The term "diabetes mellitus" describes a metabolic disorder of multiple aetiology characterized by chronic hyperglycaemia with disturbances of carbohydrate, fat and protein metabolism resulting from defects in insulin secretion, insulin action, or both. The effects of diabetes mellitus include long–term damage, dysfunction and failure of various organs (WHO 1999).
There are two main types of diabetes:
Type 1 diabetes (T1B) usually develops in childhood and adolescence and patients require lifelong insulin injections for survival.
Type 2 diabetes (T2B) usually develops in adulthood and is related to obesity, lack of physical activity, and unhealthy diets. This is the more common type of diabetes (representing 90% of diabetic cases worldwide) and treatment may involve lifestyle changes and weight loss alone, or oral medications or even insulin injections.
Other categories of diabetes
Other categories of diabetes include gestational diabetes (a state of hyperglycemia which develops during pregnancy) and "other" rarer causes (genetic syndromes, acquired processes such as pancreatitis, diseases such as cystic fibrosis, exposure to certain drugs, viruses, and unknown causes).
As well, intermediate states of hyperglycemia (impaired fasting glucose or impaired glucose tolerance) have been defined. These states are significant in that they can progress to diabetes, but with weight loss and lifestyle changes, this progression can be prevented or delayed.
In the short term, hyperglycemia causes symptoms of increased thirst, increased urination, increased hunger, and weight loss. However, in the long-term, it causes damage to eyes (leading to blindness), kidneys (leading to renal failure), and nerves (leading to impotence and foot disorders/ possibly amputation). As well, it increases the risk of heart disease, stroke, and insufficiency in blood flow to legs. Studies have shown that good metabolic control prevents or delays these complications.
Thus, the primary goal of treatment is to bring the elevated blood sugars down to a normal range, both to improve symptoms of diabetes as well as to prevent or delay diabetic complications. Achieving this goal requires a comprehensive, coordinated, patient-centred approach on the part of the health care system.