0
0
Introduction: New research has unveiled a concerning link between short-term exposure to high outdoor temperatures and alterations in the body’s immune response. The study, presented at the American Heart Association Epidemiology and Prevention | Lifestyle and Cardiometabolic Scientific Sessions 2024, sheds light on how rising global temperatures could impact human health.
Research Details: Led by Daniel W. Riggs, PhD, from the Christina Lee Brown Envirome Institute at the University of Louisville, the study examined blood samples from 624 adults in Louisville during summer months. The participants, with an average age of 49 years and mostly women, were monitored during a period when median temperatures reached 24.5 °C (76 °F) over 24 hours.
Blood work was analyzed for immune biomarkers, including inflammatory markers and infection-fighting cells, and correlated with environmental data such as temperature, humidity, and wind speed. Results were adjusted for various factors including demographics, lifestyle, and air pollution levels.
Key Findings: The study revealed a noteworthy association between heat exposure and immune system changes. For every five-degree increase in the Universal Thermal Climate Index (UTCI), there was an increase in levels of inflammatory markers such as monocytes, eosinophils, and tumor necrosis factor-alpha, along with a decrease in infection-fighting B cells.
Lead author Daniel W. Riggs emphasized the significance of these findings, particularly in light of the increasing global temperatures. Rosalind J. Wright, MD, MPH, from the Mount Sinai Health System, highlighted the broader health implications beyond cardiovascular health, stressing the importance of understanding the effects of heat exposure on immune signaling.
Implications and Questions Raised: Experts not involved in the study raised important questions about the timing and duration of heat exposure, as well as individual vulnerability factors such as lifestyle and genetics. Perry E. Sheffield, MD, MPH, from the Icahn School of Medicine at Mount Sinai, underscored the need to delve deeper into how different factors could influence susceptibility to heat-related immune changes.
Conclusion: As climate change continues to drive up temperatures globally, studies like this provide crucial insights into the complex interactions between environmental factors and human health. The findings underscore the urgent need for further research to understand and mitigate the health impacts of rising temperatures on immune function.
The study was supported by grants from the National Institute of Environmental Health Sciences, with no relevant disclosures reported by the authors.
