Kidney disease, as a complication of diabetes, accounts for more than half the cases of
kidney failure in the U.S. learn how you can protect your kidneys from damage.

Kidney disease affects about a third of people with type 1 or type 2 diabetes. It is frequently accompanied by serious problems with blood circulation. It’s important for people with diabetes to prevent the progression of kidney (renal) disease. One step that can be taken to protect renal blood vessels is controlling blood sugar (glucose) levels. Lowering high blood pressure is effective as well.

How do the kidneys work?
The kidneys filter waste from your blood. The blood enters each kidney through the renal artery—a branch of the main artery (aorta) through which blood passes when it leaves the heart. The blood vessels inside each kidney divide, becoming smaller and smaller, and finally enter microscopic structures called nephrons—there are about a million of these in each kidney.

In each nephron, blood flows into a bundle of capillaries. (Capillaries are the smallest of blood vessels.) The capillaries are inside a capsule. Pressure in the vessels causes much of the fluid part of blood to be squeezed out of the capillaries and into the capsule.

From the capsule, the fluid flows into a long tube to be filtered. Many impurities and excess substances such as glucose are removed from the blood to form urine; some are actively pumped out. Sodium is balanced to regulate blood pressure.

If the kidneys fail to eliminate excess sodium, your blood pressure will likely rise. On the other hand, because the kidneys require a certain blood pressure to work, they will produce an enzyme to raise blood pressure if it’s too low.

What causes kidney damage?
Poor glucose control can cause damage to the kidneys’ nephrons. For example, high blood sugar creates substances in the blood that contribute to damage. In people without diabetes, however, an injury or infection usually causes the damage.

The nephrons that remain un- damaged have to work harder, increasing the volume and pressure of blood that flows through them. The increases take their toll and lead to the failure of more nephrons. Proteins may be squeezed out of the capillaries and end up in the urine. Protein in the urine is one of the main signs of kidney damage. High blood sugar, high blood pressure, and an imbalance of fats in the blood may all contribute as well.

How to protect your kidneys
To protect your kidneys, you need to keep your blood sugar levels under control. The American Diabetes Association (ADA) specifies a hemoglobin A1C reading of below 7%. (Hemoglobin A1C values reflect average blood sugar levels over the previous 2 to 3 months.) Blood sugar levels before meals should be between 90 milligrams (mg) and 130 mg per deciliter (dL) of blood, and after meals peak at less than 180 mg/dL. Some diabetes pills to lower blood sugar in people with type 2 disease—including metformin—help protect the kidneys.

To delay the progression of kidney disease, angiotensin-receptor blockers(ARBs) or angiotensin-convertingenzyme (ACE) inhibitors should be used, except during pregnancy. Combining these drugs may provide more protection. They will also help lower your blood pressure, which is key to preventing kidney damage.

Regular visits to your healthcare provider are opportunities for kidney function to be evaluated.