Type 1 Diabetes Mellitus
Type 1 diabetes has been subdivided into:
Immune-mediated diabetes (Type 1A). This form of diabetes results from a cellular-mediated
autoimmune destruction of the beta cells of the pancreas. Markers of the immune destruction of the
beta cell include islet cell autoantibodies and other antibodies. One and usually more of these
autoantibodies are present in 85 - 90% of individuals when fasting hyperglycemia is initially detected.
Also, the disease has strong HLA associations.
Idiopathic diabetes (Type 1B). Some forms of Type 1 diabetes have no known etiologies. Some
of these patients have permanent insulin deficiency and are prone to ketoacidosis but have no
evidence of autoimmunity. Although only a minority of patients with Type 1 diabetes fall into this
category, of those who do, most are of African, Hispanic, or Asian origin. Individuals with this form
of diabetes suffer from episodic ketoacidosis and exhibit varying degrees of insulin deficiency
between episodes. This form of diabetes is strongly inherited, lacks immunological evidence for beta
cell autoimmunity, and is not HLA associated. An absolute requirement for insulin replacement
therapy in affected patients may come and go.
Type 1 diabetes used to be known as insulin-dependent diabetes mellitus, juvenile diabetes,
juvenile-onset diabetes, and ketosis-prone diabetes.
IN CONTRAST
Type 2 Diabetes Mellitus
The most common form of diabetes mellitus; over 90 percent of people who have diabetes have Type 2
diabetes. The onset is usually in middle age and in most cases is thought to be due to some form of
insensitivity to the action of insulin rather than to insulin deficiency. Many of the people who have this
type of diabetes are overweight. Initial treatment is by weight reduction and excercise with the later
addition of an increasing range of blood glucose lowering drugs. Ultimately it may be neccessary to give
insulin. Increasingly, geneticists are defining specific subgroups such as Maturity Onset Diabetes in the
Young; but to date, this has not led to any change in treatment plans.
Type 2 diabetes used to be called noninsulin-dependent diabetes mellitus, adult-onset diabetes,
maturity-onset diabetes, ketosis-resistant diabetes, and stable diabetes.
