Gestational Diabetes Mellitus and Energy-Dense Diet: What Is the Role of the Insulin/IGF Axis?

Placental IGFBP1 levels during early pregnancy and the risk of insulin resistance and gestational diabetes

Reduced insulin sensitivity (insulin resistance) is a hallmark of normal physiology in late pregnancy and also underlies gestational diabetes mellitus (GDM). We conducted transcriptomic profiling of 434 human placentas and identified a positive association between insulin-like growth factor binding protein 1 gene (IGFBP1) expression in the placenta and insulin sensitivity at ~26 weeks gestation. Circulating IGFBP1 protein levels rose over the course of pregnancy and declined postpartum, which, together with high gene expression levels in our placenta samples, suggests a placental or decidual source. Higher circulating IGFBP1 levels were associated with greater insulin sensitivity (lesser insulin resistance) at ~26 weeks gestation in the same cohort and in two additional pregnancy cohorts. In addition, low circulating IGFBP1 levels in early pregnancy predicted subsequent GDM diagnosis in two cohorts of pregnant women. These results implicate IGFBP1 in the glycemic physiology of pregnancy and suggest a role for placental IGFBP1 deficiency in GDM pathogenesis.

Association between maternal and fetal inflammatory biomarkers and offspring weight and BMI during the first year of life in pregnancies with GDM: MySweetheart study

Background

Gestational Diabetes Mellitus (GDM) is frequently associated with chronic, low-grade inflammation. Whether this environment affects offspring anthropometry during early childhood remains to be elucidated. The aim of this study was to investigate the associations between maternal and fetal (cord blood-umbilical artery) inflammatory biomarkers and offspring weight and BMI up to 1 year in pregnancies with GDM.

Methods

In this prospective secondary analysis of the MySweetheart study, we included 193 women with GDM and their offspring. Maternal and fetal (N=39) predictors included serum levels of inflammatory biomarkers including CRP, IL-6, and TNF-α at 24-32 weeks of gestational age (GA) and in the cord blood. Offspring outcomes were small and large for gestational age (SGA, LGA), sex- and age-adjusted weight, and BMI at birth and at 1 year. Univariate and multivariate regression models were performed. Associations were adjusted for maternal pre-pregnancy BMI, age, and ethnicity.

Results

Mean maternal age was 33.6 ± 4.8 years, and pre-pregnancy BMI 25.9 ± 5.6 kg/m2. Their mean gestational age at the 1st GDM visit was 29 ± 2.4 weeks. Gestational age at delivery was 39.7 ± 1.1 weeks, with a mean birthweight of 3.4 ± 0.46 kg; 11.8% of offspring were LGA and 10.8% were SGA. At 1 year of age, mean offspring weight was 9.8 ± 1.2 kg and BMI z-score 0.23 ± 1.1 kg/m2. In the models including only maternal predictors, TNF-α at 24-32 weeks of GA was positively associated with SGA and inversely with offspring weight and BMI at birth and at 1 year (p ≤0.034). In the models including only fetal predictors and the combined model, CRP was inversely associated with BMI at 1 year (p ≤0.020).

Conclusions

In women with GDM, maternal and fetal inflammatory biomarkers distinctively influenced offspring anthropometry during the first year of life, independent of maternal age, prepregnancy BMI and ethnicity. These results suggest that low-grade inflammation during pregnancy may affect the developing offspring by leading to a decrease in weight and BMI and may have implications for future personalized follow-up of women with GDM and their offspring.

Gestational Diabetes Mellitus: What Can Medical Nutrition Therapy Do?

Gestational diabetes mellitus (GDM) is one of the common complications during pregnancy. Numerous studies have shown that GDM is associated with a series of adverse effects on both mothers and offspring. Due to the particularity of pregnancy, medical nutrition treatment is considered to be the first choice for the treatment of GDM. This contribution reviews the research progress of medical nutrition treatment in GDM, summarizes the international recommendations on the intake of various nutrients and the influence of nutrients on the prevalence of GDM, and the improvement effect of nutritional intervention on it, in order to provide references for research in related fields of GDM and the targeted development of enteral nutrition.

Knockdown of TXNIP alleviates gestational diabetes mellitus by activating autophagy to regulate cell proliferation and apoptosis in high glucose-treated trophoblasts

Dysregulated thioredoxin-interacting protein (TXNIP) has been observed in women with gestational diabetes mellitus (GDM), but the specific role of TXNIP in GDM and the underlying mechanism remain unclear. HTR-8/SVneo cells were treated with high glucose to mimic the injured trophoblasts of GDM. In vitro, TXNIP knockdown was performed by siRNA. RTqPCR was performed to determine the expression of the corresponding genes. Cell proliferation and apoptosis were measured using CCK-8, EdU and Annexin V/PI assays. The autophagosome number was assessed using transmission electron microscopy. The expression of the autophagy substrate sequestosome 1 (P62) was evaluated by immunofluorescence. Autophagy-related proteins, including P62, light chain 3 (LC3)-I, and LC3-II, were analysed by Western blotting. HTR-8/Svneo cells treated with high glucose demonstrated reduced proliferation, increased apoptosis, decreased autophagosome formation and overall decreased autophagy. However, knockdown of TXNIP reversed the effects of HG on HTR-8/Svneo cells. However, the effect of TXNIP knockdown on HG-treated HTR-8/Svneo cells was inhibited by 3-methyladenine (3-MA) (widely used as an inhibitor of autophagy). We concluded that knockdown of TXNIP has the potential to enhance the activity of high glucose-treated human trophoblasts through autophagic activation, thereby improving pregnancy outcomes in patients with GDM.

The efficacy of magnesium supplementation for gestational diabetes: A meta-analysis of randomized controlled trials

BACKGROUND

The efficacy of magnesium supplementation is unclear for the treatment of gestational diabetes. This meta-analysis aimed to study the efficacy of magnesium supplementation for glycemic control and pregnant outcomes in women with gestational diabetes.

METHODS

Several databases including PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases have been systematically searched up to July 2023, and we included randomized controlled trials (RCTs) assessing the efficacy of magnesium supplementation for gestational diabetes. The meta-analysis was performed using the random-effect model or fixed-effect model based on the heterogeneity.

RESULTS

Five RCTs and 266 patients were included in the meta-analysis. Overall, compared with control intervention for gestational diabetes, magnesium supplementation was able to significantly decrease FPG (MD = -7.33 mg/dL; 95 % CI = -7.64 to -7.02 mg/dL; P < 0.00001) and HOMA-IR (MD = -0.99; 95 % CI = -1.76 to -0.22; P = 0.01), but resulted in no obvious impact on serum insulin (MD = -4.17 μIU/mL; 95 % CI = -8.49 to 0.14 μIU/mL; P = 0.06), preterm delivery (OR = 0.42; 95 % CI = 0.06 to 2.95; P = 0.38), macrosomia (OR = 0.34; 95 % CI = 0.08 to 1.35; P = 0.13) or BMI change (MD = -0.01 kg/m2; 95 % CI = -0.06 to 0.04 kg/m2; P = 0.63).

CONCLUSIONS

Magnesium supplementation may be effective for the treatment of gestational diabetes without taking insulin treatment.

Effects of prepregnancy dietary patterns on infant birth weight: a prospective cohort study

BACKGROUND

Maternal nutrition can have a profound effect on fetal growth, development, and subsequent infant birth weight. However, little is known regarding the influence of prepregnancy dietary patterns.

OBJECTIVES

This study aimed to explore the effects between prepregnancy dietary patterns on birth weight.

METHODS

This study included 911 singleton live-born infants from the Taicang and Wuqiang Mother-Child Cohort Study (TAWS). Baseline information and prepregnancy diet data were collected during early pregnancy. Newborn birth information was obtained from the Wuqiang County Hospital. Macrosomia, defined as a birth weight of ≥4000 g, and large for gestational age (LGA), defined as a birth weight higher than the 90th percentile for the same sex and gestational age, were the outcomes of interest. The dietary patterns were extracted using principal component analysis. Logistic regression models were used to investigate the association between prepregnancy dietary patterns (in tertiles) and macrosomia and LGA, and subgroup analysis was further explored by pre-pregnancy body mass index (BMI).

RESULTS

Four dietary patterns were identified based on 15 food groups. These patterns were named as "cereals-vegetables-fruits," "vegetables-poultry-aquatic products," "milk-meat-eggs," and "nuts-aquatic products-snacks." After adjusting for sociodemographic characteristics, pregnancy complications, and other dietary patterns, greater adherence to the "cereals-vegetables-fruits" pattern before pregnancy was associated with a higher risk of macrosomia (adjusted OR = 2.220, 95% CI: 1.018, 4.843), while greater adherence to the "nuts-aquatic products-snacks" pattern was associated with a lower risk of macrosomia (adjusted OR = 0.357, 95% CI: 0.175, 0.725) compared to the lowest tertile. No significant association was observed between prepregnancy dietary patterns and LGA. However, after subgroup analysis of pre-pregnancy BMI, "cereals-vegetables-fruits" pattern was associated with an increased risk of LGA in overweight and obese mothers (adjusted OR = 2.353, 95% CI: 1.010, 5.480).

CONCLUSIONS

An unbalanced pre-pregnancy diet increases the risk of macrosomia and LGA, especially in overweight or obese women before pre-pregnancy.

Placental RNA sequencing implicates IGFBP1 in insulin sensitivity during pregnancy and in gestational diabetes

Reduced insulin sensitivity (or greater insulin resistance) is a hallmark of normal physiology in late pregnancy and also underlies gestational diabetes mellitus (GDM) pathophysiology. We conducted transcriptomic profiling of 434 human placentas and identified a strong positive association between insulin-like growth factor binding protein 1 gene (IGFBP1) expression in the placenta and insulin sensitivity at ~ 26 weeks' gestation. Circulating IGFBP1 protein levels rose over the course of pregnancy and declined postpartum, which together with high placental gene expression levels, suggests a placental source. Higher circulating IGFBP1 levels were strongly associated with greater insulin sensitivity (lesser insulin resistance) at ~ 26 weeks' gestation in the same cohort and two additional pregnancy cohorts. In addition, low circulating IGFBP1 levels in early pregnancy predicted subsequent GDM diagnosis in two cohorts. These results implicate IGFBP1 in the glycemic physiology of pregnancy and suggest a role for placental IGFBP1 deficiency in GDM pathogenesis.

Association between maternal epicardial adipose tissue, gestational diabetes mellitus, and pregnancy-related hypertensive disorders: a systematic review and meta-analysis

Several small studies have evaluated the association between epicardial adipose tissue (EAT) and pregnancy-related cardiovascular risk factors such as gestational diabetes mellitus (GDM) or hypertensive disorders. The objective of this study was to quantitatively compare EAT thickening between patients with GDM or pregnancy-related hypertensive disorders and healthy controls. This systematic review and meta-analysis were performed according to PRISMA guidelines. A literature search was performed to detect studies that have quantified EAT in women with GDM and pregnancy-related hypertensive disorders compared to a control group. The primary outcome was EAT thickening estimated by ultrasound expressed in millimeters. Random or fixed effects models were used. Nine observational studies including 3146 patients were identified and considered eligible for this systematic review. The quantitative analysis showed that patients with GDM have a higher EAT thickness (mean difference: 1.1 mm [95% confidence interval: 1.0-1.2]; I2 = 24%) compared to the control group. Moreover, patients with pregnancy-related hypertensive disorders showed higher EAT thickness (mean difference: 1.0 mm [95% confidence interval: 0.6-1.4]; I2 = 83%) compared to the control group. In conclusion, this study demonstrated that EAT thickening is increased in patients with GDM and pregnancy-related hypertensive disorders compared with healthy controls. Whether or not this association is causal should be evaluated in prospective studies.

The Placenta: A Maternofetal Interface

The placenta is the gatekeeper between the mother and the fetus. Over the first trimester of pregnancy, the fetus is nourished by uterine gland secretions in a process known as histiotrophic nutrition. During the second trimester of pregnancy, placentation has evolved to the point at which nutrients are delivered to the placenta via maternal blood (hemotrophic nutrition). Over gestation, the placenta must adapt to these variable nutrient supplies, to alterations in maternal physiology and blood flow, and to dynamic changes in fetal growth rates. Numerous questions remain about the mechanisms used to transport nutrients to the fetus and the maternal and fetal determinants of this process. Growing data highlight the ability of the placenta to regulate this process. As new technologies and omics approaches are utilized to study this maternofetal interface, greater insight into this unique organ and its impact on fetal development and long-term health has been obtained.

Highlighting the trajectory from intrauterine growth restriction to future obesity

During the last decades several lines of evidence reported the association of an adverse intrauterine environment, leading to intrauterine restriction, with future disease, such as obesity and metabolic syndrome, both leading to increased cardiovascular and cancer risk. The underlying explanation for this association has firstly been expressed by the Barker's hypothesis, the "thrifty phenotype hypothesis". According to this hypothesis, a fetus facing an adverse intrauterine environment adapts to this environment through a reprogramming of its endocrine-metabolic status, during the crucial window of developmental plasticity to save energy for survival, providing less energy and nutrients to the organs that are not essential for survival. This theory evolved to the concept of the developmental origin of health and disease (DOHaD). Thus, in the setting of an adverse, f. ex. protein restricted intrauterine environment, while the energy is mainly directed to the brain, the peripheral organs, f.ex. the muscles and the liver undergo an adaptation that is expressed through insulin resistance. The adaptation at the hepatic level predisposes to future dyslipidemia, the modifications at the vascular level to endothelial damage and future hypertension and, overall, through the insulin resistance to the development of metabolic syndrome. All these adaptations are suggested to take place through epigenetic modifications of the expression of genes without change of their amino-acid sequence. The epigenetic modifications leading to future obesity and cardiovascular risk are thought to induce appetite dysregulation, promoting food intake and adipogenesis, facilitating obesity development. The epigenetic modifications may even persist into the next generation even though the subsequent generation has not been exposed to an adverse intrauterine environment, a notion defined as the "transgenerational transfer of environmental information". As a consequence, if the increased public health burden and costs of non-communicable chronic diseases such as obesity, hypertension, metabolic syndrome and type 2 diabetes have to be minimized, special attention should be laid to the healthy lifestyle habits of women of reproductive age, including healthy diet and physical activity to be established long before any pregnancy takes place in order to provide the best conditions for both somatic and mental health of future generations.