Dufour, Dr. Darna L., U. of Colorado, Boulder, CO - To aid research on 'Work Efficiency in Lactating Women'
DR. DARNA L. DUFOUR, University of Colorado, Boulder, Colorado, was awarded a grant in July 2004 to aid research on 'Work Efficiency in Lactating Women.' Lactation is the most costly phase of reproduction for human females and can increase a women's energy needs by 30 percent. Women can potentially meet this increase in energy needs by increasing their food energy intake, decreasing their physical activity and/or utilizing their body fat stores. This study examined a fourth way women can potentially meet their increased energy needs in lactation, that is by an increase in work (metabolic) efficiency in exercise. A sample of exclusively breastfeeding women was recruited and their work efficiency in exercise measured at peak lactation (3-4 months postpartum) and then again after weaning. Work efficiency in exercise was measured as delta efficiency (the ratio of work accomplished to energy needed to accomplish that work) using a submaximal exercise test on a cycle ergometer. The results demonstrated that delta efficiency is significantly higher at peak lactation than after weaning. Further, delta efficiency at peak lactation was significantly higher than in a control sample of non-pregnant, non-lactating women. These findings suggest that in addition to increased food energy intake, decreased physical activity and the utilization of fat stores, women can compensate for the extra energy demands of lactation through increases in work efficiency.
Houck, Kelly Marie, U. of North Carolina, Chapel Hill, NC - To aid research on 'A New Dual Burden Life History Theory Application Exploring Childhood Gut Immune Function and Overnutrition,' supervised by Dr. Amanda Thompson
Preliminary abstract: The emerging field of gut microbiota contributes to anthropological concerns by providing a new pathway to examine the effects of pathogenic, nutritional and social environments on human physiology and consequently human variation. The bacterial components and metabolites of gut microbial communities are vital factors in the regulation of the immune system and in providing energy processing. This project develops and tests a new application of childhood life history theory tradeoffs in maintenance and growth for the dual burden environment through a focus on gut immune function. This framework incorporates the increased energetic cost of both dietary- and pathogenic-induced immune activation and models the influence of gut immune function on diverting resources from linear bone growth towards adiposity. Children will be sampled from the three populated islands of the Galapagos and detailed survey data will be collected on their diet, symptom history, sociodemographics and household sanitation, along with anthropometric assessments, household water quality tests, and blood spot and fecal analyses of gut immune function biomarkers. Data will be used to test for the relationship between overnutrition and infection on gut immune activation and to determine the cost of pathogenic and dietary immune activation on tradeoffs in adiposity and linear growth.
Middleton, Emily Ruth, New York U., New York, NY - To aid research on 'Ecogeographical Influences on Trunk Modularity in Recent Humans: Colonization and Morphological Integration,' supervised by Dr. Susan C. Anton
Preliminary abstract: One of the core issues in paleoanthropology concerns the evolution of human body form -- changes in size, shape, and structure of the skeleton -- and the selective pressures influencing that evolution. The ribcage, spine, and pelvis have undergone numerous shape changes throughout our evolutionary history as we shifted from tree-dwelling apes to upright creatures who walk around on two legs, give birth to large-brained babies, and possess the unique ability to live in all types of global environments. Unlike studies that look at different regions of the skeleton in isolation, my research investigates the relationships between the bony elements of the trunk to test how changes in the shape of the hipbone, for example, affect the spine and vice versa. My research also examines the relationship between shape and environment to explore if humans have a novel, complex ability to adapt to climate in a way unlike other mammals. Looking at how the ribcage, spine, and pelvis are interrelated and how each of these regions varies with climate provides clues about how our body responds to selection. Elucidating these relationships is critical for understanding how body form in human ancestors responded to the challenges posed by difficult obstetrics and novel environments.
Snodgrass, James J., Northwestern U., Evanston, IL - To aid research on 'Energetics, Health, and Lifestyles Change among the Yakut of Siberia,' supervised by Dr. William R. Leonard
JAMES J. SNODGRASS, Northwestern University, Evanston, Illinois, received funding in May 2002 to aid research on 'Energetics, Health, and Lifestyles Change among the Yakut of Siberia,' supervised by Dr. William R. Leonard. This study examined the health consequences of economic modernization in the Yakut (Sakha), a high-latitude indigenous population of horse and cow pastoralists from the Sakha Republic of Russia. The two main research objectives were: 1) to investigate metabolic adaptation; and 2) to explore health and energy balance within the context of economic modernization. All research was conducted in the rural Siberian village of Berdygestiakh, Russia. Data were collected on: basal metabolic rate (BMR), total energy expenditure (TEE), blood pressure, body composition, diet, thyroid hormones, Epstein-Barr virus antibodies, and lifestyle and socioeconomic status. The results of this study indicate that, regardless of which reference standard is used, Yakut men and women have elevated BMRs. This study did not document any significant relationships between lifestyle measures and BMR, which suggests that genetic factors play an important role in metabolic elevation. This research provides baseline information on health and energy balance in the Yakut and investigates how specific lifestyle (e.g., physical activity and diet) and socioeconomic (e.g., income and education) factors contribute to the development of obesity and hypertension. Relatively low levels of physical activity, documented using the doubly labeled water technique, play an important role in the development of obesity in the Yakut, especially among women. Obesity and hypertension are emerging health issues among the Yakut. Affluence is associated with obesity among men, but not women; this parallels findings from nationally representative studies in Russia that document that health changes are more closely tied to socioeconomic status in men than women.
Snodgrass, J. Josh, William R. Leonard, M.V. Sorensen, L.A. Tarskaia, and M.J. Mosher. 2008. The Influence of Basal Metabolic Rate on Blood Pressure among Indigenous Siberians. American Journal of Physical Anthropology 137(2):145-155
Snodgrass, J.J., M.V. Sorensen, L.A. Tarskaia, and W.R. Leonard. 2007. Adaptive Dimensions of Health Research among Indigenous Siberians. American Journal of Human Biology 19:165-180.
Snodgrass, J.J., W.R. Leonard, L.A. Tarskaia, T.W. McDade, et al. 2007. Anthropometric Correlates of C-Reactive Protein among Indigenous Siberians. Journal of Physiological Anthropology 26:241-246.
Snodgrass, J. Josh, et al. 2006. The Emergence of Obesity among Indigenous Siberians. Journal of Physiological Anthropology 25(1):75-84.
Snodgrass, J. Josh, et al. 2006. Total Energy Expenditure in the Yakut (Sakha) of Siberia as Measured by the Doubly Labeled Water Method. American Journal of Clinical Nutrition 84:798-806.
Snodgrass, J. Josh, W.R. Leonard, L. Tarskaia, V.P. Alekseev, and V.G. Krivoshapkin. 2005. Basal Metabolic Rate in the Yakut (Sakha) of Siberia. American Journal of Human Biology 17:155-172.
Eaves-Johnson, K. Lindsay, U. of Iowa, Iowa City, IA - To aid research on 'A Spirometric and Geo-Morphometric Baseline for the Study of Thoracic Patterning in Fossil Homo,' supervised by Dr. Robert Gary Franciscus
Preliminary abstract: Due to a general, though undocumented, sense that little diagnostic information can be gleaned from them, ribs and overall thoracic morphology have been comparatively understudied relative to other anatomical regions in human paleontology. This study tests the influence of skeletal thoracic shape on respiratory variables (e.g., total lung capacity, functional residual capacity, etc.) using computed tomography (CT), to expand our understanding of modern and Neandertal thoracic patterning. The mixed-sex CT sample consists of 50 respiratorily normal subjects and 10 subjects with chronic obstructive pulmonary disorder (COPD), all between the ages of 20 and 60 (IRB: 199708651). This homogenous, living CT sample is compared with a regionally heterogeneous, mixed-sex skeletal sample from the extremes of human variation (n=134), as well as the Neandertal specimens Kebara 2, Tabun C1, Shanidar 3, and La Chapelle. Preliminary results suggest that, while gross spirometric measures, such as total lung capacity agree well with the predicted model, further study is needed to delineate the skeletal parameters most amenable to comparison for such variables as functional residual capacity. Additionally, comparisons of the Levantine Neandertals with the modern sample fail to demonstrate any significant temporal excursion from the range of modern variability with respect to these parameters.
Howells, Michaela Emily, U. of Colorado, Boulder, CO - To aid research on 'The Impact of Psychosocial Stress on Gestation Length and Pregnancy Outcomes in American Samoa,' supervised by Dr. Darna Dufour
MICHAELA E. HOWELLS, then a student at University of Colorado, Boulder, Colorado, was awarded funding in April 2011 to aid research on 'The Impact of Psychosocial Stress on Gestation Length and Pregnancy Outcomes in American Samoa,' supervised by Dr. Darna Dufour. The objective of this research is to determine the relationship between chronic maternal psychosocial stress on spontaneous abortion, gestation length, and neonate body size. In order to achieve this goal, the grantee conducted a biocultural, longitudinal, prospective study of pregnancy outcomes in 184 women experiencing significant shifts in cultural identity in American Samoa. Two interrelated indicators of psychosocial stress -- Epstein-Barr virus (EBV) antibody concentration and status incongruence -- were paired with monthly maternal interviews to assess the effects of stress on pregnancy outcomes. EBV antibody concentrations represent a broad, non-specific response to psychosocial stressors. Status incongruence is related to a woman's status within the community and arises when an individual is unable to resolve traditional and nontraditional markers of status. This study follows from their first prenatal care appointment through to their pregnancies natural conclusion and will help clarify the effects of psychosocial stress on pregnancy outcomes. Pregnancy outcomes will be assessed in terms of neonate size for gestation. Possible outcomes include spontaneous abortions, preterm births (? 36 weeks) and full-term births. This study aims to add to our knowledge of the factors associated with pregnancy loss, premature delivery, and infants born small-for-gestational-age in a non-western population of women.
Nelson, Dr. Robin Gair, Skidmore College, Saratoga Springs, NY - To aid research on 'Residential Context, Non-Kin Care and Child Health Outcomes in Jamaica'
DR. ROBIN G. NELSON, Skidmore College, Saratoga Springs, New York, was awarded a grant in April 2011 to aid research on 'Residential Context, Non-Kin Care and Child Health Outcomes in Jamaica.' This study explores the relationship between residential context, parental investment, and child health outcomes in Jamaica. It centers on an examination of the growth and development of children living in state-sponsored homes, and children who are living with biological family members. Ethnographic, anthropometric, and biometric data were collected from 125 children living in state-sponsored children's homes, and 119 children living with their biological family members in Manchester Parish. Follow-up data were collected from 70 of 125 children who were still living in childcare facilities. Preliminary analyses reveal statistically significant correlations between residence in a state-sponsored care setting and anthropometric health indicators. There are also statistically significant gendered differences in the health outcomes between girls and boys living in these state-sponsored homes. These findings parallel ethnographic data detailing highly variable and gendered childcare practices in these homes. Future analyses will compare anthropometric and biometric data of children living with biological kin, and that of their peers living in the children's homes. These findings aid in our understanding of the ways that variability in kin investment and care setting come to correlate to particular health outcomes. This study navigates the intersection of evolutionary theory and biocultural studies of child care practices and health outcomes.
Thayer, Zaneta Marie, Northwestern U., Evanston, IL - To aid research on 'Intergenerational Programming of Stress Reactivity: Role of Epigenetic Mechanisms,' supervised by Dr. Christopher Kuzawa
ZANETA THAYER, then a student at Northwestern University, Evanston, Illinois, received funding in April 2011 to aid research on 'Intergenerational Programming of Stress Reactivity: The Role of Epigenetic Mechanisms,' supervised by Dr. Christopher Kuzawa. Anthropologists have a long history of studying biological responses to environmental stress from diverse perspectives. Within our field the effects of maternal psychosocial stress on biology and health in the next generation is becoming a topic of increased interest. This research project evaluated the intergenerational effects of maternal stress experience among an ethnically and socioeconomically diverse sample of pregnant women from Auckland, New Zealand. Women who had lower socioeconomic status and who experienced ethnic discrimination had higher evening cortisol in late pregnancy and gave birth to infants with elevated cortisol reactivity and altered gene regulation (methylation) profiles. These findings are consistent with the hypothesis that maternal social environment impacts maternal and offspring biology. Notably, the types of stress exposures that impacted cortisol in the present study are relatively novel from an evolutionary perspective. Thus the evolved capacity for an intergenerational transfer of information could be maladaptive in the contemporary ecology when activated in response to structural inequalities within society. Future research evaluating diverse sources of stress and a range of biological responses in offspring are necessary to clarify whether modifications in offspring biology reflect adaptation or biological impairment.
Abrams, Elizabeth T., U. of Michigan, Ann Arbor, MI - To aid research on 'Variability in Birth Outcome following Malaria during Pregnancy,' supervised by Dr. A. Roberto Frisancho
ELIZABETH T. ABRAMS, while a student at the University of Michigan in Ann Arbor, Michigan, was awarded a grant in September 2001 to aid research on variability in birth outcomes following malaria during pregnancy, under the supervision of Dr. A. Roberto Frisancho. Malaria infections during pregnancy are associated with a number of poor birth outcomes, including intrauterine growth retardation, preterm delivery, and fetal death. Previous researchers had identified malaria-induced immune responses and birth outcomes, but the immune response to malaria could not fully account for the variation in birth outcomes. Abrams focused on a second potential determinant of poor birth outcomes: maternal and fetal iron status. She examined umbilical-cord hemoglobin levels in 33 malaria-infected and 57 uninfected women delivering in Blantyre, Malawi, in relation to maternal hemoglobin levels, malaria status, neonatal inflammation, and birth outcome. Although, as expected, maternal hemoglobin levels were significantly decreased by malaria infection during pregnancy, there was no reduction in cord levels, nor was there any significant relationship between the two. Nevertheless, cord ferritin levels were elevated in the neonates of malaria-infected mothers in relation to increased parasitemia, suggesting fetal immune activation to maternal malaria. Increased cord ferritin was associated with significantly decreased birth weight and gestational length, although maternal and cord hemoglobin levels and malaria status had no effect on birth outcome. The markers of fetal hypoxia that were examined, including erythropoietin, cortisol, and corticotrophin-releasing hormone, were not altered in malaria-infected versus uninfected women. In sum, in this population, cord hemoglobin levels were buffered from the effects of maternal malaria. However, elevated cord ferritin levels suggested fetal immune activation to malaria, which appeared to influence birth outcomes.
Abrams, Elizabeth T., and Julienne N. Rutherford. 2011. Framing Postpartum Hemorrhage as a Consequence of Human Placental Biology: An Evolutionary and Comparative Perspective. American Anthropologist 113(3):417-430.
Abrams, Elizabeth T. and Elizabeth M. Miller. 2011. The Roles of the Immune System in Women's Reproduction: Evolutionary Constraints and Life History Trade-Offs. Yearbook of Physical Anthropology 54:134-154.
Abrams, Elizabeth T., et al 2005. Malaria during Pregnancy and Fetal Haematological Status in Blantyre, Malawi. Malaria Journal 4(39):1-8.