Everyday Health: What are the long-term complications of untreated diabetes?

Ping H. Wang, MD: The long-term complications of untreated diabetes include blindness, kidney failure, and infections that can lead to amputation (gangrene). Neuropathy, which may cause pain or numbness and tingling in the hands and feet, can lead to other problems such as gastroparesis (nerve damage in the digestive system). Cardiovascular disease is a major complication and a leading cause of mortality among diabetes patients. Studies show complications like these can be significantly reduced or delayed if diabetes is well managed.

Melissa Meredith, MD (with assistance from Barb Uselman, RN/CDE, and Carol Sargent, RD/CDE) : People with diabetes are at increased risk of damage to several organs if blood sugars are not controlled. These complications usually occur after having uncontrolled diabetes for at least 10 years. The damage develops progressively over time and early intervention and treatment can prevent irreversible damage. The most common chronic complication is eye damage (retinopathy). High blood sugars can cause the small blood vessels in the back of the eye to become weak, leading to bulges in the vessels, swelling, and leaking ofblood. Unfortunately, the early changes do not usually cause problems with vision and can only be detected by an eye exam. If left untreated, blindness can occur. In fact, diabetes is the number one cause of blindness in people younger than 75. Effective treatments are available to prevent significant visual impairment and people with diabetes need to have a dilated eye exam yearly.

A second long-term complication is kidney damage (nephropathy). Diabetes is the leading cause of end-stage kidney disease resulting in dialysis or transplantation. As with the eye, kidney damage occurs overseveral years. Early signs of kidney damage can be detected with a urine sample, called a urine microalbumin. When caught early, progression of kidney damage can be stopped with medication, improvement in blood sugars, and controlled blood pressure. Nerve damage (neuropathy) is another possible complication of long-standing, uncontrolled diabetes. The most common type of nervedamage affects the nerves that go to the feet and sense such things as pain, temperature, touch, and vibration. Sometimes people will suffer from severe pain, but others may not even realize that they have lost sensation. People with nerve damage are at increased risk of amputation. Daily foot inspection is recommended to avoid sores that could lead to amputation. Many other nerves in other organs, such as the stomach, can also be damaged leading to irreversible changes that can be debilitating and hard to treat. Prevention of these complications with early and optimal blood sugar control is the goal.

Last, people with diabetes are at increased risk for heart attacks, strokes, and poor blood flow to the legs and feet. Although these are not specific complications of diabetes, up to 70% of people with diabetes will die from one of these problems. Control of blood sugar, cholesterol and blood pressure can reduce the risk of these complications.

Theresa Garnero, APRN, BC-ADM, MSN, CDE: Uncontrolled diabetes may lead to heart attacks, strokes, blindness, kidney failure, and/or amputations — especially when coupled with high blood pressure, high cholesterol, and smoking or exposure to smoke. Know these complications are not inevitable; with some effort and the right tools, they are preventable.

Gretchen Scalpi, RD, CDE: Potential long-term complications are numerous. They include:

  • Heart and blood-vessel disease: coronary-artery disease, heart attack, stroke, narrowing of arteries, and high blood pressure
  • Nerve damage (neuropathy): tingling, numbness, burning or pain of the toes or fingers
  • Kidney damage (nephropathy)
  • Eye damage (diabetic retinopathy)
  • Poor blood flow and circulation to the feet resulting in various complications
  • Increased susceptibility to skin infections or poor healing of wounds
  • Gum disease and infection