly after training ( p = 0.019 and p = 0.010, respectively), with no within-group effect of time vs. group interaction for these respective outcomes. The novel velocity-based sled model proposed here, especially under lower magnitudes of velocity loss, was able to significantly improve linear sprint performance in professional soccer players.

Associations between physical fitness components with muscle ultrasound parameters in prepuberal children.

BACKGROUND/OBJECTIVES: Muscle ultrasound is a convenient technique to visualize normal and pathological muscle tissue as it is non-invasive and real-time. This technique is related to several physical performance parameters and body composition components in adults; however, this relationship remains unexplored in early aged. We aimed to evaluate the association between physical fitness components with muscle ultrasound parameters in prepuberal children. METHODS: A sample of 282 prepuberal children aged 5-9 years (144 boys) participated in the study. A trained sonographer obtained six B-mode images from femoral rectus for muscle thickness, subcutaneous adipose tissue (SAT) and area of the muscle of interest, were captured, and muscle ultrasound parameters (echo-intensity: EI uncorrected, EI correct equations) and intramuscular adipose tissue (IMAT) were extracted. Lean muscle tissue has low EI, whereas intramuscular fat and connective tissue have high EI. Physical fitness components (cardiorespiratory fitness, upper and lower muscle strength, speed-agility, and overall fitness levels) were also evaluated. Children were categorized as fit or unfit for each specific fitness test. RESULTS: After adjustment for sex and age, higher physical fitness components and overall fitness (z-score) levels were negatively associated with EI, IMAT, and SAT (cardiorespiratory fitness ß range = -0.264 to -0.298; upper-muscular strength ß range = -0.389 to -0.457; and lower-muscular strength ß range = -0.202 to -0.279; and speed-agility ß range = -0.257 to -0.302). Children categorized as fit according to four physical fitness components had lower EI uncorrected, EI correct equation 1-2, IMAT, and SAT than unfit children for each respective tests (all Ps < 0.001). CONCLUSION: Physical fitness components are inversely associated with EI, IMAT, SAT after adjusting for potential confounders, including sex and age, in prepuberal children. The present study strengthens the idea that muscle and adiposity parameters is affected by physical fitness even from early childhood.

Discriminatory capacity of obesity indicators as predictors of high liver fat in US adolescents.

BACKGROUND: The aims of this study were to assess the potential of 16 anthropometric, body composition and endocrine indexes as predictors of high liver fat and determine the most appropriate cut-off points in US adolescents. METHODS: A cross-sectional study was conducted on a population of 816 adolescents aged 12-17 years. The FibroScan® 502V2 device was used to estimate the controlled attenuation parameter (CAP). Body fat percentage, fat mass, trunk fat percentage and trunk fat mass were measured by dual-energy X-ray absorptiometry. Anthropometric data and metabolic parameters were determined. Receiver operating characteristic curves were analysed to estimate the optimal cut-off points that best identify adolescents with high liver fat (CAP ≥90th percentile). RESULTS: In boys, triponderal mass index (TMI) had the highest area under curve (AUC) value (0.865) and the optimal cut-off score for TMI was 17.47 kg/m3 , which had 81.32 sensitivity and 82.99 specificity. In girls, trunk fat index (TFI) had the highest AUC value (0.826) and its optimal cut-off score in screening for high liver fat was 3.76 kg/m2 , which had 74.04 sensitivity and 88.03 specificity. Fat mass index (FMI) index had the second highest AUC values (0.863 in boys 0.812 in girls) in both sex; the cut-off point for the detection of high liver fat was <8.66 kg/m2 for girls and <7.45 kg/m2 for boys. CONCLUSION: Assessment of TMI in boys, TFI in girls, and FMI in both sexes are low-cost and easy-to-use parameters that may be useful as early screening tools for possible high liver fat in adolescents.

Defining values for controlled attenuation parameter and liver stiffness in youth without liver disease.

BACKGROUND: We aimed to determine the reference values to define an age-specific normal range of controlled attenuation parameter (CAP, a measure of liver steatosis) and liver stiffness measurement (LSM) values assessed by ultrasound-based transient elastography in adolescents without underlying liver disease. METHODS: A total of 462 participants were included in this cross-sectional study using data from NHANES 2017-2018. LSM and CAP were carried out using the FibroScan® M-probe. Anthropometric, metabolic and hematological parameters were measured. RESULTS: The median CAP was 199.0 dB/m (150.0-245.0 dB/m, 10th to 90th percentiles) and the median LSM was 4.7 kPa (3.4-6.3 kPa, 10th to 90th percentiles) for ages 12-19.9 years. Regression analyses show that the CAP and LSM were not positively correlated with age (boys CAP R2 = 0.001, p = 0.576 and LSM R2 = 0.012, p = 0.096; girls CAP R2 = 0.011, p = 0.113 and LSM R2 = 0.006, p = 0.236). Finally, CAP was positively associated with LSM in girls (ß = 0.189, p = 0.005) but not in boys (ß = -0.083, p = 0.202). CONCLUSIONS: The reference values indicated here for LSM and CAP will help in the screening of adolescents between ages 12 and 19.9 years and might serve as a useful method for identifying those youth at high risk of nonalcoholic fatty liver disease. IMPACT: The reference values indicated in this study for liver stiffness measurement (LSM) and controlled attenuation parameter (CAP) will help in the screening of adolescents between ages 12 and 19.9 years in clinical practice. The cutoffs of LSM and CAP might serve as a useful method for identifying those youth at high risk of nonalcoholic fatty liver disease.

Low handgrip strength is associated with higher liver enzyme concentrations in US adolescents.

BACKGROUND: Increasing evidence highlights the role of muscular strength as a protective factor for cardiometabolic health in adolescents. However, it is not known the relationship between liver enzyme concentrations, liver disease risk factors, and muscular strength among young populations. The aim of this study was to determine the association between muscle strength and liver enzymes and chronic liver disease risk among US adolescents. METHODS: Data from the NHANES cross-sectional study (2011-2014) was used. A total of 1270 adolescents were included in the final analysis (12-17 years old). Absolute handgrip strength (kg) was normalized according to body composition parameters by body weight [NHSw], whole-body fat [NHSf], and trunk fat [NHSt]). RESULTS: In boys, handgrip strength was inversely associated with higher values of aspartate aminotransferase (AST) and gamma glutamyl transpeptidase (GGT) for all estimations of muscle strength (NHSw, NHSf, and NHSt) (p < 0.050). Likewise, boys with high and intermediate NHSw, NHSf, and NHSt presented lower AST and GGT than their counterparts with low handgrip strength (p < 0.050). CONCLUSIONS: Our findings highlight the importance of muscular strength during adolescence since they could help in developing better liver enzyme profiles among adolescent population. IMPACT: Our research suggests that US adolescents with low handgrip strength have higher values of liver enzymes as well as a higher prevalence of chronic liver disease. These findings are clinically meaningful and highlight the importance of muscular strength during adolescence since they could help in developing better liver enzyme profiles among young populations.

Trajectories of 24-h movement guidelines from middle adolescence to adulthood on depression and suicidal ideation: a 22-year follow-up study.

BACKGROUND: The 24-h movement guidelines for youth and adults recommend the specific duration of physical activity, sedentary time, and sleep duration to ensure optimal health, but little is known about its relationship to mental health indicators. The aim of the study was to explore the association between 24-h movement guidelines in adolescence and its trajectories from middle adolescence (12-17 years old) to adulthood (33-39 years old) with depression and suicidal ideation in adulthood. METHODS: This prospective cohort study included individuals who participated in Waves I (1994-1995) and V (2016-2018) of the National Longitudinal Study of Adolescent Health (Add Health) in the United States. Physical activity, screen time and sleep duration were measured using questionnaires. Adults were categorized as having depression if they had a self-reported history of depression and/or prescription medication-use for depression in the previous four weeks. Suicidal ideation was assessed by a self-reported single question in both waves. Poisson regression analyses were used to estimate the incidence rate ratio (IRR) of depression and suicidal ideation at adulthood, according to meeting specific and combinations of 24-h movement guidelines at Wave I and its trajectories from adolescence to adulthood. RESULTS: The study included 7,069 individuals (56.8% women). Adolescents who met physical activity guidelines and all three guidelines at middle adolescence had lower risk of depression (IRR = 0.84, 95%CI 0.72 to 0.98) and suicidal ideation (IRR = 0.74, 95%CI 0.55 to 0.99) at adulthood than those who did not meet any of these guidelines, respectively. Individuals who met the guidelines for screen time and all three guidelines in both adolescence and adulthood had lower risk of depression (screen time, IRR = 0.87, 95% CI 0.72 to 0.98; all three, IRR = 0.37, 95% CI 0.15 to 0.92) and suicidal ideation (screen time, IRR = 0.74, 95% CI 0.51 to 0.97; all three, IRR = 0.12, 95% CI 0.06 to 0.33) than those who never met the guidelines. Additionally, individuals who did not meet all three guidelines in adolescence but met the guidelines in adulthood had lower risk of suicidal ideation than those who never met the guidelines (IRR = 0.81, 95%CI 0.45 to 0.89). CONCLUSION: Our findings highlight the importance of promoting and maintaining adherence to the 24-h movement guidelines from middle adolescence to adulthood to prevent mental health problems. However, our findings must be interpreted carefully due to declared limitations, e.g., the self-reported assessments which are subject to sources of error and bias or that the dataset used to gauge meeting a guidelines (1994-1996) was made later (2016).

Is adherence to the Mediterranean diet associated with healthy habits and physical fitness? A systematic review and meta-analysis including 565 421 youths.

The relationship between adherence to the Mediterranean diet (MD), physical activity (PA), sedentary behaviour and physical fitness levels has been analysed in several studies; however, there is mixed evidence among youth. Thus, this study aimed to meta-analyse the associations between adherence to the MD, PA, sedentary behaviour and physical fitness among children and adolescents. Three databases were systematically searched, including cross-sectional and prospective designs with a sample of healthy youth aged 3-18 years. Random effects inverse-variance model with the Hartung-Knapp-Sidik-Jonkman adjustment was used to estimate the pooled effect size (correlation coefficient (r)). Thirty-nine studies were included in the meta-analysis, yielding a total of 565 421 youth (mean age, 12·4 years). Overall, the MD had a weak-to-moderate positive relationship with PA (r 0·14; 95 % CI 0·11, 0·17), cardiorespiratory fitness (r 0·22; 95 % CI 0·13, 0·31) and muscular fitness (r 0·11; 95 % CI 0·03, 0·18), and a small-to-moderate negative relationship with sedentary behaviour (r -0·15; 95 % CI -0·20, -0·10) and speed-agility (r -0·06; 95 % CI -0·12, -0·01). There was a high level of heterogeneity in all of the models (I2 ≥ 75 %). Overall, results did not remain significant after controlling for sex and age (children or adolescents) except for PA. Improving dietary habits towards those of the MD could be associated with higher physical fitness and PA in youth, lower sedentary behaviours and better health in general.