Economic impacts and nutritional outcomes of the 2017 floods in Bangladeshi Shodagor fishing families.

OBJECTIVES: As climate change continues to increase the frequency and severity of flooding in Bangladesh and globally, it becomes increasingly critical to understand the pathways through which flooding influences health outcomes, particularly in lower-income and subsistence-based communities. We aim to assess economic pathways that link flooding to nutritional outcomes among Shodagor fishing families in Bangladesh. METHODS: We examine longitudinal economic data on kilograms of fish caught, the income earned from those fish, and household food expenditures (as a proxy for dietary intake) from before, during, and after severe flooding in August-September of 2017 to enumerate the impacts of flooding on Shodagor economics and nutrition. We also analyze seasonally collected anthropometric data to model the effects of flooding and household food expenditures on child growth rates and changes to adult body size. RESULTS: While Shodagor fishing income declined during the 2017 flooding, food expenditures simultaneously spiked with market inflation, and rice became the predominant expenditure only during and immediately following the flood. Our nutritional models show that children and adults lost more body mass in households that spent more money on rice during the flood. Shodagor children lost an average of 0.36 BMI-for-age z-scores and adults lost an average of 0.32 BMI units during the flooded 2017 rainy season, and these metrics continued to decline across subsequent seasons and did not recover by the end of the study period in 2019. CONCLUSIONS: These results show major flood-induced economic impacts that contributed to loss of child and adult body mass among Shodagor fishing families in Bangladesh. More frequent and severe flooding will exacerbate these nutritional insults, and more work is needed to effectively stabilize household nutrition throughout natural disasters and economic hardship.

Anthropometric heritability and child growth in a Caribbean village: A quantitative genetic analysis of longitudinal height, weight, and body mass index in Bwa Mawego, Dominica.

OBJECTIVES: Body size and composition vary widely among individuals and populations, and long-term research in diverse contexts informs our understanding of genetic, cultural, and environmental impacts on this variation. We analyze longitudinal measures of height, weight, and body mass index (BMI) from a Caribbean village, estimating the extent to which these anthropometrics are shaped by genetic variance in a small-scale population of mixed ancestry. MATERIALS AND METHODS: Longitudinal data from a traditionally horticultural village in Dominica document height and weight in a non-Western population that is transitioning to increasingly Westernized lifestyles, and an 11-generation pedigree enables us to estimate the proportions of phenotypic variation in height, weight, and BMI attributed to genetic variation. We assess within-individual variation across growth curves as well as heritabilities of these traits for 260 individuals using Bayesian variance component estimation. RESULTS: Age, sex, and secular trends account for the majority of anthropometric variation in these longitudinal data. Independent of age, sex, and secular trends, our analyses show high repeatabilities for the remaining variation in height, weight, and BMI growth curves (>0.75), and moderate heritabilities (h2height = 0.68, h2weight = 0.64, h2BMI = 0.49) reveal clear genetic signals that account for large proportions of the variation in body size observed between families. Secular trends show increases of 6.5% in height and 16.0% in weight from 1997 to 2017. DISCUSSION: This horticultural Caribbean population has transitioned to include more Westernized foods and technologies over the decades captured in this analysis. BMI varies widely between individuals and is significantly shaped by genetic variation, warranting future exploration with other physiological correlates and associated genetic variants.

Estimating impacts of the nuclear family and heritability of nutritional outcomes in a boat-dwelling community.

OBJECTIVES: General health status is reflected in measures of height, weight, and BMI. Assessing sources of variation in these outcomes reveals population-specific variables of importance to health and nutrition. We characterize the impacts of socioeconomic variables related to the nuclear family on health outcomes of boat-dwelling Shodagor children, mothers, and fathers, and to estimate the proportion of variation in height, weight, and BMI influenced by both genetic variation and nongenetic variation among household environments. METHODS: Bayesian linear mixed models (LMMs) estimate heritability and household-effect variance components among the Shodagor. These models also assess the influences of specific socioeconomic predictor variables on different types of individuals within the household (children, mothers, and fathers). RESULTS: Overall, models explain 61.7% of variation in height, 59.4% in weight, and 65.8% in BMI for this sample of Shodagor. Mother's decision-making and household income have expected, positive associations with children's weight and BMI. Number of children has an unexpected positive relationship to children's height and a negative relationship to father's BMI. Genetic variation explains less than 26% of phenotypic variation for each of these traits on average. CONCLUSIONS: Our results show that resource flows and distributions within Shodagor households account for a significant amount of variance in nutritional outcomes. Problems commonly associated with increasing market integration may lead to negative outcomes for children, while mother's autonomy may lead to positive outcomes. Our models also indicate that environmental factors account for more variation in these outcomes than expected, relative to genetics, and we discuss the implications.

Social Determinant Pathways to Hypertensive Disorders of Pregnancy Among Nulliparous U.S. Women.

BACKGROUND: Hypertensive disorders of pregnancy are a leading cause of maternal morbidity and mortality in the United States and impact Black mothers at disproportionately higher rates. Hypertensive disparities among racialized groups are rooted in systemic inequalities, and we hypothesize that clinical markers of allostatic load capture embodied disparities in stressors that can link upstream social determinants of health with downstream hypertensive outcomes. METHODS: We analyzed observational cohort data from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (n = 6,501) and developed a structural equation model linking latent social determinants of health, longitudinal markers of allostatic load across gestation, and hypertensive pregnancy outcomes in a multigroup framework. RESULTS: Non-Hispanic Black mothers-to-be (n = 1,155) showed higher rates of hypertensive disorders of pregnancy (32%) than non-Hispanic white women (n = 5,346, 23%). Among both groups, the social environment showed stronger direct effects on allostatic markers than via behaviorally mediated dietary, exercise, or smoking pathways. Demographic aspects of the social environment (e.g., household income, partnered status) were the most salient predictor of hypertensive risk and showed stronger effects among Black women. CONCLUSIONS: Embodied stress rooted in the social environment is a major path driving maternal hypertensive disparities in the United States, with effects that vary across racialized groups. These pathway findings underscore the greater impact of systemic stressors relative to individual health behaviors. More comprehensive and detailed analyses of sociostructural domains are needed to identify promising avenues for policy and intervention to improve maternal health.

Genetic ancestry, admixture, and population structure in rural Dominica.

The Caribbean is a genetically diverse region with heterogeneous admixture compositions influenced by local island ecologies, migrations, colonial conflicts, and demographic histories. The Commonwealth of Dominica is a mountainous island in the Lesser Antilles historically known to harbor communities with unique patterns of migration, mixture, and isolation. This community-based population genetic study adds biological evidence to inform post-colonial narrative histories in a Dominican horticultural village. High density single nucleotide polymorphism data paired with a previously compiled genealogy provide the first genome-wide insights on genetic ancestry and population structure in Dominica. We assessed family-based clustering, inferred global ancestry, and dated recent admixture by implementing the fastSTRUCTURE clustering algorithm, modeling graph-based migration with TreeMix, assessing patterns of linkage disequilibrium decay with ALDER, and visualizing data from Dominica with Human Genome Diversity Panel references. These analyses distinguish family-based genetic structure from variation in African, European, and indigenous Amerindian admixture proportions, and analyses of linkage disequilibrium decay estimate admixture dates 5-6 generations (~160 years) ago. African ancestry accounts for the largest mixture components, followed by European and then indigenous components; however, our global ancestry inferences are consistent with previous mitochondrial, Y chromosome, and ancestry marker data from Dominica that show uniquely higher proportions of indigenous ancestry and lower proportions of African ancestry relative to known admixture in other French- and English-speaking Caribbean islands. Our genetic results support local narratives about the community's history and founding, which indicate that newly emancipated people settled in the steep, dense vegetation along Dominica's eastern coast in the mid-19th century. Strong genetic signals of post-colonial admixture and family-based structure highlight the localized impacts of colonial forces and island ecologies in this region, and more data from other groups are needed to more broadly inform on Dominica's complex history and present diversity.