Diabetes and kidney disease
Diabetic nephropathy; Nephropathy - diabetic; Diabetic glomerulosclerosis; Kimmelstiel-Wilson disease
Kidney disease or kidney damage often occurs over time in people with diabetes. This type of kidney disease is called diabetic nephropathy.
Each kidney is made of hundreds of thousands of small units called nephrons. These structures filter your blood, help remove waste from the body, and control fluid balance.
In people with diabetes, the nephrons slowly thicken and become scarred over time. The nephrons begin to leak, and protein (albumin) passes into the urine. This damage can happen years before any symptoms of kidney disease begin. Some people who have type 2 diabetes that develops slowly already have kidney damage when they are first diagnosed.
Kidney damage is more likely if you:
- Have uncontrolled blood sugar (glucose)
- Are obese
- Have high blood pressure
- Have type 1 diabetes that began before you were 20 years old
- Have family members who also have diabetes and kidney problems
- Are African American, Mexican American, or Native American
Diabetes is on the rise worldwide, and is a serious, lifelong disease that can lead to heart disease, stroke, and lasting nerve, eye and foot problems. Let's talk about diabetes and the difference between the three types of diabetes. So, what exactly is diabetes and where does it come from? An organ in your body called the pancreas produces insulin, a hormone that controls the levels of your blood sugar. When you have too little insulin in your body, or when insulin doesn't work right in your body, you can have diabetes, the condition where you have abnormally high glucose or sugar levels in your blood. Normally when you eat food, glucose enters your bloodstream. Glucose is your body's source of fuel. Your pancreas makes insulin to move glucose from your bloodstream into muscle, fat, and liver cells, where your body turns it into energy. People with diabetes have too much blood sugar because their body cannot move glucose into fat, liver, and muscle cells to be changed into and stored for energy. There are three major types of diabetes. Type 1 diabetes happens when the body makes little or no insulin. It usually is diagnosed in children, teens, or young adults. But about 80% of people with diabetes have what's called Type 2 diabetes. This disease often occurs in middle adulthood, but young adults, teens, and now even children are now being diagnosed with it linked to high obesity rates. In Type 2 diabetes, your fat, liver, and muscle cells do not respond to insulin appropriately. Another type of diabetes is called gestational diabetes. It's when high blood sugar develops during pregnancy in a woman who had not had diabetes beforehand. Gestational diabetes usually goes away after the baby is born. But, still pay attention. These women are at a higher risk of type 2 diabetes over the next 5 years without a change in lifestyle. If you doctor suspects you have diabetes, you will probably have a hemoglobin A1c test. This is an average of your blood sugar levels over 3 months. You have pre-diabetes if your A1c is 5.7% to 6.4%. Anything at 6.5% or higher indicates you have diabetes. Type 2 diabetes is a wake up call to focus on diet and exercise to try to control your blood sugar and prevent problems. If you do not control your blood sugar, you could develop eye problems, have problems with sores and infections in your feet, have high blood pressure and cholesterol problems, and have kidney, heart, and problems with other essential organs. People with Type 1 diabetes need to take insulin every day, usually injected under the skin using a needle. Some people may be able to use a pump that delivers insulin to their body all the time. People with Type 2 diabetes may be able to manage their blood sugar through diet and exercise. But if not, they will need to take one or more drugs to lower their blood sugar levels. The good news is, people with any type of diabetes, who maintain good control over their blood sugar, cholesterol, and blood pressure, have a lower risk of kidney disease, eye disease, nervous system problems, heart attack, and stroke, and can live, a long and healthy life.
Often, there are no symptoms as the kidney damage starts and slowly gets worse. Kidney damage can begin 5 to 10 years before symptoms start.
People who have more severe and long-term (chronic) kidney disease may have symptoms such as:
Exams and Tests
Your health care provider will order tests to detect signs of kidney problems.
A urine test looks for a protein, called albumin, leaking into the urine.
- Too much albumin in the urine is often a sign of kidney damage.
- This test is also called a microalbuminuria test because it measures small amounts of albumin.
Your provider will also check your blood pressure. High blood pressure damages your kidneys, and blood pressure is harder to control when you have kidney damage.
A kidney biopsy may be ordered to confirm the diagnosis or look for other causes of kidney damage.
If you have diabetes, your provider will also check your kidneys by using the following blood tests every year:
When kidney damage is caught in its early stages, it can be slowed with treatment. Once larger amounts of protein appear in the urine, kidney damage will slowly get worse.
Follow your provider's advice to keep your condition from getting worse.
Keeping your blood pressure under control (below 130/80 mm Hg) is one of the best ways to slow kidney damage.
- Your provider will prescribe blood pressure medicines known as ACE inhibitors or angiotensin II receptor blockers to protect your kidneys from more damage if your microalbumin test is too high on at least two measurements.
- If your blood pressure is in the normal range and you have microalbuminuria, you may still benefit from these medicines. Your provider can help you decide what is best for you.
CONTROL YOUR BLOOD SUGAR LEVEL
You can also slow kidney damage by controlling your blood sugar level through:
- Eating healthy foods
- Getting regular exercise
- Taking oral or injectable medicines as instructed by your provider
- Some diabetes medicines are known to prevent the progression of diabetic nephropathy better than other medicines. Talk to your provider about which medicines are best for you.
- Checking your blood sugar level as often as instructed and keeping a record of your blood sugar numbers so that you know how meals and activities affect your level
OTHER WAYS TO PROTECT YOUR KIDNEYS
- Contrast dye that is sometimes used with an MRI, CT scan, or other imaging test can cause more damage to your kidneys. Tell the provider who is ordering the test that you have diabetes. Follow instructions about drinking lots of water after the procedure to flush the dye out of your system.
- Avoid taking an NSAID pain medicine, such as ibuprofen or naproxen. Ask your provider if there is another kind of medicine that you can take instead. NSAIDs can damage the kidneys, more so when you use them every day.
- Your provider may need to stop or change other medicines that can damage your kidneys.
- Know the signs of urinary tract infections and get them treated right away.
- Having a low level of vitamin D may worsen kidney disease. Ask your doctor if you need to take vitamin D supplements.
- Do not use tobacco.
Many resources can help you understand more about diabetes. You can also learn ways to manage your kidney disease.
When to Contact a Medical Professional
Contact your provider if you have diabetes and you have not had a urine test to check for protein.
Brownlee M, Aiello LP, Sun JK, et al. Complications of diabetes mellitus. In: Melmed S, Auchus RJ, Goldfine AB, Koenig RJ, Rosen CJ, eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 37.
ElSayed NA, Aleppo G, Aroda VR, et al. 12. Retinopathy, neuropathy, and foot care: standards of care in diabetes-2023. Diabetes Care. 2023;46(Suppl 1):S203-S215. PMID: 36507636
Tong LL, Adler S, Wanner C. Prevention and treatment of diabetic kidney disease. In: Feehally J, Floege J, Tonelli M, Johnson RJ, eds. Comprehensive Clinical Nephrology. 6th ed. Philadelphia, PA: Elsevier; 2019:chap 31.
Last reviewed on: 2/10/2023
Reviewed by: Sandeep K. Dhaliwal, MD, board-certified in Diabetes, Endocrinology, and Metabolism, Springfield, VA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.