Non-Insulin-Dependent Diabetes Mellitus
Etiology:
     NIDDM is not an autoimmune disorder; however, there is a strong genetic correlation to the susceptibility of NIDDM. Twin studies and family penetrance strongly support a genetic basis. There are several genes associated with NIDDM affecting insulin secretion and action as well as the regulation of body weight, however type 2 diabetes remains a geneticist’s nightmare. The links between obesity and NIDDM are complex – 60-80% of those with NIDDM are obese yet diabetes develops in fewer than 15% of obese individuals.

Pathophysiology of NIDDM:
     Unlike patients with IDDM, those with NIDDM have detectable levels of circulating insulin. The two main disorders associated with NIDDM are:
1) A decreased ability of insulin to act on peripheral tissues. Usually called insulin resistance. To learn more about insulin resistance click here:  http://my.webmd.com/content/article/56/65905.htm
2) Dysfunction of pancreatic beta cells, represented by the inability to produce sufficient amount of insulin to overcome insulin resistance.

    The common result of these two disorders is the relative deficiency of insulin. Data has found the primary reason for this to be the insulin resistance. Insulin resistance usually precedes the clinical signs by as many as 20 years.