To determine the underlying mechanism of pramlintide effects on postprandial (PP) glucagon concentrations, we studied thirteen C-peptide negative T1D subjects (Age 35±yrs, BMI 27.6±2.2 kg/m2, fasting plasma glucose 9.4±4 mM, HbA1c 7.1±1%) on two occasions in random order, with and without 30 μg of sc pramlintide at the onset of a mixed meal (75 gm carb, 15% fat and 35% protein; 8 kcal/kg) . Subjects administered insulin bolus at meal onset. 13C15N glucagon tracer was infused intravenously to estimate PP glucagon turnover. Arterialized venous samples were drawn periodically for measurements of glucose (YSI) , 13C15N-glucagon (LC-MS/MS) and glucagon (Mercodia) concentrations. Systemic glucagon turnover was calculated using non-steady state Steele's equation after determining glucagon volume of distribution. Integrated PP glucagon concentrations were lower (p<0.01) in pramlintide (Pram) than without pramlintide (No Pram) . Integrated rates of glucagon appearance and glucagon disappearance were lower (p<0.01) in Pram vs. No Pram. When adjusted for plasma glucagon concentrations, glucagon clearance was not different (p=0.7) between Pram vs. No Pram. These data demonstrate that pramlintide lowers postprandial glucagon concentrations by lowering glucagon secretion without altering clearance in subjects with T1D.
F.Ruchi: None. D.Romeres: None. M.Schiavon: None. S.Renuse: None. A.Pandey: None. C.Dalla man: Research Support; Becton, Dickinson and Company, Sanofi-Aventis Deutschland GmbH. C.Cobelli: None. R.Basu: Consultant; Sparrow Pharmaceuticals Inc, Research Support; Abbott Diabetes, AstraZeneca. A.Basu: Speaker's Bureau; Zealand Pharma A/S.
National Institute of Health (DK 085516, DK 029953)
