No negative effect of an additional pregnancy on glucose metabolism in women with previous gestational diabetes mellitus

Objective:

Gestational diabetes mellitus (GDM) is a known risk factor for type 2 diabetes, but it remains unclear whether a pregnancy itself causes a lasting impairment of glucose metabolism in women with a predisposition for diabetes. We therefore examined the effect of an additional pregnancy on glucose metabolism in women with previous GDM.

Research Design and Methods:

Nested case-control study with 82 women after GDM from the prospective PPSDiab Study, recruited in Munich, Germany from 2011 – 16. The case group completed an additional pregnancy. Each case was matched for BMI, weight change during the observation period and duration of observation to one woman without an additional pregnancy. Two study visits were done, including a 5-point oral glucose tolerance test (ogtt), medical history, anthropometrics and laboratory chemistry analyses. Primary study endpoint was the change in the area under the glucose curve (AUGC) during the ogtt from visit 1 to visit 2. Secondary endpoints were the changes in plasma glucose at 60' of the ogtt, in the insulin sensitivity index (ISI) ratio, and in the disposition index (DI) ratio.

Results:

No significant difference was found in the primary (AUGC V2/AUGC V1 (1.05(0.92 – 1.15) vs. 0.97(0.85 – 1.14); p = 0.21) and in the secondary endpoints (Δplasma glucose 60' (11.0(-9.0 – 31.0)mg/dl vs. -6.0(-30.0 – 26.0)mg/dl; p = 0.097); DI V2/DI V1 (0.9 (0.6 – 1.1) vs. 0.9 (0.7 – 1.3); p = 0.33); ISI V2/ISI V1 (0.9(0.7 – 1.1) vs. 0.9(0.6 – 1.2); p = 0.67).

Conclusion:

We saw no negative effect of an additional pregnancy on glucose metabolism. This result is reassuring for women with previous GDM and their caregivers.