High altitude adaptation mitigates anemia risk associated with diabetes among the Mosuo of Southwest China

Abstract

Human populations native to high altitude regions ([&ge;]2500 m) exhibit numerous adaptations to hypoxic stress. On the Tibetan Plateau, these include modifications of the hypoxia inducible factor (HIF) pathway to essentially uncouple erythropoiesis (red blood cell production) and blood hemoglobin (Hb) concentration--which normally increase in response to low oxygen--from hypoxia. Uncoupling of erythropoiesis and hypoxia is also observed among people with diabetes due to damage to kidney tissues. This is hypothesized to result in elevated risk for anemia among diabetics, which increases risk for cardiovascular disease and death. We tested the hypothesis that the independence of erythropoiesis from HIF among high-altitude adapted populations of the Tibetan Plateau may protect against diabetes-associated anemia. We investigated this hypothesis among the Mosuo, a population living in Yunnan Province, China (at ~2800 m altitude) that is undergoing rapid market integration and lifestyle change, with concomitant increase in risk for type 2 diabetes. We found that, although diabetes (glycated hemoglobin, HbA1c [&ge;]6.5%) is associated with anemia (females: Hb<12g/dl; males: Hb<13g/dl) among the Chinese population as a whole (N: 5,606; OR: 1.48; p: 0.008), this is not the case among the Mosuo (N: 316; OR: 1.36; p: 0.532). Both pathways uncoupling hypoxia from erythropoiesis (diabetic disease and high altitude adaptation) are incompletely understood; their intersection in protecting Mosuo with diabetes from anemia may provide insight into the mechanisms underlying each. Further, these findings point to the importance of understanding how high-altitude adaptations interact with chronic disease processes, as populations like the Mosuo experience rapid market integration.