Annals of Human Biology最新文献

Background: The agropastoral communities of Coquimbo, Chile, are characterised by their goat herding-based livelihoods, admixed ancestry, and transhumant mobility.

Aim: To explore the impact of these features on genetic diversity and interactions with neighbouring populations.

Subjects and methods: Genotypic polymorphisms of 15 STRs were analysed in 466 individuals from 15 communities. Forensic parameters were estimated. Genetic structure was assessed using R_ST, Nei's distances, MDS, dendrograms, and STRUCTURE, with 23 reference populations from Chile, South America and globally.

Results: A total of 158 alleles were observed, with frequencies ranging from 0.0011 to 0.5172. CSF1PO, D18S51, and Penta E showed deviation from Hardy-Weinberg equilibrium. The panel demonstrated high forensic performance (combined power of discrimination CPD > 0.999999999, combined power of exclusion CPE = 0.99999713817). No clear genetic structure was found within the Coquimbo communities. Regionally, Coquimbo clustered with northern Chile and north-west Argentina. Globally, it resembled other South American admixed populations, slightly differentiated from those from other regions.

Conclusions: The STRs analysed show high forensic potential, low genetic structure within the agropastoral communities, and important similarities with populations in northern Chile and north-west Argentina, supporting the relevance of trans-Andean mobility in shaping their genetic landscape.

Background and aim: We provide ethnographic, photovoice, and psychosocial stress data (food and water insecurity, potentially traumatic events, stress biomarkers) documenting the joys, hazards, and stressors of adolescents engaging in climate-sensitive pastoralist livelihoods in a global climate change hot spot. We aim to holistically capture socio-environmental relationships characterised by climate sensitive livelihoods and forms of precarity exacerbated by climate change.

Subjects and methods: Qualitative and quantitative methods were integrated to understand the embodied toll of hazards that Samburu pastoralists faced based on a sample of 161 young people. Quantitatively, we tested for associations of psychosocial stressors with both psychological distress and cell-mediated immune function (assessed through differences in IgG antibodies to Epstein-Barr virus).

Results: Qualitatively, young Samburu reported drought, food and water insecurity, wildlife encounters, and war exposure. Girls overall endorsed more posttraumatic stress symptoms, although boys reported relatively more stressors; girls overall and young people in the hotter subregion manifested more immune dysregulation.

Conclusion: In spite of important differences between climate subregions, the common elements throughout the Samburu pastoralist leanscape include food and water insecurity and overall precarity exacerbated by drought and climate change. Community-driven interventions are needed to reduce precarity for young people pursuing pastoralist livelihoods.

An association between birth month and height has been repeatedly described, but no consistent seasonal patterns can be observed. In this study, the significance of educational level as a modulating cofactor for the association between body height and birth month was analysed using an anonymous data set from 1,179,600 male conscripts born in Austria between 1971 and 2002. A distinct seasonal trend was observed. Conscripts born from June to December had shorter final body height than their counterparts born between January and May. In general, the effect of month of birth on final body height is very small. Considering socioeconomic co-factors, however, this effect was particularly noticeable for the highest and middle education classes, while the observed effect was small among the lowest education class. A low educational level seems to reduce the seasonal effect on growth and finally body height. Consequently, a clear seasonal effect in body height was observed in this Austrian population-based sample, socioeconomic stress factors, such as a low level of education, can reduce the seasonal effects.

Background: There is limited evidence on secular trends in adiposity among high-altitude children.

Aims: To describe secular trends in body mass index (BMI), excess weight and body fat skinfolds (SKF) among Peruvian children living at high altitude and to investigate the risk for excess weight in 2019 relative to 2009.

Subjects and methods: We sampled 1585 Peruvians aged 6-11 years from the Junín region. Height and weight were measured, and BMI was calculated. WHO cut-offs were used to classify children by weight status. The sum of SKF was used for analysis. BMI and sum SKF were log-transformed. Two-factor ANOVA and post-hoc contrasts were used together with trend plots for BMI_log and SKF_log. Relative risks for excess weight were estimated with 95% confidence intervals. All analyses were done in STATA.

Results: BMI_log and SKF_log means increased in both sexes from 2009 to 2019, with age-specific variation. Between 2009 and 2019, BMI values shifted from near P50 to P75 on WHO percentiles for both sexes in most age groups. The risk of excess weight was not significantly higher for most children in 2019 compared to 2009.

Conclusions: Positive secular trends in BMI_log and SKF_log were observed, with significant increases at specific ages.

Background: Deciduous teeth are closely associated with the development of the permanent teeth, drawing concern and emphasis in dental restoration and endodontics. The deciduous teeth arches and crowns can serve as a clinical diagnostic reference that contributes to the manufacture of dental restoration and dental therapy.

Aim: This study measured dimensions of deciduous molar teeth in pre-school children using digital imaging technology.

Subjects and methods: From November to December 2023, a total of 121 digital models of pre-school (3-6 years old) children in Xiamen were obtained using a digital oral scanner. The data were derived from the 3-Shape software based on the measurements on the models.

Results: There were sex differences in crown width of most deciduous teeth, but not in antimeres. There were also statistical differences in the following measurements: a) mesial-distal diameter of mandibular second deciduous molar; b) occlusal-gingival distance of the right first deciduous molar; c) the upper left first deciduous molar in different sex controls; and d) girls were all smaller than boys. There were statistical differences in maxillary and mandibular arch width at 3, 4, 5 and 6 years of age and in the maxillary arch length at different ages, but not in the mandibular arch length. There was no statistical difference in maxillary arch length between boys and girls, but a statistical difference in arch width was detected between boys and girls.

Conclusion: Significant differences existed in deciduous molar crowns and arches between children of different ages and sexes.

Background: Prader-Willi syndrome (PWS) is a complex genetic disorder characterised by infantile hypotonia, early-onset obesity, intellectual disability, hypopigmentation, small hands and feet, short stature, hypogonadism, and distinctive facial features.

Aim: To generate and report growth curves for height, sitting height, hands and feet length for Argentine children with Prader-Willi syndrome (PWS) without growth hormone treatment.

Subjects and methods: A total of 1174 anthropometric measures were obtained from 167 children (82 boys) aged 0-19 years attending Hospital Garrahan between 1992 and 2019. Standardised techniques were used in patients with molecularly confirmed PWS. The 3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentiles were estimated using the LMS method, which adjusts for skewness. Height data were plotted for comparison with the 50th percentile of the Argentine general population and German PWS without growth hormone treatment.

Results: Growth curves for height, sitting height, hands and feet length were developed from 169 children. Mean adult height was 145.3 cm in females (n = 88) and 153.2 cm in males (n = 81), which are 15.4 and 19.6 cm below the 50th percentile of the Argentine non-PWS population for girls and boys, respectively. Compared with German PWS, Argentine PWS references were 3.3 and 5.9 cm shorter in girls and boys, respectively. Mean sitting height was 9.03 cm in boys and 9.61 cm in girls, shorter than the Argentine non-PWS population.

Conclusion: Differences in adult height between Argentine and German PWS references highlight the importance of local growth standards. Country-specific reference charts are essential tools for identifying growth-impacting conditions and monitoring response to therapy.

Background: Several mechanisms have been proposed to explain how screen time may affect pubertal development.

Aim: To quantify the association between screen time exposure and timing of pubertal onset in children.

Subjects and methods: We conducted a systematic review and random-effects meta-analysis of observational studies identified through PubMed, Embase, and the Cochrane Library up to 1 May 2025. Pooled odds ratios (ORs) for early or precocious puberty per additional hour of screen time and for categorical comparisons (≥ 2 vs < 2 h/day) were estimated, along with weighted mean differences (WMDs) in daily screen hours.

Results: Of 1,284 unique records, 10 studies enrolling 97,898 children aged 2-19 years met inclusion criteria, most conducted in China. Each additional hour of screen exposure was associated with higher odds of early pubertal development (OR = 1.35; 95% CI = 1.05-1.73). The comparison of ≥ 2 vs < 2 h/day did not reach significance (1.07; 95% CI = 0.90-1.26). In girls, pooled ORs were 1.07 (95% CI = 0.84-1.37) for early puberty and 1.27 (95% CI = 0.85-1.90) for precocious puberty. Children experiencing early puberty spent on average 0.63 additional screen-hours per day compared with peers (WMD = 0.63 h; 95% CI = 0.24-1.02).

Conclusions: Screen time is associated with pubertal onset in both boys and girls, although substantial heterogeneity and cross-sectional designs limit causal inference. Future longitudinal and experimental studies are needed to clarify underlying mechanisms and inform evidence-based guidelines for healthy pubertal development.

Background: Autism Spectrum Disorder (ASD) is a prevalent condition with poorly understood aetiology. Studies indicate that children with ASD exhibit more gastrointestinal alterations, nutritional deficiencies due to selective eating, and distinct gut microbiota profiles compared to neurotypical peers.

Aim: To investigate the differences in gut microbiota composition and feeding behaviours between children with ASD and their typically developing peers.

Subjects and methods: Faecal samples from 10 male children with ASD (mean age 6.2 years), and 10 male neurotypical controls (mean age 6.1 years) were analysed using 16S rRNA sequencing to assess gut microbiota composition. Guardians completed questionnaires on demographics, birth data, initial feeding habits (i.e. feeding practices after breastfeeding), gastrointestinal symptoms, stool characteristics, and feeding behaviours, which were assessed using the Brief Autism Mealtime Behaviour Inventory (BAMBI) scale. Additionally, a 48-hour dietary recall was collected to analyse the children's nutritional intake.

Results: Significant differences in gut microbiota beta diversity were observed. Bacteroidota predominated in the control group, while Firmicutes, Actinobacteriota, and Proteobacteria were dominant in the ASD group. Genera Blautia and Bifidobacterium were enriched in controls, whereas Clostridium sensu stricto 1, Ruminococcus_torques_group, Lachnospiraceae_UCG004, and Bifidobacterium breve were more prevalent in ASD. Comorbidities, sodium intake, and BAMBI scale scores highlighted greater feeding-related behavioural issues in the ASD group.

Conclusion: Children with ASD show notable differences in gut microbiota composition and feeding behaviours. The findings emphasise the need to address gastrointestinal and nutritional factors in ASD management.

Background: Studying the extent to which delayed skeletal maturation may contribute to childhood height deficits is important for assessing potential for recovery in heights.

Aim: To investigate the discrepancy in height-for-age Z-scores (HAZ) based on chronological age (HAZ-CA) compared to bone age (HAZ-BA) and estimate proportion of HAZ deficits attributable to delayed maturation in both sexes.

Subjects and methods: Using the WHO Growth References, HAZ-CA and HAZ-BA were calculated for Guatemala City children aged 6-8.99 years participating in the Universidad del Valle de Guatemala Longitudinal Study and attending a low or a very low SEP study school. A mixed effects model was developed to describe 1638 HAZ observations (Level 1) in 1107 children (Level 2) by HAZ-type, with interaction terms for HAZ-type by age, sex, school, and birth year.

Results: On average, skeletal age was delayed by 1.1 (SD 1.0) years. Mean HAZ-CA was -1.7 (0.9) and HAZ-BA -0.6 (0.9). Greater proportions of the total height deficit were attributable to delayed skeletal maturation in males (60-87%) versus females (49-63%), and at low- (58-87%) versus very low-SES school (49-71%).

Conclusion: Delayed maturation contributes to height deficits, supporting the idea that opportunity for catch-up growth continues past early childhood in both sexes.

Background: Idiopathic short stature (ISS) is defined as height more than two standard deviations below the mean for age and sex, without an identifiable pathological cause. Pharmacologic options such as growth hormone (GH), testosterone, and aromatase inhibitors (AIs) have been studied for their potential to promote height gain in affected children and adolescents.

Aim: To compare the efficacy of GH, testosterone, and AIs in promoting height gain in children and adolescents with ISS, considering both individual and combination treatments using a network meta-analysis.

Subjects and methods: This meta-analysis was conducted in accordance with the PRISMA 2020 guidelines. A systematic search was performed across PubMed, Embase, Web of Science, Google Scholar, Semantic Scholar, and ResearchRabbit. Eligible studies were selected on the basis of predefined inclusion criteria. Standardised mean differences (SMDs) and 95% confidence intervals (CIs) were calculated. Heterogeneity was assessed via the chi-square test and I² index. Publication bias was evaluated via funnel plots and Egger's test.

Results: All the treatment groups (GH, anastrozole, letrozole, AI+GH) demonstrated significantly greater height gains than did the placebo group. Letrozole was associated with the greatest increase in height (SMD = 0.83, 95% CI = 0.38-1.28). No statistically significant differences were observed among the active treatments. Oxandrolone did not significantly differ from the placebo (SMD = 0.52, 95% CI = -0.03-1.07).

Conclusion: GH, AIs, and combination therapies improve height in children and adolescents with ISS, with letrozole showing a modest advantage but no clear superiority, highlighting the need for individualised treatment.