The military gear microbiome: risk factors surrounding the warfighter.

Combat extremity wounds are highly susceptible to contamination from surrounding environmental material. This bioburden could be partially transferred from materials in immediate proximity to the wound, including fragments of the uniform and gear. However, the assessment of the microbial bioburden present on military gear during operational conditions of deployment or training is relatively unexplored. Opportunistic pathogens that can survive on gear represent risk factors for infection following injury, especially following combat blasts, where fibers and other materials are embedded in wounded tissue. We utilized 16S rRNA sequencing to assess the microbiome composition of different military gear types (boot, trouser, coat, and canteen) from two operational environments (training in Hawai'i and deployed in Indonesia) across time (days 0 and 14). We found that microbiome diversity, stability, and composition were dependent on gear type, training location, and sampling timepoint. At day 14, species diversity was significantly higher in Hawai'i samples compared to Indonesia samples for boot, coat, and trouser swabs. In addition, we observed the presence of potential microbial risk factors, as opportunistic pathogenic species, such as Acinetobacter, Pseudomonas, and Staphylococcus, were found to be present in all sample types and in both study sites. These study outcomes will be used to guide the design of antimicrobial materials and uniforms and for infection control efforts following combat blasts and other injuries, thereby improving treatment guidance during military training and deployment.IMPORTANCECombat extremity wounds are vulnerable to contamination from environments of proximity to the warfighter, leading to potential detrimental outcomes such as infection and delayed wound healing. Therefore, microbial surveillance of such environments is necessary to aid the advancement of military safety and preparedness through clinical diagnostics, treatment protocols, and uniform material design.

Re-examining the social gradient in health: A study of Dutch men, 1850-1984.

Today, a social gradient in health is clearly visible. Individuals with higher socio-economic statuses tend to live longer lives, and are less likely to be disabled or chronically ill. However, there is debate over when the social gradient emerged: is it a constant across contexts, or a particular feature of certain societies? Often, social gradients are not found in historical contexts. This is perhaps because historical studies use mortality as their sole measure of health, which may not fully reflect the health statuses of the living. Using another health indicator may help to identify whether a social gradient in health was present in historical contexts. One alternative measure of health is body height, a barometer of population health. In this study, we accordingly examined socio-economic status's relationship to both adult mortality and body height. A sample of Dutch men (n=3396), born between 1850 and 1900, was used. Socio-economic status was measured with parental occupational class, and height was measured at age 20. Survival analyses (for mortality at age 20 or later) and linear regressions (for height at age 20) were performed. We found no clear gradient in occupational class's relationship to adult mortality. Regarding height, individuals from elite backgrounds were estimated to be 2.82 cm cm taller (95% CI: 1.41-4.24) than those from unskilled working backgrounds. While a gradient in height was present in earlier birth cohorts, it was not visible among men born between 1885 and 1900. These findings indicate that there was a social gradient in health in the late nineteenth and twentieth centuries, although the gradient perhaps changed based on the indicator and time period being examined. This may mean that the social gradient in health is more persistent over time than it appears when only examining the social gradient in mortality.

The height premium: A systematic review and meta-analysis.

The taller people are, the more money they tend to earn. This phenomenon is widely known as the height premium. However, it is not yet known whether the height premium is universal, or whether it varies by context. To that end, a systematic review of the literature was performed. Five databases were searched until August 2020. Ultimately, a list of 42 studies were included in a narrative synthesis, and 17 studies were included in a meta-analysis. Based on the meta-analysis, we found evidence that the height premium varied by context: the height premium was smaller in the U.S. and Australia, and larger in Latin America and Asia. Within geographies, there appeared to be a larger height premium for men than for women. Cultural factors, labor market structures and biology may play a role in determining the strength of the height premium.

Casting shadows: later-life outcomes of stature.

The central question in this special issue is a relatively new one in anthropometric history: how did body height affect the life course? This raises the issue of whether such an effect merely captures the underlying early-life conditions that impact growth, or whether some independent effect of stature can be discerned. Further, the effects of height on later-life outcomes need not be linear. These effects may also differ by gender, by context (time and place), and among life course domains such as occupational success, family formation or health in later life. The ten research articles in this issue use a plethora of historical sources on individuals, such as prison and hospital records, conscript records, genealogies and health surveys. These articles employ a variety of methods to distinguish between early-life and later-life effects, between intra- and intergenerational processes and between biological and socio-economic factors. Importantly, all articles discuss the impact of the specific context on their results to understand these effects. The overall conclusion is that independent later-life outcomes of height are rather ambiguous, and seem to stem more from the perception of physical strength, health and intelligence associated with height than from height itself. This special issue also reflects on intergenerational effects of the later-life outcomes of height. As populations have grown taller, it is possible that height and later-life outcomes have formed a 'virtuous cycle', resulting in taller, healthier and wealthier populations. So far, however, our research offers little support for this hypothesis.

Is paternal height related to fertility outcomes? Evidence from the Netherlands during the secular growth trend.

Over the past two centuries, the Dutch experienced a tremendous secular trend in height, and ultimately became the tallest nation in the world. Improving environmental conditions likely played the largest role in explaining these developments. But it is not yet precisely clear what factor set the Dutch head and shoulders above other nations, who were also experiencing improving environmental conditions. Could fertility also have played a role? To understand this, we would first need to know whether height and fertility were related during the secular growth trend. In this study, we investigated whether this was the case. A sample of Dutch men, birth years 1850-1900 (n = 3396), was examined. We tested the extents to which height was associated with having a certain number of children, and with having a certain number of children survive infancy. Multinomial logistic regressions were used. In terms of findings, height's relationship to fertility outcomes was curvilinear: being shorter-than-average (0.75-0.5 standard deviations below the mean height) was associated with a higher probability of being married and having five to seven children, while being moderately tall (0.5 standard deviations above the mean height) was associated with the lowest probability of being unmarried. There was no relationship between paternal height and children surviving infancy in the sample overall, but taller height was associated with a decreased risk of being in a high-mortality family among men born between 1880 and 1900. If paternal fertility played a role in the secular growth trend, we would expect to see very tall men have the most children, and clearly have the most children surviving infancy. Given this study's findings, it is unlikely that this was the case.

Height and marital outcomes in the Netherlands, birth years 1841-1900.

Adult body height appears to be significantly associated with marital outcomes: taller men across contexts have been found to be more likely to be married, and more likely to be married at younger ages. We are interested in exploring both outcomes individually and simultaneously, while using an unique, individual-level dataset of Dutch men and their brothers born between 1841 and 1900. To do so, we exploit survival models and cure models. While survival models yield a single estimate for the hazard (or age at) marriage, cure models yield two: one for the likelihood of marriage, and one for the hazard of first marriage. Cure models thus account for selection into marriage, while survival models do not. We find that, in the survival analyses, being in the shortest 20 % of heights is associated with later ages of marriage, relative to being average height. However, when we account for selection into marriage with cure models, we find that height is no longer associated with age at marriage. Instead, we see that height is associated with the likelihood of being married, with being in the bottom 20 % of heights associated with a 56.1 % decreased likelihood of being married, relative to being average height. We therefore conclude that height may be a gatekeeper for access to marriage, but it appears that other factors - likely related to the ability to set up an independent household - are more important in determining the timing of marriage for our research population.

Strengthening sense of coherence: Evidence from a physical activity intervention targeting vulnerable adults.

Sense of coherence (SOC), a concept that refers to individuals' abilities to manage, comprehend, and find meaning in their lives and the world around them, has been shown to be an important predictor of health outcomes. While SOC was initially hypothesized to be static after early-adulthood, there is growing evidence that health interventions can strengthen SOC. In this study, we accordingly examined whether SOC could be strengthened among adults in the context of a physical activity intervention. This intervention, Communities on the Move, was conducted in the Netherlands, and was primarily targeted at older adults from socially vulnerable backgrounds. Four cohorts were followed for 18 months each, between 2012 and 2016. The SOC-3 questionnaire was used to collect data on SOC at baseline (T0) and after eighteen months (T3), with information on 117 participants in both of these waves. To assess the change in SOC between T0 and T3, ordered logistic regressions were performed, as well as mixed ordered logistic regressions with random intercepts for group and program location. This study found evidence that SOC significantly changed from T0 to T3. Participants with weak SOC at baseline reported a median one-point stronger SOC at T3 (on a 6-point scale), while those with moderate or strong SOC at baseline reported a median change of zero points between T0 and T3. Further, based on the results of the regression analyses, those with weaker SOC scores were most likely to have stronger SOC at T3: having a weak SOC at baseline was associated with a 76% probability of stronger SOC, and a 4% probability of weaker SOC at T3. These results indicated that SOC may be strengthened in vulnerable older adults, particularly when their SOC is initially low.

Grow fast, die young? The causes and consequences of adult height and prolonged growth in nineteenth century Maastricht.

BACKGROUND: Both adult body height and the developmental growth trajectory have been found to be important predictors of later-life mortality. However, evidence for these relationships largely comes from contemporary populations, where most people live until old-age. It is an open question how height and growth impact later-life mortality in a population where death before old-age is more common. We therefore study the causes and mortality consequences of height and growth in a high-mortality, nineteenth-century Dutch population. METHODS: We exploit a unique dataset from three sources: conscription records with late-adolescent height, standing militia registers with adult height, and individual cause-of-death and age-at-death information. Our study is set in the Dutch city of Maastricht. To determine the causes of height and growth (either early-life environmental conditions or shared family inheritance), we use Pearson's correlation tests and multilevel linear models. To determine height and growth's consequences, we use survival analyses, for all-cause mortality and cause-specific mortality. RESULTS: Regarding the causes of height and growth, we find that prolonged growth and adolescent height are more strongly associated with external environmental factors than shared family inheritance. Adult height is more strongly related to shared family inheritance. Regarding the consequences of height and growth, we find that being taller in adulthood and growing faster are significantly associated with an increased hazard of death for the all-cause mortality model. CONCLUSIONS: While we find the 'usual suspects' for the causes of height and growth, our findings for the consequences are surprising: the tallest individuals who grow the fastest have the highest hazard of death. Our results may be explained by a selection effect: the tall, fast growers may be the least-selected in early-life, and are therefore more vulnerable than their peers in adulthood.

Assessing health outcomes in the aftermath of the great recession: a comparison of Spain and the Netherlands.

BACKGROUND: Across time and space, financial security has been shown to impact health outcomes, with the acute loss of financial security being particularly detrimental. We compare financial security's association with health in Spain and the Netherlands. These countries respectively exemplify low and high levels of financial security, general trends that have been exacerbated by the Great Recession of the 2010s. METHODS: We exploit the Spanish (n = 1001) and Dutch (n = 1010) editions of the European Social Survey 7, conducted in 2014, and condense relevant financial security- and health-related survey questions into latent variables using factor analyses. Using the component loadings as quasi-weightings, we generate one financial security variable and three health variables (mental, physical and social). Then, we run ordinary least squares regressions interacting financial security and nationality, for each of the three health outcomes. RESULTS: In unadjusted models, we find that financial security (p < 0.01) is positively associated with the three health outcomes, while being Spanish relative to being Dutch (p < 0.01) is associated with worse health outcomes. However, the results of the interaction term show that being Spanish relative to being Dutch weakens the relationship between physical health and social health, although not mental health. CONCLUSIONS: We find evidence that financial security's influence on health outcomes may vary in different contexts. This may be an important aspect of determining the Great Recession's influence on health outcomes. Our study is a first step in understanding how the relationships between financial security and health may differ in countries with different experiences of the Great Recession.

Studying the impact of the Eurozone's Great Recession on health: Methodological choices and challenges.

Europe's Great Recession provides an opportunity to study the impact of increased financial insecurity on health. A number of studies explored the impact of the Recession on health, but they often reached different conclusions. To understand the root of this debate, we undertook a systematic literature review. Articles were analysed thematically based on: geography, data type, operationalisations of wealth and health, and study design. A critical appraisal was also undertaken. Forty-two studies, published from January 2010 to October 2018, were included in our review. Twenty-six of the forty-two studies found that the Great Recession worsened physical health indicators in the Eurozone. In terms of geography, a large concentration of studies focussed on Spain and Greece, indicating that there may be a gap in understanding the health consequences for EU countries with less severe experiences of the Recession. Regarding data type, nearly all studies used secondary datasets, possibly meaning that studies were constrained by the data available. In terms of operationalisations of wealth and health, a majority of studies used single/simple measures of both, so that these multi-faceted concepts were not fully reflected. Further, fewer than half included studies used panel data, with the remaining studies unable to undertake more causal analyses. The results of the critical appraisal showed that lower-quality studies tended to not find a negative impact of the Recession on health, whereas higher quality studies generally did. In future, we recommend conducting cross-country comparisons, using (inter)nationally-representative panel data conducted over a minimum of a ten-year time horizon, and employing multi-faceted operationalisations of wealth and health. This could provide more common ground across studies, and a clearer indication of whether the Recession impacted health.

Adult body height as a mediator between early-life conditions and socio-economic status: the case of the Dutch Potato Famine, 1846-1847.

Adult body height appears to be a relatively accurate summary variable of early-life exposures' influence on health, and may be a useful indicator of health in populations where more traditional health-related indicators are lacking. In particular, previous studies have shown a strong, positive relationship between environmental conditions in early life (particularly nutritional availability and the disease environment) and adult height. Research has also demonstrated positive associations between height and socioeconomic status. We therefore hypothesize that height mediates the relationship between early-life conditions and later-life socio-economic outcomes. We also hypothesize that the period of exposure in early life matters, and that conditions during pregnancy or the first years of life and/or the years during puberty have the largest effects on height and socio-economic status. To test these relationships, we use a sample of 1817 Dutch military conscripts who were exposed during early life to the Dutch Potato Famine (1846-1847). We conduct mediation analyses using structural equation modelling, and test seven different time periods in early-life. We use potato prices and real wages to proxy early-life environmental conditions, and occupational status (using the HISCAM scale) to proxy socioeconomic status. We find no evidence of mediation, partial or full, in any models. However, there are significant relationships between potato prices in adolescence, height and socio-economic status. To determine causality in these relationships, further research is needed.

Meeting Report: The Role of Beliefs and Perception on Body Size. Proceedings of the 26th Aschauer Soiree, Held at Aschauhof, Altenhof, Germany, May 26th, 2018.

Thirty-one scientists met at Aschauhof, Germany to discuss the role of beliefs and self-perception on body size. In view of apparent growth stimulatory effects of dominance within the social group that is observed in social mammals, they discussed various aspects of competitive growth strategies and growth adjustments. Presentations included new data from Indonesia, a cohort-based prospective study from Merida, Yucatan, and evidence from recent meta-analyses and patterns of growth in the socially deprived. The effects of stress experienced during pregnancy and adverse childhood events were discussed, as well as obesity in school children, with emphasis on problems when using z-scores in extremely obese children. Aspects were presented on body image in African-American women, and body perception and the disappointments of menopause in view of feelings of attractiveness in different populations. Secular trends in height were presented, including short views on so called 'racial types' vs bio-plasticity, and historic data on early-life nutritional status and later-life socioeconomic outcomes during the Dutch potato famine. New tools for describing body proportions in patients with variable degrees of phocomelia were presented along with electronic growth charts. Bio-statisticians discussed the influence of randomness, community and network structures, and presented novel tools and methods for analyzing social network data.