Here’s why older adults often suffer from shortness of breath

Aging often brings changes to the body that can affect strength, stamina, and breathing. Now, researchers at Yale School of Medicine say they may have identified an important reason why many older adults develop persistent shortness of breath — even when routine medical tests show little wrong.

In a study published in the journal Aging Cell, scientists found that the pulmonary artery, the major blood vessel that carries blood from the heart to the lungs, becomes progressively stiffer with age. That change may contribute to declines in heart and lung performance and make it harder for older adults to stay active.

“About one out of every three patients over 65 comes in saying they feel short of breath,” said Dr. Edward Manning, an assistant professor of medicine at Yale who helped lead the study. “Often we do extensive testing and still can’t find a clear explanation.”

A closer look at an overlooked artery

The pulmonary artery plays a crucial role in breathing. It carries blood from the heart to the lungs, where oxygen is added before the blood circulates through the body.

Researchers have long known that the aorta, the body’s largest artery, stiffens with age. That stiffening is linked to damage in organs such as the heart, brain, and kidneys. But Dr. Manning and his colleagues wondered whether a similar process might occur in the pulmonary artery.

“If the aorta stiffens and affects organs throughout the body, it raises a simple question,” Dr. Manning said. “Does the pulmonary artery stiffen as well, and could that affect lung function?”

To investigate, the research team examined mechanical and biological changes in the pulmonary arteries using preclinical models. They analyzed how the vessel’s structure, elasticity, and gene activity change with age.

Signs of aging inside the artery

The researchers found clear age-related changes in the section of the pulmonary artery closest to the heart. Over time, the vessel became stiffer and less able to store and release mechanical energy, an important function that helps maintain healthy blood flow.

Those changes were linked to measurable declines in:

• Lung function
• Right-sided heart performance
• Exercise capacity

In addition, the team detected changes in gene activity that suggested the artery’s cells were aging and remodeling themselves.

One discovery involved perivascular macrophages, immune cells that sit along the outer wall of blood vessels. These cells appeared to play a role in communication among the cells that form the artery wall.

In older arteries, the macrophages showed signs of cellular aging and increased signaling activity. That suggests they might become a future target for therapies designed to slow the stiffening process.

Why stiffening matters

When arteries become stiff, pressure waves travel through them more quickly. According to Dr. Manning, this can damage the delicate lining of blood vessels and nearby capillaries in the lungs.

Similar mechanisms are already known to contribute to conditions such as chronic kidney disease and other forms of organ damage.

Researchers are still trying to determine exactly how the process begins. It is not yet clear whether stiffening starts in the pulmonary artery itself or develops after changes occur in smaller blood vessels and lung tissue.

“But our hypothesis is that once the large pulmonary artery becomes stiff, that change is closely linked to declining lung function,” Dr. Manning said.

Focusing on healthy aging

Experts say the study highlights the growing importance of research focused on maintaining physical function in later life, not just extending lifespan.

“This work is an excellent example of integrating physiology, biomechanics, and modern genetic tools in aging research,” said Dr. Naftali Kaminski, chief of Pulmonary, Critical Care, and Sleep Medicine at Yale.

For Dr. Manning, the goal of the research is straightforward: helping people stay healthier and more active as they age.

“It’s more than just trying to live longer,” he said. “We want the extra years of life to remain functional. If slowing stiffening of the pulmonary artery can help preserve breathing and heart-lung function, people can live better for longer.”

In other words, he said, the aim is simple: help people breathe better for more of their lives.