Table 1

Characteristics of the four gestational glucose tolerance groups at recruitment in pregnancy, 3 months postpartum, 1 year postpartum, and 3 years postpartum

Normal GCT NGT (n = 76)Abnormal GCT NGT (n = 96)GIGT (n = 60)GDM (n = 105)P value
At recruitment in pregnancy
 Age (years)34 (32–38)34 (32–37)34 (32–38)35 (33–38)0.71
 Ethnicity (%)0.40
  White75.075.068.365.7
  Asian6.69.411.717.1
  Other18.415.620.017.1
 Family history of T2DM (%)40.852.155.059.10.10
 Prepregnancy BMI (kg/m2)24.2 (21.5–28.4)22.8 (21.0–25.8)23.9 (22.2–29.0)25.0 (22.1–28.9)0.04
 Parity (%)0.65
  Nulliparous56.653.148.350.5
  139.537.538.341.0
  >13.99.413.38.6
 Matsuda index5.9 (4.1–7.6)5.7 (3.8–7.9)3.3 (2.6–5.0)3.1 (2.2–4.6)<0.001
 ISSI-2832 (732–993)843 (688–1,054)617 (535–760)522 (426–602)<0.001
At 3 months postpartum
 Months postpartum3 (3–4)3 (3–4)3 (3–4)3 (3–4)0.77
 BMI (kg/m2)25.6 (22.5–29.7)25.2 (22.7–28.7)26.2 (23.3–30.9)26.5 (23.2–29.8)0.46
 Waist circumference (cm)89 (82–99)86 (81–92)88 (83–94)90 (82–97)0.11
 Breastfeeding (months)3 (3–4)3 (2–3)3 (3–4)3 (2–3)0.30
 Current smoking (%)1.32.25.31.90.54
 OGTT
  Fasting glucose (mmol/L)4.4 (4.2–4.7)4.4 (4.2–4.8)4.7 (4.4–4.9)4.7 (4.4–5.0)<0.001
  2-h glucose (mmol/L)5.4 (4.7–6.1)6.1 (5.2–7.2)6.4 (5.2–7.3)6.9 (5.7–8.6)<0.001
 Matsuda index13.6 (8.7–17.4)10.5 (7.6–16.5)8.7 (6.0–13.0)8.3 (5.9–12.2)<0.001
 ISSI-2826 (670–1,086)776 (634–965)664 (539–845)637 (501–825)<0.001
At 1 year postpartum
 Months postpartum12 (11–13)12 (12–13)12 (12–13)12 (12–13)0.22
 BMI (kg/m2)24.8 (21.5–28.4)23.8 (21.8–27.9)25.4 (23.0–30.1)25.4 (22.5–29.3)0.15
 Waist circumference (cm)85 (77–92)83 (76–90)86 (80–96)87 (80–95)0.08
 Breastfeeding (months)11 (6–12)10 (6–12)9 (4–12)10 (3–12)0.36
 Current smoking (%)2.73.28.820.20
 Total physical activity8.1 (7.3–9.3)8.6 (7.3–9.3)8.3 (7.4–9.0)8.3 (7.3–9.1)0.99
  Sport index2.6 (1.8–2.8)2.3 (1.5–2.8)2.0 (1.8–2.8)2.3 (1.8–2.8)0.85
  Leisure-time index3.3 (2.8–3.5)3.0 (2.5–3.5)3.0 (2.8–3.3)3.0 (2.8–3.5)0.67
  Work index3.0 (2.6–3.3)3.1 (2.5–3.5)3.0 (2.5–3.3)3.0 (2.4–3.4)0.67
 OGTT
  Fasting glucose (mmol/L)4.6 (4.4–4.7)4.6 (4.4–4.95)4.8 (4.6–5.1)4.8 (4.5–5.1)<0.001
  2-h glucose (mmol/L)5.3 (4.6–6.0)6.0 (4.8–7.15)6.1 (5.2–7.3)6.8 (5.4–8.4)<0.001
 Matsuda index11.1 (6.4–15.5)10.0 (5.8–13.8)7.5 (4.9–12.5)7.6 (4.4–11.0)0.002
 ISSI-2832 (680–1,060)768 (603–1,013)690 (490–767)629 (487–797)<0.001
At 3 years postpartum
 Months postpartum30 (25–37)36 (29–43)39 (28–50)31 (25–37)0.002
 BMI (kg/m2)24.6 (21.8–29.1)24.0 (21.6–28.3)24.8 (23.4–30.0)25.4 (22.4–30.1)0.20
 Waist circumference (cm)85 (79–97)85 (77–92)86 (82–96)88 (80–97)0.13
 Current smoking (%)4.02.115.52.90.005
 Total physical activity8.8 (7.9–9.4)8.7 (7.9–9.3)9.0 (7.9–9.5)8.5 (8.0–9.1)0.77
  Sport index3.0 (2.8–3.5)3.0 (2.5–3.3)3.0 (2.8–3.3)3.0 (2.5–3.3)0.55
  Leisure-time index3.0 (2.5–3.5)3.0 (2.5–3.3)3.0 (2.5–3.3)3.0 (2.8–3.3)0.98
  Work index2.5 (2.2–3.0)2.8 (2.3–3.1)2.8 (2.4–3.1)2.6 (2.3–3.0)0.08
 OGTT
  Fasting glucose (mmol/L)4.6 (4.3–4.8)4.5 (4.3–4.8)4.8 (4.4–5.2)4.9 (4.5–5.2)<0.001
  2-h glucose (mmol/L)5.4 (4.7–6.4)5.9 (4.9–7.1)6.5 (5.2–7.6)6.8 (5.8–8.9)<0.001
 Matsuda index10.0 (7.3–12.8)8.2 (5.6–12.5)7.4 (4.4–10.7)6.3 (4.1–9.7)<0.001
 ISSI-2840 (716–1,087)820 (629–1,076)689 (510–937)579 (453–809)<0.001
  • Continuous data are shown as median (interquartile range) and categorical data as proportions. The P values refer to overall differences across the groups by Wilcoxon rank sum test for continuous variables and by χ2 test or Fisher exact test for categorical variables.