If you have diabetes, it’s important to understand the relationship between diabetes and your kidneys because you are at higher risk for developing kidney disease. Most people with type 1 diabetes will see some change in kidney function within five years of diagnosis, and about a third go on to develop serious kidney disease. Less is known about people with type 2 diabetes, but it can also damage the kidneys. One way for your doctor to determine if your kidneys are working well is to measure a substance in your blood and urine called creatinine. If your creatinine level is high, it could mean your kidneys are not working as efficiently as they should. If that’s the case, there are steps you can take to minimize kidney damage and keep them working as well as possible. What Your Creatinine Level Says About Your Kidney Function Creatinine is a natural waste product created from the continuous breakdown of muscle cells. Blood vessels carry away the creatinine molecules. Healthy kidneys, which have powerful filtering units in them, trap the creatinine and eliminate most of it in urine. Diabetes can damage the filtering system and reduce the ability to clean waste from your blood, so creatinine accumulates in your circulation. Kidney disease in people with diabetes is the leading cause of kidney failure in the United States. Early kidney disease has no symptoms, so it’s important to have your creatinine checked on a regular basis. What to Expect from a Creatinine Test Your doctor measures creatinine with a simple blood test called a creatinine clearance test. If the levels are high, they may follow up with a urine test. Comparing the results of the two tests can confirm whether or not you have kidney damage. What constitutes a high creatinine level? It varies from person to person, depending on age and gender, among other factors. To make things more complicated, creatinine levels can be measured in two different ways, so test results can be confusing. When you get your results, make sure you understand the values and what they mean. Sometimes, a high creatinine level is the result of factors other than kidney disease, such as dehydration or if you have eaten a lot of meat. The dietary supplement creatine, which may increase muscle mass, can also raise your creatinine levels. However, if you have diabetes, reduced kidney function is oftentimes the cause of high creatinine levels. What You Can Do If Your Creatinine Levels Are High Diabetes experts don’t know exactly why diabetes damages the kidneys, but we do know that high blood pressure, which affects many people with diabetes, contributes to kidney damage. If you have high blood pressure, your doctor may prescribe a type of medication called an ACE inhibitor. There is some evidence ACE inhibitors may slow down the progression of diabetic kidney disease. The other way to keep your kidneys as healthy as possible is to keep your blood sugar under control. Follow your doctor’s advice about diet and exercise, and make sure you take your diabetes medicine as prescribed. You can't undo permanent kidney damage, but with appropriate treatment you may be able to prevent further damage. If you do have kidney disease, there are medications and treatment options your provider can discuss with you to keep you and your kidneys working as well as possible.