Exploring the Impact of Diabetic Nephropathy on Kidney Health
Medically reviewed by Kashif J. Piracha, MDMedically reviewed by Kashif J. Piracha, MD
Diabetic nephropathy is a form of long-term, chronic kidney disease resulting from having had diabetes for several years. Diabetes causes higher-than-normal blood glucose levels, which damage some of the kidney’s blood vessels over time. Damaged blood vessels in the kidneys and other factors, like inflammation, lead to kidney damage.
Around 40% of people with diabetes eventually develop long-term kidney damage, and it is the leading cause of end-stage renal (kidney) disease worldwide.
This article discusses how diabetes affects the kidneys, including symptoms, causes, diagnosis, treatment, and general tips for preventing kidney damage.
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What Are the Symptoms of Diabetic Nephropathy?
Initially, diabetic nephropathy doesn’t cause any symptoms. However, symptoms arise as the kidneys worsen over time.
Some potential symptoms could include the following:
Dry, itchy skin
Extremely high blood pressure
Fatigue
Fruity smelling breath
Swelling in your ankles and feet
Muscle cramps
Nausea
Poor concentration
Seizures
Shortness of breath
Urinating too much or too little
Weight loss
What Causes Diabetic Nephropathy?
Diabetic nephropathy is a complication of diabetes mellitus, a medical condition that leads to high blood glucose. It can occur in almost all diabetes types, including type 2, type 1, and pancreatogenic. These types differ somewhat, but all involve the body’s ability to produce or respond to the hormone insulin.
Scientists aren’t completely clear why some people with diabetes develop kidney disease. Elevated glucose may lead to long-term damage to the blood vessels in the kidneys. Other factors common in people with diabetes, like inflammation and high blood pressure, may also play a role.
However, diabetic nephropathy doesn’t occur right when you first get diabetes. It may take around 10 years to develop, though this can vary greatly.
Other Risk Factors
Some factors increase the chance that you’ll develop diabetic nephropathy. For example, you have a higher risk of diabetic nephropathy if you are male or advanced in age. People who’ve had diabetes for a long time also have higher risks, as do people who already have other diabetes complications, like retinopathy.
Examples of additional risk factors include:
Carrying a lot of excess adipose tissue (fat)
Having elevated levels of fats in the blood (e.g., high LDL cholesterol)
Having high blood pressure
Having poorly controlled diabetes with high blood glucose levels
Smoking
You may improve these risk factors via lifestyle changes and medications.
Stages of Kidney Disease
Stage refers to how well the kidneys remove waste from the body and perform other vital functions. It’s defined by the rate at which the small components of your kidneys can filter blood to help make urine, called the estimated glomerular filtration rate or eGFR.
In stage 1, the kidneys are only slightly damaged, and in stage 2, they are a bit more so. However, symptoms are usually absent.
If the kidney damage continues, you might develop stage 3, 4, or 5 (end-stage) disease. Symptoms like swelling and fatigue might begin mildly in stage 3, then expand and worsen as the kidneys become more damaged in advanced kidney disease, stages 4 and 5.
If not treated, stage 5 kidney disease leads to symptoms that are ultimately fatal, like coma.
How Is Diabetic Nephropathy Diagnosed?
Clinicians take a medical history, perform a medical exam, and check the results of additional tests to diagnose diabetic nephropathy. Usually, someone with diabetic nephropathy already knows that they have diabetes. But if they don’t, a healthcare provider will order blood tests for diabetes, like blood glucose and hemoglobin A1c.
Screening people with diabetes for nephropathy is critical, as people with early disease might not know that they have it.
Microalbuminuria Urine Tests
Microalbuminuria urine tests can be used earliest in the disease. Normally, only very small amounts of protein, called albumin, in your blood should end up in your urine. The microalbuminuria test shows if more albumin than usual is in your urine. The term "microalbuminuria" has lately been replaced with "moderately increased albuminuria."
In a variation of this test, the albumin-to-creatinine ratio (ACR), the amount of albumin present in the urine, is divided by the amount of creatinine in your urine. People with kidney disease have higher ACRs.
Serum Creatinine Blood Test
The serum creatinine test measures the amount of creatinine in the blood. Creatinine is a waste protein that the body disposes of through the kidneys, but its levels increase in kidney disease.
Healthcare providers use serum creatinine to calculate the estimated glomerular filtration rate (eGFR). The eGFR is high in people with normal kidneys but has lower results in people with more advanced kidney disease.
Screening for Kidney Disease
The American Diabetes Association recommends using urine microalbuminuria and serum creatinine with eGFR to screen for diabetic nephropathy in people with type 1 diabetes who’ve had it for at least five years and in people with type 2 diabetes as soon as they are diagnosed, with additionally yearly screenings.
Kidney Biopsy
A kidney biopsy is an invasive procedure to remove a sample of your kidney and examine it under a microscope. It is usually not needed to diagnose diabetic nephropathy. However, it might be helpful if it’s not clear if diabetes or some other type of problem led to your kidney disease.
How Is Diabetic Nephropathy Treated?
With the exception of a kidney transplant, treatments don’t cure diabetic nephropathy, but they can help prevent your kidneys from getting worse.
Medications for Blood Glucose Management
It’s critical to keep your blood sugar under control, and many different medications can help with that. Your choices will depend on the type of your diabetes, its severity, and your personal preferences.
Some key examples include the following:
Insulin, especially for type 1 diabetes
Glucophage (metformin), which is usually the first drug used in type 2 diabetes
SGLT-2 medications like Invokana (canagliflozin)
GLP-1 medications, like Byetta (exenatide,) may slow the progression of diabetic nephropathy
However, many other medications for diabetes are potential options.
Other Medication Types
High blood pressure is common in people who have diabetes and can further damage the kidneys, so some people also need medications to lower their blood pressure. Often, healthcare providers prescribe an ACE inhibitor-type medication like Capoten (captopril).
Because heart disease is also a big problem in diabetes, many people will also need medication for that, such as a statin drug like Lipitor (atorvastatin). These medications may not directly improve your kidneys but may help prevent heart attack and stroke.
Diet and Other Lifestyle Changes
People with diabetic nephropathy need to follow a diet that is healthy for their diabetes but also their kidneys. The following eating patterns may be beneficial:
Avoiding foods high in sugar and processed carbohydrates (e.g., cookies and soft drinks)
Eating a diet with whole-grain carbohydrates and fiber, like from oatmeal and fresh fruits and vegetables
Eating foods high in omega-3 fatty acids, such as fish like salmon
Limiting protein (especially from proteins high in saturated fats, like beef or other animal source)
Limiting sodium to 2,300 mg per day or less
Some people with kidney disease may also need to limit the amount of high-potassium foods they eat, but check with a healthcare provider before making this adjustment.
Regular exercise also helps reduce glucose levels, lower blood pressure, and decrease stress in people with diabetic nephropathy, which may all help slow the disease. Ideally, over 150 minutes of aerobic activity a week is recommended. Quitting smoking is also essential.
Other Treatments for Complications
People with stage 3 diabetic nephropathy or higher may also need additional treatment to help reduce issues from chronic kidney disease. Depending on context, this might include:
Iron supplementation to treat anemia
Phosphate binders to treat bone problems related to kidney disease
Sodium bicarbonate, if the blood is becoming too acidic
Late-Stage Treatment Options
People with end-stage (stage 5) kidney failure from diabetes will die of the condition unless they are treated with dialysis or a kidney transplant. However, you might need to consider your options during stage 4 disease.
Dialysis
The majority of people with end-stage kidney disease go on dialysis. In this approach, you are connected to a machine that cleans your blood—similar to how your kidneys would have done. However, dialysis doesn’t work as well as a normal kidney, which can be time-consuming.
Some people can now receive training to safely perform dialysis at home, potentially overnight. Discuss all your dialysis options with your nephrologist (kidney specialist) or other healthcare provider.
Kidney Transplant
Some people with diabetic nephropathy can get a kidney transplant. In some cases, healthcare providers combine a kidney transplant with a pancreas transplant to treat diabetes directly.
Kidney transplants usually help people live longer and have a higher quality of life compared to dialysis. Since the body has two kidneys—and humans can live with only one—some people have a family member or friend donate a kidney for them, and others might get their kidney from a waiting list.
However, some people with diabetic nephropathy are not able to get transplants, especially if their overall medical condition is fragile.
What’s the Outlook for Someone With Diabetic Nephropathy?
People with diabetes who develop nephropathy have a higher risk of mortality than people with diabetes who don’t. These risks increase with later stages of kidney disease.
Cardiovascular disease is a significant concern for all people with diabetes, including those who have diabetic nephropathy. For example, it’s more likely that someone with type 2 diabetes and early-stage nephropathy will have a heart attack or stroke than that they will develop end-stage kidney disease.
A significant number of people with diabetic nephropathy do eventually develop end-stage disease. But not all do, especially those diagnosed early and optimally treated.
Proportionally, people with type 1 diabetes are more likely to develop end-stage kidney disease compared to people with type 2 diabetes. However, over half of people with diabetes on dialysis for nephropathy have type 2 disease because type 2 is comparatively more common.
Tips for Healthy Kidneys
If you’ve been diagnosed with diabetes but don’t have kidney damage, take steps to help prevent diabetic nephropathy or at least delay it. And if you already have some degree of kidney damage, you can act to slow or stop your kidney decline.
Work closely with your healthcare provider to monitor and control your blood glucose. Take all your medications as prescribed, and don’t miss appointments.
Discuss your dietary choices with a professional, such as a registered dietitian. Reduce highly processed carbohydrates, increase your intake of high-fiber foods like vegetables, limit your salt, and potentially change some of your protein choices.
Find an exercise that you enjoy and can do regularly.
Talk with your healthcare provider about avoiding other sources of kidney injury (e.g., from non-steroidal anti-inflammatory drugs [NSAIDs] like Advil [ibuprofen] or from excess dehydration).
Quit smoking.
Summary
Roughly 40% of people with diabetes eventually develop diabetic nephropathy. It usually doesn’t happen until you’ve had diabetes for several years. People with early-stage diabetic nephropathy often don’t have any symptoms, so all people with diabetes need kidney monitoring.
Some people with diabetic nephropathy eventually develop stage 5 kidney disease, which is fatal if not treated by dialysis or a kidney transplant.
By being proactive about your health, you can help prevent diabetic nephropathy or slow its progression. By working closely with a medical professional on therapies and lifestyle changes, you can decrease your risk of end-stage kidney disease and reduce your risk of heart attack and stroke.
Read the original article on Verywell Health.
