(746.3) Mathematical and Experimental Analysis of Body Temperature Fluctuations During Weight Change

Poster Board Number: E372

Lemuel Concepción-Díaz (Universidad del Sagrado Corazón), Rosanie Perez-Salas (Universidad del Sagrado Corazón), Javier Martinez-Boschetti (Universidad del Sagrado Corazón), Raphel Rolon-Rey (Universidad del Sagrado Corazón), Sebastian Esteras-Robles (Universidad del Sagrado Corazón), Kimberly Malpica-Diaz (Universidad del Sagrado Corazón), Shalyver Monagas-Vazquez (Universidad del Sagrado Corazón), Fernando Pereira-Rodriguez (Universidad del Sagrado Corazón), Francisco Arencibia-Albite (Universidad del Sagrado Corazón)

Human body temperature fluctuates in proportion to the balance between metabolic heat production and heat dissipation and needs to remain nearly constant as a requirement for normal physiology. The biology of temperature homeostasis is well-understood, and a low resting body temperature has been linked to increased longevity in humans and other organisms. Substantial weight loss in rodents, as result of underfeeding, leads, for instance, to a significant drop in mortality that occurs in parallel to a reduction in rectal temperature. The effects of weight gain or obesity on resting temperature are, however, not understood; and for the most part are controversial, e.g., obesity increases mortality, yet some lines of research argue that a low body temperature underlies its pathophysiology. The present work uses mathematical modeling and analytical methods to investigate the effects of body weight fluctuations on temperature. The latter methodology leads to a simple equation that estimates the whole-body heat transfer coefficient (hc). Computational simulations, on the other hand, predict two possible scenarios: 1. Resting temperature is an increasing function of body mass if hc is unaltered by weight change; 2. If body temperature is insensitive to weight change, then hc will change in the same direction as body weight. Experimental measurements validate the first case and show that obesity leads, in men and women, to a significant increment in resting temperature relative to normal body mass index subjects. This analysis also shows that hc is a decreasing power function of the temperature gradient, i.e., the difference between the body temperature and the external temperature. Our data indicates, overall, that another mechanism by which obesity increases human mortality is by producing a persistent increment in body temperature. To our knowledge, we are the first to identify such adverse obesity effect.

NSF Grant Proposal 1928543: Sagrado HSI Project Increasing Student Success in STEM