Inconclusive NAVIGATOR and ACCORD results

Two major trials of treatment to prevent diabetes or its complications have proved inconclusive (NEJM 2010; published online 14 March).

The Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) trial included 9306 people with impaired glucose tolerance and established cardiovascular disease or cardiovascular risk factors. After five years, neither drug reduced the risk of cardiovascular events compared with placebo. Valsartan (Diovan), but not nateglinide (Starlix), reduced the risk of developing diabetes (by 14 per cent).
    However, an accompanying editorial points out that that this effect is small compared with that of lifestyle change or metformin; methodological problems render the trial inconclusive, it adds.
    The Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial showed that intensification of blood pressure-lowering (<120mmHg vs <140mmHg systolic) or lipid-lowering treatment (adding fenofibrate to simvastatin to lower triglycerides and raise HDL-cholesterol) did not reduce the risk of cardiovascular events after about five years compared with placebo. ACCORD previously showed that intensification of glycaemic control did not improve cardiovascular events in type 2 diabetes (N Engl J Med 2008;358:2545-59).