title: Insulin secretion and incretin hormone concentration in women with previous gestational diabetes mellitus.
abstract: BACKGROUND
  We examined the change in the levels of incretin hormone and effects of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) on insulin secretion in women with previous gestational diabetes (pGDM).
  
  
  METHODS
  A 75-g oral glucose tolerance test (OGTT) was conducted on 34 women with pGDM. In addition, 11 women with normal glucose tolerance, matched for age, height and weight, were also tested. The insulin, GIP, GLP-1, and glucagon concentrations were measured, and their anthropometric and biochemical markers were also measured.
  
  
  RESULTS
  Among 34 women with pGDM, 18 had normal glucose tolerance, 13 had impaired glucose tolerance (IGT) and 1 had diabetes. No significant differences were found in GLP-1 concentration between the pGDM and control group. However, a significantly high level of glucagon was present in the pGDM group at 30 minutes into the OGTT. The GIP concentration was elevated at 30 minutes and 60 minutes in the pGDM group. With the exception of the 30-minute timepoint, women with IGT had significantly high blood glucose from 0 to 120 minutes. However, there was no significant difference in insulin or GLP-1 concentration. The GIP level was significantly high from 0 to 90 minutes in patients diagnosed with IGT.
  
  
  CONCLUSIONS
  GLP-1 secretion does not differ between pGDM patients and normal women. GIP was elevated, but that does not seem to induce in increase in insulin secretion. Therefore, we conclude that other factors such as heredity and environment play important roles in the development of type 2 diabetes.
authors.affiliation: Department of Internal Medicine, Hangang Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
authors.forename: Sung Hoon
authors.initials: SH
authors.lastname: Yu
authors.forename: Bongjun
authors.initials: B
authors.lastname: Cho
authors.forename: Yejin
authors.initials: Y
authors.lastname: Lee
authors.forename: Eunhye
authors.initials: E
authors.lastname: Kim
authors.forename: Sung Hee
authors.initials: SH
authors.lastname: Choi
authors.forename: Soo
authors.initials: S
authors.lastname: Lim
authors.forename: Ka Hee
authors.initials: KH
authors.lastname: Yi
authors.forename: Young Joo
authors.initials: YJ
authors.lastname: Park
authors.forename: Kyong Soo
authors.initials: KS
authors.lastname: Park
authors.forename: Hak Chul
authors.initials: HC
authors.lastname: Jang