Long-Term Postpartum Outcomes of Insulin Resistance and <i>β</i>-cell Function in Women with Previous Gestational Diabetes Mellitus
Zhirong Miao, Honghua Wu, Liu Ren, Nan Bu, Lili Jiang, Huixia Yang, Junqing Zhang, Xiaohui Guo
Abstract
Aims . The objective of the present study was to explore the long-term postpartum glucose metabolism in women with previous GDM, and study the mechanism of hyperglycemia from gestation to postpartum by investigating the postpartum insulin resistance and insulin secretion. Methods . A total of 321 females with previous GDM were followed up once during 1- to 6-years postpartum. Characteristics during pregnancy, perinatal period, and postpartum were compared between postpartum NGT and hyperglycemic women. HOMA-IR and HOMA- β were used to assess insulin resistance and insulin secretion levels with different glucose statuses. Results . The prevalence of postpartum hyperglycemia had a fluctuant increase from 25.9% at 1 year, to 53.7% at 5 year. 75 g OGTT 2 hPG during pregnancy was an independent predictor of postpartum hyperglycemia with an OR of 2.15 (95% CI 1.245, 3.722) (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:mi>P</mml:mi><mml:mo>=</mml:mo><mml:mn>0.006</mml:mn></mml:mrow></mml:math>). After ROC analysis, the best equilibrium between sensitivity (70.3%) and specificity (60.4%) for 2 hPG was 9.03 mmol/L. HOMA-IR was increased in postpartum normal glucose tolerance (NGT), prediabetes, and T2DM (1.64 vs. 2.14 vs. 4.27, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mrow><mml:mi>P</mml:mi><mml:mo><</mml:mo><mml:mn>0.001</mml:mn></mml:mrow></mml:math>), while HOMA- β was decreased (1.19 vs. 1.11 vs. 0.71, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mrow><mml:mi>P</mml:mi><mml:mo>=</mml:mo><mml:mn>0.011</mml:mn></mml:mrow></mml:math>). In pairwise comparison, except for HOMA-IR between prediabetes and T2DM, and HOMA- β between NGT and prediabetes, other differences showed significance. Conclusions . 75 g OGTT 2h PG during pregnancy higher than 9.03 mmol/L is regarded as an independent risk factor of postpartum hyperglycemia. Insulin resistance with insufficient insulin secretion compensation is still common phenomenon during long-term postpartum. Women with heavier insulin resistance in the postpartum period are more likely develop prediabetes, while decreased β -cell function contributes more to T2DM development.