Using portable filters to reduce exposure to air pollution during sleep may stabilize the large spikes in blood sugar experienced by people with prediabetes, a condition in which sugar (glucose) levels are higher than normal, a new study shows.
Led by researchers at NYU Langone Health, the team assessed more than 150 men and women with prediabetes who did not have any known buildup of cholesterol in their arteries, a condition called atherosclerosis.
Prediabetes raises the risk of heart disease and diabetes, and large swings in blood sugar during the day are tied to worsening disease. While experts have linked air pollution to both prediabetes and cardiovascular disease, until now it remained unclear whether using high efficiency particulate air (HEPA) filters at home could improve blood sugar control.
Testing this for the first time in humans, scientists had half the study participants sleep with real bedroom air filters for about a month, while the other half used sham filters that did not clean air. The real filters cut levels of tiny, harmful air particles by 36 percent.
In turn, this cleaner air was linked to a nearly 8 percent drop in daily blood sugar swings and smaller morning sugar surges after breakfast. The total extra glucose in the blood after eating breakfast fell by about 17 percent on average, while peak levels following breakfast decreased by 13 percent.
"Our findings suggest that cleaner air at home, especially in the bedroom, may help people with prediabetes keep their blood sugar steady and blunt morning spikes," said study lead author and cardiologist Sharine L. Wittkopp, MD, PhD, a clinical instructor in NYU Grossman School of Medicine's Department of Medicine and its Leon H. Charney Division of Cardiology. "Installing HEPA filters offers an easy, low cost tool to help protect heart and metabolic health along with healthy eating, regular exercise, and prescribed medications."
The results will be presented November 8 at the American Heart Association's annual Scientific Sessions.
According to the Centers for Disease Control and Prevention, nearly half of US adults have prediabetes despite prevention and treatment efforts. Besides well-known risk factors, including poor diet, physical inactivity, and smoking, past studies have connected prediabetes to pollutants from vehicle exhaust, wildfires, and emissions from power plants and industrial sites. When these particles, which can be less than one thirtieth the average width of a human hair, are inhaled, they can enter the lungs and bloodstream and lead to disease.
The new study is the first to test whether in home HEPA filtration can improve glucose control in adults with prediabetes, the authors said.
For the investigation, the research team randomly assigned volunteers in New York City to use either real or sham portable air cleaners in their bedrooms for a month and measured concentrations of indoor air pollution throughout the trial. Participants wore continuous glucose monitors, small sensors that track blood sugar every few minutes, for one week before and again after four weeks of filtration so the team could see how daily blood sugar changed over time.
An AI tool that analyzed glucose patterns was used to detect mealtimes so the team could focus on blood sugar changes that occurred during breakfast. Next, they analyzed the data using statistical models to compare each participant's readings over time, taking into account age, sex, and body mass index (a measure of obesity).
"Our results add to a growing body of evidence that poor air quality is a threat not only to lung health but to heart and metabolic health as well," said study senior author Jonathan Newman, MD, MPH, an associate professor in NYU Grossman School of Medicine's Department of Medicine and its Leon H. Charney Division of Cardiology. "These findings support broader efforts to reduce air pollution and suggest that healthcare providers should consider indoor air quality when helping patients manage their cardiometabolic risk."
According to Dr. Newman, the team next plans to run longer term studies to see whether air filtration can slow or stop the progression from prediabetes to diabetes and whether it can reduce the risk of heart attack, stroke, and other signs of cardiovascular-kidney-metabolic syndrome.
Dr. Newman cautioned that the findings may not apply to people who already have diabetes or to those living in other regions of the country, who are exposed to different types and levels of pollution.
Funding for the study was provided by the Doris Duke Foundation.
In addition to Drs. Wittkopp and Newman, NYU Langone researchers involved in the study were Souptik Barua, PhD; Parsa Asachi, MD; Filipp Kazatsker; Rujul Singh; José Alemán, MD, PhD; Jiyuan Hu, PhD; Terry Gordon, PhD; and Lorna E. Thorpe, PhD, MPH. Another study co-investigator was Robert Brook, MD, at Wayne State University.
