The biological index of frailty: A new index for the assessment of frailty in human skeletal remains

Health inequality in medieval Cambridge, 1200-1500 CE

Health inequality is not only a major problem today; it left its mark upon past societies too. For much of the past, health inequality has been poorly studied, mostly because bioarchaeologists have concentrated upon single sites rather than a broader social landscape. This article compares 476 adults in multiple locations of medieval Cambridge (UK). Samples include ordinary townspeople (All Saints), people living in a charitable institution (the Hospital of St. John), and members of a religious order (the Augustinian Friary). These groups shared many conditions of life, such as a similar range of diseases, risk of injury, and vertebral disk degeneration. However, people living on charity had more indicators of poor childhood health and diet, lower adult stature, and a younger age at death, reflecting the health effects of poverty. In contrast, the Augustinian friars were members of a prosperous, well-endowed religious house. Compared with other groups, they were taller (perhaps a result of a richer diet during their adolescent growth period); their adult carbon and nitrogen isotope values are higher, suggesting a diet higher in terrestrial and/or marine animal protein; and they had the highest prevalence of foot problems related to fashionable late medieval footwear. As this illustrates, health inequality will take particular forms depending upon the specificities of a social landscape; except in unusual circumstances where a site and its skeletal samples represent a real cross-section of society, inequality is best investigated by comparison across sites.

Comparative lifespan and healthspan of nonhuman primate species common to biomedical research

There is a critical need to generate age- and sex-specific survival curves to characterize chronological aging consistently across nonhuman primates (NHP) used in biomedical research. Accurate measures of chronological aging are essential for inferences into genetic, demographic, and physiological variables driving differences in NHP lifespan within and between species. Understanding NHP lifespans is relevant to public health because unraveling the demographic, molecular, and clinical bases of health across the life course in translationally relevant NHP species is fundamentally important to the study of human aging. Data from more than 110,000 captive individual NHP were contributed by 15 major research institutions to generate sex-specific Kaplan-Meier survival curves using uniform methods in 12 translational aging models: Callithrix jacchus (common marmoset), Chlorocebus aethiops sabaeus (vervet/African green), Macaca fascicularis (cynomolgus macaque), M. fuscata (Japanese macaque), M. mulatta (rhesus macaque), M. nemestrina (pigtail macaque), M. radiata (bonnet macaque), Pan troglodytes spp. (chimpanzee), Papio hamadryas spp. (baboon), Plecturocebus cupreus (coppery titi monkey), Saguinus oedipus (cotton-top tamarin), and Saimiri spp. (squirrel monkey). After employing strict inclusion criteria, primary analysis results are based on 12,269 NHP that survived to adulthood and died of natural/health-related causes. A secondary analysis was completed for 32,616 NHP that died of any cause. For the primary analyses, we report ages of 25th, 50th, 75th, and 85th percentiles of survival, maximum observed ages, rates of survivorship, and sex-based differences captured by quantile regression models and Kolmogorov-Smirnov tests. Our findings show a pattern of reduced male survival among catarrhines (African and Asian primates), especially macaques, but not platyrrhines (Central and South American primates). For many species, median lifespans were lower than previously reported. An important consideration is that these analyses may offer a better reflection of healthspan than lifespan. Captive NHP used in research are typically euthanized for humane welfare reasons before their natural end of life, often after diagnosis of their first major disease requiring long-term treatment with reduced quality of life (e.g., endometriosis, cancer, osteoarthritis). Supporting the idea that these data are capturing healthspan, for several species typical age at onset of chronic disease is similar to the median lifespan estimates. This data resource represents the most comprehensive characterization of sex-specific lifespan and age-at-death distributions for 12 biomedically relevant species, to date. The results clarify the relationships among NHP ages and will provide a valuable resource for the aging research community, improving human-NHP age equivalencies, informing investigators of the expected survival rates of NHP assigned to studies, providing a metric for comparisons in future studies, and contributing to our understanding of the factors that drive lifespan differences within and among species.

What's luck got to do with it? A generative model for examining the role of stochasticity in age-at-death, with implications for bioarchaeology

INTRODUCTION

The role of "luck" in determining individual exposure to health insults is a critical component of the processes that shape age-at-death distributions in mortality samples but is difficult to address using traditional bioarcheological analysis of skeletal materials. The present study introduces a computer simulation approach to modeling stochasticity's contribution to the mortality schedule of a simulated cohort.

METHODS

The present study employs an agent-based model of 15,100 individuals across a 120 year period to examine the predictive value of birth frailty on age-at-death when varying the likelihood of exposure to health insults.

RESULTS

Birth frailty, when accounting for varying exposure likelihood scenarios, was found to account for 18.7% of the observed variation in individual age-at-death. Analysis stratified by exposure likelihood demonstrated that birth frailty alone explains 10.2%-12.1% of the variation observed across exposure likelihood scenarios, with the stochasticity associated with exposure to health insults (i.e., severity of health insult) and mortality likelihood driving the majority of variation observed.

CONCLUSIONS

Stochasticity of stressor exposure and intrinsic stressor severity are underappreciated but powerful drivers of mortality in this simulation. This study demonstrates the potential value of simulation modeling for bioarchaeological research.

Periodontitis and alveolar resorption in human skeletal remains: The relationship between quantitative alveolar bone loss, occlusal wear, antemortem tooth loss, dental calculus and age at death in a low socioeconomic status, modern forensic human collection from Yucatan

OBJECTIVE

This paper assesses the relationship between the distance between the cemento-enamel junction and alveolar crest and risk factors commonly associated with periodontitis.

MATERIALS

Eighty individuals between 28 and 92 years old with known biological sex and age were analyzed from a 20th century forensic human collection from Merida, Yucatan (Mexico).

METHODS

Macroscopic assessment, along with metric analysis, was employed using a probe.

RESULTS

Ante-mortem tooth loss was positively correlated with the distance between the cemento-enamel junction and alveolar crest, as was the presence of root calculus in females.

CONCLUSIONS

Cemento-enamel junction to alveolar crest distance is not a reliable indicator of periodontitis since it is not directly related to periodontitis-causing infectious pathogens, and since ante-mortem tooth loss can affect root exposure.

SIGNIFICANCE

This study demonstrates that a purely quantitative approach to diagnosing periodontitis in archaeological and forensic human remains can be misleading.

LIMITATIONS

The skeletal collection is only representative of the low socioeconomic class of Merida, and its female cohort is underrepresented. In addition, because the Xoclan collection is modern, limitations (particularly with respect to tooth wear) of the applicability of these interpretations to older archaeological remains exist.

SUGGESTION FOR FURTHER RESEARCH

A combination of quantitative and qualitative characteristics of alveolar bone is needed to reliably diagnose periodontitis in skeletal populations.

Medieval monastic health: Variation in skeletal signs of inflammation and developmental stress between religious orders in London

OBJECTIVES

Previous bioarchaeological analyses of medieval monastic and nonmonastic cemeteries in London revealed evidence of lower risks of mortality, and thus better health, in the monastic settings. However, comparison of the two monastic communities, Bermondsey Abbey and Merton Priory, which adhered to different religious ideals, suggested lower risks of mortality in the former. This study examines patterns of skeletal biomarkers, which reflect developmental stress or inflammation, in an attempt to clarify the possible underlying mechanisms producing apparent health differences in these monastic communities.

MATERIALS AND METHODS

This study uses skeletal data on age-at-death, periosteal new bone formation (PNBF), and cribra orbitalia from 558 adults (18 years of age and older) estimated to be male from Bermondsey Abbey and Merton Priory. Biomarker age patterns are assessed via Kaplan-Meier survival analysis and binary logistic regression. Differences in frequencies of biomarkers between the monastic sites are evaluated using Chi-square and hierarchical log-linear analyses.

RESULTS

In general, PNBF is positively associated with age, and cribra orbitalia is negatively associated with age. The frequency of PNBF formation is significantly higher and that of cribra orbitalia is significantly lower in Bermondsey Abbey compared with Merton Priory.

CONCLUSIONS

The differences in frequencies of these skeletal biomarkers support previous findings suggesting that health conditions were better in Bermondsey Abbey than in Merton Priory. The age patterns of cribra orbitalia suggest that these differences reflect conditions and the greater health-promoting effects of religiosity or isolation from the lay community in Bermondsey Abbey rather than differences in selective admissions processes.

"Heal the sick": Health status and caregiving during the 17th-18th century in Northern Italy (St. Biagio cemetery, Ravenna)

OBJECTIVE

The study of health-related care provision in archeology gives important indications on the culture and community organization of past populations. This study aims to assess the health status of the skeletal assemblage recovered from the burial site of St. Biagio (Ravenna, 17th-18th Centuries); next, we identified likely instances of need for and receipt of caregiving in response to the condition, to examine evidence of community attitudes toward disease and disability.

MATERIALS AND METHODS

The skeletal assemblage is composed of 133 individuals in a generally good state of preservation. Sex and age-at-death were estimated through classical anthropological methods. Health status was inferred through the biological index of frailty (BIF) and paleopathological analysis was performed through macroscopic and radiographic investigations. The "bioarcheology of care" approach was applied to individuals who showed evidence of impairment and disability.

RESULTS

The skeletal assemblage of St. Biagio was equally represented by males and females (50% males), with a higher percentage of adults (83.4%) than subadults (10.5%), and this is reflected in the high life expectancy at birth (40.3 years). No significant differences in health status emerged between age groups and sexes, with a generally high percentage of joint diseases, antemortem trauma, and infectious diseases. Evidence of care and compassion was found in some individuals with a high degree of impairment or disability, as in the case of probable Angelman syndrome.

DISCUSSION

This study provided important insights into the biological and social aspects of an Early Modern population in Northern Italy, showing that people with functional and/or visible abnormalities were probably cared for in life and were presumably considered full members of the society.

Assessing the association of skeletal indicators of stress with mean age-at-death in sub-adults

OBJECTIVES

The present study investigated the association of skeletal indicator of stress presence with mean age-at-death as a means of understanding whether commonly studied indicators are indeed indicative of increased frailty.

MATERIALS AND METHODS

Using a medieval Gaelic population from Ballyhanna (Co. Donegal), the present study assessed the association between skeletal indicators of stress and mean age-at-death using the Kaplan-Meier survival function with log rank test to determine whether these indicators were associated with younger age-at-death, and therefore increased frailty, in sub-adults only (0 to 18 years, N = 139) and through comparison to an all-ages cohort (N = 318).

RESULTS

Only linear enamel hypoplasia was found to be associated with significantly decreased survivorship across the all-ages cohort but, conversely, was associated with increased survivorship when analysis was restricted to sub-adults. All other indicators assessed were associated with increased age-at-death for both all-age cohorts and sub-adult cohorts (cribra orbitalia), increased age-at-death when assessing all ages only (porotic hyperostosis and healed periosteal lesions); or were sufficiently rare in adults to prevent comparative analysis (stunting and micronutrient deficiency). Increased survivorship in individuals with higher numbers of co-morbid skeletal indicators was observed for both sub-adults alone and all age cohort.

DISCUSSION

These findings suggest that these commonly recorded skeletal indicators may be more accurately viewed simply as records of stressor exposure and subsequent survival only, rather than providing evidence that these sub-adults are frailer than their similarly aged-at-death peers. Thus, the demographic and sociocultural context is essential to the interpretation of observed skeletal indicators of stress.

Sex, gender, and sexuality in paleopathology: Select current developments and pathways forward

OBJECTIVE

Overall, paleopathology trails behind related fields in exploring sex, gender, and sexuality in past societies. Here, we interrogatively synthesize scholarship on topics not included in similar reviews, focusing on sex estimation methods, and considering the social determinants of health; trauma; reproduction and family; and childhood - to highlight novel, social epidemiology- and social theory-informed frameworks and interpretive devices.

CONCLUSIONS

Many paleopathological interpretations focus on sex-gender differences relative to health, with increasing use of intersectionality. Others consistently project present-day ideologies about sex, gender, and sexuality (e.g., binary sex-gender systems) into paleopathological interpretations (i.e., presentism).

SIGNIFICANCE

Paleopathologists have an ethical imperative to generate scholarship that contributes to social justice initiatives focused on dismantling structural inequalities, especially relative to sex, gender, and sexuality (e.g., homophobia), such as through denaturalizing presentist binary systems. They also have a responsibility towards greater inclusivity relative to researcher identity and diversification of method and theory.

LIMITATIONS

In addition to material limitations complicating reconstructions of sex, gender, and sexuality relative to health and disease in the past, this review wasn't comprehensive. The review was also limited by the relative paucity of paleopathological work on these topics.

SUGGESTIONS FOR FUTURE RESEARCH

The outlook for paleopathological research on sex, gender, and sexuality is, however, positive; paleopathology is well situated to tackle these aspects of social identity. Future work should consider critical, self-reflective movement away from presentism; more robust contextualization; and further engagement with social theory and social epidemiology theory and approaches, including the Developmental Origins of Health and Disease (DOHaD), social determinants of health, and intersectionality.

Skeletal Markers of Physiological Stress as Indicators of Structural Violence: A Comparative Study between the Deceased Migrants of the Mediterranean Sea and the CAL Milano Cemetery Skeletal Collection

Structural violence is an indirect form of violence that can lead to physiological consequences. Interestingly, these physiological disruptions may affect the skeletons and can therefore provide relevant information on violence and way of life in the analysis of skeletal remains. The aim of the present study was to test the hypothesis that migrants who died in the Mediterranean Sea would present physiological cranial stress markers such as cribra orbitalia (CO), porotic hyperostosis (PH), and linear enamel hypoplasia (LEH) more frequently and more severely than Italians of the 20th century. With this intent, a total of 164 crania were examined: 139 from deceased migrants recovered from a shipwreck in the Mediterranean Sea in 2015, aged between 16 and 35 years old, and 25 of the same age from the CAL Milano Cemetery Skeletal Collection. Both presence and severity of CO, PH, and LEH were evaluated. The data obtained were analyzed using Wilcoxon signed-rank and independence Chi-squared tests to compare the results between the two samples and to test whether there was an association between the sample of migrants and the occurrence of lesions. As a result, CO and PH appeared more frequently and more severely in the migrant sample. In addition, migrants were significantly associated with CO, PH, and LEH (p-values < 0.05). Although this does not imply in any way that CO, PH, and LEH are specific to migration, they should be regarded as indicators of structural violence.

Beyond the report: Prospects and challenges in forensic anthropological investigations of structural vulnerability

Forensic anthropologists are increasingly interested in accounting for embodied marginalization in addition to the biological profile. A structural vulnerability framework, which assesses biomarkers of social marginalization in individuals within forensic casework, is worthwhile but its application must be informed by ethical, interdisciplinary perspectives that reject categorizing suffering within the pages of a case report. Drawing from anthropological perspectives, we explore prospects and challenges of evaluating embodied experience in forensic work. Particular attention is paid to how forensic practitioners and stakeholders utilize a structural vulnerability profile within and beyond the written report. We argue that any investigation of forensic vulnerability must: (1) integrate rich contextual data, (2) be evaluated for potential to perpetuate harm, and (3) serve the needs of a diverse array of stakeholders. We call for a community-oriented forensic practice, wherein anthropologists may act as advocates for policy change to disrupt power structures driving vulnerability trends in their region.