Kidney Damage From Diabetes Worsens Over Time

The main function of the kidneys is to maintain the balance of minerals and water in the body and to function as a filter system to remove excess fluid and waste products. The nephrons in the kidneys are supplied with a dense network of blood vessels. A high volume of blood flows through these vessels, delivering nutrients and oxygen to the kidneys.

Diabetic kidney disease often develops slowly and with few symptoms. Many individuals do not realize they have kidney disease until it is advanced and they need dialysis or a kidney transplant to survive.¹

Kidney diseases are a leading cause of death in the United States. Approximately 1 in 3 adults with diabetes have chronic kidney disease. Every 24 hours, 170 individuals with diabetes begin treatment for kidney failure.¹ Black, Hispanic, and Indigenous individuals develop diabetes, kidney disease, and kidney failure at a higher rate than White individuals.²

Causes

Each kidney is made up of millions of tiny filters called nephrons. Over time, high blood sugar from diabetes can damage the blood vessels in the kidneys, so they do not work as well as they should.¹ Many individuals with diabetes also develop high blood pressure (HBP), which can damage kidneys.¹ Over time, uncontrolled HBP can cause the arteries around the kidneys to harden, narrow, or weaken. These damaged arteries are then unable to deliver enough blood and oxygen to the kidney tissue.³

The chances of developing kidney disease with type 1 or type 2 diabetes increase if patients are not active, are overweight, do not follow a proper diet, have a high sodium intake, smoke, have a family history of kidney disease, and/or have heart disease.²

Symptoms

In the initial stages of diabetic kidney disease, there are typically no noticeable signs or symptoms. In later stages, signs and symptoms may include protein in the urine; swelling of the ankles, eyes, feet, or hands; an increased need to urinate; and worsening blood pressure control. Further deterioration can result in confusion or difficulty concentrating, fatigue, loss of appetite, nausea and vomiting, persistent itching, a reduced need for diabetes medication or insulin, and shortness of breath.⁴

Progression

Kidney damage from diabetes can worsen over time. Damage to the kidneys can cause permanent scarring. If left untreated, kidney failure may develop. Kidney failure means the kidneys are functioning at less than 15% of normal kidney function. However, most individuals with diabetes and kidney disease do not end up with kidney failure.⁵

Complications

Complications of diabetic kidney disease may develop gradually over months or years and may include the following⁶:

•Anemia: reduced number of red blood cells

•Bone and mineral disorders: inability of kidneys to maintain balance of calcium and phosphorus in the blood

•Cardiovascular disease: damage to heart and blood vessels, which can lead to stroke

•Diabetic retinopathy: damaged blood vessels in the light-sensitive tissue of the eyes

•Edema: fluid retention can lead to HBP, fluid in the lungs, or pulmonary edema, as well as swelling in the arms and legs

•End-stage kidney disease: may require dialysis or a kidney transplant

•Erectile dysfunction: damage to blood vessels and nerves

•Festering foot sores: may result in amputation due to blood vessel and nerve damage

•Hyperkalemia: elevated levels of potassium in the blood due to an imbalance of fluid

•Pregnancy complications: for both mother and child

Prevention

To reduce the risk of developing diabetic kidney disease, some suggestions for patients include the following⁷:

•Do not smoke. Cigarette smoking can damage the kidneys and make existing kidney damage worse.

•Follow instructions on OTC medications. Follow instructions on the packages of nonprescription pain relievers, such as aspirin and nonsteroidal anti-inflammatory drugs. For patients with diabetic nephropathy, taking these types of pain relievers can lead to even more kidney damage.

•Get enough sleep. Consistently get 7 to 8 hours of good sleep each night. Patients who are not sleeping well should try to improve their sleep habits. Providers can help by offering sleep aids.

•Keep all appointments for diabetes managment. This helps patients monitor how well they are managing diabetes and screens for diabetic nephropathy and other complications.

•Limit alcohol consumption. Alcohol can increase blood pressure and add empty calories, which can increase weight.

•Maintain a healthy weight. Work to maintain a healthy weight by being physically active most days of the week. If weight loss is required, consult a doctor about weightloss strategies, such as consuming fewer calories and increasing daily physical activity.

•Manage HBP or other medical conditions. These can increase the risk of kidney disease. Controlling the conditions can delay or prevent develop-ment of kidney disease.

•Treat diabetes. With effective treatment of diabetes, diabetic kidney disease may be prevented. With proper treatment, blood glucose numbers will remain at or near goals.

Pharmacists' Role

Pharmacists play a significant role in the comprehensive management of diabetic kidney disease through education, intervention, and monitoring. Pharmacists can guide patients to appropriate, cost-effective medication while also preventing medication-induced injury. As part of a health care team, pharmacists can contribute to a smooth transition of care and help patients decrease the progression of their disease.

References

1. Diabetes and chronic kidney disease. CDC. Updated May 7, 2021. Accessed October 9, 2022. https://www.cdc.gov/diabetes/managing/diabetes-kid-ney-disease.html

2. Diabetic kidney disease. National Institute of Diabetes and Digestive and Kidney Diseases. Updated February 2017. Accessed October 9, 2022. https://www.niddk.nih.gov/health-information/diabetes/overview/prevent-ing-problems/diabetic-kidney-disease

3. How high blood pressure can lead to kidney damage or failure. American Heart Association. Updated March 4, 2022. Accessed October 9, 2022. https://www.heart.org/en/health-topics/high-blood-pressure/health-threats-from-high-blood-pressure/how-high-blood-pressure-can-lead-to-kidney-damage-or-failure

4. 10 signs you may have kidney disease. National Kidney Foundation. December 17, 2020. Accessed October 9, 2022. https://www.kidney.org/news/ekidney/august14/10_Signs_You_May_Have_Kidney_Disease

5. What is chronic kidney disease? National Institute of Diabetes and Digestive and Kidney Diseases. Updated June 2017. Accessed October 9, 2022. https://www.niddk.nih.gov/health-information/kidney-disease/chronic-kidney-disease-ckd/what-is-chronic-kidney-disease

6. Symptoms: chronic kidney disease. National Health Service. Updated August 29, 2019. Accessed October 9, 2022. https://www.nhs.uk/conditions/kidney-disease/symptoms/

7. Preventing chronic kidney disease. National Institute of Diabetes and Digestive and Kidney Diseases. Updated October 2016. Accessed October 9, 2022. https://www.niddk.nih.gov/health-information/kidney-disease/chronic-kidney-disease-ckd/prevention

About the Author

Kathleen Kenny, PharmD, RpH, has more than 25 years of experience as a community pharmacist. She is a freelance clinical medical writer based in Homosassa, Florida.