The Effect of Aging on Body Temperature: A Systematic Review and Meta- Analysis

Background: Since age is the major risk factor for chronic diseases and mortality, it seems mistaken that older adults have lower basal temperature than young individuals. Many confounding factors could hinder the achievement of a consensus, such as the different sites of measurement, control of basal conditions, health conditions, age difference compared, sex, and others. Objective: The aim was to meta-analyze previous studies in order to find a consensus regarding the effects of aging on body temperature in humans, considering different types of temperature assessments, age difference and sex. Methods: A systematic search was performed in PubMed and 16 studies comparing basal temperature between older and young adults were meta-analyzed. Results: Older adults have significantly lower body temperature than young adults (-0.17 °C (-0.30; -0.03), p=0.04). Considering the different sites of measure, while core temperature tended to be lower in older adults (-0.13 °C (-0.27; 0.01), p=0.07), and skin temperature was not different (-0.21 °C (-0.5; 0.08), p=0.15). The aging effects were more prominent in men when assessed by oral temperature and when compared between higher age difference. Conclusion: Indeed, there is a small reduction in overall temperature with aging, drove by the reduction in core temperature rather than skin temperature. The confirmation of these findings by this meta-analysis, now provide the base for the development of strategies to face the impairment in thermoregulation and metabolic efficiency with aging.