Lance Armstrong, just this name brings up an intense conversation and opinion to come out. However, for those of you who don’t know who he is, Lance is a former American road-racing cyclist. He is known for elevating the cycling community to global popularity. He won 7 consecutive Tour de France races, and he defeated cancer then came back and still was on top of the race, this is what makes him a very iconic person in and out of the bike seat. However, in 2012, the US anti-doping agency accused him of doping which he specifically was injecting Erythropoietin (EPO). EPO is a growth factor for red blood cells (RBC). It begins by stimulating RBC production (Klein 2009). EPO is synthesized by cells in the kidney which is regulated by O2 and helps the body adjust to different physiological situations (Klein 2009). EPO has a lifespan of 120 days so the spleen removes old erythrocytes and begins erythropoiesis which starts in the bone marrow (Heuberger 2013). These stem cells create identical copies of themselves and they specifical target a receptor called CFU-Es, this promotes the survival of these cells.
In cycling,
this helps performance, because they bike at all different altitudes for miles
on miles. In the medical world, EPO has a recombinant version (rHuEPO), which
is used to treat anemia in chronic renal failure patients (Heuberger 2013). However,
the harmful side effects of EPO have not been researched enough to be used as
much as it is (Heuberger 2013). The use of EPO increases specific factors of an
increase in blood pressure and enhancing coagulation, platelet reactivity, and inflammation,
which increase the risk of thrombotic events while completing in endurance athletes
(Heuberger 2013). The increase of Hct lowers the cerebral blood flow which limits
O2 supply to the brain, which increases the risk for cerebral infarction (Heuberger
2013). Overall EPO can be dangerous and needs to be prescribed medically and
watched so prevent any long-term effects.
PS. If you
want to learn more about this stud you should watch the Lance Armstrong
Documentary it is very interesting.
Heuberger, J. A., Cohen Tervaert, J. M., Schepers, F. M.,
Vliegenthart, A. D., Rotmans, J. I., Daniels, J. M., Burggraaf, J., &
Cohen, A. F. (2013). Erythropoietin doping in cycling: lack of evidence for
efficacy and a negative risk-benefit. British journal of clinical pharmacology, 75(6), 1406–1421. https://doi.org/10.1111/bcp.12034
Klein, E., Georges, A., Brossaud, J., Bosredon, K. d.,
Bordenave, L., & Corcuff, J. B. (2009). Erythropoïétine : Quand la
prescrire ? Pourquoi et comment la doser ? [Erythropoietin: indications and
measurement]. Annales de biologie clinique, 67(5), 505–515. https://doi.org/10.1684/abc.2009.0356
Madi - thanks for your post! You always hear Lance Armstrong's name thrown around, but after learning about the physiological function of EPO I really have a different perspective about what went down. I didn't know that he also beat cancer! It was interesting to me when you mentioned that the harmful side effects of EPO as a medical treatment haven't been researched much. After Lance Armstrong's situation, I thought EPO would be at the forefront of research.
ReplyDeleteI decided to look more into the side effects of its use, and found that the medical version of human erythropoietin is called Epogen (epoetin alfa). Some of the more common side effects of these injections are chest pain, fever, swelling of the face, fingers, ankles, feet, or lower legs, weight gain, constipation, heartburn, shivering, and many more. Some of equally if not more concerning side effect possibilities (that are more rare) are blurry vision, migraines, slurred speech, temporary blindness, sudden inability/loss of speech, and sudden loss of coordination. This medication has it's place and use, but there are clearly a lot of risks associated as well. Thanks for your post!
https://www.mayoclinic.org/drugs-supplements/epoetin-alfa-injection-route/side-effects/drg-20068065?p=1
Very interesting! In the world of professional sports, there are always ways people are trying to cheat. I would like to highlight the major side effects of blood doping as you mentioned. The scariest is hypertension. This makes sense though, as the more red blood cells (RBCs) in circulation, the more viscus the blood becomes. Therefore, increasing resistance and decreasing flow. Why is this so scary for athletes? When someone exercises, especially aerobically, their blood pressure can increase systolicly by 50 mmHg (Sabbahi et al., 2017)! It should be noted that diastolic pressure remains constant. This creates major problems as the pressure of heart contraction becomes extremely high, causing overuse of the most important muscle in the body.
ReplyDeleteNow how did he get caught? This seems like an easy thing to get away with… if EPO is high when measured, why can’t Lance say he has been training at altitude? Training in altitude increases RBC count to deliver oxygen in lower partial pressures (Ploszczyca et al., 2018). Unfortunately for him, there are ways to test against exogenous EPO as endogenous EPO has a greater negative charge when extracted using electrophoresis (Martin et al., 1997). What if he used his own EPO, and just stored it for a rainy day? Well, this would be much harder to detect, but the level he used was probably above the 50% limit used for competition…
Anyway, Lance Armstrong can still be considered one of the greatest of all time in some points of view.
Martin, D.T., Ashenden, M., Parisotto, R., Pyne, D., Hahn, A.G.(1997). Blood testing for professional cyclists. Australian Institute of Sport, from https://sportsci.org/news/news9703/AISblood.html
Płoszczyca, K., Langfort, J., & Czuba, M. (2018). The Effects of Altitude Training on Erythropoietic Response and Hematological Variables in Adult Athletes: A Narrative Review. Frontiers in physiology, 9, 375. https://doi.org/10.3389/fphys.2018.00375
Sabbahi, A., Ross, A., Kaminsky, L.A., Myers, J., Phillips, S.A. (2017). Peak Blood Pressure Responses During Maximum Cardiopulmonary Exercise Testing. Hypertension, 71:229-236.