Search Results (116)

Tennis is a demanding sport that requires physical abilities and optimal body composition. The aim of this study was to investigate the anthropometric characteristics, body composition, and somatotype development of young Slovenian tennis players (754 boys and 514 girls aged 12 to 18 years) over the last two decades. Using standardised anthropometric measurements and the Heath-Carter method, somatotypes were calculated and analysed by age and gender. The results showed clear age- and gender-specific trends and differences in both somatotype profiles and detailed anthropometric characteristics. Significant differences were found in height, body mass, BMI, skinfolds, girths, and limb lengths, with gender differences becoming more pronounced in the older age groups. In boys, mesomorphy increased with age, reflecting an increase in musculature, while in girls, a shift from ectomorphic to endomorphic profiles was observed during adolescence, probably influenced by pubertal and hormonal changes. Significant sex-specific differences were observed in all three somatotype components in most age groups, especially in fat mass and muscle. The longitudinal design provides valuable data and insights into the evolving physical profiles of adolescent tennis players that support more effective talent identification and training. Despite the changes that have taken place in tennis over time, standardised measurement protocols ensured comparability, making the results relevant for practitioners working with adolescents in tennis development. Full article

Background/Objectives: Childhood cancer survivors (CCS) experience chronic health problems and significant metabolic burden. Timely identification of CCS at higher metabolic risk requires novel biomarkers. Irisin, a novel myokine/adipokine has been associated with metabolic, bone and reproductive diseases, but its role in the health of CCS is unknown. The aim of this study was to examine irisin concentrations in children and adolescent CCS (vs. controls) and their association with metabolic, bone and hormonal parameters. Methods: Children and adolescent CCS, aged 8–18 years, as well as healthy controls, underwent a detailed physical, body composition, biochemical, hormonal and serum irisin assessment at least 6 months post-treatment. Results: A total of 59 children and adolescents (36 CCS, 23 controls; mean age ± SD 12.8 ± 2.9 years; 10 prepubertal, 49 pubertal) participated in the study. Serum irisin concentrations (ng/mL) were significantly lower in CCS than controls [median (IQR) 6.54 (4.12) vs. 11.70 (8.75) ng/mL, respectively, p < 0.001]. In the total study sample, serum irisin was correlated negatively with LH (r_s = −0.314, p < 0.05), CRP (r_s = −0.366, p < 0.005), age (r_s = −0.323, p < 0.05) and positively with ALP (r_s = 0.328, p < 0.05). Serum irisin was also positively correlated with ApoB and Lpa (r_s = 0.410 and 0.421, respectively, p < 0.05) in CCS, and with PTH (r = 0.542, p < 0.005) in controls. Multivariate linear regression analysis indicated parathyroid hormone (PTH) as the only independent variable affecting irisin concentrations. Conclusions: Study results reinforce the irisin–PTH interplay hypothesis. Future studies are needed to clarify the potential role of irisin as a bone biomarker of CCS in childhood and adolescence. Full article

The aim of this study was to determine whether a low dose of zearalenone (ZEN) affects the mRNA expression of the CYP1A1 (P450 cytochrome) and GSTπ1 (glutathione S-transferase) genes in the large intestine of pre-pubertal gilts. Materials: Control (C) group gilts (n = 18) received a placebo. Experimental (E) group gilts (n = 18) were orally administered 40 μg ZEN/kg body weight (BW) each day before morning feeding for 42 days. Three animals from each group were sacrificed each week of the study. Tissue samples were collected from the medial parts of the ascending colon and the descending colon on six dates. Results: Zearalenone concentrations were multiple times higher in the last three weeks of exposure, and ZEN metabolites were not detected. In phase I, CYP1A1 mRNA expression in the ascending colon was suppressed in the final three weeks of exposure, which substantially increased the ZEN concentration in the descending colon. In phase II, ZEN levels were high in the descending colon due to CYP1A1 suppression in the ascending colon. Consequently, the phase II detoxification processes could not take place due to the absence of a substrate. Conclusion: This study demonstrated that low-dose ZEN mycotoxicosis disrupts the expression of the CYP1A1 and GSTπ1 genes, which co-participate in the enzymatic biotransformation of ZEN in both examined sections of the large intestine. The above could have contributed to increased ZEN accumulation in the mucosa of the descending colon in the last three weeks of exposure. Full article

Objectives: The aim of this study was to indicate which variables are the most important determinants of swimming results in the 50 m front crawl among non-elite pre-pubertal female swimmers. Methods: The study group consisted of 14 female swimmers (at the time of the research commencement—biological age: 10.52 ± 0.37 years; body mass: 34.99 ± 2.77 kg; height: 146.00 ± 3.05 cm). The study was conducted over three years. The swimmers performed capacity training recommended by the British Swimming Federation. Every 6 months, in the participants the following parameters were measured: percentage of body fat; anthropometric measurements; aerobic and anaerobic capacity; and respiratory parameters: vital capacity—VC, forced expiratory volume—FEV1, and forced vital capacity—FVC. Additionally, a 50 m front crawl swim test was performed. Results: After adjusting for multicollinearity, the most influential determinants of swimming performance were anthropometric measures: shoulder width was the most influential predictor, with a regression coefficient of −0.66, followed by foot length (with a beta of −0.15) and chest depth (with a beta of 0.008). The remaining anthropometric and physical predictors did not contribute to the prediction of 50 m freestyle performance. Conclusions: These research results suggest to coaches and trainers that sports performance in sprint distances in pre-pubertal girls is not determined by aerobic and anaerobic capacity or body fat but is based on the somatic build of the swimmer. Full article

Objectives: This randomized controlled trial investigated the effects of an 8-week, volume-equated eccentric training program comprising Nordic hamstring and reverse Nordic exercises performed either once or twice per week on measures of physical fitness in pubertal male soccer players. Methods: A total of 34 participants were randomly assigned into a 1-day (n = 16; age = 14.58 ± 0.28 years) or 2-day (n = 18; age = 14.84 ± 0.22 years) per week training group. Physical fitness was assessed using 5 m and 10 m sprints, the 505 change in direction (CiD) speed test, Y-shaped agility test, countermovement jump (CMJ), and standing long jump (SLJ). Results: Significant group-by-time interactions were observed for the 505 CiD test, agility, and CMJ performance (effect sizes [ES] = 0.80 to 1.13). However, no significant interactions were found for the 5 and 10 m sprints or for SLJ (p > 0.05). Compared to the 1-day group, the 2-day training group showed greater improvements in CiD speed (∆7.36%; p < 0.001; ES = 0.92), agility (∆7.91%; p < 0.001; ES = 1.68), and CMJ (∆7.44%; p < 0.01; ES = 0.35), while no differences were observed in 5 and 10 m linear sprints or SLJ performance. According to individual response analysis, improvements across the physical fitness parameters beyond the smallest worthwhile change (SWC_0.2) were observed in 22–83% of players in the 1-day group and 77–100% in the 2-day group. Conclusions: In summary, the findings suggest that when training volume is matched, distributing the eccentric training regimen over two days per week may lead to greater improvements in CiD speed, agility, and CMJ performance compared to a single-day approach. Full article

We aim to provide a translational model to investigate the reproductive consequences of pubertal delay using the GnRH agonist triptorelin in transgender girls, tested in particular on testicular maturation in peripubertal rats. A total of 30 Sprague Dawley rats were utilized, with 10 subjects assigned to each of three groups from day P30 postpartum (prepubertal) until day P95 (postpubertal), mimicking treatment timing in patients. Rats received triptorelin at three time points (P30, P50, and P71), or only at P30 and P50. Control rats were injected with vehicle. Plasma testosterone levels were determined using MRM analysis. Testes and epididymides were examined histologically. There were significantly lower testosterone levels at postnatal day 48 in treated rats, indicating delayed puberty, with further reductions by day 69. By day 93, testosterone levels had recovered in rats given vehicle at P71 but remained low in the triptorelin-continuous group, suggesting the reversibility of the treatment. Treated rats had smaller testes; however, the majority of the testicular parenchyma was unaffected, with most seminiferous tubules displaying complete spermatogenesis. However, focal atrophic changes were observed in 1–30% of the parenchyma. One-third of the short-term group and half of the long-term group were classified as atrophic. Despite these changes, all treated rats had mature sperm in the epididymis, ensuring their fertility. In conclusion, triptorelin treatment promotes a decline in testosterone levels accompanied by discrete atrophy of the seminiferous tubules, which is partially reversible and compatible with sperm production and fertility preservation. Triptorelin could be an appropriate treatment prior to estrogen therapy for patients seeking gender transition. Full article

Background/Objectives. With a rapid palatal expander (RPE) is reported to be effective in increasing the volume of nasal cavities, with a restoration of physiological nasal airflow. The purpose of this retrospective clinical study was to evaluate, using Cone Beam Computed Tomography (CBCT), the volumetric changes and airflow velocity changes in the nasal cavities, retro-palatal and retro-glossal airways, resulting from the use of RPE with dental anchorage (group A), also comparing these data with patients non treated with RPE (group B). Methods. Sixteen subjects (aged 9.34 years) with transverse maxillary deficiency and unilateral posterior crossbite were treated with RPE with dental anchorage. Additionally, 8 patients (aged 11.11 years) with juvenile idiopathic arthritis, who did not undergo any orthodontic treatment, were selected as a control group. Expansion was performed until overcorrection was achieved, and the device was left in place for 6 months as fixed retention, followed by another 6 months of night-time removable retention. From the retrospective evaluation, all patients presented two CBCT scans at baseline (T0) and 1-year follow-up (T1). The 3D-Slicer software was used for each CBCT to measure the nasal (VN), retropalatal (VRP), and retroglossal (VRG) volumes, while an iterative Excel spreadsheet allowed for a pilot approximated modeling and calculation of airway flow-related data. Results. Regarding mean age, a statistically significant difference (p = 0.01 *) was found between groups, suggesting that group B is closer to the pubertal growth peak. Analysis between T0 and T1 revealed: (i) a statistically significant increase for volumes VN, VRP and VRG in group A; (ii) a statistically significant increase for VN in group B; (iii) a statistically significant decrease for all variables related to airflow velocity in both groups. Furthermore, comparison between group A and B, regarding variations between T0 and T1, found a statistically significant difference only for VN. Conclusions. Within the limitations of this pilot evaluation, the treatment with RPE revealed promising outcomes for retro-palatal, retro-glossal and nasal volumes, together with clinical changes in airflow velocities. Full article

Background/Objectives: In research on the relationship between pubertal timing and adolescent health, more attention is typically given to early rather than late maturation, as well as the associated risk of engaging in health-compromising behaviors. The aim of this study was to assess changes in HRQL (health-related quality of life) depending on subjectively perceived pubertal timing, measured in five categories. Methods: A cross-sectional online survey was conducted in spring 2024 in a western region of Poland (N = 9411; mean age 15.15 ± 1.56 years). Mean KIDSCREEN-27 index scores were compared according to self-reported pubertal timing, and five relevant general linear models were estimated, adjusting analyses for respondents’ age, sex, and the remaining four HRQL scores. Results: In the study group, 49.0% of students assessed their pubertal timing as typical, 28.5% as earlier, and 22.5% as later compared to peers of the same sex. For all five KIDSCREEN-27 dimensions, adolescents who matured at a pace perceived as typical achieved the highest quality-of-life index scores. Significantly earlier or significantly later pubertal timing was associated with a notable decrease in these indices. Some significant interactions were identified between sex or age and pubertal timing as predictors of HRQL. The strongest association with pubertal timing was observed for the Psychological Well-being dimension, where differences unfavorable to older age groups were additionally linked to delayed pubertal timing. Conclusions: Greater awareness of the relationship between perceived pubertal timing and adolescents’ well-being is warranted among preventive care physicians, parents, and school psychologists and educators. Full article

This overview explores the complex relationship between environmental factors, particularly obesity, and the timing of puberty, with a focus on how hormonal and genetic interactions are influenced by external conditions. Puberty (gonadarche) is characterised by the activation of the hypothalamic–pituitary–gonadal (HPG) axis. The onset and progression of puberty vary significantly among individuals, primarily due to genetic factors, with key genes like kisspeptin 1 (KISS1) and makorin ring finger protein 3 (MKRN3) playing a crucial role. Cohesively, this paper emphasises that environmental factors, particularly obesity and exposure to endocrine-disrupting chemicals (EDCs), have become significant influences on the timing of puberty. Childhood obesity has risen significantly in recent decades and the age of pubertal onset has declined over the same period. Obesity greatly disrupts hormone regulation in pre-pubertal children. Leptin accelerates the onset of puberty in girls but not in boys. The underlying mechanism is proposed to be the increase in Kiss1/GnRH signalling. On the contrary, excess leptin in boys suppresses testosterone production by increasing oestrogen conversion. Low adiponectin in obese girls may contribute to earlier puberty due to a reduced inhibition of Kiss1/GnRH signalling. Low adiponectin in boys is linked to delayed puberty due to its role in maintaining insulin sensitivity and testosterone production. Hyperinsulinemia influences pubertal timing through central and peripheral mechanisms. Insulin acting synergistically with leptin promotes the earlier onset of puberty in girls but not in boys. The effects of exposure to certain EDCs—mostly obesogenic chemicals that mimic the action of natural hormones—on the timing of puberty remain unclear; hence, further research on this topic is needed. Addressing and preventing obesity in children could potentially mitigate these alterations in pubertal timing. Full article

Background/Objectives: Animal models have suggested a link between maternal nutrition and offspring pubertal onset. Due to ethical and practical concerns, human studies on this topic remained scarce and focused on extreme nutritional shocks in high-income settings, such as Dutch famine. This paper expands on these findings by investigating the effects of a milder form of nutritional alteration during pregnancy—Ramadan fasting—in a middle-income context, Indonesia. We use offspring age at menarche (AAM) as an indicator of pubertal timing and female reproductive health. Our research has broader implications beyond the Muslim community, as intermittent fasting during pregnancy is also widely practiced by non-Muslims, e.g., meal-skipping. Methods: We used data from the Indonesian Family Life Survey (1993–2014, n = 8081) and Indonesian Demographic and Health Surveys (2002–2007, n = 13,241). OLS and Cox regressions were applied to compare the AAM of female Muslims who were prenatally exposed to Ramadan and those of female Muslims who were not. Exposure was determined based on the overlap between pregnancy and a Ramadan. We further subdivided this overlap into trimester-specific categories, adjusting for urban–rural residence, birth month, birth year, birth year squared, and survey wave. Results: No associations between Ramadan during pregnancy and AAM were found, irrespective of the pregnancy trimester overlapping with Ramadan. These results were stable when we restricted the sample to women with shorter recall periods and younger women at the time of survey. Conclusions: While subtle restrictions in maternal nutrition during pregnancy are critical for offspring health, the impact on menarcheal onset might be limited. Full article

Previous studies have examined the association between family dysfunction and pubertal timing in adolescent girls. However, the evidence is lacking on the role of family dysfunction during sensitive developmental periods in both boys and girls from racial and ethnic minority groups. This study aimed to determine the effect of family dysfunction on the timing of pubertal maturation among US Hispanic/Latino children and adolescents. Participants were 1466 youths (50% female; ages 8–16 years) from the Hispanic Community Children’s Health Study/Study of Latino Youth (SOL Youth). Pubertal maturation was measured using self-administered Pubertal Development Scale (PDS) items for boys and girls. Family dysfunction included measures of single-parent family structure, unhealthy family functioning, low parental closeness, and neglectful parenting style. We used multivariable ordinal logistic and linear regression analyses to examine the associations between family dysfunction and pubertal maturation (individual and cumulative measures), with adjustment for childhood BMI and socioeconomic factors, design effects (strata and clustering), and sample weights. Multivariable models of individual PDS items showed that family dysfunction was negatively associated with growth in height (OR = 0.66, 95% CI: 0.44, 0.99) in girls; no associations were found in boys. In the assessment of cumulative PDS scores, family dysfunction was associated with a lower average pubertal maturation score (b = −0.63, 95% CI: −1.21, −0.05) in boys, while no associations were found in girls. Pubertal timing lies at the intersection of associations between childhood adversity and adult health and warrants further investigation to understand the factors affecting timing and differences across sex and sociocultural background. Full article

Background/Objectives: Futsal players need peak strength, functional capacity, speed, and explosive lower-limb power for optimal performance. The aim of this study was to (i) characterize and compare anthropometric characteristics, lower limb strength/power, dynamic balance, linear sprint speed, COD performance, and COD deficit across young futsal age groups and (ii) identify key predictors of COD deficit. Methods: Thirty-three male futsal players from three age groups (U13, U15, and U17) were tested. Results: All anthropometric variables showed significant group effects with moderate to strong effect sizes, where U17 presented the largest values, followed by U15 and U13. Strength and power variables presented the same trend. The dynamic balance differed significantly across groups. Significant differences between groups with moderate effect sizes were noted in linear sprints (F = 19.54, p < 0.001, η² = 0.57), zigzag (F = 19.54, p = 0.002, η² = 0.35), and COD deficit (F = 19.54, p < 0.001, η² = 0.46). Post hoc tests revealed that U13 and U15 outperformed U17 in the COD deficit (p < 0.002). The COD deficit showed a quadratic relationship with age, initially improving but later declining in older players (p < 0.001). The body mass and the posteromedial relative difference predicted the COD deficit, with the coefficient of determination (R²) explaining 39% of the COD variance. Conclusions: Coaches and practitioners should utilize COD drills to target various movement patterns and account for pubertal timing, as growth can impact performance. Full article

The purpose of this study was to investigate changes in bone trabecular structure during adolescence using the fractal analysis (FA) method on hand–wrist radiographs (HWRs) and to evaluate the relationship of these changes with pubertal growth stages. HWRs of healthy individuals aged 8–18 years were included (N = 600). Pubertal stages were determined by the Fishman method and divided into 10 groups (early puberty [EP], pre-peak [PRPK], peak [PK], post-peak [PTPK], late puberty [LP]). FA was performed using FIJI (ImageJ) software and the BoneJ plugin on circular regions of interest (ROIs) selected from the first metacarpal bone head and distal radius. Image processing steps were applied according to the White and Rudolph method. Differences between groups were statistically evaluated. Fractal dimension (FD) values of the distal radius (RAFAM) and metacarpal bone head (MAFAM) showed significant differences according to pubertal growth stages (p < 0.05). The highest FD value was observed in the LP group, and the lowest FD value was observed in the EP group (except MAFAM in females). FD generally increased from EP to LP in the whole population, but a significant decrease was observed in all groups during the PK period. This decrease was more pronounced in RAFAM of males. These findings suggest a potential decrease of bone mechanical properties in the PK, which is found the be more suitable for orthodontic treatment in the literature. FA on HWRs is a useful and sensitive tool for quantitatively assessing pubertal changes in trabecular bone microarchitecture. The findings demonstrate a significant decrease in FD in both bone regions during the pubertal growth spurt, particularly at the peak period. This may indicate a temporary reduction in bone mechanical strength during this critical stage and could contribute to increased distal radius fracture incidence. Clinically, the relationship between FD and pubertal stages suggests this method could serve as a valuable biomarker in orthodontic treatment planning, allowing for optimized timing of interventions. Furthermore, it may aid in pediatric fracture risk assessment, potentially leading to preventative strategies for high-risk individuals. Full article

Objective: The objective of this study was to investigate the pubertal development in school-age children with obesity and to explore the body composition and lifestyle behaviors influencing its onset. Method: We enrolled 217 children, aged 6–12 years, who visited the Pediatrics Department at Beijing Jishuitan Hospital, Capital Medical University. All participants underwent a series of examinations. These assessments included body composition analysis, measurement of blood glucose and fasting insulin levels, and evaluation of secondary sexual characteristics. Statistical analysis was conducted using R4.0.3 software. Results: Of the 152 male participants, 83 (54.6%) were in the adolescent-undeveloped group, and 69 (45.4%) were in the adolescent-developed group. Of the 119 female students, 30 (25.2%) were in the adolescent-undeveloped group, and 89 (74.8%) were in the adolescent-developed group. In a comparative analysis of children, those in the adolescent development group exhibited significantly higher values for age, height, weight, body mass index (BMI), BMI-z score, body fat, muscle mass, fat-free weight, fat-free body mass index, and waist/hip ratio compared to the adolescent-undeveloped group (p < 0.05). Additionally, fasting insulin and insulin resistance index were also higher in the development group, with statistical significance observed. BMI emerged as an independent factor affecting the adolescent development of school-age girls with obesity (p < 0.05). Among boys in the adolescent development group, the consumption of sugary drinks and fried food was higher than in the undeveloped group, and moderate-intensity exercise was significantly lower, with statistical significance (p < 0.05). In girls, the adolescent development group reported longer daily sitting times and higher intakes of sugary drinks and fried foods compared to the undeveloped group, with these differences being statistically significant (p < 0.05). The consumption of fried food was positively correlated with adolescent development in children with obesity and was identified as an independent influencing factor of adolescent development (p < 0.05). Conclusions: A high body mass index (BMI) in girls with obesity and high intake of fried foods in both genders are strong predictors of early puberty in school-age children. Full article

Milk is the principal nutrient of newborn humans and a diagnostic feature of the order Mammalia. Its release is elicited as a reflex by infant sucking under the control of the hormone oxytocin. While it is recognized that breast milk optimally promotes infant longitudinal growth and development, this review explores facts and controversies regarding the extent to which the milks of several dairy animals and infant formula milk (IF) approximate special properties and bioactivities of breast milk. It also provides evidence that early exposure to undernutrition during the very rapid fetal and early infancy growth predominantly and permanently stunts longitudinal growth trajectory in both animals and humans and is often followed in later life by obesity and metabolic dysfunction, and sometimes also by precocious timing of sexual maturation. There is a knowledge gap as to whether there may be additional critical periods of nutritional vulnerability in human development, which is characterized by a relatively prolonged period of slow childhood growth bracketed by the rapid fetal–neonatal and pubertal growth spurts. It is also unclear whether any quantitative differences in caloric intake and supply during neonatal period may influence developmental fatness programming. A further knowledge gap exists regarding the role of infant microbiome composition and development in the possible epigenetic programming of longitudinal growth or fatness in later life. Extending the research of early developmental programming to the entire period of human growth from conception to the end of puberty, examining infant caloric intake and supply as possible factors modulating the epigenetic programming in favor of obesity, and examining the role of infant gut microbiome in developing infant’s capacity to process nutrients may provide a better understanding of the interaction between critical nutritional influences in the control of human longitudinal growth and later-life obesity. Full article