Non-insulin dependent diabetes mellitus (NIDDM) is the most common form of the hyperglycaemic state. Although NIDDM exists in all populations, its prevalence varies greatly, depending upon age and race, and appears to be increasing. It is estimated that NIDOM occurs in 5% of 50-year-old-adults and 20% of the 80-year-old population with a linear progression between these age groups. Aberrant insulin secretion from pancreatic p-cells, and insulin resistance in peripheral tissues with reduced glucose uptake (particularly in muscle and liver) are the primary pathogenic mechanisms believed to be responsible for the metabolic abnormalities associated with NIDDM. Insulin resistance progresses to overt diabetes at the rate of approximately 5% of patients per year.