Kidney Disease (Nephropathy)
Kidneys—what would we do without them? Loaded with millions of tiny blood vessels that act as filters to remove waste from our blood, kidneys are remarkable organs.
But unfortunately, this filtering system sometimes breaks down. Failing kidneys lose their ability to filter out waste products, resulting in kidney disease.
Care for Your Kidneys
How does diabetes cause kidney disease?
When our bodies digest the protein we eat, the process creates waste products. In the kidneys, millions of tiny blood vessels (capillaries) with even tinier holes in them act as filters. As blood flows through the blood vessels, small molecules such as waste products squeeze through the holes. These waste products become part of the urine. Useful substances, such as protein and red blood cells, are too big to pass through the holes in the filter and stay in the blood.
Diabetes can damage this system. High levels of blood glucose (blood sugar) make the kidneys filter too much blood. All this extra work is hard on the filters. After many years, they start to leak and useful protein is lost in the urine. Having small amounts of protein in the urine is called microalbuminuria.
When kidney disease is diagnosed early, during microalbuminuria, several treatments may keep kidney disease from getting worse. Having larger amounts of protein in the urine is called macroalbuminuria. When kidney disease is caught later during macroalbuminuria, end-stage renal disease (ESRD) usually follows.
In time, the stress of overwork causes the kidneys to lose their filtering ability. Waste products then start to build up in the blood. Finally, the kidneys fail. This failure, ESRD, is very serious. A person with ESRD needs to have a kidney transplant or to have the blood filtered by machine (dialysis).
Who gets kidney disease?
Not everyone with diabetes develops kidney disease. Factors that can influence kidney disease development include genetics, blood glucose management, and blood pressure.
The better a person keeps diabetes and blood pressure well-managed, the lower their chance of getting kidney disease.
What are the symptoms?
The kidneys work hard to make up for the failing capillaries, so kidney disease produces no symptoms until almost all function is gone. Also, the symptoms of kidney disease are not specific. The first symptom of kidney disease is often fluid buildup. Other symptoms of kidney disease include loss of sleep, poor appetite, upset stomach, weakness, and difficulty concentrating.
It is vital to see a doctor regularly. The doctor can check blood pressure, urine (for protein), blood (for waste products), and organs for other complications of diabetes.
How can I prevent it?
Diabetes-related kidney disease can be prevented by keeping blood glucose in your target range. Research has shown that tight blood glucose management reduces the risk of microalbuminuria by one third. In people who already had microalbuminuria, the risk of progressing to macroalbuminuria was cut in half. Other studies have suggested that tight management can reverse microalbuminuria.
Treatments for Kidney Disease
Important treatments for kidney disease are management of blood glucose and blood pressure. Blood pressure has a dramatic effect on the rate at which the disease progresses. Even a mild rise in blood pressure can quickly make kidney disease worsen. Four ways to lower your blood pressure are:
- Losing weight, if needed, or maintaining a healthy weight
- Eating a kidney-friendly eating plan (see Kidney Friendly Eating Plan section below)
- Avoiding alcohol and tobacco
- Getting regular physical activity
In addition to these steps and your diabetes medication, certain medications lower blood pressure. There are several kinds of blood pressure drugs. Work with your health care team about other medications that may be helpful for you to lower your risk of kidney disease.
Kidney Friendly Eating Plan
You can plan a kidney-friendly meal by eating a balanced diet with a variety of whole, minimally processed foods and by following these general meal planning tips:
- Choose foods lower in sodium, like whole grains and fresh or frozen fruits and vegetables. Products labeled as “low sodium” may use potassium chloride in place of sodium. Check the ingredient list to make sure you can safely eat low-sodium foods.
- Choose more complex, nutrient-dense carbohydrate sources prepared without much added sugar or fat.
- Choose more heart-healthy fats like olive and avocado oils.
- Choose more plant-based proteins like beans, lentils, and tofu.
Talk to your health care provider about limiting fluid intake and to your registered dietician nutritionist (RDN) about other nutrition considerations. You may need to limit certain nutrients like sodium, potassium, and phosphorus in your eating plan. Your nutrition care plan might change over time depending on the status of your condition. Your RDN or health care provider will tell you if changes are needed based on your blood test results.
Once kidneys fail, dialysis is necessary. The person must choose whether to continue with dialysis or to get a kidney transplant. This choice should be made as a team effort. The team should include your doctor, diabetes educator, RDN, a nephrologist (kidney doctor), a kidney transplant surgeon, a social worker, and a psychologist.