Wednesday, December 14, 2016
Erythropoietin (EPO) is a great drug for people who have chronic anemia (low red blood cell count) because of chronic disease. It stimulates the bone marrow to produce red blood cells and is useful for those with chronic kidney disease including those on dialysis, cancer, chemotherapy and inflammatory bowel disease. For the most part, these are the only people who should be taking this medication. But don’t tell that to endurance athletes who want the benefit of extra oxygen carrying capacity in their bloodstream. Blood doping is not legal, it acts like a performance enhancing drug and has life threatening complications.
Erythropoietin is manufactured within the kidney and is very sensitive to the body’s environment. Receptors can judge the amount of red blood cells within the bloodstream and if there aren’t enough, the level of EPO rises and causes the bone marrow to manufacture more red cells. Red cells contain hemoglobin, the molecule that attaches to oxygen in the lung and delivers it all the organs and tissues in the body, including muscles. Muscles need oxygen and glucose to function aerobically and get maximum performance. The more oxygen that can be delivered, potentially the longer the muscle can contract and the further and faster an athlete can run.
EPO is very sensitive to the body’s hypoxic (hypo=less +oxic=oxygen) stress, meaning that if oxygen concentrations in the bloodstream decrease, even over a short period of time, EPO concentrations increase, more red blood cells are manufactured and the concentration in the bloodstream increases. More hemoglobin presumably means more oxygen deliver and the hypoxic stress is relieved.
Patients with kidney disease, or those who become anemic from cancer or chemotherapy, cannot generate enough natural EPO to stimulate the bone marrow. Fortunately, over the past generation, pharmaceutically created EPO can be injected to help treat anemia and allow a better quality of life. More red cells allow the patient to be able to not feel constantly short of breath or weak.
Now imagine an endurance athlete who would like the benefit of 5 or 10% more red blood cells and oxygen carrying capacity in the blood. Not only would the length of activity be increased for training but so would the speed. The Olympic motto “faster, higher, stronger” “citius, altius, fortius” was meant to be achieved by perseverance and training, not necessarily living better by chemistry. Injecting erythropoietin or its cousin, the long acting darbypoietin would be a short cut to the hours spent training. It comes with a cost and that is the increased risk of stroke and heart attack. Too many red blood cells can cause blood to sludge and not flow easily through the narrow blood vessels in the body…arterioles, venules and capillaries.
EPO was a chemical way to enhance the body. Old school blood doping used more crude methods. An athlete would donate a unit of blood (about 500cc or a pint) a month or more before a competition and store it. Red blood cells have a shelf life of about 90 days if cared for properly and during that time, the body would gradually replace the lost blood. Just before the event, the blood would be transfused back into the athlete and voila…more oxygen carrying hemoglobin magically available to help performance. Same risks as EPO for heart attack and stroke.
The body’s naturally occurring EPO has a different chemical signature than artificial EPO, so testing has caught up can tell the difference proving who has been less than nice should they inject the drug.
There are legal ways to blood dope, if you have enough money. At altitude, the air contains less oxygen than it does at sea level. The body’s receptors recognize this oxygen deficiency causing EPO levels to rise and force the bone marrow to create more red blood cells to compensate for fewer oxygen molecules available with each breath. Unfortunately, training at altitude is less efficient than training at sea level, so the athlete needs to sleep at higher altitudes and train lower down. This is expensive and more than a little inconvenient. Nike developed a high-tech solution called Project Oregon. The company built a tightly sealed house in Portland where filters could decrease oxygen in the air inside to a level found at 12,000 feet. Athletes sleep at altitude and walk out the door to train at sea level. Nice if you can afford it.
There are opportunities to bend the rules. Blood doping is not legal and is potentially life threatening, however your body can be tricked into doing it legally by the letter of the rule, not necessarily by the intent. It has been a long time since the concept of a level playing field for all actually mattered.
This entry was tagged blood transfusion, bone marrow, complications, darbypoeitin, EPO, erythropoeitin, heart attack, oxygen, red blood cells, stroke