An excerpt from What Is It and How Did I Get It? Early Stage Chronic Kidney Disease.
The symptoms of kidney disease don’t show up until you’ve lost most of your kidney function. That’s when you’ll experience the fatigue that’s not always a result of anemia, the muscle cramps that usually – but not always – present themselves in your calves, nausea, vomiting, appetite loss, easy bruising, itching and the shortness of breath when you exert yourself. If you’re like me, you started feeling them as soon as you read about them, but they weren’t really there. It was a classic case of medical student syndrome. That’s when you are convinced you have the disease (or, in my case, the symptoms) as soon as you learn about it. Actually, according to my nephrologist, I’m probably at least 20 years away from such symptoms. So how do the doctors know I have CKD?
It’s all in the numbers, the numbers of your estimated GFR that is. But what is the GFR, and why is it estimated? Isn’t medicine an exact science? It seems not.
GFR means the Glomerular Filtration Rate. Big help, isn’t it? Filtration Rate sounds easy enough, but what is a Glomerular? The dictionary tells us that filtrate is the part of a liquid that passed through a filter. So, glomerular filtration measures the filtrate from the glomerular. According to The Gale Encyclopedia of Medicine, a glomerular is a small tuft of blood capillaries in the kidney responsible for filtering out waste products. So far, so good. Now, how does this relate to CKD?
It is considered the best indication of measuring kidney function when used as part of a formula that includes age, gender, body size, race and serum creatinine level. Creatinine is a waste product of muscle activity. What actually happens is that our bodies use protein to build muscles and repair themselves. This used protein becomes an amino acid which enters the blood and ends up in the liver where it is once again changed. This time it’s changed into urea which goes through the kidneys into the urine.
The harder the muscles work, the more creatinine that is produced and carried by the blood to the kidneys where it also enters the urine. This in itself is not toxic, but measuring the urea and creatinine shows the level of the clearance of the harmful toxins the body does produce. These harmful toxins do build up if not voided until a certain level is reached which can make us ill. Working kidneys filter this creatinine from your blood. When the blood levels of creatinine rise, you know your kidneys are slowing down. During my research, I discovered that a non-CKD patient’s blood is cleaned about 35 times a day. A CKD patient’s blood is cleaned progressively fewer times a day depending upon the stage of the patient’s disease. In Kathryn Seidick’s, Or You Can Let Him Go, she quotes her son’s doctor, “The word you will come to love or dread, Mr. and Mrs. Seidick, is creatinine. This is a substance constantly secreted by muscles, and its presence in the blood shows better than anything how well the kidney is doing. If the creatinine is low, 0.5 to 1.5, the kidney is doing well; if it is high, the kidney is in trouble.” This book was published in 1984, but Dr. Gruskin’s words are still apt, although he was referring to a child’s creatinine levels. A mature man’s can be between 0.6 to 1.2, and a mature woman’s between 0.5 and 1.0. It can be even lower for children and, as you age, it lowers even more. The more websites I visited, the more variation [albeit very slight] I noticed in acceptable ranges for non-CKD creatinine levels.
Once diagnosed, you’ve got to continue monitoring the progress of this disease. I take a blood test and give a random urine sample [that’s the pee in a cup kind] once a year and six months later, another blood test accompanied by a 24 hour urine test and give another random urine sample. Other than that, at this early stage, I follow the renal diet, and try (desperately in my case) to watch my weight including counting calories and exercising daily, whether I want to or not. I should be trying to ingest the Dietary Reference Intake or DRI for vitamins and minerals, but find I often rely on my daily vitamin to do that. If I were a smoker, I would have had to stop. Come to think of it, I was a social smoker, but I think it wouldn’t be fair to tell you how easy it was to quit since I only smoked maybe a pack a month.
I am careful about my blood pressure. Right now, my nephrologist and I, working as a team, are checking it twice a day. That means he tells me to take a reading at 10 a.m. and before dinner at 6 p.m. daily with my home blood pressure equipment and I do it. I found my equipment right in the pharmacy and was surprised that it was both a good brand and not too expensive. I’ve noticed when I’m ill [UTI, flu, etc.], my blood pressure is higher. When I’m not, it’s usually within range, which is about 130/85 for me since I have neither diabetes nor proteinuria. The nephrologist and I are actually watching for low blood pressure since it was too low before my HBP medication was cut in half. My nephrologist is treating me for one aspect of Stage 3. It seems I’m not producing enough Vitamin D, so I now take more Vitamin D supplements.
-Gail Rae is author of What Is It and How Did I Get It? Early Stage Chronic Kidney Disease.