The 84th Annual Meeting of the American Association of Physical Anthropologists (2015)


Withdrawn. Metabolic and endocrine changes during immune activation

MICHAEL P. MUEHLENBEIN.

Anthropology, Indiana University

March 26, 2015 11:15, Grand Ballroom D Add to calendar

Immunocompetence is an integral part of organismal life histories, and is involved in physiological trade-offs with other functions like growth. There remains a paucity of data on the actual energetic demands of human immune functions relative to other species. Here I provide a comparative analysis to qualify and quantify the energetic costs of immunity in humans, relying heavily on a series of studies documenting relative metabolic and endocrine changes during immune activation resulting from either naturally acquired infections or immunizations. Increased metabolic demands during immune activation appear to be met largely through the pleiotropic actions of various hormones, including testosterone, cortisol, thyroid hormones, estrogens, dehydroepiandrosterone, leptin, and oxytocin. Changes in hormones during immune activation reflect the manifold interactions between these physiological systems. A number of unanswered questions remain: for example, how do these hormones regulate sickness behavior; are there differential energetic costs of developing, activating, and redistributing immune responses; and how do metabolic costs of immune activation vary within and among people? Future analyses in human ecological immunology must include detailed effects of a variety of hormones in both men and women, utilizing various functional measures of immunity (e.g., bacteria killing assay, hemolytic complement assay, lymphocyte proliferation, etc.) in a variety of experimental regimes: during health, in response to infections of varying severity, and in people experiencing varying degrees of energy flux. Trade-offs between immunity and other functions may only become apparent under certain conditions, or during particular critical windows at certain points in the life course.