Topic: Biology

Scientists discovered why people living at high elevations develop diabetes less often. Red blood cells absorb glucose from circulation when oxygen is scarce, lowering blood sugar levels.

Researchers have long noticed that people who live in areas with low oxygen levels tend to get diabetes less frequently than those at sea level. But until now, the reason behind this trend was unclear. A team of scientists at Gladstone Institutes has finally uncovered the explanation. They found that when oxygen is scarce, red blood cells start absorbing large amounts of glucose from the bloodstream. This means they act like sugar sponges under conditions similar to those found on high mountains.

The researchers demonstrated that red blood cells can change their metabolism when oxygen levels drop. This shift helps them deliver oxygen to tissues more efficiently at high altitude. At the same time, it lowers circulating blood sugar, offering a potential explanation for reduced diabetes risk.

According to senior author Isha Jain, PhD, the study resolves a longstanding question in physiology. 'Red blood cells represent a hidden compartment of glucose metabolism that has not been appreciated until now,' she says. 'This discovery could open up entirely new ways to think about controlling blood sugar.'

The team's findings were published in Cell Metabolism and could have significant implications for diabetes treatment.

In the study, Jain's lab used mice as test subjects. They found that when these mice were exposed to low oxygen air, their blood glucose levels dropped dramatically. The animals cleared sugar from their bloodstream quickly after eating, which is typically linked to lower diabetes risk.

However, when researchers examined major organs to determine where the glucose was being used, they found no clear answer. 'When we gave sugar to the mice in hypoxia, it disappeared from their bloodstream almost instantly,' says Yolanda Martí-Mateos, PhD, a postdoctoral scholar in Jain's lab and first author of the new study.

Using a different imaging method, the researchers discovered that red blood cells were serving as the missing 'glucose sink', meaning they were taking in and using significant amounts of glucose from circulation. This was unexpected because red blood cells have traditionally been viewed as simple oxygen carriers.

Follow-up experiments confirmed the finding. Under low oxygen conditions, the mice produced more red blood cells overall, and each individual cell absorbed more glucose compared with cells formed under normal oxygen levels.

To uncover the molecular details behind this shift, Jain's group partnered with Angelo D'Alessandro, PhD, of the University of Colorado Anschutz Medical Campus, and Allan Doctor, MD, from University of Maryland, who has long studied red blood cell biology.

Why It Matters

This discovery could lead to new ways to control blood sugar levels, which is crucial for managing diabetes. It also highlights the importance of understanding how our bodies adapt to different environments, a key consideration in fields like space exploration and high-altitude medicine.

Key Facts

• People who live at high elevations tend to develop diabetes less often than those at sea level.
• Red blood cells absorb glucose from circulation when oxygen is scarce, lowering blood sugar levels.
• The shift in red blood cell metabolism helps deliver oxygen to tissues more efficiently and lowers circulating blood sugar.
• This discovery could open up entirely new ways to think about controlling blood sugar.
• The study was published in Cell Metabolism and was conducted by a team of scientists at Gladstone Institutes.

Key Terms

Hypoxia

A condition where oxygen levels are scarce, often found at high elevations or in certain medical conditions.

Implications

This discovery could lead to new ways to control blood sugar levels, which is crucial for managing diabetes. It also highlights the importance of understanding how our bodies adapt to different environments, a key consideration in fields like space exploration and high-altitude medicine.