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1. The intersections of industrialization: Variation in skeletal indicators of frailty by age, sex, and socioeconomic status in 18th‐ and 19th‐century England

   https://doi.org/10.1002/ajpa.23881  

   Yaussy, Samantha L. ( June 2019 , American Journal of Physical Anthropology)

   Intersectionality theory argues that various categories of identity and forms of systemic oppression interact and produce inequalities in resource access, economic opportunities, and health outcomes. However, there has been little explicit engagement with this theory by bioarchaeologists examining disparate health outcomes in the past. This study examines the associations among frailty, age at death, sex, and socioeconomic status (SES) in 18th‐ and 19th‐century England.

   The sample for this study comes from four industrial‐era cemeteries from England, ca. 1711–1857. The associations among adult age (18+ years), SES, sex, and three skeletal indicators of stress (dental enamel hypoplasia [DEH,n= 293], cribra orbitalia [CO,n= 457], periosteal lesions [PNB,n= 436]) are examined using hierarchical log‐linear analysis.

   Significant interactions existed among the variables examined for two skeletal indicators: high SES females had lower frequencies of CO relative to other groups and males between ages 30–45 years exhibited higher frequencies of PNB compared to females or males of older or younger ages, regardless of SES. Additionally, sex and SES were consistently associated with age at death.

   These results suggest that patterns of stress indicators cannot be examined solely across unilateral axes of age, SES, or sex. Intersecting axes of privilege, marginalization, and structural oppression may have buffered high SES females from some negative health outcomes (CO) while predisposing them to others (risk of maternal mortality). Likewise, the hazardous working conditions relegated to adult males may have heightened the risk of injury, infection, and death for middle‐aged men in industrial‐era England.

    

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2. Allometric scaling and growth: Evaluation and applications in subadult body mass estimation

   https://doi.org/10.1002/ajpa.24329  

   Yim, An‐Di ; Konigsberg, Lyle W. ; Hwa, Hsiao‐Lin ; Chang, Chin‐Chen ; Chen, Jo‐Yu ; Liu, Hon‐Man ( May 2021 , American Journal of Physical Anthropology)

   Previously developed methods in subadult body mass estimation have not been tested in populations other than European–American or African–American. This study uses a contemporary Taiwanese sample to test these methods. Through evaluating their accuracy and bias, we addressed whether the allometric relationships between body mass and skeletal traits commonly used in subadult body mass estimation are conserved among different populations.

   Computed tomography scans of lower limbs from individuals aged 0–17 years old of both sexes were collected from National Taiwan University Hospital along with documented body weight. Polar second moment of area, distal femoral metaphyseal breadth, and maximum superior/inferior femoral head diameter were collected either directly from the scans or from reconstructed 3D models. Estimated body mass was compared with documented body mass to assess the performance of the equations.

   Current methods provided good body mass estimates in Taiwanese individuals, with accuracy and bias similar to those reported in other validation studies. A tendency for increasing error with increasing age was observed for all methods. Reduced major axis regression showed the allometric relationships between different skeletal traits and body mass across different age categories can all be summarized using a common fitted line. A revised, maximum likelihood‐based approach was proposed for all skeletal traits.

   The results suggested that the allometric relationships between body mass and different skeletal traits are largely conserved among populations. The revised method provided improved applicability with strong underlying theoretical justifications, and potential for future improvements.

    

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3. Advanced age protects resistance arteries of mouse skeletal muscle from oxidative stress through attenuating apoptosis induced by hydrogen peroxide

   https://doi.org/10.1113/JP278255  

   Norton, Charles E. ; Sinkler, Shenghua Y. ; Jacobsen, Nicole L. ; Segal, Steven S. ( July 2019 , The Journal of Physiology)

   Vascular oxidative stress increases with advancing age.

   We hypothesized that resistance vessels develop resilience to oxidative stress to protect functional integrity and tested this hypothesis by exposing isolated pressurized superior epigastric arteries (SEAs) of old and young mice to H₂O₂.

   H₂O₂‐induced death was greater in smooth muscle cells (SMCs) than endothelial cells (ECs) and lower in SEAs from oldvs. young mice; the rise in vessel wall [Ca²⁺]_iinduced by H₂O₂was attenuated with ageing, as was the decline in noradrenergic vasoconstriction; genetic deletion of IL‐10 mimicked the effects of advanced age on cell survival.

   Inhibiting NO synthase or scavenging peroxynitrite reduced SMC death; endothelial denudation or inhibiting gap junctions increased SMC death; delocalization of cytochrome C activated caspases 9 and 3 to induce apoptosis.

   Vascular cells develop resilience to H₂O₂during ageing by preventing Ca²⁺overload and endothelial integrity promotes SMC survival.

   Advanced age is associated with elevated oxidative stress and can protect the endothelium from cell death induced by H₂O₂. Whether such protection occurs for intact vessels or differs between smooth muscle cell (SMC) and endothelial cell (EC) layers is unknown. We tested the hypothesis that ageing protects SMCs and ECs during acute exposure to H₂O₂(200 µm, 50 min). Mouse superior epigastric arteries (SEAs; diameter, ∼150 µm) were isolated and pressurized to 100 cmH₂O at 37˚C. For SEAs from young (4 months) mice, H₂O₂killed 57% of SMCs and 11% of ECs in malesvs. 8% and 2%, respectively, in females. Therefore, SEAs from males were studied to resolve the effect of ageing and experimental interventions. For old (24 months) mice, SMC death was reduced to 10% with diminished accumulation of [Ca²⁺]_iin the vessel wall during H₂O₂exposure. In young mice, genetic deletion of IL‐10 mimicked the protective effect of ageing on cell death and [Ca²⁺]_iaccumulation. Whereas endothelial denudation or gap junction inhibition (carbenoxolone; 100 µm) increased SMC death, inhibiting NO synthase (l‐NAME, 100 µm) or scavenging peroxynitrite (FeTPPS, 5 µm) reduced SMC death along with [Ca²⁺]_i. Despite NO toxicity via peroxynitrite formation, endothelial integrity protects SMCs. Caspase inhibition (Z‐VAD‐FMK, 50 µm) attenuated cell death with immunostaining for annexin V, cytochrome C, and caspases 3 and 9 pointing to induction of intrinsic apoptosis during H₂O₂exposure. We conclude that advanced age reduces Ca²⁺influx that triggers apoptosis, thereby promoting resilience of the vascular wall during oxidative stress.

    

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4. Sex differences in adult famine mortality in medieval London

   https://doi.org/10.1002/ajpa.23930  

   DeWitte, Sharon_N ; Yaussy, Samantha_L ( October 2019 , American Journal of Physical Anthropology)

   Recurrent famine events during the medieval period might have contributed to excess mortality during the Black Death in London, England (c. 1349–1350). Previous research using conventional methods of age estimation revealed that adult males experienced lower risks of mortality under “normal” (attritional) but not famine mortality conditions following the Black Death. However, given the biases inherent in conventional age estimation methods, this study reassesses sex differences in risks of medieval adult famine mortality using ages estimated via transition analysis, which avoids some of the limitations of conventional age estimation methods.

   We apply hazards analysis (the Gompertz model of adult mortality) to ages estimated for human skeletal remains (n= 1245) from London cemeteries dated to the pre‐Black Death (c. 1000–1250 CE) and post‐Black Death (c. 1350–1540 CE) periods.

   The results reveal no sex differences in risks of mortality before the Black Death but indicate that adult males faced lower risks of mortality after the Black Death during conditions of normal and famine mortality.

   These findings largely support those of our previous research, which suggested that selective mortality during the Black Death or sex‐biased improvements in standard of living following the epidemic reduced risk of mortality for adult males in the post‐Black Death period under normal mortality conditions. However, the use of transition analysis age estimates also revealed a reduced risk of mortality for post‐Black Death adult males under famine conditions.

    

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5. Association of type 2 diabetes mellitus with dementia‐related and non–dementia‐related mortality among postmenopausal women: A secondary competing risks analysis of the women's health initiative

   https://doi.org/10.1002/alz.13416  

   Titcomb, Tyler J. ; Richey, Phyllis ; Casanova, Ramon ; Phillips, Lawrence S. ; Liu, Simin ; Karanth, Shama D. ; Saquib, Nazmus ; Nuño, Tomas ; Manson, JoAnn E. ; Shadyab, Aladdin H. ; et al ( August 2023 , Alzheimer's & Dementia)

   Alzheimer's disease (AD) and AD‐related dementias (ADRD) are leading causes of death among older adults in the United States. Efforts to understand risk factors for prevention are needed.

   Participants (n = 146,166) enrolled in the Women's Health Initiative without AD at baseline were included. Diabetes status was ascertained from self‐reported questionnaires and deaths attributed to AD/ADRD from hospital, autopsy, and death records. Competing risk regression models were used to estimate the cause‐specific hazard ratios (HRs) and 95% confidence intervals (CIs) for the prospective association of type 2 diabetes mellitus (T2DM) with AD/ADRD and non‐AD/ADRD mortality.

   There were 29,393 treated T2DM cases and 8628 AD/ADRD deaths during 21.6 (14.0–23.5) median (IQR) years of follow‐up. Fully adjusted HRs (95% CIs) of the association with T2DM were 2.94 (2.76–3.12) for AD/ADRD and 2.65 (2.60–2.71) for the competing risk of non‐AD/ADRD mortality.

   T2DM is associated with AD/ADRD and non‐AD/ADRD mortality.

   Type 2 diabetes mellitus is more strongly associated with Alzheimer's disease (AD)/AD and related dementias (ADRD) mortality compared to the competing risk of non‐AD/ADRD mortality among postmenopausal women.

   This relationship was consistent for AD and ADRD, respectively.

   This association is strongest among participants without obesity or hypertension and with younger age at baseline, higher diet quality, higher physical activity, higher alcohol consumption, and older age at the time of diagnosis of type 2 diabetes mellitus.

    

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