Puberty is a period of shifting energy priorities and changing body composition. This study explores the relationship between inflammation, as measured by C-reactive protein, and traditionally associated metrics such as waist-hip-ratio, BMI, and skin-folds in a population of Gambian female adolescents (n=67). Adipose tissue, particularly visceral adipose tissue, is proinflammatory, and BMI has evidenced a strong relationship with inflammation in adults and children in Western societies. This relationship is more complicated in non-Western societies, and very little work has examined how body composition metrics may relate to inflammation during puberty, especially in non-Western populations.
These adolescent females are lean (mean BMI = 20.5) and have relatively low CRP (median CRP = 0.11 mg/L, mean = 0.41 mg/L). Even among very lean participants, fat percent, WAZ, and BMI are all positively related to CRP, though BMI has the strongest relationship. Interestingly, there is an independent and negative association between triceps skinfolds and CRP - individuals with more adipose tissue stored in triceps have lower CRP levels. Unlike Western populations, waist-hip-ratio is not related to inflammation. These participants are still undergoing the pelvic maturational process of puberty, and WHR may not tie as strongly to visceral adiposity as in adults.
During the 2012 AAPA Open Forum, “The Ethics of Practice and the Practice of Ethics: an open dialogue among bioanthropologists”, it became clear that many researchers felt that the available ethical training and resources do not adequately address the unique needs of researchers in biological anthropology. Participants identified several areas of focus as deserving attention within our community, including the ethics inherent in field work, common challenges in working with skeletal remains, and the need for intradisciplinary conversation concerning professional relationships within our field. This symposium aims to address these identified needs, as well as other ethical challenges in our field. The symposium offers perspectives both on the application of ethics to procedural topics such as repatriation, field site management, or gaining family consent, and to emerging ethical topics that necessitate discussion, such as the Open Access movement. It is our sincerest hope that by extending the current discourse on ethics, we can begin to address the unique ethical challenges and questions that biological anthropologists engage during their research.
In recent years researchers have investigated the potential of lasting effects from early life environments on later human health and immune function. Here, we add to this growing research body (Moore et al. 2001; McDade et al. 2010), and report on the relationships between CRP and early life variables, current investment in growth, and other markers of immune function in a population of adolescent females in the Gambia.
In preliminary analysis in our sample (n=55), we find a negative correlation between CRP and ponderal index (t =-2.28, p = 0.03) and a negative trend with infant growth (p=.08), in regressions accounting for current age and BMI. Longitudinal data allows us to ask if CRP is predictive of weight or height gain over the next 6 months, and unlike studies with children (McDade et al. 2008), it does not appear that elevated CRP is predictive of growth. In Western populations the adipokine leptin has been positively related to CRP, independent of BMI (Shamsuzzaman et al. 2004). While CRP does display a positive relationship with leptin in our population, this relationship appears to be entirely mediated by the effects of BMI. Additional analysis will further explore these relationships.
There is considerable evidence connecting early life conditions to later life disease, yet it is not clear how these relationships are formed. Early life influences on immune phenotype have been postulated, and evidence for this is growing. This research suggests that birth size, and potentially early life growth, are related to later life inflammation.
Much of our understanding of the immune system is based on research from Western populations, yet immune function is mediated by environmental conditions. Little is known about how the immune system develops in the face of limited energy and increased pathogen load, or whether these demands modify the relationships seen in Western populations. This study contributes to our knowledge of immune functioning in non-Western populations by analyzing the relationship between Epstein-Barr Virus (EBV) and other immune components in the Shuar, an indigenous Ecuadorian population living in a high pathogen environment. Our hypothesis is that in high pathogen environments increased EBV is a biomarker of investment in humoral immune function, and will be positively associated with IgE and negatively associated with CRP. IgE is another component of acquired immunity, and CRP is an innate inflammatory immune response. At least one past study, which was conducted in 2008, has suggested that EBV has a negative relationship with innate immune response in high pathogen environments. Participants in our study are a cross sectional sample of 220 Shuar villagers, broken into age and sex groups in accordance with previous work that demonstrates age related trade-offs in immune functioning. Biomarkers were measured in dried blood spots. Preliminary analysis indicates sex differences in EBV (p =.05), but no differences among age groups. Multivariate analysis suggests that interactions between EBV, IgE and CRP, controlling for nutritional status, are sensitive to individual and local factors. Understanding these variations in immune pathways is an important new direction in research.