What is diabetic nephropathy?
Diabetic nephropathy is a type of progressive kidney disease that may occur in people who have diabetes. It affects people with type 1 and type 2 diabetes, and risk increases with the duration of the disease and other risk factors like high blood pressure and a family history of kidney disease.
Over 40 percent of cases of kidney failure are caused by diabetes, and it’s estimated that approximately 180,000 people are living with kidney failure caused by complications of diabetes. Diabetes is also the most common cause of end-stage renal disease (ESRD). ESRD is the fifth and final stage of diabetic nephropathy.
Diabetic nephropathy progresses slowly. With early treatment, you can slow or even stop the progression of the disease. Not everyone who develops diabetic nephropathy will progress to kidney failure or ESRD, and having diabetes does not mean you will develop diabetic nephropathy.
What are the symptoms of diabetic nephropathy?
The early stages of kidney damage often do not cause noticeable symptoms. You may not experience any symptoms until you are in the late stages of chronic kidney disease.
Symptoms of ESRD may include:
- general overall unwell feeling
- loss of appetite
- itchy and dry skin
- nausea or vomiting
- swelling of your arms and legs
What causes diabetic nephropathy?
Each of your kidneys has about one million nephrons. Nephrons are small structures that filter waste from your blood. Diabetes can cause the nephrons to thicken and scar, which make them less able to filter waste and remove fluid from the body. This causes them to leak a type of protein called albumin into your urine. Albumin can be measured to help diagnose and determine the progression of diabetic nephropathy.
The exact reason this occurs in people with diabetes is unknown, but high blood sugar levels and high blood pressure are thought to contribute to diabetic nephropathy. Persistently high blood sugar or blood pressure levels are two things that can damage your kidneys, making them unable to filter waste and remove water from your body.
Other factors have been shown to increase your risk of getting diabetic nephropathy, such as:
- being African-American, Hispanic, or American Indian
- having a family history of kidney disease
- developing type 1 diabetes before you are 20 years of age
- being overweight or obese
- having other diabetes complications, such as eye disease or nerve damage
How is diabetic nephropathy
If you have diabetes, your doctor will mostly likely perform yearly blood and urine tests on you to check for early signs of kidney damage. That is because diabetes is a risk factor for kidney damage. Common tests include:
Microalbuminuria urine test
A microalbuminuria urine test checks for albumin in your urine. Normal urine does not contain albumin, so the presence of the protein in your urine is a sign of kidney damage.
BUN blood test
A BUN blood test checks for the presence of urea nitrogen in your blood. Urea nitrogen forms when protein is broken down. Higher than normal levels of urea nitrogen in your blood may be a sign of kidney failure
Serum creatinine blood test
A serum creatinine blood test measures creatinine levels in your blood. Your kidneys remove creatinine from your body by sending creatinine to the bladder, where it is released with urine. If your kidneys are damaged, they cannot remove the creatinine properly from your blood.
High creatinine levels in your blood may mean that your kidneys are not functioning correctly. Your doctor will use your creatinine level to estimate your glomerular filtration rate (eGFR), which helps to determine how well your kidneys are working.
If your doctor suspects that you have diabetic nephropathy, they may order a kidney biopsy. A kidney biopsy is a surgical procedure in which a small sample of one or both of your kidneys is removed, so it can be viewed under a microscope.
Early treatment can help slow down the progression of kidney disease. There are five stages of kidney disease. Stage 1 is the mildest stage and kidney functionality can be restored with treatment. Stage 5 is the most severe form of kidney failure. At stage 5, the kidney is no longer functional, and you will need to have dialysis or a kidney transplant.
Your glomerular filtration rate (GFR) can be used to help your doctor determine the stage of your kidney disease. Knowing your stage is important because that will affect your treatment plan. To calculate your GFR, your doctor will use the results from a creatinine blood test along with your age, gender, and physique.
|Stage||GFR||Damage and functionality|
|Stage 1||90+||mildest stage; kidneys have some damage, but are still functioning at a normal level|
|Stage 2||89-60||kidneys are damaged and have some loss of functionality|
|Stage 3||59-30||kidney has lost up to half of its functionality; can also lead to problems with your bones|
|Stage 4||29-15||severe kidney damage|
|Stage 5||<15||kidney failure; you will need dialysis or a kidney transplant|
How is diabetic nephropathy treated?
There is no cure for diabetic nephropathy, but treatments can delay or stop the progression of the disease. Treatments consist of keeping blood sugar levels under control and blood pressure levels within their target range through medications and lifestyle changes. Your doctor will also recommend special diet modifications. If your kidney disease progresses to ESRD, you will require more invasive treatments.
Regularly monitoring your blood sugar levels, using proper dosages of insulin, and taking medications as directed by your doctor can keep your blood sugar levels under control. Your doctor may prescribe ACE inhibitors, angiotensin receptor blockers (ARBs), or other blood pressure medications to keep your blood pressure levels down.
Diet and other lifestyle changes
Your doctor or dietitian will help you plan a special diet that is easy on your kidneys. These diets are more restrictive than a standard diet for people with diabetes. Your doctor may recommend:
- limiting protein intake
- consuming healthy fats, but limiting consumption of oils and saturated fatty acids
- reducing sodium intake to 1,500 to 2,000 mg/dL or less
- limiting potassium consumption, which could include reducing or restricting your intake of high potassium foods like bananas, avocados, and spinach
- limiting consumption of foods high in phosphorus, such as yogurt, milk, and processed meats
Your doctor can help you develop a customized diet plan. You can also work with a dietitian to help you better understand how to best balance the foods you eat.
Your doctor may also recommend an exercise plan for you to help keep your blood pressure low and your kidneys healthy.
If you have ESRD, you will likely need dialysis or a kidney transplant, in addition to treatments for earlier stages of kidney disease.
Dialysis is a procedure that helps to filter the waste out of your blood. There are two main types of dialysis: hemodialysis and peritoneal dialysis. Your doctor will help you decide which is best for you.
The other option for treatment is a kidney transplant. For a kidney transplant, a kidney from a donor will be placed into your body. The success of dialysis and kidney transplants differs with each person.
What is the outlook for diabetic nephropathy?
Disease progression depends on many factors. Following a treatment plan and making recommended lifestyle changes can slow the disease’s progression and keep your kidneys healthy longer.
Tips for healthy kidneys
If you’ve been diagnosed with diabetes, there are steps you can take to keep your kidneys healthy and reduce your risk for diabetic nephropathy.
- Keep your blood sugar levels within their target range.
- Manage your blood pressure and get treatment for high blood pressure.
- If you smoke, quit. Work with your doctor if you need help finding and sticking to a smoking cessation plan.
- Lose weight if you’re overweight or obese.
- Maintain a healthy diet that’s low in sodium. Focus on eating fresh or frozen produce, lean meats, whole grains, and healthy fats. Limit your intake of processed foods which can be loaded with salt and empty calories.
- Make exercise a regular part of your routine. Start slowly and be sure to work with your doctor to determine the best exercise program for you. Exercise can help you maintain a healthy weight and reduce your blood pressure.