Complications of diabetes
Diabetes complications are divided into microvascular (due to damage to small blood vessels) and macrovascular (due to damage to larger blood vessels). Microvascular complications include damage to eyes (retinopathy) leading to blindness, to kidneys (nephropathy) leading to renal failure and to nerves (neuropathy) leading to impotence and diabetic foot disorders (which include severe infections leading to amputation). Macrovascular complications include cardiovascular diseases such as heart attacks, strokes and insufficiency in blood flow to legs. There is evidence from large randomized-controlled trials that good metabolic control in both type 1 and 2 diabetes can delay the onset and progression of these complications.
Diabetic retinopathy (eye disease)
Diabetic retinopathy is a leading cause of blindness and visual disability. It is caused by small blood vessel damage to the back layer of the eye, the retina, leading to progressive loss of vision, even blindness.
Usually the patient complains of blurred vision, although other visual symptoms may also be present.
Diagnosis of early changes in the blood vessels of the retina can be made through regular eye examinations.
Good metabolic control can delay the onset and progression of diabetic retinopathy. As well, early detection and treatment of vision-threatening retinopathy can prevent or delay blindness. This involves regular eye examinations and timely intervention
Nephropathy (kidney disease)
Diabetic kidney disease is also caused by damage to small blood vessels in the kidneys. This can cause kidney failure, and eventually lead to death. In developed countries, this is a leading cause of dialysis and kidney transplant.
Patients usually have no symptoms early on, but as the disease progresses, they may feel tired, become anemic, not think clearly, and even develop dangerous electrolyte imbalances.
Early diagnosis can be made by a simple urine test for protein as well as a blood test for kidney function.
If diagnosed at an early stage, several measures can retard the progression to kidney failure. These include control of high blood glucose, control of high blood pressure, intervention with medication in the early stage of kidney damage, and restriction of dietary protein.
Neuropathy (nerve disease)
Diabetes causes nerve damage through different mechanisms, including direct damage by the hyperglycemia and decreased blood flow to nerves by damaging small blood vessels. This nerve damage can lead to sensory loss, damage to limbs, and impotence in diabetic men. It is the most common complication of diabetes.
The symptoms are many, depending on which nerves are affected: for example, numbness in extremities, pain in extremities, and impotence. Decreased sensation to feet can lead to patients not recognizing cuts and developing foot infections. If not treated early, these can lead to amputation (more about diabetic foot disease below).
Early diagnosis is made by early recognition of symptoms by patients and health care providers as well as by careful examination by health care providers at regular intervals.
If detected early, and blood glucose brought under control, these complications can also be prevented or delayed.
Diabetic foot disease, due to changes in blood vessels and nerves, often leads to ulceration and subsequent limb amputation. It is one of the most costly complications of diabetes, especially in communities with inadequate footwear. It results from both vascular and neurological disease processes. Regular inspection and good care of the foot can prevent amputations. Comprehensive foot programs can reduce amputation rates by 45-85%.
Hyperglycemia damages blood vessels through a process called “atherosclerosis”, or clogging of arteries. This narrowing of arteries can lead to decreased blood flow to heart muscle (causing a heart attack), or to brain (leading to stroke), or to extremities (leading to pain and decreased healing of infections).
The symptoms of these different conditions are varied: ranging from chest pain to leg pain, to confusion and paralysis.
While early detection of these complications can delay progression, early detection of other risk factors such as smoking, high blood pressure, high serum cholesterol and obesity is even more important.
Controlling these other risk factors along with blood glucose can prevent or delay cardiovascular complications.