Changes of postpartum sensibility of insulin and function of islet β cell with abnormal screening glucose challenge test results only in pregnancy

Abstract

Objective To investigate the characteristics of insulin sensitivity and function of islet β cell with abnormal glucose challenge test (GCT) results only in pregnancy during pregnancy and postpartum 6 to 12 weeks of age. Methods The 120 women with abnormal GCT and normal OGTT were collected as the study group and the rest 80 women with normal GCT as the control group. Homeostasis model insulin resistance index (HOMA-IR) and ISOGTT were applied to assess the status of insulin sensibility, Homeostasis β cell function index (HBCI) and 30 min net increment of insulin/30 min net increment of glucose(ΔI30/ΔG30) were used to evaluate the basic function of islet β cells. Compare relevant indicators of 24 to 28 weeks during pregnancy and 6 to 12 weeks postpartum . Date analysis were performed using SPSS 11.5. Results (1)24 to 28 weeks during pregnancy, no significant difference was found area under the glucose curve (AUCG), glycosylated hemoglobin (HbA1c) and ΔI30/ΔG30; compared to the normal GCT group, the abnormal GCT group exhibited higher fasting insulin (FIns), HOMA-IR (14±6 vs 13±4, t=12.814; 2.8±1.3 vs 2.5±0.9, t=11.7, all P<0.01); lower ISOGTT(0.8±0.6 vs 1.1±1.0, t=4.837, P<0.05) and Homeostasis β-cell function index (HBCI) (369±301 vs 567±486, t=5.321, P<0.05); (2)The birth weight of the study group was significantly higher than that of the control group ((3.4±0.2) vs (3.2±0.1) kg, P<0.01); (3)At 6 to 12 weeks postpartum, however, compared to the normal GCT group, the abnormal GCT group exhibited higher AUCG(30.7±2.6 vs 27.7±1.2, P<0.01), HbA1c ((5.6±0.3)% vs(5.3±0.2)%, P<0.01), FIns (12±5 vs 11±3, P<0.05) and HOMA-IR(2.5±0.9 vs 2.2±0.6, P<0.01); lower ISOGTT(1.0±0.6 vs 1.5±1.0, P<0.01) and HBCI (179±95 vs 307±165, P<0.01); (4)At 6 to 12 weeks postpartum, 9.1% of abnormal GCT group were abnormal glucose metabolism. 1.2% of control group were abnormal glucose metabolism. Both group showed significant difference(P<0.05). Conclusions The abnormal GCT is associated with pregnancy and postpartum glycemia, insulin resistance, and islet β cell dysfunction. Factors that may portend an increased future risk of abnormal glucose metabolism in this patient population. Key words: Blood glucose; Glucose challenge test; Insulin sensibility; β cell function; Pregnancy