Diabetes

Diabetes mellitus is one of the most common chronic diseases, affecting over 6% of the adult population in Western society, and with a prevalence that is rising dramatically worldwide. However, diabetes mellitus is not a single disease, but rather a number of distinct disorders. They share, in common, deficient action of the hormone insulin. This can be due to an absolute deficiency of insulin production and secretion by the β-cells of the pancreatic Islets of Langerhans. However, in many types of diabetes mellitus there is an impaired cellular response to insulin; this insulin resistance imposes a requirement for increased insulin levels to maintain metabolic control. In this case, diabetes occurs when there is insufficient insulin to meet this increased demand. The most common forms of diabetes are due to both environmental and genetic factors, but some forms of diabetes are caused by genetic defects in proteins involved in insulin secretion or insulin action. Deficiency of insulin, whether absolute or relative, leads to a failure to control carbohydrate and lipid metabolism. Inadequately controlled diabetes leads to acute complications, such as ketoacidosis, and chronic complications, such as retinopathy and cardiovascular disease. Multiple modes of treatment are used to reduce the risk of complications.