Diabetes is the leading cause of kidney disease. An estimated 1 in 3 adults with diabetes may develop kidney disease (also called diabetic nephropathy) in their lifetime.
Diabetes is a condition characterized by an inability to regulate blood sugar levels. Chronically high blood sugar levels are toxic to small blood vessels and causes injury to the kidneys over time. When your kidneys are damaged, they begin to lose their ability to filter blood effectively.
This article will discuss how diabetes increases your risk of kidney disease, as well as early symptoms of diabetic kidney disease, prevention strategies, and how the condition is diagnosed and treated.
What Your Kidneys Do
The kidneys are two fist-sized, bean-shaped organs located on either side of the spine. Their main purpose is to filter your blood to remove wastes and maintain fluid and electrolyte balance. The kidneys also release hormones that regulate body systems such as blood pressure.
Your kidneys filter your body’s entire blood volume about 30 times per day. Blood is filtered several times while in the kidneys, which returns about 99% of the water in your blood back into the circulation system. The remaining water and any waste products are carried away through the production of urine.
The other vital function of the kidneys is to maintain fluid levels. Electrolytes like sodium and hormones like antidiuretic hormone (ADH), aldosterone, and atrial natriuretic peptide (ANP) play a role in this. These hormones respond to the body’s needs to increase or decrease fluid volume, maintaining blood pressure and the body’s overall homeostasis (balance).
Diabetes and Kidney Damage
The kidneys are the body’s filtration system, helping to maintain the body’s fluid volume. The kidneys remove waste by producing urine. They also regulate electrolytes like sodium and potassium. Any injury to the kidneys or the blood vessels that supply it results in the inability to properly filter blood.
Causes and Risk Factors of Kidney Damage
When the kidneys become injured, they lose their ability to retain essential protein, remove waste products from the blood, and maintain electrolyte and fluid homeostasis in the body.
The two main culprits of kidney damage related to diabetes are high blood pressure (hypertension) and uncontrolled blood sugar levels.
Hypertension in those with diabetes causes nephropathy, which is the deterioration of kidney function, because elevated blood pressure levels cause the blood vessels to stiffen. As a result, less oxygen-rich blood reaches the kidney, compromising the organ’s ability to function.
High blood pressure in the setting of diabetes is defined as a systolic blood pressure (top number) greater than or equal to 140 mmHg or a diastolic blood pressure (bottom number) greater than or equal to 90 mmHg.
However, for individuals with diabetes, high blood pressure, and other risk factors for heart disease, a goal systolic blood pressure less than 130 mmHg and a diastolic blood pressure less than 80 mmHg may be appropriate if it is safe for you.
High blood sugar levels are toxic to blood vessels, especially the small blood vessels that serve the kidneys. The mechanisms and pathways that lead to this damage are complicated and not well understood, but regulating blood sugar levels has been shown to improve kidney function.
Additional risk factors for diabetic nephropathy include:
- Drug use
- Older age
- Medical conditions such as obesity and hypercholesterolemia
Symptoms of Diabetic Nephropathy
Early on you may feel little to no symptoms at all, but as your kidney damage progresses you may begin to experience:
The closer you get to the final stage of diabetes nephropathy, called kidney failure, or end-stage renal disease (ESRD), the more likely you will need specific medications or procedures to manage your symptoms.
Diagnosis and Tests
If you have diabetes, urine and blood tests are done on an ongoing basis to evaluate potential kidney damage.
An albumin blood test is one common test. The presence of albumin in the blood is a sign that the kidneys are not retaining protein as well as they should. Blood in the urine is also a sign of injury.
The presence of high levels of creatinine, a waste product, indicates that the kidney’s filtration mechanism is compromised. Creatinine in the blood can provide information about the kidney’s glomerular filtration rate (eGFR), or how well they are filtering blood.
Early detection of diabetic kidney disease determines the types of treatment that will work best for you. Getting routine screenings by a healthcare provider is one way to uncover early signs of kidney disease. The following treatments may stop the progression and even reverse the course of your kidney disease:
- Lifestyle changes: Employing preventive measures such as quitting smoking; losing weight; limiting protein, sugar, and sodium in your diet; engaging in routine exercise; and managing blood pressure and blood sugar.
- Taking prescribed medications: Angiotensin-converting enzyme inhibitors (ACE inhibitors), such as Capoten (captopril) and Vasotec (enalapril), or angiotensin receptor blockers (ARBs), such as Cozaar (losartan) and Diovan (valsartan), can lower blood pressure and decrease the amount of protein in the urine (slowing the progression of diabetic neuropathy). If you have type 2 diabetes and diabetic kidney disease, your healthcare provider may suggest adding a sodium-glucose co-transporter 2 (SGLT2) inhibitor such as Jardiance (empagliflozin) and Invokana (canagliflozin). Lastly, the newly approved drug Kerendia (finerenone) has been shown to delay the progression of chronic kidney disease and reduce the risk of kidney failure.
- Diabetes management: Use insulin as directed by a healthcare provider, and monitor blood sugar levels to keep them in a healthy range.
If you develop end-stage renal disease, you may be a candidate for hemodialysis, especially if you are on the waiting list for a kidney transplant.
Hemodialysis is the process of mechanically filtering blood via a machine. In the procedure, blood is removed from the body, put through the machine, filtered, and then placed back into the body. This is done at a hospital dialysis unit or clinic and must be repeated three or four days per week.
Peritoneal dialysis (PD) is an alternative treatment that may be performed at home for those who are homebound or cannot get to a clinic or hospital. PD works by infusing a solution through a port into your abdominal cavity. The solution absorbs waste products, which are then drained through a port.
If hemodialysis does not restore your kidney function, you may need a kidney transplant if you are deemed a viable candidate for the procedure by a healthcare provider.
Preventing Diabetic Kidney Disease
Careful control of your blood sugar (glucose) levels can help slow the progression, or perhaps prevent, kidney disease. This usually requires a combination of lifestyle changes, including eating a diet low in sodium and sugar, and taking insulin or oral medication.
High blood sugar levels that characterize diabetes can slowly damage the kidneys over time, disrupting its ability to filter blood throughout the body. Early diagnosis and treatment can help you manage your blood sugar levels, slowing the progression and in some cases, preventing the development of diabetic kidney disease.
A Word From Verywell
Diabetes is the leading cause of kidney disease in the United States, but early detection and treatment are key to staving off its impact. Early on you may not experience symptoms so getting a routine checkup by a healthcare provider should be an essential component of your diabetes treatment regimen.
If you are diagnosed with diabetic nephropathy, the best treatment for you will be based on your age, overall health, extent of disease, tolerance for specific medications, procedures, or therapies, and your opinion or preference.
Frequently Asked Questions
How many diabetic patients will develop kidney disease?
According to the Centers for Disease Control and Prevention (CDC), about approximately 1 in 3 adults with diabetes has chronic kidney disease (CKD).
Does your urine change color when your kidneys are failing?
Sometimes kidney damage causes blood to enter the urine which may cause your urine to darken in color.
Can kidney damage be reversed?
Kidney damage cannot be reversed but careful control of your blood pressure and blood sugar levels, as well as taking your medications as prescribed, can slow the progression of your kidney disease.
Does diabetic kidney disease get worse over time?
Diabetic kidney disease is a chronic, progressive condition that worsens over time without treatment.