Researchers Find Link Between Rising Stroke Rates and Changing Temperatures

As if a rapidly changing climate doesn’t present enough problems – from more extreme (and frequent) weather events to rising oceans – a new study suggests that it also might be responsible for spiking stroke rates.

The research, which appeared in the latest online issue of Neurology, highlights a public health crisis the study’s authors say that policymakers around the world must address quickly.

“Dramatic temperature changes in recent years have affected human health and caused widespread concern,” Quan Cheng, Ph.D., of Xiangya Hospital Central South University in Changsha, China, and one of the study’s authors wrote. “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.”

The findings follow research from New York University last year that rising temperatures contribute to cognitive decline. The paper, which appeared in the Journal of Epidemiology and Community Health, found that high exposure to extreme heat could be associated with faster cognitive decline among residents of poor neighborhoods, but not for those in wealthier areas. 

“Our research finds that cumulative exposure to extreme heat can undermine cognitive health, but it does so unequally across the population,” Eunyoung Choi, a postdoctoral associate at the NYU School of Global Public Health and the first author of the study, explained.

Researchers Leveraged Multiple Datasets

The researchers conducted the ecological meta-analysis with data culled from a variety of sources, including the Climate Research Unit Gridded Time Series, World Bank databases, and the Global Burden of Diseases study.

The authors discovered a link between rising temperatures and more than half a million deaths worldwide in 2019. The authors add that low temperatures still account for the primary burden, but the incidence of strokes due to high temperatures is escalating rapidly, especially among lower socioeconomic populations, notably in regions such as Africa.

Further examination showed that revealed that aging, population growth and epidemiologic changes also emerged as significant drivers of the increased burden. Additionally, the study’s authors found that men bore more of the burden than women. While, geographically, Central Asia suffered the most.

The overall results, the authors wrote, underscore an urgent need for prioritized interventions.

A Landmark Stroke Study

While earlier research has shown that extreme temperatures increase stroke burden – because it interferes with some physiological activities –  this study is the first to comprehensively assess the global burden linked to extreme temperatures.

The study covered the underlying mechanisms tying extreme temperatures to increased stroke risk, blaming contributing factors such as dehydration, elevated blood pressure, and blood viscosity. 

Panel data analysis also highlighted a link between increased air pollution and rising stroke rates, emphasizing the importance of environmental factors in stroke prevention.

Authors Concede Drawbacks, Push for Action

Despite the study’s comprehensive approach, the study’s authors conceded the research included some limitations, such as an inability to establish causality at the individual level and a dearth of data on classical risk factors such as hypertension and high cholesterol levels.

Finally, the study underscores the complex interplay between climate change and human health, especially concerning strokes. The authors insist that policymakers must take urgent action to address the escalating burden of strokes attributable to nonoptimal temperatures, with a focus on vulnerable populations and regions.

Further Reading

Climate Change is Making Migraines and Other Neurological Diseases Worse

Strokes Still Hit Black Americans Earlier, Research Shows

Therapeutic Dilemma of Wake-up Stroke: Clinical and Brain Imaging Characteristics and Reperfusion as a Treatment Option