ISEMPH Presentation: Carolyn Hodges-Simeon
Life history theory suggests that nutritional and disease ecology affects the timing of puberty, and that trade-offs between life history demands are especially acute in resource-limited populations. Although this is assumed to apply to both adrenal and gonadal puberty, few studies have examined trade-offs affecting adrenal maturation. Following life history theory, it is predicted that those with greater energy budgets will show accelerated adrenal puberty and linear growth. Further, controlling for differences in overall energy budget, those with a heavier immune load should show diminished investment in adrenal androgen levels. To test these hypotheses, salivary dehydroepiandrosterone-sulfate (as a measure of adrenal maturation; DHEA-S), anthropometrics (i.e. population-specific BMI-for-age residuals, height), and a measure of mucosal immunity (i.e. secretory IgA; sIgA) were measured in a group of rural Bolivian adolescents (90 males and 81 females) aged 8 to 23. Multiple regression analysis showed that higher BMI levels approached significance (p = 0.07) as a predictor of DHEA-S among males only (β = 0.15). However, DHEA-S was strongly associated with higher (not lower, as predicted) mucosal immunity in males (β = 0.51) and females (β = 0.52). DHEA-S was unrelated to height. Results are discussed in light of potential developmental functions of DHEA-S.