my personal edition > diabetes > news


  E-Mail this DGReview to a colleague

DGReview

Troglitazone Improves Cardiovascular Risk Factors Better Than Metformin In Type 2 Diabetes

The addition of troglitazone to treatment for type 2 diabetics not responding fully to sulfonylureas appears to improve cardiovascular disease risk factors to a greater extent than does metformin.

Classic risk factors do not account fully for the increased prevalence of cardiovascular disease among type 2 diabetics. However, a growing body of evidence suggests that insulin resistance and hyperinsulinemia act as cardiovascular disease risk factors in type 2 diabetes.

Against this background, researchers from the VA San Diego Healthcare System and University of California, San Diego, VA Medical Center, Phoenix, and Quest Diagnostics, California, compared the effect of metformin and troglitazone on cardiovascular disease risk factors in 22 subjects with type 2 diabetes. The patients showed poor glycemic control (HbA_1c >8.5 percent) despite taking glyburide 10 mg twice daily. The authors titrated from starting doses of metformin (850 mg) and troglitazone (200 mg), both once daily, until patients attained fasting plasma glucose levels of <120 mg/dl.

After four months, adding metformin and troglitazone decreased fasting plasma glucose and HbA_1c to a similar extent. On the other hand, troglitazone reduced insulin resistance, based on hyperinsulinemic-euglycemic clamp measurements, nearly twice as much as metformin.

Metformin did not significantly alter blood pressure or low density lipoprotein (LDL) size. Moreover, metformin did not influence levels of LDL cholesterol, high density lipoprotein (HDL) cholesterol, triglycerides or plasminogen activator inhibitor-1. Levels of C-reactive protein, a marker of inflammation, declined by 33 percent in patients taking metformin.

In contrast, troglitazone increased LDL size, which makes this lipoprotein less atherogenic. Moreover, troglitazone increased levels of HDL cholesterol, while reducing triglyceride concentrations. Furthermore, troglitazone reduced levels of C-reactive protein by 60 percent.

The authors concluded that in patients with type 2 diabetes who do not fully respond to maximal sulfonylurea doses, adding troglitazone improves cardiovascular disease risk factors to a greater extent than metformin. They added that troglitazone's benefits seem to reflect improved insulin resistance rather than better glycemic control.
Diabetes Care 2002;25:542-549. "Differential Effects of Metformin and Troglitazone on Cardiovascular Risk Factors in Patients With Type 2 Diabetes"

E-Mail this DGReview to a colleague

To print, use this version