 Upon completion of baseline metabolic and vascular studies patients will be started on pioglitazone, 30 mg per day Visit 6. Patients will be asked to continue with their previous medical regimen and will be followed by the PInursing team at the Texas Diabetes Institute. All participants will be contacted weekly by phone to ascertain that there are no adverse events during the initiation period of 4 weeks, at which time the dose of pioglitazone will be increased to 45 mg per day. All patients will be required to return for office visits at 6 weeks intervals during the entire 6 months of the study Visits 7-10. All available records of capillary blood glucose, adverse events and other major events will be collected and added to a confidential file under the patients assigned number. Office visits every six weeks are intended to review patients interim medical history to document adverse events, to emphasize adherence to the medical regimen, to obtain blood for laboratory determinations, and record vital signs, body weight, neurologic and fundoscopic findings. Blood and urine measurements similar to those in Visit 2 also will be obtained. Metabolic and vascular studies similar to those described above Visits 3,4,5 before the initiation of pioglitazone therapy will be performed again at 3 and 6 months Visits 8 and 10 and insulin clamps with muscle biopsies will be repeated at the end of the 6 month period Visit 10. Patients will be discontinued from the study program for any of the following reasons: 1 the principal investigator decides that the subject should be withdrawn, either because of serious adverse events or clinically significant laboratory abnormalities; 2 the subject requests that heshe be withdrawn; 3 the subject becomes pregnant during the study; and 4 the subject is non-compliant with study guidelines, recommendations, and for the treatment regimen. Early termination at any time will be accompanied by collection of data as outlined in Visit 10. Any patient who is withdrawn from the study will be followed for as long as necessary to establish a stable therapeutic program. 