The role of erythropoietin in the “stroke belt” phenomenon

Global geographic disparities in stroke mortality rates are substantial. In the US alone, higher stroke mortality rates are reported in the Southeast part particularly along the coastline while lower rates have been observed in the Mountain region. The phenomenon has been called the “stroke belt”. Although many theories have attempted to explain such nonrandom distribution of stroke mortality rates, no conclusive explanations have been drawn so far. I hypothesize that this nonrandom stroke distribution is related to regional differences in individual levels of erythropoietin (EPO), a hormone, which production depends on the tissue hypoxia due to variation in altitude. If successful, future studies based on this hypothesis may open up new avenues for treatment of such an important health issue as stroke. More importantly, future studies based on this theory may shed the lights on the mechanism of stroke as well as other diseases which have nonrandom geographic distribution not only in the US but also internationally.