type 1 diabetes mellitus

(T1DM) one of the two major types of diabetes mellitus: an autoimmune disease that results in the destruction beta cells of the pancreas, leading to loss of the ability to secrete insulin. It is characterized by abrupt onset of symptoms, insulinopenia, and dependence on exogenous insulin to sustain life; peak age of onset is 12 years, although onset can be at any age. It is probably caused by a combination of factors, including viral infection and genetic and autoimmune factors; islet cell antibodies are usually detectable at diagnosis. When it is inadequately controlled, lack of insulin causes hyperglycemia, protein wasting, and production of ketone bodies owing to increased fat metabolism, and the hyperglycemia leads to overflow glycosuria, osmotic diuresis, hyperosmolarity, dehydration, and diabetic ketoacidosis. It is accompanied by angiopathy of blood vessels, particularly the small ones (microangiopathy), which affects the retinas, kidneys, and basement membrane of arterioles throughout the body. Other symptoms include polyuria, polydipsia, polyphagia, weight loss, paresthesias, blurred vision, and irritability; if untreated, diabetic ketoacidosis progresses to nausea and vomiting, stupor, and potentially fatal hyperosmolar coma (diabetic coma). Called also insulin-dependent, juvenile, juvenile-onset, and Type I d. mellitus.

Fluorescein-labeled anti-islet autoantibodies in islet cells, characteristic of type 1 diabetes mellitus.