American Journal of Human Biology最新文献

{"title":"Correction to “Background, Rationale, and Methodological Overview of the REACT Project—Return-To-Action on Growth, Motor Development, and Health After the COVID-19 Pandemic in Primary School Children”","authors":"","doi":"10.1002/ajhb.70299","DOIUrl":"https://doi.org/10.1002/ajhb.70299","url":null,"abstract":"<p>\u0000 <span>Pereira, S.</span>, <span>P. T. Katzmarzyk</span>, <span>D. Hedeker</span>, et al. <span>2024</span>. “ <span>Background, Rationale, and Methodological Overview of the REACT Project—Return-To-Action on Growth, Motor Development, and Health After the COVID-19 Pandemic in Primary School Children</span>.” <i>American Journal of Human Biology</i> <span>36</span>, no. <span>7</span>: e23968. https://doi.org/10.1002/ajhb.23968.\u0000 </p><p>In Section “2.4.1. Child-level variables”, in paragraph 2 of the “Physical growth and body composition” sub-section, the text “Body mass is measured with a portable bioimpedance scale (Tanita® BC-553)” was incorrect. This should have read: “Body mass is measured with a portable bioimpedance scale (Tanita® SC-240)”.</p><p>In Section “2.4.1. Child-level variables”, in paragraph 4 of the “Health-related behaviors” sub-section, the text “All responses are categorized into six response options: (1) not watching; (2) less than 1 h; (3) 1–2 h; (4) 2–3 h; (5) 4–5 h; and (6) 5 h or more.” was incorrect. This should have read: “All responses are categorized into seven response options: (1) never; (2) less than 1 h; (3) 1 h; (4) 2 h; (5) 3 h; (6) 4 h; and (7) 5 h or more”.</p><p>We apologize for this error.</p>","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"38 6","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajhb.70299","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148324434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relationships Between Estradiol Levels and Vaginal Lactobacillus Abundance Across the Menstrual Cycles in Women","authors":"Karolina Koczur,&nbsp;Mateusz Blukacz,&nbsp;Andrzej Galbarczyk,&nbsp;Edyta Golińska,&nbsp;Magdalena Klimek,&nbsp;Kinga Słojewska,&nbsp;Magdalena Strus,&nbsp;Monika Ścibor,&nbsp;Anna Tubek-Krokosz,&nbsp;Grazyna Jasienska","doi":"10.1002/ajhb.70291","DOIUrl":"10.1002/ajhb.70291","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>Microbiota of the urogenital tract is crucial for women's reproductive and sexual health and is largely dominated by <i>Lactobacillus</i> strains. A reduction of these bacteria within the vaginal microbial community has been linked to gynecological disorders and infections. It is assumed that the urogenital microbiota composition is influenced by estrogens; however, in most studies estrogen levels were not reliably measured. This study aimed to investigate the relationship between salivary estradiol levels and the abundance of <i>Lactobacillus</i> species in the vaginal microbiota of healthy, reproductive-age women across three menstrual cycles.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The participants were 39 women between 20 and 35 years with regular menstrual cycles. Over three cycles, participants collected daily saliva samples for measuring estradiol levels and vaginal swabs at several time points. Three model approaches were tested: immediate, delayed, and cumulative effect models. Additional day-specific analyses and adjustments for body fat or BMI were conducted.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>No statistically significant associations were found between estradiol concentrations and <i>Lactobacillus</i> abundance in any of the models.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study did not support a link between salivary estradiol levels and <i>Lactobacillus</i> abundance in healthy, reproductive-aged women with regular menstrual cycles. These findings do not imply that estradiol is not an important factor regulating the vaginal <i>Lactobacillus</i>, but suggest that variation in estradiol levels does not correlate with the abundance of these bacteria. Studies that measure estrogen levels in multiple samples rather than assume their concentrations based on menopausal status or cycle phase are necessary to better understand the hormonal regulation of vaginal microbiota.</p>\u0000 </section>\u0000 </div>","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"38 6","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148310256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dam-Induced Displacement and Disruption Are Associated With Salivary Cortisol Concentration and Patterns of Diurnal Variation","authors":"Cassie C. Lee,&nbsp;Aaron A. Miller,&nbsp;Thomas W. McDade,&nbsp;Patrick M. Owuor","doi":"10.1002/ajhb.70296","DOIUrl":"10.1002/ajhb.70296","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>This study assesses the stress-related impacts of the construction of the Thwake Multipurpose Dam in Makueni, Kenya by examining salivary cortisol concentrations and patterns of diurnal variation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>One set of evening, waking, and 30-min post-waking saliva samples was collected across 221 women who were displaced by the dam or who lived upstream or downstream of the dam development site. Salivary cortisol concentration was analyzed using a commercially available assay kit. Multivariable linear regression was used to assess the relationship between displacement status and waking cortisol concentration, evening cortisol concentration, cortisol awakening response, and diurnal difference.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Log-transformed evening cortisol concentration (displaced: <i>β</i> = 0.365, <i>p</i> = 0.018; downstream: <i>β</i> = 0.675, <i>p</i> = 0.007) and diurnal difference (displaced: <i>β</i> = 0.034, <i>p</i> = 0.049) were significantly associated with displacement status.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Both displaced and downstream communities demonstrate stress-related hormonal differences associated with dam-induced disruption. Future policy and research addressing the health impacts of hydroelectric dam development should include downstream communities in addition to those directly displaced by development.</p>\u0000 </section>\u0000 </div>","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"38 6","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajhb.70296","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148303921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ethnic Variability in Anthropometric Trajectories Across the Lifespan: Findings From a Nationwide Survey in Peru","authors":"Lorena Saavedra-Garcia,&nbsp;Akram Hernández-Vásquez,&nbsp;Jamee Guerra Valencia","doi":"10.1002/ajhb.70295","DOIUrl":"10.1002/ajhb.70295","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Introduction</h3>\u0000 \u0000 <p>Anthropometric indicators are widely used for nutritional assessment and cardiometabolic risk, but their age-related patterns may differ by ethnicity, potentially limiting the applicability of global thresholds. To examine age-related trajectories of BMI and seven nonconventional anthropometric indicators by ethnicity in Peruvian adults.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A cross-sectional analysis was conducted using nationally representative data from the 2021–2023 Demographic and Health Survey (ENDES). Adults aged 20–80 years with complete anthropometric data and self-reported ethnicity (Quechua-Aymara, Afro-Peruvian, Other) were included (<i>n</i> = 77 592). Eight indicators were analyzed: BMI, tri-ponderal mass index (TMI), a body shape index (ABSI), body roundness index (BRI), relative fat mass (RFM), weight-adjusted waist index (WWI), waist-to-BMI ratio, and conicity index. Generalized Additive Models for Location, Scale, and Shape (GAMLSS) were used to estimate smoothed percentile curves (3rd, 50th, and 97th) across age and ethnicity.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Percentile curves revealed distinct age-related trajectories by ethnicity. Quechua-Aymara men had lower values across percentiles for BMI, TMI, RFM, and BRI, but not consistently for ABSI, WWI, and conicity index. In women, patterns were more heterogeneous, with earlier and lower peaks for Quechua-Aymara at lower percentiles, while Afro-Peruvian and Other women showed gradual increases. For ABSI, WWI, and conicity index, men showed a linear increase with age, while women showed rising trajectories only at the upper percentiles. The waist-to-BMI ratio displayed a J-shaped pattern in both sexes, with more ethnic variability at lower percentiles in women.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Ethnic disparities in anthropometric trajectories highlight the limitations of global thresholds and support the need for population-specific reference standards.</p>\u0000 </section>\u0000 </div>","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"38 6","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148279779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Longitudinal Changes and Correlates of 24-Hour Movement Behaviors in Brazilian Older Adults","authors":"Carla Bianca Tabosa Oliveira,&nbsp;Daniele Samara Dantas Lopes,&nbsp;Marcyo Câmara,&nbsp;Lucas Fellipo Cruz Ribeiro,&nbsp;Francisco Dalton Alves de Oliveira,&nbsp;Tiago V. Barreira,&nbsp;Debra L. Waters,&nbsp;Ludmila L. P. Cabral,&nbsp;Eduardo Caldas Costa","doi":"10.1002/ajhb.70294","DOIUrl":"10.1002/ajhb.70294","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>The 24 h movement behavior cycle (24hMB) has been increasingly studied in older adults. However, longitudinal changes in the 24hMB cycle and its potential correlates are poorly understood, particularly in low to middle-income countries. This study investigated longitudinal changes of 24hMB and their potential correlates in Brazilian older adults.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The 24hMB was assessed in community-dwelling older adults aged 60–80 years using hip accelerometry (ActiGraph GT3X+) over 1 week at baseline and follow-up. Outcomes included nocturnal sleep time (NST), sedentary time, light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA). Longitudinal changes and associations between changes in 24hMB and potential baseline correlates (age, sex, body mass index, post-secondary education, and multimorbidity) were examined using generalized estimating equations.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>A total of 86 participants were analyzed (67.4 ± 5.3 years; mean follow-up: 4.0 ± 0.4 years). No changes were observed in NST (<i>p</i> &gt; 0.05). However, sedentary time increased (36 ± 86 min/day), while LPA (16 ± 63 min/day) and MVPA (9 ± 20 min/day) decreased over 4 years (<i>p</i> &lt; 0.05). Older age was associated with reduced NST and increased sedentary time over time. Female sex was associated with reduced NST and increased sedentary time and MVPA. No associations were found between multimorbidity, BMI, and education level and changes in 24hMB (<i>p</i> &gt; 0.05).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>After a 4-year period, older adults experienced an overall increase in sedentary time and a decrease in physical activity, while NST remained stable. The correlates associated with changes in NST, sedentary time, and physical activity may help inform targeted interventions to improve 24hMB.</p>\u0000 </section>\u0000 </div>","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"38 6","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148273068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Maternal Education, Reproductive Behavior, and Fertility Outcomes in Pakistan: Evidence From the Pakistan Demographic and Health Survey 2017–2018","authors":"Xiaofen Qiu,&nbsp;Mukhtiar Hussain Ibupoto","doi":"10.1002/ajhb.70293","DOIUrl":"10.1002/ajhb.70293","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Introduction&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;This study examines the association between maternal education, human reproductive behavior, and fertility adaptation in Pakistan, using nationally representative data from the Pakistan Demographic and Health Survey (PDHS) 2017–2018. It aims to assess how different levels of maternal education influence fertility outcomes, particularly children ever born, while controlling for key demographic, socioeconomic, and reproductive factors.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Methods&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;The study utilizes cross-sectional data from ever-married women aged 15–49 years (&lt;i&gt;N&lt;/i&gt; = 14 500). Fertility behavior is measured using children ever born (CEB) as a count variable. Maternal education is categorized into four levels: no education, primary, secondary, and higher education. Descriptive and bivariate analyses are conducted to examine fertility differentials, followed by multivariate regression models, including Poisson and Negative Binomial regression, to estimate adjusted incidence rate ratios (IRRs). Logistic regression is additionally employed to assess high fertility (CEB ≥ 4). All analyses account for the complex survey design using sampling weights.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Results&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;The findings reveal a strong and statistically significant inverse relationship between maternal education and fertility behavior. Women with higher education have substantially lower fertility compared to those with no education. Specifically, higher education is associated with nearly a 49% reduction in children ever born (IRR = 0.51, &lt;i&gt;p&lt;/i&gt; &lt; 0.001), while secondary education reduces fertility by approximately 28%. The results indicate a clear dose–response relationship, with stronger effects observed at higher levels of education. Additionally, age at marriage, urban residence, wealth status, and modern contraceptive use are significantly associated with reduced fertility. These findings remain robust across multiple model specifications.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Conclusions&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;Maternal education emerges as a critical determinant of fertility behavior in Pakistan, operating through multiple pathways, including delayed marriage, increased contraceptive use, and enhanced reproductive autonomy. The findings highlight the importance of expanding access to secondary and higher education for women as a key strategy for lower fertility intensity and improved reproductive outcomes. The findings contribute to understanding how maternal education shapes reproductive behavior and fertility outcomes within the broader sociocultural and ecological context of a high-fertility population.&lt;/p&gt;\u0000 ","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"38 6","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148267031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Patterns of Chronic Stress in Diurnal Salivary Cortisol Already Predict Epigenetic Age Acceleration in Young Adults in the Cebu Longitudinal Health and Nutrition Survey","authors":"Sasha R. Post,&nbsp;Calen P. Ryan,&nbsp;Nanette R. Lee,&nbsp;Delia B. Carba,&nbsp;Sonny A. Bechayda,&nbsp;Julie L. MacIsaac,&nbsp;Kristy Dever,&nbsp;David T. S. Lin,&nbsp;Parmida Atashzay,&nbsp;Michael S. Kobor,&nbsp;Christopher W. Kuzawa","doi":"10.1002/ajhb.70290","DOIUrl":"10.1002/ajhb.70290","url":null,"abstract":"<div>\u0000 \u0000 <p>Epigenetic clocks estimate biological aging through age-related DNA methylation patterns and are known to accelerate in response to adversity. While cortisol links stress experiences to cellular aging, the relationship between circadian cortisol and epigenetic age acceleration (EAA) remains unclear. To address this gap, we use data from the Cebu Longitudinal Health and Nutrition Survey (CLHNS) to explore linear relationships between diurnal salivary cortisol and a suite of epigenetic clocks. In 2005, when cohort members were 20–22 years old, saliva samples were obtained to measure bedtime cortisol, waking cortisol, and the cortisol awakening response (CAR). Additionally, DNA methylation was measured in whole blood to calculate EAA with multiple epigenetic clocks: principal components-based first-generation clocks trained on chronological age (PC Horvath, PC Hannum), second-generation clocks trained on chronological age and health markers (PC PhenoAge, PC GrimAge, PC DNAmTL), and DunedinPACE, a clock trained on the pace of change in aging-related biomarkers. Elevated bedtime cortisol and a blunted CAR—markers of chronic stress—significantly predicted EAA across second-generation clocks and DunedinPACE, even when stratifying by sex and adjusting for immune cell fractions. After multiple hypothesis test correction, elevated bedtime cortisol remained a significant predictor of EAA, although effect sizes were small. Associations were attenuated by adjusting for immune cell fractions, suggesting that links between chronic stress and EAA may operate through stress-related changes to the composition of the immune system. These findings indicate that, in the CLHNS cohort, cortisol-based measures of chronic stress already predict acceleration of multiple epigenetic clocks in young adulthood.</p>\u0000 </div>","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"38 6","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148267054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal and Sex Differences in Children's Body Composition Under In-Term PA Versus Vacation Non-PA Periods: A 40-Month Natural-Experiment Observation","authors":"Xiang Pan,&nbsp;Yibo Gao,&nbsp;Lupei Jiang,&nbsp;Mingzhe Li,&nbsp;Deqiang Zhao,&nbsp;Jiaxin Chen,&nbsp;Chunmiao Wang,&nbsp;Xiaoyun Mao,&nbsp;Yanfeng Zhang","doi":"10.1002/ajhb.70292","DOIUrl":"10.1002/ajhb.70292","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>To characterize seasonal body composition changes in Chinese schoolchildren, contrasting in-term periods (school-based physical activity [PA] active) with vacations (PA suspended), and to test whether BMI, body fat percentage (BFP), and weight respond uniformly across sex and season.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Natural-experiment observational analysis of a school-monitored cohort enriched for elevated baseline adiposity (92.0% overweight or obese, Chinese WS/T 586); the research team was not involved in the school-delivered PA program's design or delivery. We measured 342 children (212 boys, 130 girls; mean age 10.2 y) from two Beijing primary schools at up to 10 time points over 40 months (September 2021–December 2024) by bioelectrical impedance (1178 observations). Three 12-week windows were defined (in-term, winter vacation, summer vacation); paired changes were tested by Wilcoxon tests and era-stratified trajectories by linear mixed-effects models, with GAMM smooths for visualization only.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Across 268 in-term paired observations, BMI declined 0.42 ± 1.10 kg/m² (Cohen <i>d</i> = −0.38), an active reversal while the PA program ran. Both vacations produced gains (winter ΔBMI +0.78, summer +0.95 kg/m²). Effect sizes diverged across indicators: summer d(weight) = +1.48 &gt; d(BMI) = +0.71 &gt; d(BFP) = +0.57. Summer BFP rose 2.6-fold more in girls than boys (+2.32 vs. +0.91 pp., <i>p</i> = 0.032).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Under this in-term/vacation alternation, children's body composition showed marked seasonal directionality, with active reversal in term and gains during vacations. The indicator-specific effect-size divergence and the 2.6-fold female-skewed summer BFP response are consistent with sex-stratified, tissue-specific dynamics aligning with peri-pubertal sexual dimorphism.</p>\u0000 </section>\u0000 </div>","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"38 6","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148259924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relationships Among Maternal Epstein–Barr Virus Antibodies, COVID-19, and Stress in Mothers up to 1-Year Postpartum","authors":"Emma Anastasi,&nbsp;Delaney J. Glass,&nbsp;Tiffany D. Pan,&nbsp;Eleanor Brindle,&nbsp;Beatrice Caffe,&nbsp;Caroline B. Smith,&nbsp;Amanda E. Kunkle,&nbsp;Maia A. Kent,&nbsp;Alexandra D. Navarrete,&nbsp;Christina D. W. Pace,&nbsp;Dan T. A. Eisenberg,&nbsp;Ryan M. Pace,&nbsp;Janet E. Williams,&nbsp;Sylvia H. Ley,&nbsp;Celestina Barbosa-Leiker,&nbsp;Mark A. McGuire,&nbsp;Michelle K. McGuire,&nbsp;Courtney L. Meehan,&nbsp;Melanie A. Martin","doi":"10.1002/ajhb.70289","DOIUrl":"https://doi.org/10.1002/ajhb.70289","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>Both psychosocial stress and current infection can increase the likelihood of reactivation of latent Epstein–Barr virus (EBV). Pregnancy and infection with SARS-CoV-2 can be stressful and modulate immune function. However, it is unknown how SARS-CoV-2 infection and stress further interact among postpartum women to affect EBV antigen and antibody expression.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We examined associations among COVID-19 diagnosis, self-reported stress, and EBV immunoglobulin G (IgG) in previously collected data from 45 breastfeeding US women (1–18 months postpartum) during the height of the COVID-19 pandemic. Between June 2020 and March 2021, stress survey data and capillary dried blood HemaSpot samples were collected from 25 SARS-CoV-2 infected and 20 non-infected participants at multiple time points over the course of 60 days. Samples (<i>N</i> = 104) were later assayed for EBV IgG. Statistical methods were pre-registered, and relationships among SARS-CoV-2 infection, stress, and EBV IgG were analyzed via mixed-effects regression models, adjusting for time postpartum and time elapsed since enrollment.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>There was a statistically significant association between self-reported stress and EBV IgG levels, with higher average stress associated with higher average EBV IgG. EBV IgG relative concentration did not vary independently with COVID-19 positivity status or the number of COVID-19 symptoms.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Results suggest that EBV IgG relative concentrations were elevated across sample participants by stress, but not by the relatively mild cases of COVID-19 the mothers experienced.</p>\u0000 </section>\u0000 </div>","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"38 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajhb.70289","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148238233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Relationship Between 2D:4D Digit Ratio and Polycystic Ovary Syndrome: A Systematic Review","authors":"Tuba Güner Emül,&nbsp;Emine Kaplan Serin","doi":"10.1002/ajhb.70288","DOIUrl":"https://doi.org/10.1002/ajhb.70288","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>This systematic review aimed to synthesize current evidence on the association between 2D:4D ratios and PCOS.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A comprehensive literature search was performed in PubMed, Web of Science, Scopus, and Cochrane Library databases between May and June 2025. Two independent researchers conducted study screening, data extraction, and quality appraisal using the Joanna Briggs Institute critical appraisal tools.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Eleven studies published between 2005 and 2024, with sample sizes ranging from 40 to 400 participants, were included. Study designs were cross-sectional or case–control, and measurement techniques involved calipers, photocopies, or digital analysis. Nine studies reported significantly lower 2D:4D ratios in women with PCOS compared to healthy controls, supporting the hypothesis of increased prenatal androgen exposure. However, two studies found no significant association, likely due to methodological heterogeneity, small sample sizes, or diagnostic inconsistencies.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The majority of included studies suggest that lower 2D:4D ratios may reflect elevated prenatal androgen exposure in women with PCOS, indicating its potential as a non-invasive biomarker. Nonetheless, variability in diagnostic criteria, measurement methods, and study populations limits generalizability. Further large-scale, standardized research is required to determine clinical utility and to establish population-specific reference values.</p>\u0000 </section>\u0000 </div>","PeriodicalId":50809,"journal":{"name":"American Journal of Human Biology","volume":"38 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajhb.70288","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148174589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}