Glucagon-like peptide-1 levels in patients with polycystic ovary syndrome after glucose load

Abstract

Objective To explore the levels of glucagon-like peptide-1(GLP-1) after oral glucose tolerance test (OGTT) in patients with polycystic ovary syndrome (PCOS). Methods From June 2013 to August 2014, 33 cases of PCOS patients and 30 healthy women with matched age and body mass index (BMI) were enrolled in this study. The levels of glucose, insulin and GLP-1 were evaluated, the values of homeostasis model assessment for insulin resistance (HOMA-IR), glucose area under curve(AUCGLU), insulin area under curve(AUCINS), GLP-1 area under curve(AUCGLP), early phase glucose change(ΔGLU30), insulin change(ΔINS30) and GLP-1 change(ΔGLP30) were calculated by OGTT in all the subjects. Data were compared with t test between the two groups. Multiple stepwise regression analysis was used to analysize multiple factors of measurement data. Results There was no significant difference in age and BMI between the two groups(t=0.280, 1.375, both P>0.05). The fasting glucose and insulin and the levels of 1 hour after OGTT were significantly higher in PCOS group than those in control (GLU 0 h:(5.3±0.6) vs (5.0±0.5) mmol/L, 1 h: (7.8±2.0) vs (7.0±1.0) mmol/L; INS 0 h: (20±14) vs (13±6) mU/L, 1 h: (144±56) vs (114±50) mU/L;t= 2.709, 2.079, 2.457, 2.283, all P<0.05), while, the fasting GLP-1 levels of PCOS group was significantly lower than that in control ((5.0±2.4) vs (6.6±3.0) pmol/L,t=-2.309,P<0.05). There was no significant difference in GLP-1 levels after OGTT between the two groups. The values of HOMA-IR and AUCGLU, ΔGLP30 after glucose load were all significantly higher in PCOS group than those in the control(t=2.712, 2.290, 2.557, all P<0.05). The fasting GLP-1 was positively correlated with fasting glucose and insulin (r=-0.355, -0.552,P<0.05). Multiple regression analysis suggested that the fasting GLP-1 was an important influencing factor of testosterone level(β=0.191,P=0.027). Conclusion Abnormal secretion of GLP-1 occurrs in PCOS patients, maily lower in fasting GLP-1, which is associated with insulin resistance, glucose metabolism disorder and testosterone level. Key words: Polycystic ovary syndrome; Glucagon-like peptide-1; Oral glucose tolerance test