Clinical features
Many diabetics do not have complications of diabetes, and well-controlled diabetics without complications will not have any clinical findings. However, people with diabetes may experience complications of varying severity.
It normally takes several years for complications to develop in Type I (juvenile) diabetes, but a person recently diagnosed with Type II diabetes (but which has been present for several years) may already be suffering from complications at the time of diagnosis.
Complications affect the following systems:
Complications affect the following systems:
- The vascular system (both the large and small vessels of the body)
- The eyes
- The kidneys
- The nervous system
- The skin
- Click here for details about Hypoglycaemic and Hyperglycaemic Episodes
The development of complications can be reduced or prevented by tight control of blood glucose.
The Vascular System
Diabetes aggregates with other risk factors such as hypertension (high blood pressure), raised blood lipids (fats), and smoking, to cause damaging changes to both small and large blood vessels of the body.
Atherosclerosis is between 2 - 6 times more common in people with diabetes and tends to occur younger. Diabetes carries an increased risk for stroke (twice as common), heart attacks (3 - 5 times more common) and disease of the peripheral circulation (i.e. the legs). Reduced circulation in the legs and feet causes claudication (leg cramps on walking) and very reduced circulation in the feet can ultimately lead to gangrene.
The Eyes
Diabetes can lead to eye problems, and may lead to blindness, though this is largely preventable these days.
The affected person should have regular eye checks to look for changes.
Diabetics are more susceptible to cataracts, blurring of vision (when blood sugar levels are high), and Retinopathy. The latter is caused by abnormalities of the blood vessels of the retina, therefore screening of the eyes on a regular basis, (to check for new blood vessel formation) is necessary. Persistent high blood sugar levels are more likely to lead to narrowing, thickening and leaking of the blood vessels in the body. This is easily seen in the retina, and the background retinopathy may eventually lead to macular retinopathy (the part of the eye which sees 6/6 vision is affected) and also a condition called proliferative retinopathy, where new blood vessels are formed.
Reduction of blood vessel supply to the retina because of blood vessel damage, or leakage (i.e. ischaemia of the retina), and haemorrhage from the new blood vessels, can affect vision. On the other hand, new blood vessel formation can lead to haemorrhage into the back of the eyeball (vitreous haemorrhage.)
However, if these signs are noticed, the patient should be referred urgently to the Ophthalmologist, who, by obliterative laser treatment, can seal the blood vessels that are leaking and prevent new vessel formation (the entire retina is treated with scattered laser burns but the area of the macula and the optic disc are not touched). The treatment prevents the process, which results in new vessel formation in the retina and, as a consequence, this is very effective in preventing visual loss but severe visual loss may occur in some patients.
To consider H/R Mobility Severely Visually Impaired (SVI) criteria, click on the link H/R Mobility Severely Visually Impaired (SVI) deeming provisions.
The Kidneys
Over a period of time, as a result of poor circulation and elevated levels of blood sugar, the kidneys become damaged.
There are special urine tests to detect early kidney damage, and these tests look for the presence of small amounts of albumin in the urine.
Microalbuminuria - demonstrates minute amounts of protein in the urine, which occurs long before a urine testing stick (dipstix) would detect the presence of protein in the urine.
Proteinuria - the detection of the presence of protein in the urine by dipstix, may indicate that kidney disease is well established.
At the first sign of microalbuminuria, in order to delay further damage to the kidneys, drugs called ACE inhibitors are given to delay the progression of damage, and energetic measures to control blood pressure (for the same reason) are undertaken.
Kidney failure leading to the need for dialysis and renal (kidney) transplantation is a regular complication of this disease.
The Nervous System
The nerves are thought to be damaged by both high blood glucose and small vessel damage.
Separate, single nerves may be affected (especially affecting the eye muscles); this is called mononeuritis multiplex.
More commonly the longest nerves of the body are affected symmetrically, causing pain, tingling and/or a burning feeling in the feet and hands. This is worse at night. This is known as symmetrical sensory neuropathy. A “glove and stocking” loss of sensation may occur in the hands and feet but the hands often are not so affected.
Because of lack of feeling in joints such as the knee or ankle, these joints may be overused and become swollen and distorted (Charcot’s joints).
A well-known complication of sensory neuropathy is foot ulceration, which can arise from repeated minor trauma (i.e. from ill- fitting footwear), which may not be so noticeable.
Autonomic neuropathy is usually a symptom of established disease, the symptoms being mainly gastrointestinal and affecting the bladder.
Acute painful neuropathy is characterised by a painful, burning sensation of the legs particularly at night.
Amyotrophy is a reversible condition where there is painful wasting (decrease in bulk with subsequent weakness) of the quadriceps muscles of the legs.
The Skin
The skin can be affected, in that diabetics are more susceptible to infections such as boils and infections of cuts and small wounds.
Also, because of associated reduced nerve sensation and blood flow, minor trauma may go unnoticed and lead to non-healing wounds and ulcers.
Amended April 2011
