NEW YORK TIMES
July 19, 2008
Expert Q & A
The Challenges of Anemia: Defining It, and Living With ItBy ERIC SABO
Dr. Allen Nissenson is a professor of medicine and director of the dialysis program for the David Geffen School of Medicine at the University of California, Los Angeles. He has written two medical textbooks on kidney disease treatment and was president of the National Anemia Action Council, a patient advocacy group.
Q: Anemia can result from a wide range of diseases and conditions. What are the most prominent causes?
A: The biggest categories are nutritional anemias, which are mainly iron deficiency, but also deficiencies in folic acid or vitamin B12. Another major cause is bleeding, usually from the gastrointestinal tract. Chronic diseases that have an inflammatory component, like rheumatoid arthritis, can also cause anemia.
And then there’s cancer itself, or the side effects from treating cancer, that can cause anemia. Another prominent cause is deficiencies in erythropoietin, or Epo, a hormone that stimulates red blood cell production, which is almost entirely a problem in people with kidney disease.
Q: A lot of symptoms of anemia share the same characteristics as being overworked or just tired. How do you tell the difference between normal fatigue and anemia?
A: You really can’t. One of the dilemmas with anemia is that the symptoms are pretty ubiquitous: tiredness, weakness, some difficulty in thinking clearly. They’re all kind of vague.
So what we tell people is if you have these symptoms and they go on for a long time or seem to be interfering with your ability to function normally, then you should see your doctor. One of the things you need to get checked is your hemoglobin level — the protein that carries oxygen in red blood cells — to see if that’s part of the anemia.
Q: Is there a specific cutoff point of hemoglobin that indicates whether someone is anemic?
A: One of the challenges is defining what normal is, and there’s no uniform acceptance of normal hemoglobin levels. The one most doctors use is from the World Health Organization. A hemoglobin level below 13 for men and below 12 for women is considered anemic.
Q: Nutritional deficiencies are a common cause of anemia. Do these arise from a poor diet or underlying disease?
A: Bleeding is one of the most prominent causes of iron deficiency, because when you bleed you lose red blood cells that contain iron. But there still is a significant prevalence of nutritional iron deficiencies, which is much more common in pregnant women and children because of their diets.
Nutritional iron deficiency is the biggest cause of anemia worldwide, and it’s a problem is some segments of the United States. For folate or vitamin B12, it’s much less common to be deficient.
Q: How difficult is to live with anemia?
A: It’s very tough. One of the things we learned, however, is that the ability of the body to adapt is tremendous. Over time, even people with moderately severe anemia say, “You know, I really don’t feel that bad.”
Although people are fatigued or can’t do as much as they could before, they slowly adapt their lifestyle. Instead of walking to the grocery store once a week, they may go once a month and buy everything they need because they’re too tired to keep going back. There’s a lot of adaptation that takes place, but anemia can be very debilitating.
Q: Is anemia life-threatening?
A: The only life-threatening anemia is if you have massive hemorrhaging. But chronic anemia can be life-threatening indirectly in the sense that prolonged, severe anemia can cause the heart to enlarge and overwork, leading to heart failure. So through that mechanism, anemia can lead to serious morbidity or mortality.
Q: The Food and Drug Administration has issued warnings on three similar anemia drugs: Procrit, Aranasep and Epogen. How safe are these to use?
A: The studies that raised the red flags were either in cancer patients or in people with kidney disease, and they all showed something similar: if you attempt to correct the anemia completely back up to normal hemoglobin levels, that’s not a good idea. You start getting strokes or heart attacks, blood-clotting problems or increased mortality.
The recent studies that the F.D.A. flagged were just studies. Kidney specialists weren’t practicing this way — they were waiting for the studies. So we’re going to continue practicing the way we were, which is to give modest doses of the drugs, with modest improvements in hemoglobin.
Q: Are the drugs potentially dangerous for the elderly or other groups?
A: There are no studies to help us figure that out. There’s no question that since cancer patients and kidney patients are so different, but the same problem has arisen, I think people need to be extremely cautious with the use of these drugs.
One dilemma now is that if someone wanted to do a study on normalizing hemoglobin levels in the elderly with these drugs, I think an institutional review board that has to approve the ethics of studies like this would have a very difficult time because of the concerns of the risks.
Q: The F.D.A. says the drugs are safe to use in small doses that keep oxygen-carrying hemoglobin just below a level that is considered normal. Is this enough to help anemia patients feel better?
A: The quality of life benefit is seen with pretty modest increases of hemoglobin. It looks like you get the biggest bang for the buck early on. If you push the doses, then you start to see the toxicity.
Q: Are red blood cell transfusions a potentially safer option given the new concerns about the drugs?
A: As long as you’re aiming for a moderate increase in hemoglobin, the drugs are so much simpler and have few or any side effects unless you start pushing them hard. Whereas with transfusions, you still have the risk of infectious diseases and other issues.
Q: Are there lifestyle measures, like diet or exercise, that can treat anemia?
A: In the chronic conditions, there is probably very little that can be done. Obviously for nutritional anemia, improving nutrition will help. Probably the only thing you can do is to go to a higher altitude, because there’s less oxygen available.
As a result, the cells that make Epo detect that and then stimulate Epo to make more red blood cells. Even people with chronic illnesses have slightly higher hemoglobin when they go to altitude for a period of time.
http://health.nytimes.com/ref/health/healthguide/esn-anemia-expert.html#
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