An unwelcome inheritance: childhood obesity after diabetes in pregnancy

Epigenetic programming of obesity in early life through modulation of the kynurenine pathway

Childhood obesity is a global health concern that has its origins before birth. Although genetics plays a crucial role, increasing evidence suggests that epigenetic modifications during fetal life could also influence its incidence. In this model, during the fetal period, interactions between genetic makeup, intrauterine factors, and environmental conditions, increase the risk of childhood obesity. This is in accordance with the Developmental Origins of Health and Disease (DOHaD) hypothesis, in which specific intrauterine environments can have long-lasting effects on the immune system's essential functions during crucial stages of fetal growth, resulting in permanent changes to the immune function of the offspring. Consequently, dysfunction can consequently make the offspring more prone to inflammatory and immune-related disorders later in life. In this review, we examine how maternal inflammation could influence the risk of childhood obesity. We propose that during pregnancy, modification of the expression of critical genes in metabolic and signaling pathways, such as the kynurenine (Kyn) pathway, occurs due to increased levels of maternal inflammation. We also propose that such expression differences are mediated by epigenetic changes. Furthermore, we also hypothesize that the Kyn pathway produces metabolites that have immunoregulatory effects and may play a crucial role in regulating inflammation during pregnancy. As a result, interventions aimed at improving maternal inflammation may be able to help alleviate the risk of childhood obesity.

Impact of Gestational Diabetes Mellitus on Fetal Growth and Nutritional Status in Newborns

BACKGROUND

Gestational diabetes mellitus (GDM) is one of the most prevalent complications associated with pregnancy, exhibiting a gradual rise in prevalence worldwide. Given the potential for numerous short- and long-term complications for both mother and child, patients diagnosed with GDM require individualised treatment to compensate for metabolic abnormalities and ultimately reduce the risk of the known adverse consequences of impaired glucose tolerance.

METHODS AND RESULTS

The manuscript presents a summary of the current knowledge on changes in maternal metabolism during physiological pregnancy and pregnancy complicated by gestational diabetes. Furthermore, the article provides a synthesis of the findings from recent research examining the impacts of gestational diabetes and the therapeutic modalities employed on the nutritional status of the fetus and neonate. Additionally, the review elucidates the function of the placenta and placental hormones in fetal development, as well as the impact of hyperglycemia, insulin resistance and adipokines on fetal and neonatal nutritional programming and predisposition to metabolic complications in adulthood.

CONCLUSIONS

The metabolic environment, resulting from abnormal glucose tolerance during pregnancy, exerts a particularly significant impact on fetal growth and, consequently, on the birth weight and fat mass of the newborn infants. This is a pivotal factor influencing the nutritional and metabolic programming of the developing fetus, predisposing the individual to the development of metabolic complications throughout their lifetime.

Associations of High BMI and Excessive Gestational Weight Gain With Pregnancy Outcomes in Women With Type 1 Diabetes: A Systematic Review and Meta-analysis

BACKGROUND

The increased risk of pregnancy complications in type 1 diabetes is mainly attributed to maternal hyperglycemia. However, it is unclear whether other potentially modifiable factors also contribute to risk in this population.

PURPOSE

We sought to assess whether high BMI and excessive gestational weight gain (GWG) are associated with perinatal complications in type 1 diabetes.

DATA SOURCES

We searched Medline, Embase, PubMed, Scopus, Web of Science, and Cochrane databases to January 2024.

STUDY SELECTION

Studies examining associations between periconception BMI or GWG and perinatal complications in type 1 diabetes were included.

DATA EXTRACTION

We used a predesigned data extraction template to extract study data including year, country, sample size, participants' characteristics, exposure, and outcomes.

DATA SYNTHESIS

We included 29 studies (18,965 pregnancies; 1978-2019) in the meta-analysis. A 1 kg/m2/1 kg increase in preconception BMI or GWG was associated with a 3% and 11% increase, respectively, in perinatal complications (BMI odds ratio [OR] 1.03 [95% CI 1.01-1.06]; GWG OR 1.11 [95% CI 1.04-1.18]). Preconception BMI ≥ 25 kg/m2 or excessive GWG was associated with a 22% and 50% increase, respectively, in perinatal complications (BMI OR 1.22 [95% CI 1.11-1.34]; GWG OR 1.50 [95% CI 1.31-1.73]). BMI was associated with congenital malformation, preeclampsia, and neonatal intensive care unit admission. Excessive GWG was associated with preeclampsia, cesarean delivery, large for gestational age, and macrosomia.

LIMITATIONS

Limitations included retrospective study design, variable measurement for exposures and outcomes, small number of studies for some outcomes, and no data from Asia and Africa.

CONCLUSIONS

Addressing maternal BMI prepregnancy and preventing excessive GWG should be key clinical priorities to improve outcomes in pregnant women with type 1 diabetes.

Initiation of metformin in early pregnancy results in fetal bioaccumulation, growth restriction, and renal dysmorphology in a primate model

BACKGROUND

In recent years, pragmatic metformin use in pregnancy has stretched to include prediabetes mellitus, type 2 diabetes mellitus, gestational diabetes mellitus, and (most recently) preeclampsia. However, with its expanded use, concerns of unintended harm have been raised.

OBJECTIVE

This study developed an experimental primate model and applied ultrahigh performance liquid chromatography coupled to triple-quadrupole mass spectrometry for direct quantitation of maternal and fetal tissue metformin levels with detailed fetal biometry and histopathology.

STUDY DESIGN

Within 30 days of confirmed conception (defined as early pregnancy), 13 time-bred (timed-mated breeding) Rhesus dams with pregnancies designated for fetal necropsy were initiated on twice-daily human dose-equivalent 10 mg/kg metformin or vehicle control. Pregnant dams were maintained as pairs and fed either a control chow or 36% fat Western-style diet. Metformin or placebo vehicle control was delivered in various treats while the animals were separated via a slide. A cesarean delivery was performed at gestational day 145, and amniotic fluid and blood were collected, and the fetus and placenta were delivered. The fetus was immediately necropsied by trained primate center personnel. All fetal organs were dissected, measured, sectioned, and processed per clinical standards. Fluid and tissue metformin levels were assayed using validated ultrahigh performance liquid chromatography coupled to triple-quadrupole mass spectrometry in selected reaction monitoring against standard curves.

RESULTS

Among 13 pregnancies at gestational day 145 with fetal necropsy, 1 dam and its fetal tissues had detectable metformin levels despite being allocated to the vehicle control group (>1 μmol metformin/kg maternal weight or fetal or placental tissue), whereas a second fetus allocated to the vehicle control group had severe fetal growth restriction (birthweight of 248.32 g [<1%]) and was suspected of having a fetal congenital condition. After excluding these 2 fetal pregnancies from further analyses, 11 fetuses from dams initiated on either vehicle control (n=4: 3 female and 1 male fetuses) or 10 mg/kg metformin (n=7: 5 female and 2 male fetuses) were available for analyses. Among dams initiated on metformin at gestational day 30 (regardless of maternal diet), significant bioaccumulation within the fetal kidney (0.78-6.06 μmol/kg; mean of 2.48 μmol/kg), liver (0.16-0.73 μmol/kg; mean of 0.38 μmol/kg), fetal gut (0.28-1.22 μmol/kg; mean of 0.70 μmol/kg), amniotic fluid (0.43-3.33 μmol/L; mean of 1.88 μmol/L), placenta (0.16-1.00 μmol/kg; mean of 0.50 μmol/kg), fetal serum (0.00-0.66 μmol/L; mean of 0.23 μmol/L), and fetal urine (4.10-174.10 μmol/L; mean of 38.5 μmol/L) was observed, with fetal levels near biomolar equivalent to maternal levels (maternal serum: 0.18-0.86 μmol/L [mean of 0.46 μmol/L]; maternal urine: 42.60-254.00 μmol/L [mean of 149.30 μmol/L]). Western-style diet feeding neither accelerated nor reduced metformin bioaccumulations in maternal or fetal serum, urine, amniotic fluid, placenta, or fetal tissues. In these 11 animals, fetal bioaccumulation of metformin was associated with less fetal skeletal muscle (57% lower cross-sectional area of gastrocnemius) and decreased liver, heart, and retroperitoneal fat masses (P<.05), collectively driving lower delivery weight (P<.0001) without changing the crown-rump length. Sagittal sections of fetal kidneys demonstrated delayed maturation, with disorganized glomerular generations and increased cortical thickness. This renal dysmorphology was not accompanied by structural or functional changes indicative of renal insufficiency.

CONCLUSION

Our study demonstrates fetal bioaccumulation of metformin with associated fetal growth restriction and renal dysmorphology after maternal initiation of the drug within 30 days of conception in primates. Given these results and the prevalence of metformin use during pregnancy, additional investigation of any potential immediate and enduring effects of prenatal metformin use is warranted.

Obesity and dyslipidemia in early life: Impact on cardiometabolic risk

Childhood obesity with its growing prevalence worldwide presents one of the most important health challenges nowadays. Multiple mechanisms are involved in the development of this condition, as well as in its associations with various cardiometabolic complications, such as insulin resistance, diabetes, metabolic dysfunction-associated steatotic liver disease and cardiovascular diseases. Recent findings suggest that childhood obesity and associated dyslipidemia at least partly originate from epigenetic modifications that take place in the earliest periods of life, namely prenatal and perinatal periods. Hence, alterations of maternal metabolism could be fundamentally responsible for fetal and neonatal metabolic programming and consequently, for metabolic health of offspring in later life. In this paper, we will review recent findings on the associations among intrauterine and early postnatal exposure to undesirable modulators of metabolism, development of childhood obesity and later cardiometabolic complications. Special attention will be given to maternal dyslipidemia as a driven force for undesirable epigenetic modulations in offspring. In addition, newly proposed lipid biomarkers of increased cardiometabolic risk in obese children and adolescents will be analyzed, with respect to their predictive potential and clinical applicability.

Integrated care of diabetes during pregnancy: a Qatari nationwide cohort

Background

Diabetes in pregnancy (DIP) is associated with adverse fetal and maternal outcomes. DIP is classified as either pre-existing or new-onset diabetes mellitus (DM), which is classified into gestational DM (GDM) and newly detected type 2 (N-T2D). All pregnant women in Qatar who are not known to have pre-existing DM are offered screening for DIP during the first antenatal care visit and after 24 weeks gestation. The study aims to report the DIP screening rates, the prevalence of DIP, and the impact of the universal screening program on adverse pregnancy outcomes.

Methods

This retrospective study included all women who gave birth in Hamad Medical Corporation (HMC) hospitals between 2019 and 2022. New-onset DIP was defined using the WHO-2013 criteria. The primary outcomes were the screening rates and the prevalence of DIP in Qatar. The secondary outcomes were the difference in preterm delivery, C-section, macrosomia, large for gestational age (LGA), small for gestational age (SGA), and intra-uterine fetal death (IUFD) between women with or without GDM.

Findings

We included 94,422 women who gave birth to 96,017 neonates (85.7%) out of 112,080 neonates born nationwide. The number of women with pre-existing diabetes was 2496 women. Of 91,926 eligible women, 77,372 (84.2%) were screened for DIP. The prevalence of GDM is 31.6% (95% CI: 31.3-32.0%); N-T2D is 2.2% (95% CI: 2.1-2.3%), and pre-existing Type 2 DM and Type 1 DM was 2.6% (95% CI: 0.8-3.0%) and 0.2% (0.19-0.25), respectively. Compared to the non-GDM group, women with GDM were older (30.8 ± 5.3 versus 29.7 ± 5.2 years, p < 0.001). After adjusting for age, women with GDM had lower risk of IUFD and SGA (0.63 [95% CI 0.50-0.80, p < 0.001], 0.88 [95% CI 0.84-0.92, p < 0.001] respectively) but higher risk of C-section and LFD (1.07 [95% CI 1.04-1.10, p < 0.001], 1.09 [95% CI 1.01-1.15, p = 0.01], respectively, compared to women with no-GDM.

Interpretation

Of the women eligible for screening, 84.2% were screened by the DIP program in Qatar. The prevalence of DIP in Qatar is 36.9%. Integrated care is critical for the screening and management of diabetes during pregnancy.

Fundings

The authors did not receive any funding for this project.

Early-Pregnancy Serum Maternal and Placenta-Derived Exosomes miRNAs Vary Based on Pancreatic β-Cell Function in GDM

CONTEXT

Pancreatic β-cell function impairment is a key mechanism for developing gestational diabetes mellitus (GDM). Maternal and placental exosomes regulate maternal and placental responses during hyperglycemia. Studies have associated exosomal micro-RNAs (miRNAs) with GDM development. To date, no studies have been reported that evaluate the profile of miRNAs present in maternal and placental exosomes in the early stages of gestation from pregnancies that develop GDM.

OBJECTIVE

We assessed whether early-pregnancy serum maternal and placenta-derived exosomes miRNA profiles vary according to pancreatic β-cell function in women who will develop GDM.

METHODS

A prospective nested case-control study was used to identify exosomal miRNAs that vary in early-pregnancy stages (<18 weeks of gestation) from women with normoglycemia and those who developed GDM based on their pancreatic β-cell function using the homeostasis model assessment of pancreatic β-cell function (HOMA-%β) index. Early-pregnancy serum maternal and placenta-derived exosomes were isolated to obtain miRNA profiles. Potential target and pathway analyses were performed to identify molecular and metabolic pathways associated with the exosomal miRNAs identified.

RESULTS

In early-pregnancy stages, serum maternal exosome size and concentration are modified in GDM group and fluctuate according to HOMA-%β index. Serum maternal exosomal hsa-miR-149-3p and hsa-miR-455-3p in GDM are related to insulin secretion and signaling, lipolysis, and adipocytokine signaling. Early-pregnancy serum placenta-derived exosomes hsa-miR-3665 and hsa-miR-6727-5p in GDM are related to regulating genes involved in response to immunological tolerance of pregnancy and pathways associated with placental dysfunction.

CONCLUSION

Early serum exosomal miRNAs differ depending on their origin (maternal or placental) and pancreatic β-cell function. This research provides insights into the interactions between maternal and placental exosomal miRNAs and may have implications for identifying potential biomarkers or therapeutic targets for GDM.

The Role of the Glycemic Index and Glycemic Load in the Dietary Approach of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is a common metabolic disorder that often develops during pregnancy, characterized by glucose intolerance and insulin resistance (IR). To ensure the well-being of both the mother and the fetus, the body undergoes multiple metabolic and immunological changes that result in peripheral IR and, under certain hereditary or acquired abnormalities, GDM in predisposed women. The adverse short- and long-term effects of GDM impact both the mother and the fetus. Nutrition seems to play an important role to prevent GDM or improve its evolution. An emphasis has been given to the proportion of carbohydrates (CHO) relative to protein and lipids, as well as dietary patterns, in GDM. The effects of CHO on postprandial glucose concentrations are reflected in the glycemic index (GI) and glycemic load (GL). Diets rich in GI and GL may induce or exacerbate IR, whereas diets low in GI and GL appear to enhance insulin sensitivity and improve glycemic control. These positive outcomes may be attributed to direct interactions with insulin and glucose homeostasis or indirect effects through improved body composition and weight management. This comprehensive narrative review aims to explore the significance of nutrition, with a focus on the critical evaluation of GI and GL in the dietary management of women with GDM.