Mechanism by which high-dose aspirin improves glucose metabolism in type 2 diabetes

Recent studies have implicated fatty acid-dependent activation of the serine kinase IKKbeta, which plays a key role in tissue inflammation, in the pathogenesis of insulin resistance. High doses of salicylates have recently been shown to inhibit IKKbeta activity and might therefore ameliorate insulin resistance and improve glucose tolerance in patients with type 2 diabetes. To rest this hypothesis, we studied nine type 2 diabetic subjects before and after 2 weeks of treatment with aspirin (similar to7 g/d). Subjects underwent mixed-meal tolerance tests and hyperinsulinemic-euglycemic clamps with [6,6-H-2(2)]glucose to assess glucose turnover before and after treatment. High-dose aspirin treatment resulted in a similar to25% reduction in fasting plasma glucose, associated with a similar to15% reduction in total cholesterol and C-reactive protein, a similar to50% reduction in triglycerides, and a similar to30% reduction in insulin clearance, despite no change in body weight. During a mixed-meal tolerance test, the areas under the curve for plasma glucose and fatty acid levels decreased by similar to20% and similar to50%, respectively. Aspirin treatment also resulted in a similar to20% reduction in basal rates of hepatic glucose production and a similar to20% improvement in insulin-stimulated peripheral glucose uptake under matched plasma insulin concentrations during the clamp. In conclusion, these data support the hypothesis that IKKbeta represents a new target for treating type 2 diabetes mellitus.