Aim:To investigate the acute and chronic effects of nateglinide versus acarboseon plasma asymmetric dimethylarginine (ADMA) levels and lipid profiles inpatients with newly-diagnosed type 2 diabetes.Methods:A crossover trial ofnateglinide and acarbose was conducted on 16 drug-nave patients with newly-diagnosed type 2 diabetes during a total period of 9 weeks.Plasma glucose,seruminsulin,free fatty acids (FFA),lipids and lipoproteins,and plasma ADMA weremeasured.Results:The efficiencies of a single dose of nateglinide (120 mg) andacarbose (50 mg) for lowering postprandial hyperglycemia were similar.Com-pared to acarbose,nateglinide significantly increased postprandial insulin releaseafter a standard meal test in patients with type 2 diabetes.Nateglinide acutelydecreased postprandial 120 min FFA concentrations and 240 min ADMA levelsmore significantly than acarbose.The fasting high-density lipoprotein choles-terol level increased and the low-density lipoprotein cholesterol level decreasedsignificantly,but the fasting levels of triglycerides,total cholesterol,and ADMAwere unchanged after 4 weeks of treatment with nateglinide.Acarbose did notaffect fasting lipid profiles or the ADMA levels after 4 weeks of treatment.Conclusion:These results suggest that the reduction of postprandial FFA andADMA concentrations induced by nateglinide may be associated with the partialrestoration of early-phase insulin secretion and may impart a cardiovascularadvantage in comparison with acarbose. Aim: To investigate the acute and chronic effects of nateglinide versus acarboseon plasma asymmetric dimethylarginine (ADMA) levels and lipid profiles in patients with newly-diagnosed type 2 diabetes. Methods: A crossover trial of nateglinide and acarbose was conducted on 16 drug-nave patients with newly established -diagnosed type 2 diabetes during a total period of 9 weeks. Plasma glucose, seruminsulin, free fatty acids (FFA), lipids and lipoproteins, and plasma ADMA weremeasured. Results: The efficiencies of a single dose of nateglinide (120 mg) and acarbose 50 mg) for lowering postprandial hyperglycemia were similar.Com-pared to acarbose, nateglinide significantly increased postprandial insulin releaseafter a standard meal test in patients with type 2 diabetes. Nateglinide acutelydecreased postprandial 120 min FFA concentrations and 240 min ADMA levelsmore significantly than acarbose. fasting high-density lipoprotein choles-terol level increased and the low-density lipoprotein cholesterol level decreaseds ignificantly, but the fasting levels of triglycerides, total cholesterol, and ADMAwere unchanged after 4 weeks of treatment with nateglinide. Acarbose did notaffect fasting lipid profiles or the ADMA levels after 4 weeks of treatment. Confc: These results suggest that the reduction of postprandial FFA and ADMA concentrations induced by nateglinide may be associated with the partial reduction of early-phase insulin secretion and may impart a cardiovascularadvantage in comparison with acarbose.