There’s no sugar-coating it: More than two and five American adults have prediabetes.
This condition causes higher-than-normal blood sugar levels that spike with certain foods. Without lifestyle changes, up to 70% of them will develop type 2 diabetes.
But prediabetes is a warning sign, not a life sentence. Doctors will recommend losing weight, changing their diet, and getting more exercise in to get out of the prediabetic blood sugar zone.
New research says another tool could help manage prediabetes — while you sleep.
Sleeping with air purifiers stabilized blood sugar levels in people with prediabetes during the day, researchers at NYU Langone found.
Here’s how what’s in your air affects your blood.
Air pollution and prediabetes
Foods like grains and sugars break down into glucose which goes into the bloodstream. In response, the pancreas makes insulin to move the glucose into cells for energy.
In people with prediabetes, insulin production struggles to keep up with the blood sugar, causing dramatic blood sugar spikes. Over time, those spikes put increased demand on the pancreas, decreasing its function, making the condition worse — potentially leading to type 2 diabetes.
Research has been growing on the link between air pollution and diabetes. Experts believe that microscopic pieces of dust, dirt, smoke and soot enter the lungs and get into the bloodstream.
This can contribute to everything from heart disease to stroke, cancer, and kidney disease. But in diabetes, they believe it’s triggering inflammation that damages cells, disrupting how they respond to insulin.
A 2024 study on mice suggests that air pollution creates inflammation in the brain, either directly or from inflammation in the lungs. The brain’s immune system reacts, and disrupts insulin signaling in the hypothalamus.
Clearing the air
For the first time in humans, researchers tested whether high-efficiency particulate air (HEPA) filters could control the blood sugar spikes that make prediabetes worse.
They had half the participants sleep with real filters for a month, while the other half slept with fake filters that didn’t actually clean the air. Participants wore continuous glucose monitors that took blood sugar measurements every few minutes.
The real filters cleaned 36% of harmful air particles. The cleaner air was associated with nearly a 8% drop in blood sugar swings.
“Our findings suggest that cleaner air at home, especially in the bedroom, may help people with prediabetes keep their blood sugar steady,” said lead author and cardiologist Sharine L. Wittkopp.
One of the most impactful swings are the ones right after breakfast.
Blood sugar in the morning can already be high because of the dawn phenomenon — when cortisol and growth hormone signal the liver to boost glucose early in the morning to provide energy to wake up. Insulin can also fall over night, another factor increasing blood glucose.
By the time you eat breakfast, blood sugar is already high.
Researchers of this new study found that air purifiers helped with this. Total blood sugar after eating breakfast fell by 17% on average, and peak levels lowered by 13%.
Other benefits
Separate research suggests that air pollution cardiovascular disease worse, and increase risk of cardiovascular events like heart attack.
“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 author Jonathan Newman.
“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.”
Not all air filters are created equal. HEPA filters trap microscopic irritants like dust, pollen, mold and bacteria and are required to meet standards from the Department of Energy in the US.
“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.” Wittkopp said.


