Effect of exenatide on serum insulin level and insulin resistance in obese subjects with impaired glucose regulation

Abstract

Objective To investigate the effect of exenatide on serum insulin and plasma glucose in obese subjects with impaired glucose regulation(IGR). Methods A total of 75 obese subjects with IGR were enrolled from May 2011 to November 2012 in Quanzhou First Hospital Affiliated Fujian Medical University. A total of 62 eligible subjects were divided into the hyperinsulinemia group (HIns, fasting serum insulin ≥15 mU/L and(or)2-hour serum insulin ≥80 mU/L post glucose load, n=32) and the non-hyperinsulinemia group (NHIns, n=30) by the serum insulin level. Fasting and 2h plasma glucose in OGTT, insulin , C-peptide and body weight were measured at the baseline, D5 and D14 of exenatide treatment. Insulin resistance was evaluated by the homeostasis model assessment (HOMA-IR) and the gutt insulin sensitivity index. Paired t test was used to test within group change. One-way ANOVA was applied to compare differences of continuous variables between subgroups. Rates were compared by using the χ2 test. Results Compared with the baseline, fasting and 2 h glucose significantly improved at D5 in the two groups, but without further decrease at D14 in the two groups(t=4.42, 9.78, 4.00, 8.66 with all P 0.05). Gutt insulin sensitivity index increased at D5 in the HIns groups(t=-9.84, P<0.05)with further increase at D14(F=55.96, P<0.05). Compared with the baseline, the Gutt insulin sensitivity index significantly increased at D5 in the NHIns group(t=-4.27, P<0.05). Body weight significantly decreased in the HIns group and the NHIns group at D14(t=14.13, 12.00, all P<0.05), while showed no change at D5 in both groups. None of the subjects withdrew because of adverse event including hypoglycemia. Conclusions Exenatide short-term treatment in obese subjects with IGR can benefit glucose regulation, improve insulin resistance and control body weight. Key words: Exenatide; Obesity; Impaired glucose regulation; Hyperinsulinism