Nephropathy refers to the deterioration of kidney function. You may have heard it discussed in terms of its later stages: early kidney disease or kidney failure.
People with diabetes are at a
Given the serious consequences of nephropathy, it’s important for people with diabetes to understand how to monitor and maintain their kidney health.
As many as 40 percent of people with type 2 diabetes (T2D) and 30 percent of people with type 1 diabetes (T1D) are at risk of developing kidney disease. Middle-aged African Americans, Native Americans, and Hispanics are diagnosed with diabetic kidney disease at higher rates than the general population with diabetes.
Kidneys filter waste out of the blood and send that waste out of the body in urine. They help regulate the amount of salt and minerals in the body. And they produce hormones that regulate blood pressure, make red blood cells, and help keep bones strong.
Over time, elevated blood glucose levels damage blood vessels in the kidneys and weaken kidney function. Once this damage reaches a certain level, it is diagnosed as kidney disease.
If not addressed, this damage can progress to the point where the kidneys fail and are no longer able to filter waste. When this happens, the work that a person’s kidneys used to do needs to be replaced, either with regular dialysis sessions or a kidney transplant.
At its worst, nephropathy can lead to end stage renal disease (ESRD), an ultimately fatal organ failure.
Nephropathy doesn’t show any clear symptoms early on.
The symptoms that might show up include:
- fluid retention
- upset stomach
- loss of appetite
The above symptoms don’t specifically point to kidney issues, though, and are often dismissed.
A combination of urine and blood tests are used to monitor kidney health and diagnose diabetes-related kidney disease.
Urine samples and microalbuminuria
A urine sample is taken and checked for signs of protein in your urine.
One of those proteins is albumin, which is made in the liver and normally found in your blood plasma. When albumin appears in the urine it is called
Microalbuminuria is also considered a risk marker for cardiovascular disease along with early kidney disease. Often, your doctor will order a microalbuminuria test if they believe you might be at risk for kidney damage or disease.
eGFR measurement of kidney function
From a blood sample an estimated glomerular filtration rate (eGFR) is calculated.
Creatinine, a normal waste product from muscle use, is measured. Based on blood creatinine levels, age, body size, and gender, a calculation is made to determine the person’s eGFR. The eGFR provides one measure of kidney function. For those who are experiencing kidney issues, it also identifies which stage of kidney disease the person is in.
There is some
How creatinine is measured in this test has a bias that affects African Americans. The readings established for patients who identify as African American assume a higher muscle mass than in other people taking this lab test — regardless of the person’s actual body build. It’s thought that this may account for (at least in part) why African Americans tend to have poorer outcomes once diagnosed with kidney disease.
The National Institutes of Health (NIH), National Kidney Foundation, and American Society of Nephrology have all called for change in the way eGFR is calculated, to eliminate this inherent racial bias.
Annual kidney screening for people with diabetes
The American Diabetes Association’s 2022 Standards of Care recommend annual kidney health screenings for all people with T2D and for those with T1D beginning 5 years after diagnosis.
Anyone diagnosed with kidney disease may need to complete screenings more often to track progression and guide their treatment.
When caught early in its progression nephropathy can be slowed, stopped, and in some cases reversed.
The effectiveness of this intervention relies on a number of factors, including early detection and diligent health management.
- keeping glucose levels within target range
- managing blood pressure so that it is within target range
- carefully monitoring use of over-the-counter medicines that are known to affect the kidneys, including common anti-inflammatories and painkillers
- a diet that limits protein, sodium, and potassium
- keeping cholesterol levels in check
- being active
- not smoking
- limiting alcohol
- managing stress
The most effective way to preserve kidney health is to actively manage blood glucose levels and blood pressure. Keeping both of these within target range supports healthy kidney function and reduces the likelihood that diabetes or hypertension will progress.
A number of medications, while not curing diabetic nephropathy, offer some benefit in managing kidney health and function. These include:
- SGLT2 inhibitors and GLP1 receptor agonists, which provide some protection to the kidneys while bringing glucose levels down.
Finerenone, a nonsteroidal mineralocorticoid receptor antagonist, slows progression for people who unable to use SGLT2 inhibitors or who are at higher risk of developing kidney disease or cardiovascular issues.
- ACE (angiotensin-converting enzyme) inhibitors or
ARBs (angiotensin receptor blockers)reduce blood pressure levels.
- Diuretics remove extra fluid from the body.
- Cholesterol-lowering medications support cardiovascular health.
Phases of diabetes-related kidney diease
The progression of diabetes-related nephropathy is mapped out over five stages, each defined by its corresponding eGFR level. In general, the higher the better.
Stage 1: No symptoms. Defined as having a normal eGFR (90+).
Stage 2: No specific symptoms. Defined as having a mild decrease in kidney function and an eGFR between 60 and 89.
Stage 3: Symptoms like puffiness, water retention, or brown urine may start to appear. This stage of kidney function is characterized as having a moderate decrease and an eGFR between 30 and 59.
Stage 4: Symptoms show up more acutely now. There is a severe reduction of kidney function and an eGFR between 15 and 29.
Stage 5: This is kidney failure. The eGFR is less than 15. At this stage, dialysis or kidney transplant is needed.
Throughout stages 1 through 4, actively managing kidney health along with possibly some medication can have a positive effect.
But at stage 5, the kidneys no longer function and more drastic treatment must be taken.
Kidney dialysis for nephropathy
Dialysis requires spending 4 or more hours several days a week actively receiving treatment.
Usually dialysis happens at a treatment center and requires sitting quietly while connected to a dialysis machine as it filters the blood.
Transplants for this diabetes-related complication
Kidney transplant requires major surgery along with extensive pre- and post-operative care. It can be difficult to find a compatible organ donor and can be very expensive. The average kidney transplant cost in 2020, according to this report, was $442,500.
Nephropathy is one of the more serious, potentially life threatening complications of diabetes. But ending up with diabetes-related kidney disease is not inevitable. Managing kidney health through a combination of healthy habits, monitoring, and medication is the formula for keeping the kidneys functioning and avoiding dialysis or a kidney transplant.