Comparison of glucose metabolism and anthropometry in women with previous gestational diabetes treated with metformin vs. insulin: 9-year follow-up of two randomized trials

Postnatal Cardiometabolic Health After Metformin Use in Gestational Diabetes: A Secondary Analysis of the EMERGE Trial

AIM

Women with gestational diabetes mellitus (GDM) display adverse lifetime cardiometabolic health. We examined whether early metformin in GDM could impact cardiometabolic risk factors postpartum.

METHODS

EMERGE, a double-blind, placebo-controlled trial, randomized pregnancies 1:1 to placebo or metformin at GDM diagnosis and followed participants from randomization until 12 ± 4 weeks postpartum. In total, 478 pregnancies were available for postpartum maternal assessment, 237 and 241 assigned to metformin and placebo respectively. Weight (kg), body mass index (BMI) (kg/m2), waist circumference (cm), and blood pressure (mmHg) were measured, infant feeding method documented, and blood specimens drawn for a 75-gram oral glucose tolerance test, fasting insulin, C-peptide, and lipid analysis.

RESULTS

Despite similar weight and BMI at trial randomization, participants receiving metformin had significantly lower weight (79.5 ± 15.9 vs 82.6 ± 16.9 kg; P = .04) and BMI (29.3 [5.6] vs 30.5 [5.4]; P = .018) at the postpartum visit. However, no difference in weight change from randomization to 12 weeks postpartum was observed between metformin and placebo groups. Overall, 29% (n = 139) of the cohort met criteria for prediabetes or diabetes, with no positive impact with metformin. There were also no differences in measurements of insulin resistance, blood pressure, or lipids between groups.

CONCLUSION

Early metformin use in GDM did not impact important cardiometabolic parameters in the early postpartum period despite significant benefits in weight gain and insulin use in pregnancy.

Treatment of Diabetes in Pregnancy With Metformin

Metformin is a commonly used drug in the treatment of type 2 diabetes and has been used to treat gestational diabetes since the 1970s. In pregnancy, its proven benefits include reduced gestational weight gain and reduced fetal size; some studies have shown reduced risk of cesarean delivery and lower rates of hypertension. Metformin can reduce the need for insulin therapy but does not eliminate such need in many patients. Despite these benefits, metformin crosses the placenta and has been associated with increases in the risk of giving birth to small-for-gestational-age neonates in some studies of individuals with type 2 diabetes in pregnancy. In addition, higher body mass index (BMI) z-scores have been observed among exposed offspring in some of the long-term follow-up studies. Nevertheless, metformin's low cost, ease of administration, and global reach make it a reasonable intervention in a population affected by rising rates of obesity and diabetes in pregnancy. Further follow-up studies are required to monitor the long-term health of exposed offspring.

Long-Term Impact on Offspring (5 to 11 Years of Age) of Metformin Use in Pregnancy in Mothers With Diabetes: A Systematic Review and Meta-Analysis

OBJECTIVE

Data are scant on the impact of metformin use in gestational diabetes mellitus/diabetes in pregnancy on long-term outcomes in children and mothers beyond 5 years of childbirth. This systematic review and meta-analysis aimed to evaluate the long-term impact of metformin use in pregnancy on children and their mothers.

METHODS

Electronic databases were searched for studies evaluating metformin compared with insulin for managing gestational diabetes mellitus/diabetes in pregnancy. The primary outcome was the change in body mass index (BMI) in children at the ages of 5 to 11 years. The secondary outcomes were alterations in other anthropometric measures, obesity, and changes in the levels of lipids and adipocytokines in children and mothers.

RESULTS

Children at the age of 9 years born to mothers who were treated with metformin during pregnancy had similar BMI (mean difference [MD], 1.09 kg/m2 [95% confidence interval {CI}, -0.44 to 2.62]; P = .16; I2 = 16%), waist circumference-to-height ratio (MD, 0.13 [95% CI, -0.05 to 0.30]; P = .16; I2 = 94%), dual-energy X-ray absorptiometry (DXA) total fat mass (MD, 0.68 kg [95% CI, -2.39 to 3.79]; P = .66; I2 = 70%), DXA total fat percent (MD, 0.04% [95% CI, -3.44 to 3.51]; P = .98; I2 = 56%), DXA total fat-free mass (MD, 0.81 kg [95% CI, -0.96 to 2.58]; P = .37; I2 = 55%), magnetic resonance imaging visceral adipose tissue volume (MD, 80.97 cm3 [95% CI, -136.47 to 298.41]; P = .47; I2 = 78%), and magnetic resonance spectroscopy liver fat percentage (MD, 0.27% [95% CI, -1.26 to 1.79]; P = .73; I2 = 0%) to those born to mothers who were treated with insulin. Serum adiponectin, leptin, alanine aminotransferase, and ferritin were comparable among groups. In children between the ages of 9 and 11 years, the occurrence of obesity, diabetes, or challenges in motor and social development were comparable between the 2 groups. After 9 years of childbirth, BMI and the risk of developing diabetes were similar between the 2 groups of women.

CONCLUSION

Metformin use in pregnancy did not show any adverse effects compared with insulin on long-term outcomes in children and their mothers.

Association of Polyphenols Consumption with Risk for Gestational Diabetes Mellitus and Preeclampsia: A Systematic Review and Meta-Analysis

Gestational Diabetes Mellitus (GDM) and preeclampsia (PE) affects 6-25% of pregnancies and are characterized by an imbalance in natural prooxidant/antioxidant mechanisms. Due to their antioxidant and anti-inflammatory properties, polyphenols consumption during the pregnancy might exert positive effects by preventing GDM and PE development. However, this association remains inconclusive. This systematic review and metanalysis is aimed to analyze the association between polyphenol-rich food consumption during pregnancy and the risk of GDM and PE. A systematic search in MEDLINE, EMBASE, and Web of Science (Clarivate Analytics, London, United Kingdom) for articles dated between 1 January 1980 and July 2022 was undertaken to identify randomized controlled trials and observational studies evaluating polyphenol-rich food consumption and the risk of GDM and PE. The Newcastle-Ottawa Scale was used to evaluate the quality of these included studies. Twelve studies were included, of which eight articles evaluated GDM and four studied PE. A total of 3785 women presented with GDM (2.33%). No association between polyphenol consumption and GDM was found (ES = 0.85, 95% CI 0.71-1.01). When total polyphenol intake was considered, a lower likelihood to develop GDM was noted (ES = 0.78, 95% CI 0.69-0.89). Furthermore, polyphenol consumption was not associated with PE development (ES = 0.90, 95% CI 0.57-1.41). In conclusion, for both outcomes, pooled analyses showed no association with polyphenol-rich food consumption during pregnancy. Therefore, association of polyphenol intake with a decreased risk of GDM and PE remains inconclusive.