Understanding Diabetic Kidney Disease

Too often, diabetes may lead to kidney disease. For that reason, it is important that kidney problems are caught early so you can take steps to prevent more serious kidney disease from developing. That's why it's also important to check the health of your kidneys with a microalbuminuria test.

The kidneys filter and clean about 50 gallons of blood every day. This removes waste products that your body doesn't need. Diabetes can be hard on the kidneys. When blood sugar is high, the kidneys filter more blood than normal. Over time, their tiny filters start to leak. When this happens, substances that normally stay in the blood pass into the urine. The protein albumin is one of those substances. When small amounts of albumin appear in the urine (microalbuminuria), this is an early sign of kidney damage.

If early damage isn't found and treated, the kidneys become more diseased over time. Large amounts of albumin leak into the urine. This is called macroalbuminuria. Over a period of time, the kidneys may shut down entirely. The only treatments at that point are dialysis or a kidney transplant. Dialysis is the cleansing of the blood by a machine.

Early kidney disease has no symptoms. The American Diabetes Association recommends a comprehensive kidney health evaluation that includes a random urine albumin-to-creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR). The eGFR shows how well your kidneys clean your blood, and the UACR shows if there is albumin in your urine, which may mean that your kidneys are damaged. Little or no albumin in the urine means your kidneys are normal. A moderate amount means early kidney damage. A large amount means more severe kidney disease. UACR is collected through a urine sample, and eGFR is collected through a blood sample.

The American Diabetes Association recommends that people who have type 2 diabetes have kidney function tested every year. People with type 1 diabetes should be tested once a year if they're older than age 10 or have had diabetes for 5 years or longer. If you take certain medicines, have high blood pressure, or have more albumin in your urine than is normal, you may need to be tested more often.

If your test shows that you have elevated albumin levels in your urine, it's very important that you get treatment to slow the progression of kidney disease. You'll need to keep your glucose controlled as much as possible. Staying in your target range can greatly cut the risk of developing more serious kidney disease. To reduce stress on your kidneys, you'll also need to control your blood pressure. Your doctor may recommend that you eat only moderate amounts of protein. Maintaining good heart health by lowering cholesterol and managing high blood pressure is also important for controlling microalbuminuria. And if you smoke, talk with your doctor about ways to quit. Quitting smoking will help prevent more kidney damage, as well as many other health problems.

Other changes that may help prevent more kidney disease include losing weight if you have excess weight or obesity, eating a low-salt diet, cutting back on the amount of alcohol you drink, getting more exercise, and not taking NSAIDS, such as ibuprofen.

Several types of medicine can slow kidney damage:

• SGLT2 inhibitors (like empagliflozin or dapagliflozin) protect the kidneys. These are often the first medicine your doctor will start. They work even if you don't have high blood pressure.
• ACE inhibitors (like lisinopril) or ARBs (like losartan) help protect kidneys by lowering blood pressure.
• GLP-1 medicines (like semaglutide) may also help protect kidneys and lower heart risk.
• Finerenone is a newer medicine that can be added to help protect kidneys if you still have too much protein in your urine.

Your doctor will choose the best medicines for you based on your kidney tests and other health conditions.

If you have healthy kidneys now, keeping your glucose in your target range can lower your risk for kidney damage by a third. Diabetes along with high blood pressure is a major cause of kidney disease. Take blood pressure medicine as directed, get regular exercise, and follow a heart-healthy eating plan. You can do a lot right now to prevent or delay kidney disease.