The influence of estrogen on the thermoregulatory responses to heat stress in pre and postmenopausal women

As average global temperatures continue to rise, the frequency, duration, and severity of extreme heat events are also increasing. Further, the population of aged adults is increasing globally, resulting in a larger population of those who are most vulnerable to heat-related morbidity and mortality. Recent heat waves report older women (65+ yrs) as the most vulnerable group during extreme environmental heat events due to an inability to maintain heat balance at lower temperature and humidity combinations than age matched men. Female reproductive hormones alter thermoregulatory responses to heat stress through central and peripheral mechanisms. Reductions in reproductive hormones throughout and after menopause could mediate this age specific sex difference, however, the extent to which the increase in heat vulnerability in older women can be attributed to menopause-induced estrogen reductions separate from age-related physiological declines is unclear. The purpose of the current study is to determine the independent role of estrogen on reflex control of cutaneous vasodilation and sweating in pre and postmenopausal women of equal age. Through an estrogen knock down and add back model, we will mechanistically examine the impact of estrogen on thermoregulatory mechanisms during passive whole-body heating. Our global hypothesis is that estrogen mitigates age-related impairments in convective and evaporative heat loss and reductions in estrogen throughout the menopause transition accelerates the aging process, impairing thermoregulation and increasing heat vulnerability. This project and associated training plan will serve as a vehicle for exceptional predoctoral training for the candidate. Project Number: 1F31AG096955-01 | Fiscal Year: 2025 | NIH Institute/Center: National Institute on Aging (NIA) | Principal Investigator: Olivia Leach | Institution: PENNSYLVANIA STATE UNIVERSITY, THE, UNIVERSITY PARK, PA | Award Amount: $40,985 | Activity Code: F31 | Study Section: Special Emphasis Panel[ZRG1 F06-F (20)] View on NIH RePORTER: https://reporter.nih.gov/project-details/11241185