Aim To study the effect of simvastatin on adiponectin(APN)and nuclear factor-kappa B inhibitor kinase(IKK)mRNA expression in adipose tissue of insulin resistant rats.Methods Insulin resistant rat model was induced by high-fat diet feeding.Twenty-five male Wistar rats were randomly divided into two groups fed with either basic chow(n=10)or high-fat diet(n=15)for 10 weeks,then assessed by euglycemic-hyperinsulinemia clamp technique.And rats in high-fat group were randomly divided into simvastatin intervention group(n=5)and non-simvastatin intervention group(n=5).Rats in simvastatin intervention group were fed with simvastatin 10 mg/(kg·d)in gavage.After 5 weeks intervenient treatment,APN and IKK mRNA expressions were tested with RT-PCR.Results The glucose infusion rate(GIR)in high-fat group decreased significantly compared with basic chow group 0.76±0.28 mg/(kg·min)vs 4.26±0.70 mg/(kg·min),P<0.01.There were no obvious difference on APN mRNA expression of adipose tissue between simvastatin intervention group and non-simvastatin intervention group(0.25±0.12 vs 0.29±0.11,P>0.05);but they decreased significantly compared with basic chow group respectively(1.18±0.12,P<0.05).IKK mRNA expression of adipose tissue in simvastatin intervention group decreased significantly compared with non-simvastatin intervention group(0.15±0.03 vs 1.21±0.03,P<0.05),with no obvious difference from basic chow group(0.15±0.03,P>0.05).Conclusion Simvastatin could not increase APN mRNA expression in adipose tissue of insulin resistant rats induced by high-fat diet feeding.But simvastatin may restore IKK mRNA expression in adipose tissue of insulin resistant rats induced by high-fat diet feeding,which maybe benefit from the anti-inflammatory effect beyond the lipid-lowering effect.