DIABETES MELLITUS

What is Diabetes mellitus?

Diabetes mellitus, (often called simply diabetes), is a syndrome characterized by disordered metabolism and inappropriately high blood sugar (hyperglycaemia) resulting either from low levels of the hormone insulin or from abnormal resistance to insulin's effects coupled with inadequate levels of insulin secretion to compensate. The characteristic symptoms are excessive urine production, thirst and increased fluid intake, and blurred vision; these symptoms may be absent if the blood sugar is only mildly elevated.

There are three main forms of diabetes mellitus: diabetes type 1, diabetes type 2, and gestational diabetes (occurring during pregnancy), which have similar signs, symptoms, and consequences, but different causes and population distributions. Of the estimated 13 - 14 million people in the United States with diabetes, between 90 - 95% have noninsulin-dependent or type II diabetes. All forms are due to the beta cells of the pancreas being unable to produce sufficient insulin to prevent hyperglycaemia. Diabetes type 1 is often due to autoimmune destruction of the pancreatic beta cells, which produce insulin. Diabetes type 2 is characterized by insulin resistance in target tissues, but some impairment of beta cell function is necessary for its development. Gestational diabetes is similar to the diabetes type 2, in that it involves insulin resistance; the hormones of pregnancy can cause insulin resistance in women genetically predisposed to developing this condition.

Gestational diabetes as a rule resolves with delivery of the child, but diabetes types 1 & 2 are chronic conditions with exception of diabetes type 2 caused by obesity that may be reversed with appropriate treatment. All types have been treatable since insulin became medically available in 1921. Type 1 diabetes, in which insulin is not secreted by the pancreas, is directly treatable only with injected or inhaled insulin, although dietary and other lifestyle adjustments are part of management. Diabetes type 2 may be managed with a combination of dietary treatment, tablets and injections and often insulin supplementation.

Diabetes can cause many complications. Acute complications (hypoglycaemia, ketoacidosis or nonketotic hyperosmolar coma) may occur if the disease is not adequately controlled. Serious long-term complications include chronic renal failure, retinal damage (which can lead to blindness), cardiovascular disease (doubled risk), nerve damage (of several kinds), and micro vascular damage, which may cause impotence and poor healing. Poor healing of wounds, particularly of the feet, can lead to gangrene, which may require amputation. Adequate treatment of diabetes, as well as increased emphasis on blood pressure control and lifestyle factors (such as not smoking and keeping a healthy body weight), may improve the risk profile of most aforementioned complications. In the developed world, diabetes is the most significant cause of adult blindness in the non-elderly, the leading cause of non-traumatic amputation in adults, and diabetic nephropathy is the main illness requiring renal dialysis.

Type 1 Diabetes