AIM: The aim of this study was to determine whether the influence of insulin therapy on fasting and stimulated C-peptide levels in type 2 diabetic subjects is due to plasma glucose reduction or a direct effect of exogenous insulin. METHODS: Plasma glucose and serum C-peptide levels were determined before and after IV injection of 1mg glucagon on three separate days in 21 type 2 diabetic subjects. Day 1: without pharmacological treatment and fasting plasma glucose > 11.1 mmol/L; day 2: fasting plasma glucose 4.4-7.8 mmol/L, 1h after withdrawing intravenous regular insulin infusion; day 3: fasting plasma glucose 4.4-7.8 mmol/L with bed-time NPH insulin. RESULTS: Fasting and glucagon stimulated C-peptide levels were higher on day 1 than days 2 and 3. Fasting, but not stimulated C-peptide levels, were lower on day 3 than day 2. These differences were not appeared when the percentage of C-peptide increment or the C-peptide/glucose ratio were compared in the three days. CONCLUSIONS: Blood glucose reduction instead of exogenous insulin is responsible for the C-peptide decrease during insulin therapy in type 2 diabetic subjects.
AIM: The aim of this study was to determine whether the influence of insulin therapy on fasting and stimulated C-peptide levels in type 2 diabetic subjects is due to plasma glucose reduction or a direct effect of exogenous insulin. METHODS: Plasma glucose and serum C-peptide levels were determined before and after IV injection of 1mg glucagon on three separate days in 21 type 2 diabetic subjects. Day 1: without pharmacological treatment and fasting plasma glucose > 11.1 mmol/L; day 2: fasting plasma glucose 4.4-7.8 mmol/L, 1h after withdrawing intravenous regular insulin infusion; day 3: fasting plasma glucose 4.4-7.8 mmol/L with bed-time NPH insulin. RESULTS: Fasting and glucagon stimulated C-peptide levels were higher on day 1 than days 2 and 3. Fasting, but not stimulated C-peptide levels, were lower on day 3 than day 2. These differences were not appeared when the percentage of C-peptide increment or the C-peptide/glucose ratio were compared in the three days. CONCLUSIONS: Blood glucose reduction instead of exogenous insulin is responsible for the C-peptide decrease during insulin therapy in type 2 diabetic subjects.
Authors: Heather F Pidcoke; Lisa A Baer; Xiaowu Wu; Steven E Wolf; James K Aden; Charles E Wade Journal: Am J Physiol Regul Integr Comp Physiol Date: 2014-04-23 Impact factor: 3.619
Authors: Suzy V Hope; Sophie Wienand-Barnett; Maggie Shepherd; Sophie M King; Charles Fox; Kamlesh Khunti; Richard A Oram; Bea A Knight; Andrew T Hattersley; Angus G Jones; Beverley M Shields Journal: Br J Gen Pract Date: 2016-04-14 Impact factor: 5.386
Authors: Angus G Jones; Timothy J McDonald; Beverley M Shields; Anita V Hill; Christopher J Hyde; Bridget A Knight; Andrew T Hattersley Journal: Diabetes Care Date: 2015-08-04 Impact factor: 19.112