By Stanley Rosen, MD

It is estimated that more than 20 million Americans are at immediate risk for Chronic Kidney Disease (CKD), which is described as Stages 1 through 5 according to severity and level of kidney function remaining. Although there may be many causes of kidney disease, the two major causes are hypertension and diabetes.

Kidney disease is viewed as a “silent disease,” because patients rarely experience symptoms until late in the progression of CKD – when it’s too late and dialysis or transplantation is required. However, diagnosis must be and can be made in the early stages so that treatment can begin to slow its progression. Early detection of CKD is especially important, because this disease can also trigger severe vascular and cardiac diseases. The following information review preventative steps one can take to monitor their kidney disease to hopefully delay the progression of this disease and the need for renal replacement therapies (RRT) such as dialysis or transplantation.

Early Diagnosis
Early diagnosis is the key to monitoring and controlling any disease. Early diagnosis for CKD can be made by the measurements of urinary microalbumin and serum creatinine. Urinary microalbumin measures the amount of albumin (protein) in the urine. Protein in the urine, also called “spilling protein,” is a sign that the kidneys are not functioning properly. The microalbumin level can give an estimate of the kidney function as well as the severity of vascular and heart disease.

The serum creatinine measurement is used to estimate the percentage of renal function remaining. Serum creatinine is the most commonly used test of kidney function. Serum refers to the liquid part of the blood. Creatinine is a normal product of muscle breakdown and is produced at approximately the same rate every day in each person. Creatinine is normally removed by the kidneys, when it is not, that is another indication of CKD.

Because symptoms are not an early warning sign of CKD, all persons with hypertension, diabetes and a family history of renal disease should be tested for CKD regularly. The progression of CKD can be drastically slowed by various methods, including ACE inhibitors, e.g. lisinopril or ARBs, which help treat hypertension and congestive heart failure, reduce protein in the urine, and preserve the filtering membrane of the kidney.

Controlling Hypertension, Cholesterol and Diabetes
Control of hypertension is mandatory in helping to slow the progression of kidney disease. The optimal level of blood pressure remains controversial, but the goal should be less than 130/85. Combinations of medicines may be needed to achieve this goal, especially in those with diabetes.

The role of statins (pharmaceutical medicines that lower cholesterol) in slowing down damage to the kidneys is also controversial to its effectiveness, but should be used to control any abnormalities in cholesterol to prevent cardiovascular disease that may be a result of kidney damage.

Diabetes, which is elevated blood sugar, is very destructive to the kidneys and must be carefully controlled. Blood tests for HGAC (Hemoglobin A1C) coordinates well with the average blood sugar for the previous several months and should be maintained as close as possible to normal (less than 6.0).

Likewise, the kidneys play a major role in metabolizing many medications. It may be required that dosages of certain medications be reduced or avoided to help preserve kidney function. If unable to ward certain medications such as digoxin (used in cardiac arrhythmias) and antibiotics (such as gentamicin and vancomycin) then blood levels should be closely monitored by a physician. Dosage of insulin may be reduced as renal function decreases and metformin (an oral diabetic drug) may need to be stopped when kidney function is less than 30 percent. Always tell your doctors about your CKD whenever new medications are prescribed.

As previously stated, some medications speed up damage to the kidney; however some of these medications may be bought over the counter in your local drugstore without a prescription. Pain medications classified as Non-Sterodial Anti-Inflammatory Drugs (NSAID) are notorious for causing kidney damage when used in excess over a long period of time. These NSAIDs include ibuprofen, Aleve and Naprosyn. They must be used with care in those with CKD and never on a continual basis. It’s important to read the labels on all medications bought without a prescription and be sure to ask your doctor whether they are safe for you.

Beware of Certain Medical Tests
Some radiological tests used in the investigation of kidney and other diseases may use a contrast agent such as iodine or gadolinium to enhance the contrast of structures or fluids within the body during medical imaging such as an X-ray or MRI. These contrast agents may have undesirable effects in CKD patients. Intravenous (IV) iodine contrast agents may cause Acute Kidney Injury (AKI), which may be temporary or permanent. Persons with diabetes are especially susceptible. Intravenous (IV) gadolinium used with MRI may damage multiple organs when used in CKD patients and should be given only after due consideration is determined by a physician as to the benefit/risk ratio toward the patient.

Diet and Nutrition are Key
Diet plays an important role in maintaining kidney function in an individual with CKD. It is extremely important to consult a renal dietitian as to an appropriate meal plan for you as this professional will take into consideration your physicians requests as well as your food likes and dislikes. Salt intake should be closely monitored by individuals at risk for CKD as well as those already diagnosed with CKD. Other dietary adjustments are recommended as renal function decreases below 40 percent when phosphorus and parathyroid hormone levels begin to elevate. Both of these speed up damage to the cardiovascular system and calcification in the heart. Treatment with medicine to remove the phosphorus is essential in such a situation and dietary consultation, by a renal dietitian, to assist in the choice of foods to maintain a tasty and nutritious diet is encouraged. A low protein diet has been advocated, but recently this concept has been questioned. Current medical trials show patients do not comply with the diet and may lead to malnutrition in patients.

Yet another key nutritional aspect to know is the absorption of various nutrients may be impaired in a patient with CKD, including iron and vitamin D. If low levels of iron and vitamin D are confirmed in blood tests, supplements will be prescribed by your physician. Anemia may also occur due to a lack of the hormone erythropoietin naturally produced by the kidneys. This can be improved by replacing the hormone with biweekly injections of a man-made version of the hormone, commonly known as ESAs (erythropoietin stimulating agents).

When kidney function decreases below 30 percent, other disturbances may occur, including high potassium, high blood acidity and high uric acid. Diet and medications will also control these issues.

In conclusion, attention should be made to lifestyle. Obesity and smoking aggravate CKD. However exercise activity, just like diet, is proven to slow the progress of this disease. Studies have shown that emotional health also plays an important role in good health, so strong bonding with family and friends and enjoyment of hobbies is beneficial to your overall well-being. But when kidney function is reduced to 25 percent, options for management in anticipation of the kidneys failing completely should be considered. These include the following:

• In-center hemodialysis
• Home hemodialysis
• Home peritoneal dialysis
• Renal transplantation
• Or none of the above

Statistics are quite clear that when preparation is made early, the outcome is vastly improved regarding both quality of life and survival.

Stanley Rosen, MD, is currently Clinical Professor of Medicine at the University of California, Irvine and practices in Laguna Hills, CA. He is an advocate for Quality Patient Care as Chairman of the Medical Review Board of the Southern California Renal Disease Council. He was elected to Fellowship in the American College of Physician, Royal College of Physicians of London and Royal College of Physicians of Edinburgh.

This article originally appeared in the January 2011 issue of aakpRENALIFE.

Posted 2/10/2011.

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