Precious McCowan was just 9 years old when she learned she had type 1 diabetes. Her doctors told her that she'd need to take insulin and test her blood sugar several times a day. They also explained that uncontrolled diabetes could affect her eyesight, limbs, and kidneys.
"I'm hearing this at a young age and I'm thinking, 'I'm fine,'" says McCowan, now 38. "When I became an adult, no one mentioned it to me again."
Once she was in college and no longer under her parents' care, McCowan let her eating habits and doctor visits slip. In 2007, her doctors diagnosed her with chronic kidney disease. Within 3 years, she had to go on dialysis to rid her body of the wastes that her damaged kidneys could no longer filter out.
Diabetes is the No. 1 cause of kidney failure, which happens when your kidneys lose most of their ability to work. About 30% of people with type 1 diabetes and up to 40% of those with type 2 will eventually develop kidney failure and need dialysis or a kidney transplant.
Kidney damage can sneak up on you. Often it doesn't cause any symptoms. Regular checkups and good blood sugar control are important to prevent or delay kidney disease.
How Can Diabetes Affect Your Kidneys?
Your kidneys contain about a million tiny filters called nephrons. These filters remove wastes from blood and deliver it into your urine while leaving protein and other substances you need in your blood.
"Over time, high blood sugar levels from diabetes pulls water and other fluids into the blood vessels of the kidneys, causing very high pressure inside the kidney filters," explains Matthew Niemi, MD, a nephrologist at UMass Memorial Medical Center. That pressure buildup damages the nephrons.
High blood sugar can happen when you don't take your diabetes medications or make the right dietary choices, he says. Many people with diabetes also have high blood pressure, which can damage your kidneys even more.
Damaged kidneys don't filter as well as they once did. They start to leak protein into your urine.
How Long Does It Take for Diabetes to Damage Kidneys?
"It takes about 10 years to get diabetic kidney disease," says Salem Almaani, MBBS, a nephrologist at The Ohio State University Wexner Medical Center.
People with type 1 diabetes often get kidney damage earlier because they're diagnosed at a younger age. But the number of young people with type 2 diabetes has been rising. And many people live with type 2 for a while before they're diagnosed.
Some people with diabetes progress very quickly to kidney disease, also called diabetic nephropathy. Others develop kidney damage more slowly or never get it. We don't know why kidney disease affects certain people more than others, Almaani says.
How Can I Tell if I Have Kidney Damage?
You probably won't know until you get tested. Diabetic kidney disease often doesn't cause symptoms. "People can live for many years not having any idea that their kidney function is low," says Niemi, also an assistant professor at UMass Chan Medical School.
Your doctor will check for kidney damage with urine and blood tests. A test called estimated glomerular filtration rate (eGFR) shows how well your kidneys filter blood.
The American Diabetes Association recommends having these tests at least once a year if you:
- Have type 2 diabetes
- Have had type 1 diabetes for at least 5 years
- Have diabetes and high blood pressure
What's It Like to Live With Diabetic Kidney Damage?
Kidney damage can affect you in many ways, especially if it gets to the point where you need dialysis, in which a machine is used to filter wastes from your blood.
"Dialysis is life-altering," Almaani says.
Not only is it time consuming, but people who are on dialysis tend to have a lot of fatigue.
"You lose what you used to do," says Eric O'Neal, 37, who was diagnosed with diabetic kidney disease in his mid-20s. "I couldn't work. And that was a big hit to me because I worked my whole life."
In pregnancy, kidney disease increases the risks to both mother and baby. McCowan's doctors had to deliver her son at 27 weeks into her pregnancy to keep her from going into end-stage kidney disease.
How Can I Protect My Kidneys?
You can't reverse kidney damage once it's happened, but you can slow it down.
The standard treatment for diabetic kidney disease includes blood pressure medications called ACE inhibitors and ARBs. "These medicines work by lowering pressure on the kidney filters," Niemi says.
More recently, he says, doctors have used another type of drug called SGLT2 inhibitors. They keep your kidneys from absorbing sugar back into your blood, so more of it gets released into your urine. Though these drugs were designed to lower blood sugar, they also help preserve kidney function.
Researchers are also looking into other medications, which could provide further options in the near future.
Lifestyle changes like diet and exercise are also key to protecting your kidneys. Watch your intake of carbs, which affect blood sugar levels. And limit salt, which raises blood pressure, Almaani suggests.
Where Can I Find Help Managing Kidney Disease?
Living with diabetic kidney disease can be "an emotional rollercoaster," O'Neal says. Having a strong support system is essential. He says his wife has been his biggest supporter throughout his treatment.
Also important is having a team of providers to help you care for your kidneys. The foundation of that team is the primary care doctor or endocrinologist who treats your diabetes. A specialist called a nephrologist can help you manage kidney disease. You may want to add a dietitian into the mix, to make sure you're on a diabetes- and kidney-friendly diet.
Visit your doctors regularly, follow their advice, and ask questions, says McCowan. "If you don't understand something, ask the doctor to explain it to you. Keep all of your health care providers on board. Communicate with them."
And if you have diabetes and haven't already done so, get screened for kidney disease.
"There are so many people walking around with CKD [chronic kidney disease] and they don't know it," she says.
Photo Credit: Andrii Lutsyk / Ascent Xmediam / Getty Images
American Family Physician: "Diabetic Kidney Disease: Diagnosis, Treatment, and Prevention."
Eric O'Neal, 37, Kansas City, MO.
Matthew Niemi, MD, nephrologist, UMass Memorial Medical Center; assistant professor, UMass Chan Medical School.
National Kidney Foundation: "Diabetes — A Major Risk Factor for Kidney Disease," "Diabetes and Chronic Kidney Disease," "Preventing Diabetic Kidney Disease: 10 Answers to Questions," "What You Should Know About Albuminuria (Proteinuria)."
National Institute of Diabetes and Digestive and Kidney Diseases: "Diabetic Kidney Disease."
Pediatric Nephrology: "Human nephron number: implications for health and disease."
Precious McCowan, 38, Dallas, TX.
Salem Almaani, MBBS, nephrologist, The Ohio State University Wexner Medical Center.