Sex-related Variation Research Articles

Variation in Demographics, Hospital, and Patient-Reported Outcomes Following Total Hip Arthroplasty According to Biological Sex

BackgroundThe effect of biological sex on the outcomes of total hip arthroplasty (THA) remains unclear. Accounting for biological sex in research is crucial for reproducibility and accuracy. Average combined data may mask sex-related variation and obscure clinically relevant differences in outcomes. The aim of this study is to investigate hospital and patient-reported outcome measures (PROMs) after THA by biological sex to elucidate differences and ultimately provide more equitable care. MethodsWe performed a retrospective review of patients undergoing primary THA at a single large academic center between January 2013 and August 2020. Demographics, operative variables, hospital outcomes, and PROMs were compared between men and women patients. The PROMs included preoperative, 6-weeks, 6-months, and 1-year Single Assessment Numeric Evaluation, Visual Analog Scale, Hip Disability and Osteoarthritis Outcome Score Joint Replacement, University of California, Los Angeles, and Patient-Reported Outcomes Measurement Information System mental and physical scores, as well as satisfaction scores. ResultsA total of 6,418 patients were included (55% women). Women were older (P < .001), had a lower body mass index (P < .001), and were more likely to have public insurance (P < .001). Fewer women were discharged to home or self-care (P < .001). Women had higher rates of cementation (P < .001) and fracture within 90 days (P < .001), and these associations remained significant with adjusted multivariable analyses. Women had significantly higher pain and lower functional scores preoperatively; postoperatively, most PROMs were equivalent. ConclusionsImportant differences were observed in several areas. Demographic parameters differed, and a variable effect of biological sex was observed on surgical and hospital outcomes. Women had an increased incidence of cemented femoral components (indicated for osteoporotic bone) and postoperative fractures. Women’s PROMs demonstrated globally lower functional scores and higher pain preoperatively. Differences attributed to sex should continue to be investigated and accounted for in risk-stratification models. Future studies are needed to elucidate the underlying causes of observed biological sex differences and are essential for equitable arthroplasty care.

Cell-type-specific effects of age and sex on human cortical neurons

Altered transcriptional and epigenetic regulation of brain cell types may contribute to cognitive changes withadvanced age. Using single-nucleus multi-omic DNA methylation and transcriptome sequencing (snmCT-seq) in frontal cortex from young adult and aged donors, we found widespread age- and sex-related variation in specific neuron types. The proportion of inhibitory SST- and VIP-expressing neurons was reduced in aged donors. Excitatory neurons had more profound age-related changes in their gene expression and DNA methylation than inhibitory cells. Hundreds of genes involved in synaptic activity, including EGR1, were less expressed in aged adults. Genes located in subtelomeric regions increased their expression with age and correlated with reduced telomere length. We further mapped cell-type-specific sex differences in gene expression and X-inactivation escape genes. Multi-omic single-nucleus epigenomes and transcriptomes provide new insight into the effects of age and sex on human neurons.

Seasonal and sex-related variation in vitamin D status and its association with other biochemical markers in young individuals: A cross-sectional study.

While several studies have investigated the association between vitamin D deficiency and biochemical parameters, the results are still inconsistent and mostly overlook seasonal variations. This study explored the relationships between 25-hydroxy-vitamin D (25(OH)D) concentrations, biochemical markers, and seasonal variation among young males and females. A cross-sectional study was conducted among 203 individuals aged 18-24 years of both sexes residing in Brasilia, Brazil (latitude: 15°S). Sociodemographic variables, season of blood collection, and serum levels of 25(OH)D, total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, glycated hemoglobin (HbA1c), glucose, insulin, hs-CRP, parathyroid hormone, ionized calcium, and alkaline phosphatase were included. Descriptive statistics and differences among groups, correlations, and linear regression tests were performed. The mean age of the participants was 21.17±1.7 years, and the mean serum 25(OH)D level was 25.76±7.0 ng/mL. Of the participants, 50.7% had vitamin D insufficiency (20 to 29.9 ng/mL), and 23.2% were vitamin D deficient (≤20 ng/mL). Vitamin D deficiency was higher in the spring (53.2%) and among females (29.5%). In young men with vitamin D insufficiency/deficiency (≤29.9 ng/mL) (n = 49), 25(OH)D levels were inversely correlated with HOMA-β (r = -0.234, p = 0.032) and triglyceride (r = -0.415, p = 0.003) levels. However, there were no significant correlations between 25(OH)D concentrations and biochemical markers among women with insufficient and deficient vitamin D levels. This study found a high prevalence of vitamin D insufficiency/deficiency among young individuals living in Brasília, Brazil, particularly women and during the spring season. Our findings suggest that lower 25(OH)D levels (≤29.9 ng/mL) may be associated with insulin resistance and an increased risk of cardiovascular disease in young men studied. However, further studies with larger representative samples are needed to explore the mechanisms underlying the association between vitamin D and biochemical parameters.

Abstract 16: County-Level Racial Residential Segregation and Sedentary Behavior in US Adults

Introduction: Sedentary behavior (SB) is highly prevalent and shows an increasing trend in United States (US) adults, resulting in adverse health outcomes, such as cardiovascular disease, cancer, and diabetes. Yet, potential environmental determinants of SB, including racial residential segregation, remain understudied. Hypothesis: County-level segregation will be associated with sedentary time in a nationwide sample of US adults, and this relationship will be moderated by sex. Methods: We analyzed data from 2637 US adults aged 20-75 years (mean age [45.1 years], female [50.6%] from the population-based AmeriSpeak panel in 2019. Participants completed the Activities Completed over Time in 24-hours (ACT24) previous-day recall, a validated population-level measure of total daily SB (hours/day). County segregation was expressed as the isolation index at the county level for non-Hispanic (NH) White, NH Black, and Hispanic adults (vs all other races/ethnicities). The isolation index ranges from 0 to 1, with a higher value indicating higher segregation and therefore, a higher average probability of contact among residents of the minority group and, thus, a lower probability of contact among residents of the minority group and all other races/ethnicities. We used survey-weighted linear regression models to assess the relationships of race-specific isolation index with time spent in SB, adjusting for age, sex, marital status, education, occupation, household income, body mass index, census region, and county-level poverty. Additionally, we stratified these relationships by sex. Results: Overall, US adults reported a mean of 9.5 hours/day of sedentary time. Counties with higher NH White isolation showed a significant inverse relationship with sedentary time (β = -1.52, 95% confidence interval [-2.75, -0.29], p = 0.017). Counties with higher NH Black isolation showed a non-significant inverse relationship with sedentary time (β = -0.30 [-2.53, 1.94], p = 0.790), and counties with higher Hispanic isolation showed a non-significant positive relationship (β = 0.32, [-1.64, 2.28], p = 0.743). In sex-stratified analysis, only NH White isolation among White females showed a significant inverse relationship with sedentary time (β = -2.14 [-4.19, -0.09], p = 0.041). Conclusions: NH White adults, particularly females, residing in more segregated counties reported less sedentary time in this population-based nationwide sample of US adults. SB was not strongly associated with isolation for NH Black and Hispanic adults. Future studies could aim to replicate (or not) our findings with larger samples of underrepresented minority populations and further explore potential mechanisms for sex related variation in the association between residential segregation and sedentary behavior.

Sex-specific recruitment rates contribute to male-biased sex ratio in Adélie penguins.

Sex-related differences in vital rates that drive population change reflect the basic life history of a species. However, for visually monomorphic bird species, determining the effect of sex on demographics can be a challenge. In this study, we investigated the effect of sex on apparent survival, recruitment, and breeding propensity in the Adélie penguin (Pygoscelis adeliae), a monochromatic, slightly size dimorphic species with known age, known sex, and known breeding history data collected during 1996-2019 (n = 2127 birds) from three breeding colonies on Ross Island, Antarctica. Using a multistate capture-mark-recapture maximum-likelihood model, we estimated apparent survival (), recapture (resighting) probability (), and the probability of transitioning among breeding states and moving between colonies (; colony-specific non-juvenile pre-breeders, breeders, and non-breeders). Survival rate varied by breeding status and colony, but not sex, and pre-breeders had higher survival rates than breeders and non-breeders. Females had a higher probability of recruiting into the breeding population each year and may enter the breeding pool at younger ages. In contrast, both sexes had the same probability of breeding from year to year once they had recruited. Although we detected no direct sex effects on survival, the variation in recruitment probability and age-at-first reproduction, along with lower survival rates of breeders compared to pre-breeders, likely leads to shorter lifespans for females. This is supported by our findings of a male-biased mean adult sex ratio (ASR) of 1.4 males for every female ( proportion of males = 0.57, SD = 0.07) across all colonies and years in this metapopulation. Our study illustrates how important it can be to disentangle sex-related variation in population vital rates, particularly for species with complex life histories and demographic dynamics.

Relationship between Cerebral Microinfarcts and Dementia by Sex: Findings from a community-based Autopsy Study.

Cerebral microinfarcts are common in older adults and are associated with cognitive impairment. Less is known about sex-related variation in the relationship between cerebral microinfarcts and dementia in older adults, the examination of which was the objective of this study. This case-control study was based on the 727 participants (419 women) in the Adult Changes in Thought (ACT) autopsy data. Microinfarcts were ascertained by blinded board-certified neuropathologists, and dementia diagnoses were made by the ACT Consensus Diagnosis Conference per DSM-IV. Multivariable logistic regression models were used to estimate adjusted odds ratio (aOR) and 95% confidence interval (CI). Microinfarcts were present in 49% (356/727) of the participants, which was numerically higher in women: 51% (213/419) vs 46% (143/308). aOR (95% CI) for dementia associated with any microinfarct for female and male participants were 1.45 (0.91-2.30) and 1.24 (0.75-2.06), respectively (p for interaction, 0.34). Respective aORs (95%CIs) associated with ≥2 microinfarcts were 1.37 (0.79-2.36) and 1.53 (0.84-2.78), with interaction p, 0.84. Subcortical microinfarcts were present in 36% (138/381) and 23% (78/346) of patients with and without dementia (aOR, 1.65; 95% CI, 1.14-2.38). Respective aOR (95% CI) in female and male participants were 1.70 (1.03-2.82) and 1.59 (0.90-2.80), (p for interaction, 0.55). There was no association with cortical microinfarcts (aOR, 1.19; 95% CI, 0.83-1.69). These findings suggest that association between microinfarcts and dementia is primarily mediated by subcortical microinfarcts, but we found no evidence of sex-related variation. Future studies with greater power are needed to determine if the associations we found are replicable.

Age and sex-related variations in murine laryngeal microbiota.

The larynx undergoes significant age and sex-related changes in structure and function across the lifespan. Emerging evidence suggests that laryngeal microbiota influences immunological processes. Thus, there is a critical need to delineate microbial mechanisms that may underlie laryngeal physiological and immunological changes. As a first step, the present study explored potential age and sex-related changes in the laryngeal microbiota across the lifespan in a murine model. We compared laryngeal microbial profiles of mice across the lifespan (adolescents, young adults, older adults and elderly) to determine age and sex-related microbial variation on 16s rRNA gene sequencing. Measures of alpha diversity and beta diversity were obtained, along with differentially abundant taxa across age groups and biological sexes. There was relative stability of the laryngeal microbiota within each age group and no significant bacterial compositional shift in the laryngeal microbiome across the lifespan. There was an abundance of short-chain fatty acid producing bacteria in the adolescent group, unique to the laryngeal microbiota; taxonomic changes in the elderly resembled that of the aged gut microbiome. There were no significant changes in the laryngeal microbiota relating to biological sex. This is the first study to report age and sex-related variation in laryngeal microbiota. This data lays the groundwork for defining how age-related microbial mechanisms may govern laryngeal health and disease. Bacterial compositional changes, as a result of environmental or systemic stimuli, may not only be indicative of laryngeal-specific metabolic and immunoregulatory processes, but may precede structural and functional age-related changes in laryngeal physiology.

RELATIONSHIP BETWEEN CEREBRAL MICROINFARCTS AND DEMENTIA BY GENDER AMONG COMMUNITY-BASED OLDER ADULTS

Abstract Cerebral microinfarcts are common in older adults and associated with cognitive impairment. Less is known about sex-related variation in the relationship between microinfarcts and dementia in older adults, the examination of which was the objective of this study. This case-control study was based on 727 participants (308 men, 419 women) in the Adult Changes in Thought (ACT) autopsy data. Microinfarcts (presence, number, and location) were ascertained by blinded board-certified neuropathologists, and dementia diagnoses (yes, no) were made by the ACT Consensus Diagnosis Conference per DSM-IV criteria. Multivariable logistic regression analyses were conducted to examine the relationship. Microinfarcts were present in 356 (49%) participants (144 had one; 211 ≥2, 257 cortical, 216 subcortical), and 381 (52.4%) had dementia. More participants with dementia had ≥2 microinfarcts, although there was no difference in the distribution of a single microinfarct. Adjusted OR (95% CI) for dementia associated with any microinfarct was 1.36 (0.97–1.91). Respective ORs (95% CIs) in women and men were 1.45 (0.91–2.30) and 1.24 (0.75–2.06; p for interaction, 0.34). Adjusted OR (95% CI) for dementia associated with cortical and subcortical microinfarcts were 1.19 (0.83–1.69) and 1.65 (1.14–2.38), respectively, without any evidence of heterogeneity (p for interaction, 0.96 and 0.55, respectively). The presence of subcortical microinfarcts, but not cortical, had a significant association with dementia in older adults, but there was no evidence of a sex-related heterogeneity in that association. Future studies need to examine strategies to delay and manage vascular risk factors contributing to subcortical microinfarcts.

The role of sex on sign-tracking acquisition and outcome devaluation sensitivity in Long Evans rats

Cues that predict rewards can trigger reward-seeking behaviors but also can, in some cases, become targets of motivation themselves. One behavioral phenomenon that captures this idea is sign-tracking in which animals, including humans, interact with reward-predictive cues even though it is not necessary to do so. Sign-tracking in rats has been studied in the domain of motivation and in how motivated behaviors can or cannot become excessive and habit-like over time. Many prior studies look at sign-tracking examine this behavior in male subjects, but there are few papers that look at this behavior in female subjects. Moreover, it is unknown where there might be sex-related variation in how flexible sign-tracking is when faced with changing reward values. Therefore, we asked if there were sex differences in the acquisition of sign-tracking behavior and if there were any sex differences in how sensitive animals were in their sign-tracking following reward devaluation. In contrast to previous reports, we found that males and females show no differences in how they acquire sign-tracking and in ultimate sign-tracking levels following training. Additionally, we found no difference in how quickly males and females learned to devalue the food reward, and we found no differences in sign-tracking levels by sex following outcome devaluation. We believe that this is primarily due to our experiment being performed in the Long Evans strain but also believe that there are many other factors contributing to differences between our study and previous work.

Season- and sex-related variation in mucin secretions of the striped Venus clam, Chamelea gallina (Linnaeus, 1758) (Bivalvia: Veneridae)

An in situ analysis of mucin secretions along the annual cycle was performed on the striped Venus clam, Chamelea gallina. Individuals of both sexes from an exploited stock of Margherita di Savoia (Southern Adriatic Sea, Central Mediterranean Sea) were made in June 2020 and 2021, and in January 2021 and 2022, representative of summer and winter seasons, respectively. Tissues from the foot and the gills were analyzed for histochemical and lectin-histochemical analyses. Staining with Periodic Acid-Schiff, Alcian Blue pH 2.5 and High-Iron-Diamine indicated that mucins from both the foot and the gills were acidic, mostly sulfated. Lectin-binding analyses with PNA, SBA, WGA, LTA, UEA-I, AAA, SNA, MAA-II and ConA indicated the presence of N-acetyl-glycosaminylated, mannosylated and fucosylated residuals in the saccharidic chains. In the gills, the amount of acidic and glycosaminylated residuals was higher in summer in both sexes, whereas fucosylation was similar along the sampling period and mannosylation was never observed. In the foot, both surface epithelial and subepidermal secreting cells increased sulfation in winter in males, but not in females. Glycosaminylation and fucosylation were observed only in the surface cells of males. Mannosylated residuals were observed in all the foot cell types in both sexes. It is hypothesized that the observed qualitative and quantitative variations in mucin secretion is linked to the reproductive cycle.

Hemispheric Asymmetry Gender Differences in Preadolescent Children

Background: Investigating various postnatal parameters of cerebral hemispheres is of great practical value.Objective: To study gender differences in hemispheric parameters and interhemispheric interactions in preadolescent children.Materials and methods: The retrospective study assessed archived brain magnetic resonance images of 60 eight-year-old boys and 60 eight-year-old girls. The analyzed parameters were as follows: 1) hemispheric length; 2) hemispheric width; 3) hemispheric height; 4) width-longitudinal index of a hemisphere; 5) altitude-longitudinal index of a hemisphere; 6) length of frontal lobes; 7) length of parietal lobes; 8) length of occipital lobes; 9) length of temporal lobes. Quantitative indicators were assessed for normal distribution using the Kolmogorov–Smirnov test. Source data were accumulated and arranged in Microsoft Excel 2016 spreadsheets. Statistica 10.0 was used for the statistical analysis. The results were considered statistically significant with P &lt; 0.05.Results: The analysis of cephalometric indicators suggests sex-related variation in the cerebral hemispheres. Based on the obtained data we can identify morphometric parameters of interhemispheric variability that may act as one of the morphometric criteria for the brain asymmetry. The study results can be widely used for neuroimaging.Conclusions: We determined cephalometric reference values for various cerebral hemispheres parts in preadolescent children.

Reproductive phase-dependent and sexually dimorphic expression of leptin and its receptor in different parts of brain of spotted snakehead Channa punctata.

The reproductive phase-wise leptin (lep) and its receptor (lepr) expression in different parts of the brain of adult male and female spotted snakehead Channa punctata reveals sexual dimorphism in the brain leptin system. In anterior, middle and posterior parts of the brain of males, a maximum lep was observed in resting, spawning and postspawning reproductive phases, respectively. In females, a high level of lep was seen during the preparatory phase in the anterior brain, preparatory and postspawning phases in the middle brain and resting and postspawning phases in the posterior brain. Nonetheless, the transcript level of lepr was recorded highest during the spawning phase, irrespective of sex and region of the brain. Regardless of the reproductive state of fishes, lep and lepr were seen considerably high in middle and posterior parts of male brain than that of female, implying the involvement of factors other than sex steroids for sex-related variation in the leptin system in these regions of the brain. Nonetheless, no sex difference was evidenced in the expression of either ligand or its receptor in the anterior brain. In summary, the presence of lep and lepr in different regions of the brain and variation in their expression depending on sex and reproductive phases raise the possibility of pivotal actions of leptin in influencing neuronal circuitry and thereby reproductive functions.

Age and Sex-Related Anatomical Variation in Vessel Diameters of Circle of Willis in Patients of Subarachnoid Haemorrhage Using Digital Subtraction Angiography: A Retrospective Descriptive study

Introduction: Subarachnoid Haemorrhage (SAH) is a distinct form of stroke characterised by bleeding in the subarachnoid space. The incidence of SAH is influenced by various factors, including age, gender, and geographic location. Aim: To evaluate age and sex-related anatomical variation in vessel diameters of the Circle of Willis (CoW) in patients with SAH in Eastern India. Materials and Methods: A retrospective descriptive analysis was conducted on patients with ruptured intracranial aneurysms who were admitted to the Institute of Neurosciences in Kolkata and diagnosed with SAH using brain computed tomography between January 2014 and September 2015. Digital Subtraction Angiography (DSA) was performed on 50 patients, aged 15 to 70 years. The vessel diameters of CoW components were measured using specialised software. Statistical analysis using the Mann-Whitney test was conducted to assess differences in vessel diameters based on age and sex. Results: The results showed that older patients (≤40 years) had larger vessel diameters compared to younger patients (&lt;40 years) in most segments of the CoW, indicating possible age- related atherosclerotic changes. Among female patients, the younger age group exhibited a significantly larger mean vessel diameter of 1.67 mm in the Anterior Cerebral Artery (ACA) (A1) segment of the left-side compared to the older age group with a mean vessel diameter of 1.32 mm in the same segment (p-value=0.045). In general, males had larger vessel diameters than females, except in specific segments. Conclusion: The knowledge gained from this research can contribute to improve the accuracy and effectiveness of interventions, such as endovascular coiling or surgical clipping, and ultimately optimising patient outcomes.

The Distribution of Major Brain Metabolites in Normal Adults: Short Echo Time Whole-Brain MR Spectroscopic Imaging Findings.

This prospective study aimed to evaluate the variation in magnetic resonance spectroscopic imaging (MRSI)-observed brain metabolite concentrations according to anatomical location, sex, and age, and the relationships among regional metabolite distributions, using short echo time (TE) whole-brain MRSI (WB-MRSI). Thirty-eight healthy participants underwent short TE WB-MRSI. The major metabolite ratios, i.e., N-acetyl aspartate (NAA)/creatine (Cr), choline (Cho)/Cr, glutamate + glutamine (Glx)/Cr, and myoinositol (mI)/Cr, were calculated voxel-by-voxel. Their variations according to anatomical regions, sex, and age, and their relationship to each other were evaluated by using repeated-measures analysis of variance, t-tests, and Pearson’s product-moment correlation analyses. All four metabolite ratios exhibited widespread regional variation across the cerebral hemispheres (corrected p < 0.05). Laterality between the two sides and sex-related variation were also shown (p < 0.05). In several regions, NAA/Cr and Glx/Cr decreased and mI/Cr increased with age (corrected p < 0.05). There was a moderate positive correlation between NAA/Cr and mI/Cr in the insular lobe and thalamus and between Glx/Cr and mI/Cr in the parietal lobe (r ≥ 0.348, corrected p ≤ 0.025). These observations demand age- and sex- specific regional reference values in interpreting these metabolites, and they may facilitate the understanding of glial-neuronal interactions in maintaining homeostasis.

Non-invasive Tear Film Assessment in Normal Population: Effect of Age, Sex, and Interparametric Relationship.

Purpose:To investigate age- and sex-related differences in tear film parameters of normal Indian population and study interparametric relationships.MethodsHealthy subjects with no ocular disease (median ocular surface disease index = 0) were subjected to an automated evaluation of tear meniscus height (TMH), non-invasive tear breakup time (NIBUT) using Keratograph 5M (OCULUS GmbH, Wetzlar, Germany), and tear osmolarity using the TearLab Osmolarity System (TearLab Corporation, California, USA). A mixed-effects model with random intercepts at the patient level was used to evaluate the relationships between explanatory (age, gender, and tear osmolarity) and outcome variables (TMH and NIBUT).ResultsA total of 237 subjects (474 eyes; 150 males) were enrolled with a mean age of 40 ± 17 years (range, 10-78 years). The mean values (± standard deviation) of TMH, NIBUT, and tear osmolarity were 0.34 ± 0.07 mm, 10.95 ± 2.02 s and 289.0 ± 5.8 mOsm/L, respectively. Age had a significant positive relationship with TMH (p < 0.0001; 0.002 mm/year; r = 0.12), but there was no effect on NIBUT (p = 0.26) and tear osmolarity (p = 0.27). There were no sex-based differences in tear film parameters. Interparametric relationship revealed no significant association between TMH and NIBUT (p = 0.12) or tear osmolarity and TMH (p = 0.83) or tear osmolarity and NIBUT values (p = 0.48).ConclusionsIn a normal Indian population, TMH is weakly affected by age and is independent of sex, NIBUT, and tear osmolarity. Tear breakup time and osmolarity show no significant age- and sex-related variation.

Sex classification using the human sacrum: Geometric morphometrics versus conventional approaches.

The human pelvis shows marked sexual dimorphism that stems from the conflicting selective pressures of bipedal locomotion and parturition. The sacrum is thought to reflect this dimorphism as it makes up a significant portion of the pelvic girdle. However, reported sexual classification accuracies vary considerably depending on the method and reference sample (54%-98%). We aim to explore this inconsistency by quantifying sexual dimorphism and sex classification accuracies in a geographically heterogeneous sample by comparing 3D geometric morphometrics with the more commonly employed linear metric and qualitative assessments. Our sample included 164 modern humans from Africa, Europe, Asia, and America. The geometric morphometric analysis was based on 44 landmarks and 56 semilandmarks. Linear dimensions included sacral width, corpus depth and width, and the corresponding indices. The qualitative inspection relied on traditional macroscopic features such as proportions between the corpus of the first sacral vertebrae and the alae, and sagittal and coronal curvature of the sacrum. Classification accuracy was determined using linear discriminant function analysis for the entire sample and for the largest subsamples (i.e., Europeans and Africans). Male and female sacral shapes extensively overlapped in the geometric morphometric investigation, leading to a classification accuracy of 72%. Anteroposterior corpus depth was the most powerful discriminating linear parameter (83%), followed by the corpus-area index (78%). Qualitative inspection yielded lower accuracies (64–76%). Classification accuracy was higher for the Central European subsample and diminished with increasing geographical heterogeneity of the subgroups. Although the sacrum forms an integral part of the birth canal, our results suggest that its sex-related variation is surprisingly low. Morphological variation thus seems to be driven also by other factors, including body size, and sacrum shape is therefore likely under stronger biomechanical rather than obstetric selection.

Disparities by Sex in COVID-19 Risk and Related Harms Among People with Opioid Use Disorder.

Objectives: (1) Report sex-specific prevalence of coronavirus disease 2019 (COVID-19) test positivity among an opioid use disorder (OUD) cohort (2) Assess sex-specific rates of opioid overdose and mortality. Methods: A retrospective cohort study was performed on all adult patients with OUD who received a COVID-19 test in calendar year 2020 at a large academic medical center in Richmond, Virginia. Our study outcomes were positive COVID-19 test, opioid overdose, and all-cause in-hospital mortality. Sex-stratified multivariable logistic regression assessed sociodemographic factors associated with COVID-19 test positivity. Results: A total of 2,600 patients (males = 1,294, females = 1,306) with OUD received a COVID-19 test. Approximately 5% across both sexes tested positive for COVID-19 (p = 0.420), whereas 7% presented with an opioid overdose (males 10%; females 4%; p < 0.0001). However, mortality rates were similar across sex. Among males, individuals in the other racial group had increased odds of COVID-19 test positivity (adjusted odds ratio or AOR: 5.03, 95% confidence interval [CI]: 1.70-14.88), whereas black females had higher odds of COVID-19 test positivity (AOR: 1.92, 95% CI: 1.01-3.62) compared to their white counterparts. Conclusions: Opioid overdose, more often than COVID-19, impacted the health of patients with OUD presenting to a public safety net health system. Despite a female advantage documented in the general population for COVID-19 susceptibility, COVID-19 test positivity rates were similar across sex in an OUD cohort; yet, racial disparities emerged with notable sex-related variation. Sex and gender are important variables that modify health outcomes, including OUD and COVID-19, and should be further investigated using an intersectionality framework.

Sex Contextualism

This paper develops the conceptual framework of “sex contextualism” for the study of sex-related variables in biomedical research. Sex contextualism offers an alternative to binary sex essentialist approaches to the study of sex as a biological variable. Specifically, sex contextualism recognizes the pluralism and context-specificity of operationalizations of ‘sex’ across experimental laboratory research. In light of recent policy mandates to consider sex as a biological variable, sex contextualism offers constructive guidance to biomedical researchers for attending to sex-related biological variation. As an alternative to and critique of biological binary sex essentialism, sex contextualism contributes to current debates in philosophy of biology, feminist science studies, and social ontology on the construction of categories of gender/sex differences in scientific research.

New insights on hip bone sexual dimorphism in adolescents and adults using deformation-based geometric morphometrics.

Morphological variation of the human pelvis, and particularly the hip bone, mainly results from both female-specific selective pressure related to the give birth of large-headed newborns, and constraints in both sexes for efficient bipedal locomotion, abdominal stability, and adaptation to climate. Hip bone morphology has thus been extensively investigated using several approaches, although the nuances of inter-individual and sex-related variation are still underappreciated, and the effect of sex on ontogenetic patterns is debated. Here, we employ a landmark-free, deformation-based morphometric approach to explore variation in modern human hip bone shape and size from middle adolescence to adulthood. Virtual surface models of the hip bone were obtained from 147 modern human individuals (70 females and 77 males) including adolescents, and young and mature adults. The 3D meshes were registered by rotation, translation, and uniform scaling prior to analysis in Deformetrica. The orientation and amplitude of deviations of individual specimens relative to a global mean were assessed using Principal Component Analysis, while colour maps and vectors were employed for visualisation purposes. Deformation-based morphometrics is a time-efficient and objective method free of observer-dependent biases that allows accurate shape characterisation of general and more subtle morphological variation. Here, we captured nuanced hip bone morphology revealing ontogenetic trends and sex-based variation in arcuate line curvature, greater sciatic notch shape, pubic body and rami length, acetabular expansion, and height-to-width proportions of the ilium. The observed ontogenetic trends showed a higher degree of bone modelling of the lesser pelvis of adolescent females, while male variation was mainly confined to the greater pelvis.

Belt-induced abdominal injuries in recent frontal impact CIREN cases

Objective The objective is to report sex-related variation in 3-point belt–related abdominal injuries in Crash Injury Research Engineering Network (CIREN) cases. Methods A query of CIREN cases was made for those with the highest ranked Collision Deformation Classification (CDC) to the front plane, a principal direction of force (PDOF) ±20° from 0°, and Abbreviated Injury Scale (AIS) 2+ abdomen injuries attributed to the seat belt. Patterns of injury were categorized as above the crest of the ilium, injuries below the crest of the ilium, and injuries above and below the ilium. This was done in the context of autonomous vehicle occupant kinematics testing results. Twelve 5th and 95th percentile 3-point belt–restrained postmortem human subjects were subjects; test speeds and recline angles varied. Abdomen injuries were anticipated; none were observed. Results Thirty-five occupants with belt-related abdominal injuries were identified. Seventeen case occupants sustained an injury only within the pelvic contents: 5 women and 12 men. Nine of the 17 were at or above the 81st percentile for height, 13 were between the 62nd and 80th percentile for height, and 4 were less than the 50th percentile for height. Conclusions The stature component of the body mass index (BMI) appears to be a plausible candidate for an independent variable that is a contributing factor explaining the incidence of pelvic contents injuries when a 3-point belt–restrained occupant is involved in a frontal impact.