Keeping your kidneys healthy with diabetes comes down to a handful of consistent habits: tight blood sugar control, blood pressure management, the right medications, routine screening, and dietary adjustments. About one in three people with diabetes develops some degree of kidney disease, but the progression is not inevitable. Most kidney damage from diabetes happens slowly over years, which means the choices you make now have a real impact on where your kidney function lands a decade from now.
Blood Sugar Control Is the Single Biggest Factor
Sustained high blood sugar damages the tiny blood vessels inside your kidneys that filter waste from your blood. Over time, this causes them to leak protein into your urine and gradually lose filtering capacity. The landmark trials in diabetes care, including the DCCT for type 1 and the UKPDS for type 2, demonstrated that keeping your A1C below 7% significantly reduced both the development and progression of diabetic kidney disease compared to less aggressive control (targets below 9%).
Most guidelines recommend aiming for an A1C between 6.5% and 7%. If you’re 65 or older, the American Diabetes Association suggests a slightly relaxed target of 7.5% or below, since aggressive blood sugar lowering in older adults can increase the risk of dangerous lows. The key isn’t perfection on any single day. It’s your average over months, which is exactly what A1C measures.
Blood Pressure Matters Almost as Much
High blood pressure accelerates kidney damage by putting extra strain on those same fragile filtering vessels. If you already have protein leaking into your urine (a condition called albuminuria), the target is below 130/80 mmHg. If your urine tests show no protein, keeping your systolic pressure (the top number) between 120 and 130 is a reasonable goal. Staying under 140/90 is the minimum.
Many people with diabetes need one or two blood pressure medications to reach these targets, even with lifestyle changes. Two specific classes of medication deserve special mention because they do more than just lower blood pressure.
Medications That Directly Protect the Kidneys
If your doctor has prescribed a blood pressure pill called an ACE inhibitor or an ARB, it’s likely doing double duty. These medications relax the tiny blood vessel leaving each kidney filter, which reduces the pressure inside the filter itself. That lower pressure means less protein leaks through and less long-term scarring. For anyone with diabetes and even mildly elevated urine protein, one of these two drug classes is typically the first choice.
A newer class of diabetes medication originally designed to lower blood sugar, SGLT2 inhibitors, has turned out to be remarkably protective for the kidneys. A large meta-analysis found that these drugs reduced the risk of progressive kidney disease by 36% in people with diabetes. They work partly by reducing how hard the kidneys have to filter and partly by lowering blood pressure and blood sugar simultaneously. If you have type 2 diabetes and any sign of kidney stress, ask whether you’re a candidate.
GLP-1 receptor agonists, the injectable medications that have gained attention for weight loss, also show kidney benefits. The FLOW trial, published in the New England Journal of Medicine, found that semaglutide reduced major kidney events by 24% and slowed the annual decline in kidney function in people with type 2 diabetes and existing kidney disease. It also lowered the risk of death from cardiovascular causes by 29%. These results were strong enough that the trial was stopped early because the benefits were clear.
Get Screened Every Year, at Minimum
Diabetic kidney disease is silent in its early stages. You won’t feel it. The only way to catch it is through two simple tests: a urine test that checks for albumin (a protein that shouldn’t be there in large amounts) and a blood test that estimates your kidney’s filtering rate, called eGFR. The ADA recommends both tests at least once a year for everyone with diabetes.
If your results already show elevated protein (above 300 mg/g) or your eGFR has dropped into the 30 to 60 range, screening should happen twice a year. Kidney function is staged on a five-point scale based on eGFR: stage 1 is 90 or above (normal filtering with other signs of damage), stage 2 is 60 to 89, stage 3 is 30 to 59, stage 4 is 15 to 29, and stage 5 is below 15, which is kidney failure. Catching a decline at stage 2 or early stage 3 gives you the most room to slow things down.
Adjust Your Diet Before Problems Start
Sodium
The American Diabetes Association recommends keeping sodium below 2,300 mg per day. That’s roughly one teaspoon of table salt, but most of the sodium in a typical diet comes from processed and restaurant food, not the shaker. Reading labels and cooking more meals at home are the most practical ways to get there.
Protein
If your kidney function is still normal, you don’t need to restrict protein. But once your eGFR drops below 60, current guidelines suggest reducing protein intake to about 0.6 to 0.8 grams per kilogram of body weight per day. For a 170-pound person, that works out to roughly 46 to 62 grams of protein daily, which is noticeably less than what most people eat. A chicken breast alone has about 30 grams. This doesn’t mean avoiding protein entirely. It means being deliberate about portions and spreading intake across meals. It’s worth noting that the evidence behind this recommendation isn’t as strong as the evidence for blood sugar or blood pressure control, so it’s a conversation to have with your care team rather than a rigid rule.
Potassium
For people with diabetes and healthy kidneys, adequate potassium intake (around 4,680 mg per day from fruits, vegetables, and legumes) supports healthy blood pressure. However, if your kidney function has already declined significantly, your kidneys may struggle to clear excess potassium, and your doctor may ask you to limit high-potassium foods like bananas, potatoes, and tomatoes. The direction of the recommendation flips depending on your kidney stage, which is another reason regular screening matters.
Avoid Medications That Strain the Kidneys
Over-the-counter pain relievers like ibuprofen and naproxen (NSAIDs) can disrupt blood flow to the kidneys. For most healthy people, occasional use is fine. But in people with diabetes, especially those with any degree of existing kidney disease, these drugs can trigger acute kidney injury and accelerate chronic decline. The FDA has specifically flagged this risk in high-risk patients. Acetaminophen is generally a safer alternative for routine pain, though it’s worth confirming with your pharmacist if you take other medications.
Certain herbal supplements and high-dose vitamin C can also stress the kidneys. If you take any supplements regularly, mention them at your next appointment so they can be checked against your kidney function.
Exercise and Weight Management
Physical activity improves insulin sensitivity, lowers blood pressure, and helps with weight control, all of which take pressure off the kidneys. You don’t need intense exercise. Regular walking, cycling, or swimming for 150 minutes a week delivers meaningful benefits. Losing even 5% to 7% of your body weight, if you’re carrying extra, can improve blood sugar control enough to shift your A1C by a measurable amount.
Smoking is worth mentioning here because it constricts blood vessels throughout the body, including in the kidneys, and accelerates the vascular damage diabetes already causes. Quitting smoking is one of the highest-impact changes you can make for kidney longevity.