Long-Term Complications of Diabetes Mellitus

Damage to the blood vessels of the eye can cause loss of vision (diabetic retinopathy). Laser surgery can seal the leaking blood vessels of the eye and prevent permanent damage to the retina. Sometimes, other forms of surgery or injectable medications may be used. Therefore, people with diabetes should have yearly eye examinations to check for early signs of damage.

The kidneys can malfunction, resulting in chronic kidney disease that may require dialysis or kidney transplantation. Doctors usually check the urine of people with diabetes for abnormally high levels of protein (albumin), which is an early sign of kidney damage. At the earliest sign of kidney complications, people are often given medications that slow the progression of kidney damage, for example angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs), sodium-glucose co-transporter-2 (SGLT2) inhibitors, and glucagon-like peptide-1 (GLP-1) receptor agonists.

Damage to nerves can manifest in several ways. If a single nerve malfunctions, an arm or leg may suddenly become weak. If the nerves to the hands, legs, and feet become damaged (diabetic polyneuropathy), sensation may become abnormal, and tingling or burning pain and weakness in the arms and legs may develop. Damage to the nerves of the skin makes repeated injuries more likely because people cannot sense changes in pressure or temperature.

Diabetes causes many changes in the body. The following changes in the feet are common and difficult to treat:

• Damage to the nerves (neuropathy) affects sensation to the feet, so that pain is not felt. Irritation and other forms of injury may go unnoticed. An injury may wear through the skin before any pain is felt.

• Changes in sensation alter the way people with diabetes carry weight on their feet, concentrating weight in certain areas so that calluses form. Calluses (and dry skin) increase the risk of skin breakdown.

• Diabetes can cause poor circulation in the feet, making ulcers more likely to form when the skin is damaged and making the ulcers slower to heal.

Because diabetes can affect the body’s ability to fight infections, a foot ulcer, once it forms, easily becomes infected. Because of neuropathy, people may not feel discomfort due to the infection until it becomes serious and difficult to treat, leading to gangrene. People with diabetes are more than 30 times more likely to require amputation of a foot or leg than are people without diabetes.

Foot Ulcer

Image

© Springer Science+Business Media

Atherosclerosis of large blood vessels in the heart, brain, and legs leads to heart attacks, strokes, and peripheral artery disease. Atherosclerosis tends to occur at a younger age in people with diabetes than in people who do not have diabetes.

Diabetic cardiomyopathy is thought to result from many factors, including epicardial atherosclerosis, high blood pressure, and left ventricular hypertrophy, microvascular disease, endothelial and autonomic dysfunction, obesity, and metabolic disturbances. People develop heart failure due to impairment in left ventricular systolic and diastolic function and are more likely to develop heart failure after a heart attack (myocardial infarction).

People with type 2 diabetes and heart failure, either with reduced or preserved ejection fraction should be treated with a sodium-glucose co-transporter 2 (SGLT2) inhibitor. Those with symptomatic heart failure with preserved ejection fraction and obesity may also receive a glucagon-like peptide 1 (GLP-1) receptor agonist.

People with diabetes often develop bacterial and fungal infections typically of the skin and mouth. When the levels of glucose in the blood are high, white blood cells cannot effectively fight infections. Any infection that develops tends to be more severe and takes longer to resolve in people with diabetes. Sometimes, an infection is the first sign of diabetes.

One such infection is a yeast infection called candidiasis. Candida yeast is a normal resident of the mouth, digestive tract, and vagina that usually causes no harm. In people with diabetes, however, Candida can overgrow on mucous membranes and moist areas of the skin causing rashes in those areas.

People with diabetes are also particularly likely to have ulcers and infections of the feet and legs because of poor circulation to the skin. Too often, these wounds heal slowly or not at all. When wounds do not heal, they typically become infected and this can result in gangrene (tissue death) and bone infection (osteomyelitis). Amputation of the foot or part of the leg may be needed.

It is common for people with type 2 diabetes to also have steatotic liver disease  (formerly called fatty liver disease), in which abnormal fat deposits collect in the liver. Steatotic liver disease can sometimes progress to more serious liver disease including cirrhosis. Doctors diagnose liver problems if the results of blood tests that measure how well the liver is functioning or imaging of the liver is abnormal, and they confirm the diagnosis with a liver biopsy. Losing weight, maintaining good control of blood sugar levels, and treating high cholesterol can be helpful.

One of the challenges of trying to strictly control the levels of glucose in the blood is that low blood glucose levels (hypoglycemia) may occur with some commonly used antihyperglycemic medications (such as insulin or sulfonylureas [for example, glyburide, glipizide, and glimepiride]). Recognizing the presence of low blood glucose is important because treatment of hypoglycemia is an emergency. Symptoms may include hunger pangs, racing heartbeat, shakiness, sweating, and inability to think clearly. or sulfonylureas [for example, glyburide, glipizide, and glimepiride]). Recognizing the presence of low blood glucose is important because treatment of hypoglycemia is an emergency. Symptoms may include hunger pangs, racing heartbeat, shakiness, sweating, and inability to think clearly.

If hypoglycemia is very severe, sugar must get into the body quickly to prevent permanent harm and relieve symptoms. Most of the time, people can eat sugar. Almost any form of sugar will do, although glucose works more quickly than table sugar (typical table sugar is sucrose). Many people with diabetes carry glucose tablets or glucose gel packs. Other options are to drink a glass of milk (which contains lactose, a type of sugar), sugar water, or fruit juice or to eat a piece of cake, some fruit, or another sweet food. In more serious situations, it may be necessary for emergency medical professionals to inject glucose into a vein.

Another treatment for hypoglycemia involves the use of glucagon. Another treatment for hypoglycemia involves the use of glucagon.Glucagon can be injected into a muscle or inhaled as a nasal powder and causes the liver to release large amounts of glucose within minutes. Small transportable kits containing a syringe or autoinjector pen filled with glucagon are available for people who frequently have episodes of low blood glucose to use in emergency situations when sugar cannot be ingested by mouth.