Differences in pregnancy outcomes and characteristics between insulin- and diet-treated women with gestational diabetes.
BACKGROUND
Our aim was to evaluate the difference in pregnancy outcomes and characteristics between insulin- and diet-treated women with gestational diabetes (GDM).


METHODS
Retrospective analysis of the medical files from 2010-2013 of women with GDM diagnosed with the Carpenter & Coustan criteria attending two clinics, one in a university and another in a non-university hospital. Characteristics associated with insulin use were analyzed. Multivariable logistic regression was used to adjust for confounders. For women attending the university hospital, indices of insulin sensitivity such as the reciprocal of the homeostasis model assessment of insulin resistance (1/HOMA-IR) and an index of beta-cell function, the Insulin Secretion-Sensitivity Index-2 (ISSI-2) were calculated.


RESULTS
Over a 4 year period, 601 women were identified with GDM of whom 22.9% were obese at first prenatal visit. 24.2% needed insulin. Insulin did not prevent adverse outcomes, as women on insulin had higher rates of large-for-gestational age infants (LGA) (28.5% vs. 13.1 %, p < 0.0001) and more cesarean sections (44.1% vs. 27.0%, p = 0.001), remaining significant after adjustment for confounders. Compared to diet-treated women, women on insulin more often had an ethnic minority background (33.3 % vs. 21.6%, p = 0.004), more often had a history of GDM (21.5% vs. 10.4%, p = 0.002), were more often multiparous (59.3% vs. 47.6%, p = 0.044) and were diagnosed with GDM earlier in pregnancy (weeks 25.3 ± 4.9 vs. 27.1 ± 3.7, p < 0.0001). When undergoing an oral glucose tolerance test, women treated with insulin had a higher fasting glycaemia (97.6 ± 18.8 vs.87.7 ± 10.3, p < 0.0001), a higher 1-hour glycaemia (197.7 ± 30.1 vs.184.5 ± 25.8, p < 0.0001), a higher 2-hour glycaemia (185.2 ± 28.5 vs. 175.0 ± 22.8, p < 0.0001), more often 3 and 4 abnormal values (58.1% vs. 37.8%, p < 0.0001 and 24.8% vs. 7.7%, p < 0.0001) and higher HbA1c levels (5.5 ± 0.6 vs 5.2 ± 0.5, p < 0.0001). ISSI-2 (1.3 ± 0.5 vs. 1.7 ± 0.5, p < 0.0001) and 1/HOMA-IR [0.01 (0.001-0.002) vs. 0.02 (0.01-0.03), p = 0.027] were lower in women on insulin. Women on insulin more often received corticoids in preparation of preterm delivery (11.0% vs. 2.4%, p < 0.0001).


CONCLUSIONS
Compared to diet-treated women with GDM, women treated with insulin have a higher risk profile, impaired beta-cell function and lower insulin sensitivity. Rates of LGA and cesarean sections were higher in insulin-treated women.
Department of Endocrinology, UZ Gasthuisberg, KU Leuven, Herestraat 49, 3000, Leuven, Belgium. katrien.benhalima@uzleuven.be.
Katrien
K
Benhalima
Department of Endocrinology, UZ Gasthuisberg, KU Leuven, Herestraat 49, 3000, Leuven, Belgium. karolien.robyns@uzleuven.be.
Karolien
K
Robyns
Department of Endocrinology, OLV ziekenhuis Aalst-Asse-Ninove, Moorselbaan 164, 9300, Aalst, Belgium. Paul.Van.Crombrugge@olvz-aalst.be.
Paul
P
Van Crombrugge
Department of Endocrinology, OLV ziekenhuis Aalst-Asse-Ninove, Moorselbaan 164, 9300, Aalst, Belgium. Natascha.Deprez@olvz-aalst.be.
Natascha
N
Deprez
Department of Obstetrics and Gynecology, OLV ziekenhuis Aalst-Asse-Ninove, Moorselbaan 164, 9300, Aalst, Belgium. Bruno.Seynhave@olvz-aalst.be.
Bruno
B
Seynhave
Department of Obstetrics and Gynecology, UZ Gasthuisberg, KU Leuven, Herestraat 49, 3000, Leuven, Belgium. roland.devlieger@uzleuven.be.
Roland
R
Devlieger
Department of Obstetrics and Gynecology, UZ Gasthuisberg, KU Leuven, Herestraat 49, 3000, Leuven, Belgium. johan.verhaeghe@uzleuven.be.
Johan
J
Verhaeghe
Department of Endocrinology, UZ Gasthuisberg, KU Leuven, Herestraat 49, 3000, Leuven, Belgium. chantal.mathieu@uzleuven.be.
Chantal
C
Mathieu
Department of Endocrinology, OLV ziekenhuis Aalst-Asse-Ninove, Moorselbaan 164, 9300, Aalst, Belgium. Frank.Nobels@olvz-aalst.be.
Frank
F
Nobels
D000328:Adult; D001530:Belgium / Q000453:epidemiology; D001786:Blood Glucose / Q000378:metabolism; D002585:Cesarean Section / Q000706:statistics & numerical data*; D016640:Diabetes, Gestational / Q000097:blood / Q000178:diet therapy* / Q000188:drug therapy*; D005215:Fasting; D005260:Female; D005320:Fetal Macrosomia / Q000453:epidemiology*; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007328:Insulin / Q000627:therapeutic use*; D007333:Insulin Resistance; D050417:Insulin-Secreting Cells / Q000502:physiology; D008913:Minority Groups / Q000706:statistics & numerical data; D010298:Parity; D011247:Pregnancy; D011256:Pregnancy Outcome; D012189:Retrospective Studies
D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin; C517652:hemoglobin A1c protein, human