Extreme temperatures are linked to increased stroke mortality

Extreme temperatures are linked to increased stroke mortality, disproportionately affecting low-income regions, according to a new multinational study involving nearly 6 million strokes. The research revealed that out of every 1000 ischemic or hemorrhagic stroke deaths, around 11 were due to extreme hot and cold days.

"Our findings advance the understanding of climate change's impact on stroke," said lead author Barrak Alahmad, MD, MPH, PhD, from Harvard T.H. Chan School of Public Health. "With more extreme temperatures, we anticipate a rise in fatal strokes and growing disparity between high- and low-income countries."

The study, the largest of its kind, analyzed stroke mortality data from 522 cities across 25 countries, spanning from 1970 to 2019. It found that extreme cold contributed to 9.1 excess ischemic stroke deaths and 11.2 hemorrhagic stroke deaths per 1000, while extreme heat contributed to 2.2 and 0.7 excess deaths, respectively.

Low-income countries face higher risks of heat-related hemorrhagic stroke deaths, potentially due to poorer healthcare access and less effective temperature control. The researchers highlighted the urgent need for improved clinical care and climate adaptation strategies to reduce stroke mortality, particularly in vulnerable regions.