Red Blood Cells Act as Hidden Sugar Sponges at High Altitude

The Mystery of Mountain Diabetes Protection Solved

Scientists have finally cracked a decades-old medical puzzle: why people living in high-altitude regions develop diabetes far less often than their sea-level counterparts. In the US, people living 1,500m (4,920ft) above sea level are 12 per cent less likely to have diabetes than those living at altitudes below 500m (1,640ft) . The answer lies in an unexpected place—our red blood cells.

When oxygen levels drop, red blood cells switch into a new metabolic mode and absorb large amounts of glucose from the blood. This helps the body cope with thin air while also reducing blood sugar levels . Research published in Cell Metabolism reveals that these cells, previously thought to be simple oxygen carriers, transform into powerful glucose-absorbing machines when faced with the thin air of mountain living.

A Cellular Sugar Sponge System

The discovery emerged from experiments where researchers exposed mice to low-oxygen conditions that mimic high-altitude environments. "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 . Initially, scientists couldn't locate where this glucose was going—it wasn't being consumed by the usual suspects like muscle, brain, or liver tissue.

Using advanced imaging techniques, the team discovered that red blood cells were serving as the missing "glucose sink." Their research showed that in hypoxia, red blood cells use glucose to generate a molecule that enhances oxygen release to tissues. This extra oxygen delivery is especially important when oxygen is limited . The cells essentially reprogram their metabolism to become more efficient at both oxygen delivery and sugar absorption.

From Discovery to Treatment

The research team didn't stop at understanding the mechanism—they developed a potential treatment based on their findings. Researchers tested a drug called HypoxyStat, recently developed in Jain's lab to imitate the effects of low oxygen exposure. HypoxyStat is an oral medication that causes hemoglobin in red blood cells to bind oxygen more tightly, reducing the amount delivered to tissues. In mouse models of diabetes, the drug completely reversed high blood sugar levels and performed better than existing treatments .

The team also found that the metabolic benefits of chronic hypoxia continued for weeks to months even after mice were returned to normal oxygen levels . This suggests that the protective effects of high-altitude living might persist even after returning to lower elevations, offering hope for sustained diabetes management strategies.

Beyond Diabetes Prevention

The implications extend far beyond diabetes treatment. D'Alessandro notes that these findings could be relevant to exercise physiology and to pathological hypoxia after traumatic injury. Trauma remains a leading cause of death in younger populations, and changes in red blood cell production and metabolism may affect how glucose is distributed and how muscles perform . Athletes training at altitude may also benefit from understanding how their bodies naturally optimize glucose metabolism in low-oxygen environments.

This breakthrough represents a fundamental shift in how scientists view red blood cells—from passive oxygen transporters to active metabolic participants. The research opens entirely new avenues for diabetes treatment that don't rely solely on traditional insulin-based approaches, potentially offering hope to millions of people worldwide struggling with blood sugar management.