Understanding Renal Anemia
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Editor’s Note: Have you ever wondered why you feel tired so easily if your kidneys are not working well? Or curious about how your kidney function affects the amount of oxygen in your body? In this post, our guest blogger Dr. Jenna Henderson explains in detail why anemia is caused by kidney damage and how it can be managed with current therapies. This information is for educational and informational purposes only.
Many kidney patients wonder why they feel so tired all of the time, and often the answer is anemia. A deficiency of the blood can happen at any stage of kidney problems but is of greatest concern for those with the advanced renal disease. There are also different types of anemia and many kidney patients have more than one reason for anemia. For someone without kidney ailments the solution to anemia may be as simple as increasing the amount of iron in their diet, but with renal patients, it is usually more complicated than that.
Anemia and Red Blood Cells
The human body has trillions of red blood cells coursing through our blood vessels, delivering oxygen to our cells. Each of those red blood cells lasts in our body for about 120 days. When a red blood cell dies, it needs to be replaced to keep our red blood cell count in a normal range. Our bone marrow is constantly turning out new red blood cells. But what tells the bone marrow to make new red blood cells is a hormone called erythropoietin. And that hormone is made by the kidneys. It’s one of the many jobs of the kidneys to respond when our red blood cell count goes low and produce erythropoietin.
If the kidneys are too damaged to produce enough erythropoietin, we will experience anemia. This doesn’t happen right away but is usually a gradual process. We may experience the signs and symptoms of anemia as our kidney function declines. We feel tired and cold. The skin looks pale. There may be headaches, shortness of breath, dizziness or loss of libido. Another common complaint with anemia is that our hair falls out more easily.
If we don’t produce enough erythropoietin, this will show up on our blood test. Our blood tests measure red blood cells (RBC), hematocrit (HCT) and hemoglobin (HGB) and kidney patients often have numbers lower than normal. It is good to check your levels each time your nephrologist does a blood test to see if anemia is an issue for you.
Kidney function is often poor by the time the kidneys stop making erythropoietin. But patients with early stages may experience anemia as well. When the kidneys leak protein into the urine, erythropoietin may also be lost. For these patients, it’s not that the kidneys aren’t making the hormone, but they can’t hold onto it.
Not only does anemia feel bad, it’s bad for you. The organs of your body are depending on a good supply of oxygenated blood to function and this includes the kidneys. Correcting anemia is important to ensure your health and well-being.
Synthetic Hormone for Anemia
In past decades the only way to correct renal anemia was through a blood transfusion. Luckily today we have a synthetic form of erythropoietin that can help us get back on track. Known as Procrit or EPO, this synthetic hormone has been a life-changer for many kidney patients. Kidney patients may be given injections of EPO and dialysis patients have the hormone injected right into the dialysis line.
This synthetic hormone is not without risks including the risk of blood clots. (This makes sense as you need blood to form a blood clot.) For most kidney patients though the advantages of correcting anemia outweigh potential risks. However, EPO is a very expensive drug and insurance may not cover it until the anemia is severe.
Many patients ask me if there is anything natural that can help their anemia. One such natural substance is the amino acid L-carnitine which has been shown to raise the red blood cell count in renal patients. There are also herbal medicines that can help with anemia. These should always be taken under the supervision of a naturopathic doctor who understands kidney disease as well as potential interactions with medications.
Although this is a controversial topic, it bears mentioning that unpasteurized milk contains the actual hormone erythropoietin. This is the calf’s source of the hormone in mother’s milk before they make their own. Erythropoietin is broken down in the pasteurization process. It is interesting to note that athletes who drink raw milk have been accused of blood doping as they may have above normal levels of red blood cells. If a kidney patient were to consider this approach they would need to weigh potential risks and benefits carefully.
For some kidney patients, the problem with anemia might not be their total red blood cell count but a problem of missing nutrients. This type of anemia is a matter of quality in the red blood cells and not just quantity. For this type of anemia we look to measurements on the blood test that include: mean corpuscular volume (MCV), red distribution width (RDW) and mean corpuscular hemoglobin (MCH). If these numbers are off, the problem may not be the total number of red cells, but what they’re carrying and how they’re formed.
When the body makes red blood cells, it requires vitamin B6, folate, and B12. If we’re lacking in these nutrients, it can be a problem for us, resulting in red blood cells that don’t form properly. For many Americans meat in the diet is our source of B-vitamins and a renal diet that is low in protein may also be low in B-vitamins. It can also be harder for the elderly to absorb B12 than it is for younger people. Dialysis patients always have to supplement their B-vitamins as these water-soluble nutrients are washed out during the dialysis process.
Another important nutrient for anemia is iron. Not only do we have to make enough red blood cells and form them properly, the red blood cells require iron to carry oxygen. Iron by itself usually will not fix anemia in kidney patients, but it is an essential nutrient for correcting anemia. Unfortunately, vegetarian sources of iron are not as well-absorbed as animal sources and a low protein diet might also lack for iron. Dialysis patients may require injections of iron into their dialysis machines and patients with chronic kidney disease may be told to take an iron supplement. (If constipation becomes a problem, there are non-constipating iron supplements available.)
The Break Down
The anemia kidney patients experience is often complex and may have more than one cause. Fortunately, there are ways to address anemia. Understanding the causes and treatment options available can help kidney patients return to normal. It is it very important to discuss anemia with your healthcare professional.