Diabetes Mellitus and Your Kidneys

If you have diabetes it is crucial to talk to your doctor about kidney disease. According to the Centers for Disease Control and Prevention (CDC), roughly 1 in 3 patients with diabetes also have chronic kidney disease. Chronic Kidney Disease, also known as CKD, can be managed through lifestyle changes, medication, and management of other chronic conditions, such as diabetes.

The kidneys help control blood pressure, make hormones, and most importantly act as a blood filtration system. Our bodies produce waste when we digest protein. The kidneys filter the waste products, toxins, and extra water from the blood and secrete it as urine. As the blood flows through the kidneys, the small waste molecules squeeze through tiny holes to become part of the urine. Larger particles such as protein and red blood cells are too big to pass through the holes and remain in the blood. The kidneys usually work to remove waste from our blood, but some diseases, such as diabetes, can cause our kidneys to break down.

How Does Diabetes Cause Kidney Disease?

High levels of blood sugar over an extended length of time can damage the kidneys. Just like with other vessels in the body, elevated blood glucose can injure the blood vessels of the kidneys. When the blood vessels become injured, they are no longer able to filter waste properly from the body. This damage results in waste and extra water building up in our bodies. It can also cause larger molecules, such as protein, to be filtered into the urine instead of remaining in the blood. When this occurs, your doctor will diagnose it as microalbuminuria. Microalbuminuria is a medical term for when albumin, a protein, is found in the urine. Microalbuminuria is usually the first sign of kidney disease. Kidney damage does not happen rapidly, and will usually occur slowly over many years. When diagnosed early, there are steps you can take to prevent it from worsening.

What Is Chronic Kidney Disease?

Roughly 15% of US adults are estimated to have chronic kidney disease reports to the CDC.

Chronic Kidney Disease, or CKD, occurs when the kidneys become damaged and cannot filter blood as well as they previously were able to. Because blood isn’t being filtered properly, excess fluid and waste build up in the blood, which can cause many other health problems, including heart disease and stroke. Other health effects of CKD are:

  • Low red blood cell counts
  • Increased risk of infections
  • Low calcium levels and high potassium and phosphorous levels
  • Lack of appetite
  • Depression

CKD doesn’t start severe, as it progresses slowly over time. If caught early, treatment and management of your CKD can prevent it from progressing to end-stage renal disease, also known as ESRD. ESRD is the term used when your kidneys are no longer functioning, also referred to as kidney failure. If left untreated, CKD will progress to kidney failure and can also affect your heart. If your kidneys do fail, you may need a kidney transplant or dialysis to help filter your blood. It can take many years for CKD to progress to ESRD, especially with the assistance of medical intervention and lifestyle modifications.

How Do I Know if I Have Kidney Disease?

Kidney damage can be quickly identified by testing your urine, also called a urinalysis. Your doctor will be looking for small particles of a protein called albumin in your urine. If they find albumin in your urine, it is the first sign of kidney damage for diabetics and they will most likely order further testing to determine the severity.

A 24-hour urine test and bloodwork can be performed to determine how severe your kidney damage is. Both methods look at how well the kidneys are filtering blood to be able to monitor disease progression over the years. An ultrasound of the kidneys can also identify an enlarged kidney, which is indicative of the early stages of kidney disease, or a shrunken kidney which is indicative of ESRD.

Though most people with kidney damage do not have severe symptoms, slight changes in your body may indicate the beginning signs of kidney disease including:

  • Fatigue
  • Nausea and vomiting
  • Loss of appetite
  • Shortness of breath
  • Persistent itching
  • Confusion
  • Reduced need for insulin or other diabetic medications
  • Swelling of hands, eyes, feet, or legs
  • Increased need to urinate
  • Poor blood pressure control

Woman viewing Kidney ultrasound

What Increases My Chances of Developing Kidney Disease?

Having diabetes for a long time increases your chances of developing kidney disease. Also having extended periods with elevated blood sugar and blood pressure increases your chances of developing kidney disease. Kidney damage is also found to occur at much higher rates in African Americans, American Indians, and Hispanics/Latinos compared to Caucasians. Other factors that increase your risk of developing kidney disease are:

  • You smoke cigarettes
  • You eat foods high in salt
  • You are not physically active
  • You are overweight
  • You have heart disease
  • You have a family history of kidney disease

Does Kidney Damage Get Worse Over Time?

Kidney damage can worsen over time if left untreated. Eventually, it will progress to kidney failure if you are not careful. If you work with your diabetes care team, you can take the necessary steps to prevent any further damage from occurring. Following the advice from your doctors will help delay the progression of kidney disease and improve your overall health.

How Can I Keep My Kidneys Healthy?

The best way to prevent diabetes-related kidney damage is to manage your diabetes through lifestyle changes, medication management, and regular checkups with your diabetes care team. Key factors in keeping your kidneys healthy are maintaining your blood sugar within its target range and controlling your blood pressure.

Keep Your Blood Sugar Within the Target Range

It is vital to keep your blood sugar within its target range through the use of insulin or other diabetic medications. As a diabetic, your physician will test your A1C regularly. Your A1C is a blood test that shows your average blood glucose levels over the past three months. Usually, having an A1C of less than 7% is the goal for diabetics. An A1C of more than 7% can indicate you had elevated blood sugar levels over the last three months. Long periods of elevated blood sugar will damage the blood vessels in your kidneys, so it is important to keep this number low. Keeping your blood sugar within its target range is one of the most important things you can do to protect your kidneys from further damage.

Injecting Insulin

Control Your Blood Pressure

Managing your blood pressure is the next most important task in protecting your kidneys. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) defines blood pressure as, “the force of blood pushing against the walls of your blood vessels”. Higher than normal blood pressure forces your heart to work harder, which can cause heart disease, strokes, and kidney disease. Elevated blood pressure can cause extra stress on the blood vessels of the kidney, causing further kidney damage. The goal for most diabetics is to keep their blood pressure below 140/90mm Hg, but consult with your team as to what your individual goal should be.

High blood pressure, also called hypertension, can be managed through lifestyle changes and medications. Healthy habits such as eating a low salt diet and exercising regularly will naturally bring your blood pressure down. There are also two common types of medications used to manage hypertension. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) are both commonly used medications to treat hypertension in diabetic patients. Continue to work with your diabetes care team to manage your blood pressure to prevent kidney damage.

Man Checking Blood Pressure