Patients with insulin resistance, but no overt diabetes mellitus, are generally overweight, usually have a sedentary lifestyle, and frequently have a family history of diabetes mellitus. Insulin-resistant phenotype is commonly associated with cardiovascular risk factors such as hypertension and dyslipidemia (decreased HDL and increased VLDL, LDL and triglycerides). Current available therapies for NIDOM include insulin and oral hypoglycemic agents (e.g. sulphonylurea compounds and biguanides). Sulphonylureas achieve blood glucose control by enhancing pancreatic insulin secretion. However, a significant failure rate does exist for this mode of treatment, and many patients who have received long term treatment with sulphonylureas do require exogenous insulin therapy when there is no longer adequate pancreatic insulin secretion (even in response to sulphonylureas). Single therapy with the biguanide, metformin, or combination therapy with an additional sulphonylurea may also be administered to NIDDM patients. However, the overall effect of metformin on glycemic control seems to be smaller than that of sulphonylureas, and in many cases, combination therapy does not stop the need for insulin after a period of time.