Oral arginine has no acute effect on blood glucose concentrations or glucose production in type 2 diabetic volunteers

A 49-year old male with type 2 diabetes mellitus was given 3 grams (gm) of oral arginine per hour for 10-hours, the effects on plasma glucose, insulin, C-peptide and glucose concentrations were determined. Oral arginine administration decreased plasma glucose concentrations and glucose production by approximately 40% over an 8-hr study (5%/hr). Supplemental arginine is inexpensive and may provide physicians with an additional tool in the treatment of type 2 diabetes. Six obese volunteers with type 2 diabetes were studied to document the effects of oral arginine on fasting glucose concentration and glucose production rate (GPR). Patients were admitted to the General Clinical Research Center for a 3-day stay. Oral arginine was ingested at 3-gm per hour starting at 4 am until 2 pm on day 2 or day 3 (randomized to arginine or to no-arginine supplement). Oral arginine administration was well tolerated and failed to increase C-peptide or insulin concentrations over the 10-hr period of administration. Unlike what was documented in the first diabetic patient, the prospective administration of oral arginine failed to reduce glucose concentrations (9.9 +/- 1.8 vs 10.3 +/- 1.8 mM) or GPR (14.7 +/- 1.5 vs 15.7 +/- 2.3 mumol/kg/min; arginine vs no-arginine; NS). The fall in blood glucose over the 8-hour period was not significantly increased during oral arginine administration (3.3% vs 2.6% per hour, arginine vs no-arginine, NS). These data demonstrate that 3-gm per hour of oral arginine had no effect on GPR or fasting blood glucose concentration in obese type 2 diabetic volunteers. (C) 2003 Elsevier Science Inc. All rights reserved.