A disorder caused by insufficient or absent production of the hormone insulin by the pancreas, or because the tissues are resistant to the effects. Insulin is responsible for the absorption of glucose into cells. Lack of insulin causes high blood levels of glucose, resulting in the passage of large quantities of urine and excessive thirst. Other symptoms are weight loss, hunger, and fatigue. Urinary tract infections may also occur. Lipid (fat) metabolism is affected and small blood vessels degenerate. Undiagnosed diabetes can lead to blurred vision, boils, and tingling or numbness of the hands and feet. There are 2 main types of diabetes mellitus, both of which tend to run in families. Type 1 (insulin-dependent) diabetes is the less common form of the disorder and usually develops in childhood or adolescence. In this type of diabetes, insulin-secreting cells in the pancreas are destroyed, and insulin production ceases. Type 2 (noninsulindependent) diabetes generally develops gradually, mainly in people over the age of 40. Although insulin is still produced, there is not enough for the body’s needs as the tissues become relatively resistant to its effects. Symptoms may be present in only a 3rd of people with this type of diabetes; it is often diagnosed only when complications occur. Treatment aims to keep blood glucose as normal as possible. It involves achieving and maintaining a normal weight, regular physical activity, dietary management, and, if necessary, treatments with antidiabetic drugs. People with type 1 diabetes require regular insulin injections. Carbohydrate intake is spread out over the day, intake of fats should be kept low, and selfmonitoring of blood glucose levels is important. If the glucose/insulin balance is not maintained, hyperglycaemia or hypoglycaemia may develop. Treatment of type 2 diabetes usually consists of dietary measures, weight reduction, and antidiabetic drugs, often hypoglycaemic drugs such as sulphonylureas. Some people eventually need insulin injections. Complications of diabetes mellitus include retinopathy, peripheral neuropathy, and nephropathy. Ulcers on the feet are another risk. People with diabetes mellitus also have a greater risk of atherosclerosis, hypertension, other cardiovascular disorders, and cataracts. With modern treatment and sensible self-monitoring, nearly all diabetics can look forward to a normal lifespan.
Diabetes mellitus |
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