It has long been observed that residents of high altitudes, such as the Caucasus, Andes and Himalayas, suffer from diabetes at a much lower rate compared to low altitudes.
A study conducted on mice at the University of California, San Francisco, and published in the journal Cell Metabolism, revealed an unexpected role in regulating metabolism: red blood cells (erythrocytes).
A scientific team led by biochemist Isha Jain placed mice in conditions containing 8% oxygen, while the normal level is no less than 21%. The rodents developed hypoxia, which led to a sharp drop in blood sugar levels, without any increase in glucose uptake from the muscles or liver.
To investigate the role of red blood cells, scientists conducted a series of experiments. In mice suffering from hypoxia, artificially reducing their red blood cell count to normal levels eliminated the hypoglycemic effect. Conversely, transfusing additional red blood cells into mice breathing normal air resulted in a rapid decrease in glucose levels. It became clear that both the quantity and quality of red blood cells directly influence blood sugar levels.
Study co-author Daniel Tennant explains, "This is a basic corrective mechanism; the body not only increases the number of red blood cells, but also changes their structure to consume more sugar in order to improve oxygen delivery."
This effect explains the benefit of high-altitude training for athletes, where the blood becomes a more efficient vehicle for transporting resources.
This discovery is changing the algorithm for finding diabetes drugs, as scientists are proposing to target red blood cells instead of trying to increase sugar burning in muscles or the liver. In Isha Jain's lab, the experimental compound HypoxyStat was tested; it mimics the body's hypoxic state and stimulates red blood cells to absorb glucose more actively.
Isha Jain concludes that "this opens the door to a completely different approach to treating diabetes."
