• Posted April 11, 2024

Climate Change May Be Fueling a Rise in Stroke Deaths

Intense weather fluctuations caused by climate change could be contributing to an increase in stroke deaths, a new study claims.

Freezing cold fronts and broiling heat waves are associated with more than half a million deaths annually in recent years, researchers report April 10 in the journal Neurology.

“Dramatic temperature changes in recent years have affected human health and caused widespread concern,” said researcher Quan Cheng, of Xiangya Hospital at Central South University in Changsha, China.

“Our study found that these changing temperatures may increase the burden of stroke worldwide, especially in older populations and areas with more health care disparities,” Cheng added in a journal news release.

Bone-chilling cold fronts in particular were linked to more strokes, researchers said.

But temperatures that swing too high or too low can both increase a person's risk of stroke, researchers added in background notes.

Lower temperatures cause a person's blood vessels to constrict, increasing blood pressure. High blood pressure is a primary risk factor for stroke.

On the other hand, higher temperatures can cause dehydration, which thickens and slows blood -- factors also associated with stroke.

Stroke deaths in the United States increased 26% between 2011 and 2021, according to the American Heart Association. Some of this could be tied to climate change, the researchers argue.

For the study, the team looked at three decades of health records for more than 200 countries and territories, comparing stroke deaths to the local temperature at the time.

There were more than 521,000 stroke deaths in 2019 linked to temperatures that swung too low or too high, researchers estimate.

Cold fronts were linked to more than 474,000 of those deaths, results show.

That's a hefty chunk of the 6.6 million total deaths worldwide attributable to stroke in 2019, according to the American Heart Association.

The stroke death rate linked to temperature changes were 7.7 deaths per 100,000 people for men and 5.9 per 100,000 for women, researchers said.

Central Asia was the region with the highest temperature-associated stroke death rate, at 18 per 100,000.

“More research is needed to determine the impact of temperature change on stroke and to target solutions to address health inequalities,” Cheng said. “Future research should aim to reduce this threat by finding effective health policies that address potential causes of climate change, such as the burning of fossil fuels, deforestation and industrial processes.”

More information

Johns Hopkins Medicine has more about stroke.

SOURCE: American Academy of Neurology, news release, April 10, 2024