RESEARCH ARTICLE Ambient Temperature and Cerebrovascular Hemodynamics in the Elderly

Background and Purpose Some prior studies have linked ambient temperature with risk of cerebrovascular events. If causal, the pathophysiologic mechanisms underlying this putative association remain unknown. Temperature-related changes in cerebral vascular function may play a role, but this hypothesis has not been previously evaluated. Methods We evaluated the association between ambient temperature and cerebral vascular function among 432 participants65 years old from the MOBILIZE Boston Study with data on cere-brovascular blood flow, cerebrovascular resistance, and cerebrovascular reactivity in the middle cerebral artery. We used linear regression models to assess the association of mean ambient temperature in the previous 1 to 28 days with cerebrovascular hemodynam-ics adjusting for potential confounding factors. Results A 10°C increase in the 21-day moving average of ambient temperature was associated wit