By Robert C. Stanton, MD, Special to Everyday Health
The kidneys play an important role in your health and well-being by filtering waste products and excess fluids from your blood. If your kidneys cannot do their job, you will need dialysis — filtering of your blood by a machine – or a kidney transplant.
If you have diabetes, you also have an elevated risk of developing kidney disease. High levels of blood glucose can damage the blood vessels in your kidneys and cause kidney disease. When these tiny vessels are harmed, your kidneys are incapable of properly filtering your blood. This can also lead to excess protein in your urine and a buildup of waste material in your blood.
Diabetes is the leading cause of kidney failure, accounting for 44 percent of the new cases of kidney disease, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).
Although people with diabetes are more likely to be diagnosed with kidney disease, you can slow its progress significantly if you catch it early and get treated. Here are three ways you can lower your risk of developing kidney disease:
Maintain good control over your blood glucose levels. Controlling your blood glucose levels can prevent many complications from diabetes. To help counteract diabetic kidney disease, try aiming for an A1C reading of less than 7 percent, or a similar number as advised by your healthcare provider.
Control your blood pressure. Uncontrolled diabetes, like high blood pressure, can also impair blood vessels in the kidneys. Aim for a blood pressure reading of less than 140/90, according to guidelines by the Eighth Joint National Committee (JNC 8) and the American Diabetes Association(ADA). At Joslin, we suggest an even lower blood pressure reading of 130/80 for young people, and those who have an indication of kidney disease.
Don’t smoke. If you already smoke, make plans to begin a smoking cessation program. Nicotine narrows and restricts blood vessels, and diabetes does the same thing, effectively doubling the negative effects on your vascular system. Remember, while you can’t change the fact that you have diabetes, you can avoid damage caused by nicotine.
By following these three principles you can significantly decrease your risk for developing kidney disease. At Joslin, we also recommend that people with diabetes have two annual tests to help detect early signs of kidney disease.
The microalbumin test. This test tracks excess protein in the urine, a condition known as microalbuminuria. A normal urine albumin level is less than 30 milligrams. Anything above that level is an early sign of kidney disease. The standard urine dipstick used in doctors’ offices is not accurate enough to measure this; a special machine is required. Ask your healthcare provider about the microalbumin test or the albumin-creatinine ratio. If the results are abnormal, I recommend repeating the test one month later.
Glomerular filtration rate (GFR) test. GFR is a simple and effective test that measures your blood creatinine levels. If your kidney function decreases, your creatinine levels increase. By routinely measuring the glomerular filtration rate of your kidneys, your healthcare provider can see how efficiently your kidneys are filtering your blood. This is an important indicator of how well your kidneys are functioning. The blood-sample creatinine results are plugged into a formula that estimates your kidneys’ filtering capacity. One commonly used formula is called the modification of diet in renal disease (MDRD) equation.
I cannot overemphasize the importance of using the MDRD equation to measure your blood creatinine levels. The creatinine value alone can be misleading, as it must be interpreted within the context of age and gender. Often patients can have more advanced kidney disease than their blood creatinine value alone suggests. For this reason, the National Kidney Foundation strongly urges all physicians to use the MDRD equation; however, kidney specialists aside, few physicians use it routinely. An accurate estimate of your kidney function is essential for your doctor to decide which treatment protocols you need.
While kidney disease poses a serious risk to people with diabetes, yearly testing and aggressive treatment can significantly slow any decline in kidney function and reduce your risk of developing kidney disease.
Dr. Robert C. Stanton serves as chief of the kidney and hypertension section at the Joslin Diabetes Center, where he treats patients with kidney disease, with a special focus on diabetic kidney disease. He is also a principal investigator in the section on vascular cell biology. In addition to his research activities, Dr. Stanton is an associate professor of medicine at Harvard Medical School.