title: Beta-cell function declines within the first year postpartum in women with recent glucose intolerance in pregnancy.
abstract: OBJECTIVE
  Both gestational diabetes mellitus (GDM) and mild glucose intolerance in pregnancy identify women at increased risk of future type 2 diabetes. In this context, we queried whether metabolic changes that occur in the 1st year postpartum vary in relation to gestational glucose tolerance status.
  
  
  METHODS
  Three-hundred-and-ninety-two women underwent glucose challenge test (GCT) and oral glucose tolerance test (OGTT) in pregnancy followed by repeat OGTT at both 3 months' postpartum and 12 months' postpartum. The antepartum testing defined four gestational glucose tolerance groups: GDM (n = 107); gestational impaired glucose tolerance (GIGT) (n = 75); abnormal GCT with normal glucose tolerance (NGT) on OGTT (abnormal GCT NGT) (n = 137); and normal GCT with NGT on OGTT (normal GCT NGT) (n = 73).
  
  
  RESULTS
  The prevalence of dysglycemia progressively increased across the groups from normal GCT NGT to abnormal GCT NGT to GIGT to GDM at both 3 months' postpartum (2.7% to 10.2% to 18.7% to 34.6%, P < 0.0001) and 12 months' postpartum (2.7% to 11.7% to 17.3% to 32.7%, P < 0.0001). Between 3 and 12 months' postpartum, the groups did not differ with respect to changes in waist circumference, weight, or insulin sensitivity. Importantly, however, they exhibited markedly different changes in beta-cell function (Insulin Secretion-Sensitivity Index-2 [ISSI-2]) (P = 0.0036), with ISSI-2 declining in both the GDM and GIGT groups. Furthermore, on multiple linear regression analysis, both GDM (t = -3.06, P = 0.0024) and GIGT (t = -2.18, P = 0.03) emerged as independent negative predictors of the change in ISSI-2 between 3 and 12 months' postpartum.
  
  
  CONCLUSIONS
  Women with GDM and GIGT exhibit declining beta-cell function in the 1st year postpartum that likely contributes to their future diabetic risk.
authors.affiliation: Leadership Sinai Centre for Diabetes, Mount Sinai Hospital, Toronto, Canada. rretnakaran@mtsinai.on.ca
authors.forename: Ravi
authors.initials: R
authors.lastname: Retnakaran
authors.forename: Ying
authors.initials: Y
authors.lastname: Qi
authors.forename: Mathew
authors.initials: M
authors.lastname: Sermer
authors.forename: Philip W
authors.initials: PW
authors.lastname: Connelly
authors.forename: Anthony J G
authors.initials: AJ
authors.lastname: Hanley
authors.forename: Bernard
authors.initials: B
authors.lastname: Zinman
mesh_terms: D000328:Adult; D016640:Diabetes, Gestational / Q000503:physiopathology*; D005260:Female; D018149:Glucose Intolerance / Q000503:physiopathology*; D005951:Glucose Tolerance Test; D006801:Humans; D050417:Insulin-Secreting Cells / Q000473:pathology / Q000502:physiology*; D016014:Linear Models; D008875:Middle Aged; D049590:Postpartum Period; D011247:Pregnancy