The research team recruited 20 women in midlife who were not taking hormone therapy and, using a device that measures skin conductance, biologically monitored their hot flashes for 24 hours. They also conducted MRI brain imaging on participants to detect white matter hyperintensities, which are bright spots on the scan that are thought to develop due to disease of the brain’s small blood vessels. Participants also kept electronic hot flash diaries.
The women reported an average of three hot flashes per day, but the monitoring showed greater frequency, at an average of eight per day as some were likely not self-reported because they occurred during sleep, Dr. Thurston said. Women who had more monitor-detected hot flashes, particularly during sleep, also had a greater number of white matter hyperintensities on their brain scans.
“Other factors like age and cardiovascular risk factors did not explain this effect, so these findings suggest there is a relationship between menopausal hot flashes and blood vessel changes in the brain,” Dr. Thurston said. “Further work is needed to understand whether one causes the other, or if hot flashers are a signal of some other vascular process that impacts brain health.”
Dr. Thurston notes that it might be particularly important for women who are experiencing numerous hot flashes to consider modifying cardiovascular risk factors by quitting smoking and treating high blood pressure.