Heat Exposure Linked to Increased Risk of Hospitalization for Diabetes

ALBANY, N.Y. (March 22, 2024) – The threat posed to human health by extreme heat has been steadily rising as a result of climate change, with February of 2024 setting a new record for the hottest February ever recorded. At the same time, the prevalence of diabetes has increased rapidly, placing significant strain on health care systems around the world. 

To address these growing threats, Dawn Gao, a PhD student in the Department of Epidemiology and Biostatistics, teamed up with UAlbany faculty members, including Shao Lin of the Department of Environmental Health Sciences, Akiko Hosler of the Department of Epidemiology and Biostatistics, and Sam Friedman of the Department of Sociology, to co-author a paper investigating the relationship between heat exposure and hospitalization related to diabetes. The study builds upon a growing body of evidence showing a relationship between extreme heat and a higher risk of complications resulting from diabetes. 

“Today approximately 11 percent of the U.S. population lives with diabetes, and this number is only increasing. We also expect to see a greater number of extreme weather events, including extreme heat. It is important that we understand what additional risks these individuals may face during times of extreme heat so that we can develop warning systems and prepare hospitals,” says Lin. 

Using hospital admission data from New York state between 2013 and 2020, the study sought to determine whether the timing of heat exposure might also impact its effect on risk of hospitalization among people with type I or type II diabetes. They also analyzed interactions between other risk factors and demographic features such as socio-economic status, exposure to pollution, and other health conditions that could modify the extreme heat – diabetes relationship. 

The results of the study indicate that heat exposure is associated with an overall increased risk of hospitalization for diabetes complications. Gao, Lin, Hosler, and their colleagues also found that heat exposure during transitional months, particularly May, is more strongly associated with hospitalization than during the summer months. Consistent with previous findings on the impact of extreme heat on other health outcomes, the authors explained that transitional months may be more dangerous because our bodies require time to adjust to hotter weather, and many people have not yet prepared adequately for extreme heat by purchasing fans, air conditioners, and making other behavioral modifications. Diabetes also raises the risk of dehydration, compounding the effects of heat. 

Diabetes patients with comorbidities such as cardiovascular disease and foot ulcers were especially vulnerable during the month of May. Additional risk factors identified in the study include being female, over the age of 65, living in an urban area, and being enrolled in Medicaid. Other risk factors, such as obesity, tobacco use, and non-compliance with medical treatments also led to increased risk of hospitalization, but only during the month of July. The reason for these differences is not fully understood. 

“This is the first study to investigate the impact of heat exposure on diabetes-related hospitalizations in transitional and summer months separately,” explains Hosler. “It is also one of very few studies that assessed the impacts of heat exposures on diabetic subtypes, complications, and comorbid conditions. Additional studies are needed to confirm our results. Also, we only included patients with severe diabetes in our study—we need to do more work to measure the impact of heat on the wider population of people living with diabetes.” 

Although further research is needed, the study by Gao, Lin, Hosler and their colleagues is consistent with many previous studies on the relationship between heat and diabetes. It also confirms that extreme weather caused by climate change is likely to have the greatest impact on the most vulnerable among us—those who suffer from health issues, reside in urban areas, and live below the poverty line.

This paper was published in Science of Total Environment and is a component of Gao’s PhD dissertation with Lin as the committee chair and others as committee members.