This topic is very important. Did you know that approximately 44 percent of new cases of kidney failure are caused by diabetes and 26.8 percent are caused by high blood pressure? (1)  Approximately 30 percent of people with type one diabetes and 10-40 percent of people with type 2 diabetes develop kidney failure over time. (2) Kidney failure is treated by going on dialysis or by receiving a transplanted kidney.  One should also know that there are many more people with diabetes that have both diabetes and chronic kidney disease (CKD) that has not progressed to kidney failure. Chronic kidney disease is defined as the loss of one-third or more of a person’s kidney function for over three months. (3) It is found that over 35 percent of adults with diabetes also have CKD. (4)

chronic kidney disease and the link to diabetes and hypertensionPresented are seven important questions and their answers about kidneys, kidney disease and diabetes.

1. What are the functions of the kidneys?

  • The kidneys filter our blood and remove waste products and fluid through the formation of urine.  Our blood circulates through our kidneys approximately one time every 2 hours or 12 times a day. In adults, our kidneys produce between 1-2 liters of urine daily.
  • The kidneys produce hormones. The first is erythropoietin which helps stimulate red blood cell production. Renin is a hormone that helps control our blood pressure and active vitamin D helps with our calcium uptake and bone health.
  • The kidneys helps regulate the minerals in our body. (5)

2. Why do some people with diabetes develop kidney disease? It is thought that having high glucose levels over time overworks the kidneys leading to damage.  When damaged, the kidneys leak a certain kind of protein called albumin into the urine. High blood pressure can also damage the kidneys. (6) In the United States, approximately 60 percent of people with diabetes have hypertension (high blood pressure). (7) Genetics also play a role in some people developing kidney disease.

3. How do I know if I have kidney disease if I have diabetes? People with diabetes should ask to get tested for kidney disease at least once per year. The National Kidney Foundation recommends three simple tests to check for kidney disease. In summary the steps are:

  • Have your blood pressure checked at every medical visit. If it is elevated, ask to come back to confirm hypertension (high blood pressure).
  • Ask that a urine sample be analyzed for protein and blood. These are not normally found in the urine. The doctor may also look at the protein to creatinine ratio as well as the albumin to creatinine ratio.
  • Ask your doctor to also check your glomerular filtration rate. This is a blood test to see if your kidneys are removing adequate waste from your blood.

For more information visit the National Kidney Foundation’s page for recommendations on the “three simple tests”.

4. What can I do to help prevent kidney disease if I have diabetes?

The Center for Disease Control and Prevention (CDC) recommend the following to help keep your kidneys healthy:

  • Stay within your blood glucose target goals as much as possible and get your hemoglobin A1c tested at least two times a year. The preference is four times a year (every three months).

  • Keep your blood pressure at the level recommended by your physician. Many people with and without diabetes need the help of medications to control blood pressure. Angiotensin-converting-enzyme inhibitors (ACE inhibitors) are a classification of medicines that many experts recommend for people with diabetes. Research on ACE inhibitors indicate a positive side effect of slowing down kidney disease progression. Some doctors may even order an ACE inhibitor for a person with diabetes even when they do not have high blood pressure. Medications in this classification commonly end with the four letters “pril”. Examples are Captopril, Lisinopril, Ramipril, Enalapril and Benazepril. To get blood pressure under control, more than one blood pressure medication is often needed. (8) Another classification of medications that are used when a person cannot take an ACE inhibitors are the angiotensin receptor blockers (ARB).

The 2014 Standards of Medical Care for Diabetes, suggests introducing blood pressure medications if the systolic blood pressure (top number) is higher than 139 mmHg. In some people with diabetes especially if they are young, the goal is to introduce blood pressure medications if the systolic blood pressure is over 129 mmHg. The bottom number is called the diastolic blood pressure and people with diabetes should be treated if it is greater than 79 mmHg. In summary, people with blood pressure higher than 139/79 mmHg should ask their doctor if it is appropriate to add medication to help control their blood pressure. (9)

  • Keep your cholesterol values in the target range given to you by your doctor.

  • Eat fruits and vegetables (for people with diabetes this would be according to their food plan).

  • Exercise as suggested by your diabetes professionals.

  • Take your medications for both diabetes and high blood pressure as ordered by your doctor.

To read more about how Diabetes and High Blood Pressure raise Kidney Disease Risk visit the CDC website.

5. I heard there are different stages to kidney disease can you tell me more?

The Renal Association provides a nice table including the stages of kidney disease, description and treatments.

6. What should I eat if I have CKD and diabetes? The National Kidney Foundation has a great deal of information on nutrition and diet information if you have CKD. Remember if you have CKD, you need to control your diet for both renal disease and diabetes.

7. What new information is available that is easy to understand?

          The National Chronic Kidney Disease Fact Sheet, 2014 was just released by the CDC.

People with diabetes need to take proper care of their kidneys. Ask your medical team about your kidney health and if you need to learn more about your kidneys and do anything differently to handle your individual needs.