As the number of individuals diagnosed with diabetes increases, so does the risk of kidney disease.

Consequently, diabetes is the leading cause of kidney disease in the United States.

“Diabetes makes the kidneys work overtime,” says John Shepherd, M.D., a nephrologist with Pinehurst Nephrology Associates.

The kidneys filter waste products and water in the blood, then send the filtered product to the bladder as urine and recycle the clean blood back to the bloodstream. Diabetic kidney disease damages the kidneys’ ability to filter, which allows larger particles, especially albumin (protein), to pass through.

High blood sugars and high blood pressure, as well as other risk factors, such as smoking and alcohol use, can accelerate kidney disease. “Individuals with diabetes tend to have high blood pressure,” says Melissa Herman, R.D., manager of FirstHealth’s Diabetes Self-Management Program. “When a person’s blood pressure is elevated, it damages the kidneys. The damage makes the blood pressure worse, which causes more kidney damage, and so on. “Also, high blood sugar and high blood pressure make the red blood cells thick. This makes it hard for the red blood cells to pass through the blood vessels, and it scars them. So you have the kidneys fighting high blood pressure and fighting the extra sugar. The red blood cells start changing, and the hormone levels that control blood pressure also start to change.” Over time, the damage affects how the kidneys process wastes and the kidneys begin to leak small amounts of protein, called albumin, into the urine. The condition, called mincoalbuminuria, is a signal that the kidneys are beginning to work overtime.

Jennifer Klenzak, M.D., a nephrologist at Pinehurst Nephrology Associates, examines one of her patients, Betty Ledbetter, who has diabetes and kidney problems.

According to the standards of care published by the American Diabetes Association, people should have their urine checked once a year for the presence of protein. “This is the best way to get an early diagnosis of kidney disease,” says Jennifer Klenzak, M.D., also a nephrologist at Pinehurst Nephrology Associates.

Early detection is the key to stopping the advance of kidney disease. “It is much easier to prevent the progression of the disease, if it is caught early,” Herman says.

People with diabetes are urged not to wait until they feel symptoms to request a urine test, called a micro albumin test. “There are very few symptoms, if any, in the early stages of kidney disease,” Herman says. “By the time people begin to feel bad, the damage to their kidneys has occurred.”

At this point, Herman points out, people might have 90 percent kidney failure by the time they go to the doctor. They will then need dialysis to replace their kidneys’ normal function.

“I have patients come in and tell me that they don’t understand why they need dialysis, because they can still urinate,” says Dr. Klenzak. “I tell them that it’s not the quantity of the urine that indicates the disease, it’s the quality.”

The other problem with waiting until a person feels bad, she adds, is that the symptoms are the same as those for the cold or the flu: fatigue, loss of appetite, lack of energy, nausea, vomiting, itching and/or a headache. An individual may also have no appetite, a metallic taste in the mouth, shortness of breath or swelling.

Thanks to new therapies that have been discovered in the past 10 years, people who are diagnosed in the early stages of kidney disease can still maintain good quality of life.

A combination of ACE inhibitors and another group of drugs known as ARBs help control blood pressure. When blood pressure is maintained below 130/80, and blood sugar levels are controlled, the chances that the red blood cells will become rigid and damage the arteries decreases.

Left undiagnosed, kidney disease will progress until the damage is irreversible. During the last two stages of kidney disease (stages 4 and 5 or end-stage renal disease), the kidneys are working at only 10 to 20 percent of their normal filtering capacity. With end-stage renal disease, a person needs dialysis to replace the kidney’s normal function.

Many of the same recommendations that are made to diabetes patients about controlling their blood sugar and blood pressure are made to individuals whose kidney disease is caught in an early stage. Changes in diet, regular exercise and use of appropriate medications will all help prevent a further decline in kidney function.

Smoking cessation is also essential, because smoking changes the blood vessels and compounds the problems caused by diabetes.

“Follow up with your primary care provider,” says Dr. Shepherd. “Strict control of blood sugar is the best way to keep the kidneys under control. Changing your lifestyle is as important as anything a doctor can do for you.”

Herman agrees, emphasizing that patients should be empowered to take responsibility for their own care.

“In today’s world, many people do not see the same provider each time they go for a check-up,” she says, “so it’s important for them to make sure that everything that they need done in a visit is taken care of. People should ask if the provider tested their urine for protein. They need to take charge of their own health.”

Physicians know that the best way that they can help limit kidney damage is to see people when kidney disease is at its earliest stages. “An early referral translates into better outcomes for patients,” says Dr. Klenzak.

“We want people to come in as soon as they see a change in their urine, or in their blood,” says Dr. Shepherd.