Anaemia in the first trimester and poor physiological plasma expansion during pregnancy negatively impact foetal weight and newborn anthropometrics: An observational cohort study in Tanzania.

OBJECTIVES: Anaemia during pregnancy is a major health challenge affecting pregnancy outcome worldwide. The objectives of this study were to investigate the impact of severe-moderate anaemia in the first trimester, as well as changes in haemoglobin during pregnancy among non-anaemic women, on foetal weight, placental blood flow and newborn anthropometrics. METHODS: In a prospective cohort study, 346 women residing in rural Tanzania were followed throughout pregnancy with serial ultrasound and newborn anthropometrics assessed within 24 h of delivery. Associations between placental blood flow, foetal weight and newborn anthropometrics with either first trimester severe-moderate anaemia (haemoglobin≤9.5 g/dL) or changes in haemoglobin from the first to the third trimester among non-anaemic women, were assessed by mixed model regression and multiple linear regression, adjusting for maternal and foetal co-variables. Foetal weights and birthweight were converted to z-scores using a population based sex-specific weight reference. RESULTS: Severe-moderate anaemia in the first trimester was associated with significantly reduced foetal weight z-scores (adjusted mean difference (aMD) -0.44 (95% CI -0.81, -0.07)) and newborn anthropometric indices (birth weight z-score aMD -0.55 (-0.9, -0.13), abdominal circumference aMD -11 mm (95% CI -20, -3)). There were no association between first trimester severe-moderate anaemia and placental blood flow. Among women who were non-anaemic in the first trimester, women with the least reduction in haemoglobin (Δ ≥ -0.3 g/dL) delivered significantly smaller newborns (birthweight z-score aMD -0.55 (-0.91, -0.20), abdominal circumference aMD -10 mm (95% CI -17, -3), compared to women with the greatest reduction (Δ haemoglobin ≤ -1.4 g/dL)). CONCLUSIONS: Severe-moderate anaemia in early pregnancy was associated with smaller newborn anthropometrics which was reflected in smaller mean foetal weights in the second and third trimester. Furthermore, among women who were non-anaemic in the first trimester, there was an association between smaller newborn anthropometrics and limited haemoglobin decrease during pregnancy, possibly reflecting insufficient plasma expansion.

Family Therapy for Kosovar Mothers Who Experienced Conflict-Related Sexual Violence and Their Children in Postwar Times: A Pilot Randomised Waitlist-Controlled Trial.

Women who have experienced conflict-related sexual violence report significant long-term effects, including posttraumatic stress disorder (PTSD), depression and relationship difficulties. Research has demonstrated that maternal trauma is associated with children's behavioural difficulties and challenges in family functioning, such as impaired communication and harsh parenting. This pilot study is aimed at evaluating the preliminary effectiveness of family therapy for Kosovar mothers who experienced conflict-related sexual violence in 1998-1999 and later developed PTSD and their children in improving family functioning and reducing behavioural difficulties in postwar times. Sixty-four mothers were randomised to an intervention group or a waitlist control group. Data was collected during a screening phase, at baseline before intervention initiation, after the intervention group completed family therapy and once the waitlist control group received the intervention. Generalised linear mixed models were used to analyse group differences in family functioning and children's behaviours over time. At follow-up, mothers in the intervention group reported improved family functioning. However, mothers in the waitlist control group reported significantly fewer behavioural difficulties than mothers in the intervention group before the control group had started family therapy. There was no significant interaction between group condition and time for child-rated family functioning. Overall, this pilot study suggests that family therapy could be effective in reducing the effects of intergenerational trauma related to PTSD and conflict-related sexual violence. Future research should evaluate the long-term effects of family therapy to assess if immediate effects were maintained.

Impact of prolonged fasting on insulin secretion, insulin action, and hepatic versus whole body insulin secretion disposition indices in healthy young males.

The extent to which reduced insulin secretion during prolonged fasting reflects failure to compensate for whole body insulin resistance or a normal adjustment to potentially increased hepatic insulin action is unknown. We examined the effects of 36- versus 12-h fasting on insulin secretion and whole body versus hepatic insulin action in 13 healthy young males. Hepatic glucose production and insulin action were studied using stable isotopes, whereas whole body insulin action and insulin secretion were studied using an intravenous glucose tolerance test (IVGTT) and minimal modeling. Insulin, glucose, and lipid profiles were subsequently measured during a refeeding meal test. Prolonged fasting caused a minor reduction of first-phase insulin secretion in a context of improved hepatic insulin action, contrasting an increase in whole body insulin resistance. Accordingly, prolonged fasting was associated with opposite-directed effects on hepatic versus whole body insulin secretion disposition indices. Thirty-six-hour fasting compared with 12-h fasting was associated with increased serum insulin levels during the refeeding meal test. In conclusion, reduced insulin secretion during prolonged fasting may represent a healthy response to improved hepatic insulin action. Use of insulin secretion disposition indices without taking organ-specific insulin action into account may lead to erroneous conclusions.NEW & NOTEWORTHY Thirty-six-hour prolonged, compared with 12-h overnight fasting, is associated with slightly reduced first-phase insulin secretion in the face of opposite-directed changes in hepatic versus whole body insulin action in healthy young males. The paradoxical finding of increased hepatic versus decreased whole body insulin secretion disposition indices during prolonged fasting challenges the physiological understanding and validity of insulin secretion disposition indices not taking organ-specific insulin action into account.

Increased expression of microRNA-15a and microRNA-15b in skeletal muscle from adult offspring of women with diabetes in pregnancy.

Offspring of women with diabetes in pregnancy exhibit skeletal muscle insulin resistance and are at increased risk of developing type 2 diabetes, potentially mediated by epigenetic mechanisms or changes in the expression of small non-coding microRNAs. Members of the miR-15 family can alter the expression or function of important proteins in the insulin signalling pathway, affecting insulin sensitivity and secretion. We hypothesized that exposure to maternal diabetes may cause altered expression of these microRNAs in offspring skeletal muscle, representing a potential underlying mechanism by which exposure to maternal diabetes leads to increased risk of cardiometabolic disease in offspring. We measured microRNA expression in skeletal muscle biopsies of 26- to 35-year-old offspring of women with either gestational diabetes (O-GDM, n = 82) or type 1 diabetes (O-T1DM, n = 67) in pregnancy, compared with a control group of offspring from the background population (O-BP, n = 57) from an observational follow-up study. Expression of both miR-15a and miR-15b was increased in skeletal muscle obtained from O-GDM (both P < 0.001) and O-T1DM (P = 0.024, P = 0.005, respectively) compared with O-BP. Maternal 2 h post OGTT glucose levels were positively associated with miR-15a expression (P = 0.041) in O-GDM after adjustment for confounders and mediators. In all groups collectively, miRNA expression was significantly positively associated with fasting plasma glucose, 2 h plasma glucose and HbA1c. We conclude that fetal exposure to maternal diabetes is associated with increased skeletal muscle expression of miR-15a and miR-15b and that this may contribute to development of metabolic disease in these subjects.

Epigenome- and Transcriptome-wide Changes in Muscle Stem Cells from Low Birth Weight Men.

Background: Being born with low birth weight (LBW) is a risk factor for muscle insulin resistance and type 2 diabetes (T2D), which may be mediated by epigenetic mechanisms programmed by the intrauterine environment. Epigenetic mechanisms exert their prime effects in developing cells. We hypothesized that muscle insulin resistance in LBW subjects may be due to early differential epigenomic and transcriptomic alterations in their immature muscle progenitor cells.Results: Muscle progenitor cells were obtained from 23 healthy young adult men born at term with LBW, and 15 BMI-matched normal birth weight (NBW) controls. The cells were subsequently cultured and differentiated into myotubes. DNA and RNA were harvested before and after differentiation for genome-wide DNA methylation and RNA expression measurements.After correcting for multiple comparisons (q ≤ 0.05), 56 CpG sites were found to be significantly, differentially methylated in myoblasts from LBW compared with NBW men, of which the top five gene-annotated CpG sites (SKI, ARMCX3, NR5A2, NEUROG, ESRRG) previously have been associated to regulation of cholesterol, fatty acid and glucose metabolism and muscle development or hypertrophy. LBW men displayed markedly decreased myotube gene expression levels of the AMPK-repressing tyrosine kinase gene FYN and the histone deacetylase gene HDAC7. Silencing of FYN and HDAC7 was associated with impaired myotube formation, which for HDAC7 reduced muscle glucose uptake.Conclusions: The data provides evidence of impaired muscle development predisposing LBW individuals to T2D is linked to and potentially caused by distinct DNA methylation and transcriptional changes including down regulation of HDAC7 and FYN in their immature myoblast stem cells.

Intrauterine programming of obesity and type 2 diabetes.

The type 2 diabetes epidemic and one of its predisposing factors, obesity, are major influences on global health and economic burden. It is accepted that genetics and the current environment contribute to this epidemic; however, in the last two decades, both human and animal studies have consolidated considerable evidence supporting the 'developmental programming' of these conditions, specifically by the intrauterine environment. Here, we review the various in utero exposures that are linked to offspring obesity and diabetes in later life, including epidemiological insights gained from natural historical events, such as the Dutch Hunger Winter, the Chinese famine and the more recent Quebec Ice Storm. We also describe the effects of gestational exposure to endocrine disruptors, maternal infection and smoking to the fetus in relation to metabolic programming. Causal evidence from animal studies, motivated by human observations, is also discussed, as well as some of the proposed underlying molecular mechanisms for developmental programming of obesity and type 2 diabetes, including epigenetics (e.g. DNA methylation and histone modifications) and microRNA interactions. Finally, we examine the effects of non-pharmacological interventions, such as improving maternal dietary habits and/or increasing physical activity, on the offspring epigenome and metabolic outcomes.

Telomere length is reduced in 9- to 16-year-old girls exposed to gestational diabetes in utero.

AIMS/HYPOTHESIS: Shortened telomere length is a marker of cell damage and is associated with oxidative stress, chronic inflammation and metabolic disease. We hypothesised that the offspring of women with gestational diabetes mellitus (GDM) with increased risk of cardiovascular and metabolic diseases might exhibit shorter telomere length. METHODS: We investigated telomere length in 439 GDM and 469 control group offspring, aged between 9 and 16 years, recruited from the Danish National Birth Cohort. Relative telomere length was measured in peripheral blood DNA (n = 908) using a quantitative PCR approach. Multivariate regression analysis was used to investigate the association between mothers' GDM status and telomere length in the offspring. RESULTS: Female offspring had longer telomeres than males. Offspring of mothers with GDM had significantly shorter telomere length than control offspring, but this difference was observed only in girls. There was a negative association between telomere length and GDM exposure among the female offspring (14% shorter telomeres, p = 0.003) following adjustment for the age of the offspring. Telomere length in female offspring was negatively associated with fasting insulin levels and HOMA-IR (p = 0.03). Maternal age, smoking, gestational age, birthweight and the offspring's anthropometric characteristics were not associated with telomere length (p ≥ 0.1). CONCLUSIONS/INTERPRETATION: The 9- to 16-year-old girls of mothers with GDM had shorter telomeres than those from the control population. Further studies are needed to understand the extent to which shortened telomere length predicts and/or contributes to the increased risk of disease later in life among the offspring of women with GDM.

Metabolic response to 36 hours of fasting in young men born small vs appropriate for gestational age.

AIMS/HYPOTHESIS: Being born small for gestational age (SGA) is associated with an increased risk of type 2 diabetes in an affluent society, but could confer an improved chance of survival during sparse living conditions. We studied whether insulin action and other metabolic responses to prolonged fasting differed between 21 young adults born SGA and 18 matched controls born appropriate for gestational age (AGA). METHODS: A frequently sampled IVGTT and indirect calorimetry measurements were performed after a 36 h fast. Endogenous glucose production, insulin sensitivity (SI), first-phase insulin secretion and glucose effectiveness were estimated by stable isotope tracer techniques and minimal modelling. Muscle and fat biopsies were obtained after 35 h of fasting. RESULTS: During fasting, SGA individuals experienced a more pronounced decrease in serum insulin and lower plasma triacylglycerol levels compared with AGA individuals. In addition, energy expenditure decreased in SGA but increased in AGA individuals. After fasting, SGA individuals displayed lower fat oxidation than AGA individuals. SG was reduced in SGA compared with AGA individuals, whereas hepatic or whole body insulin action (SI) did not differ between groups. SGA individuals had increased muscle PPARGC1A DNA methylation. We found no differences in adipose tissue PPARGC1A DNA methylation, muscle and adipose tissue PPARGC1A mRNA expression, or muscle glycogen levels between the groups. CONCLUSION: Compared with AGA individuals, SGA individuals displayed a more energy-conserving and potentially beneficial [corrected] cardiometabolic response to 36 h fasting. The role of increased muscle PPARGC1A DNA methylation in mediating this response requires further study.

Genetic, nongenetic and epigenetic risk determinants in developmental programming of type 2 diabetes.

Low birthweight (LBW) individuals and offspring of women with gestational diabetes mellitus (GDM) exhibit increased risk of developing type 2 diabetes (T2D) and associated cardiometabolic traits in adulthood, which for both groups may be mediated by adverse events and developmental changes in fetal life. T2D is a multifactorial disease occurring as a result of complicated interplay between genetic and both prenatal and postnatal nongenetic factors, and it remains unknown to what extent the increased risk of T2D associated with LBW or GDM in the mother may be due to, or confounded by, genetic factors. Indeed, it has been shown that genetic changes influencing risk of diabetes may also be associated with reduced fetal growth as a result of reduced insulin secretion and/or action. Similarly, increased risk of T2D among offspring could be explained by T2D susceptibility genes shared between the mother and her offspring. Epigenetic mechanisms may explain the link between factors operating in fetal life and later risk of developing T2D, but so far convincing evidence is lacking for epigenetic changes as a prime and direct cause of T2D. This review addresses recent literature on the early origins of adult disease hypothesis, with a special emphasis on the role of genetic compared with nongenetic and epigenetic risk determinants and disease mechanisms.

Do WHO criteria for gestational diabetes fit a rural population in Tanzania? - A follow-up study assessing mother and child health six years after a pregnancy diagnosed with gestational diabetes.

AIMS AND METHODS: In low- and middle- income countries (LMICs) consequences of gestational diabetes (GDM) is understudied. Using a prospective cohort of mothers (n = 197)and children (n = 251), from rural north-eastern Tanzania, we assessed prediabetes and type 2 diabetes (T2D) prevalence six years after a pregnancy with/without GDM. RESULTS: The prevalence of prediabetes (49.4 % vs. 46.4 %) orT2D (20.0 % vs. 16.1 %), p ≥ 0.36, based on fasting plasma glucose (FPG) or HbA1clevels (prediabetes: 16.9 % vs. 13.8 % and T2D 1.2 % vs. 0 %, p = 0.47), andcardio-metabolic health parameters,weresimilar between women with/without previous GDM. These results were supported by similar perinatal outcomes and child health at follow-up.The overall prevalence ofprediabetes/T2D was high, but no differences in other cardio-metabolic risk markers were observed in women with prediabetes/T2D compared to women with normal glucose tolerance. CONCLUSIONS: Despite high prevalence of GDM amongTanzanian women, the diagnosis was not associated with adverse pregnancy outcomes, nor with increased risk of prediabetes or T2D at follow-up. FPG and HbA1c may be poor markers for diabetes in this population, and further follow-up studies with longer time intervals are warranted to evaluate which GDM diagnostic criteria are most optimal for women in rural Tanzania and similar LMIC settings.

Human Genetic Variation at rs10071329 Correlates With Adiposity-Related Traits, Modulates PPARGC1B Expression, and Alters Brown Adipocyte Function.

Human genetic variation in PPARGC1B has been associated with adiposity, but the genetic variants that affect PPARGC1B expression have not been experimentally determined. Here, guided by previous observational data, we used clustered regularly interspaced short palindromic repeats/CRISPR associated protein 9 (CRISPR/Cas9) to scarlessly edit the alleles of the candidate causal genetic variant rs10071329 in a human brown adipocyte cell line. Switching the rs10071329 genotype from A/A to G/G enhanced PPARGC1B expression throughout the adipogenic differentiation, identifying rs10071329 as a cis-expression quantitative trait loci (eQTL). The higher PPARGC1B expression in G/G cells coincided with greater accumulation of triglycerides and higher expression of mitochondria-encoded genes, but without significant effects on adipogenic marker expression. Furthermore, G/G cells had improved basal- and norepinephrine-stimulated mitochondrial respiration, possibly relating to enhanced mitochondrial gene expression. The G/G cells also exhibited increased norepinephrine-stimulated glycerol release, indicating improved lipolysis. Altogether, our results showed that rs10071329 is a cis-eQTL, with the G/G genotype conferring enhanced PPARGC1B expression, with consequent improved mitochondrial function and response to norepinephrine in brown adipocytes. This genetic variant, and as yet undetermined eQTLs, at PPARGC1B could prove useful in genotype-based precision medicine for obesity treatment.

An epigenome-wide study of a needs-based family intervention for offspring of trauma-exposed mothers in Kosovo.

INTRODUCTION: Maternal stress and trauma during pregnancy have been shown to influence cortisol levels and epigenetic patterns, including DNA methylation, in the offspring. This study aimed to determine whether a tailor-made family intervention could help reduce cortisol levels in children born to traumatized mothers, and to determine whether it effected offspring DNA methylation. The secondary aim was to determine whether the family intervention influenced DNA methylation aging, a marker of biological aging. METHODS: A needs-based family intervention was designed to help address relational difficulties and family functioning, and included a focus on family strengths and problem-solving patterns. Women survivors of sexual violence during the Kosovar war in 1998-1999, and their families (children with or without partners) were randomly assigned to 10 sessions of a family therapy over a 3-5-month period, or to a waitlist control group. Both mothers and children completed assessments prior to and after the intervention phase. Children's blood samples collected at these two time points were used to measure cortisol and epigenome-wide DNA methylation patterns (Illumina EPIC array). Cortisol levels, and genome-wide DNA methylation changes pre-/postintervention were compared between children in the intervention and the waitlist groups. DNA methylation age and accelerated biological aging were calculated. RESULTS: Sixty-two women-child dyads completed the study, 30 were assigned first to the intervention group, and 32 to the waitlist control group. In adjusted linear regression, the family intervention was associated with a significant decline in cortisol levels compared to the waitlist control (ß = -124.72, 95% confidence interval [CI]: -197.4 to -52.1, p = .001). Children in the intervention group, compared to the waitlist control group, showed >1% differential methylation degree at 5819 CpG (5'-C-phosphate-G-3') sites across the genome (p < .01), with the largest methylation difference being 21%. However, none of these differences reached genome-wide significant levels. There was no significant difference in DNA methylation aging between the two groups. CONCLUSION: We find evidence that a tailored family-based intervention reduced stress levels in the children (based on cortisol levels), and modified DNA methylation levels at a number of sites across the genome. This study provides some preliminary evidence to suggest the potential for tailored interventions to help break the intergenerational transmission of trauma, however, large studies powered to detect associations at genome-wide significant levels are needed.

Epigenetics of the non-coding RNA nc886 across blood, adipose tissue and skeletal muscle in offspring exposed to diabetes in pregnancy.

BACKGROUND: Diabetes in pregnancy is associated with increased risk of long-term metabolic disease in the offspring, potentially mediated by in utero epigenetic variation. Previously, we identified multiple differentially methylated single CpG sites in offspring of women with gestational diabetes mellitus (GDM), but whether stretches of differentially methylated regions (DMRs) can also be identified in adolescent GDM offspring is unknown. Here, we investigate which DNA regions in adolescent offspring are differentially methylated in blood by exposure to diabetes in pregnancy. The secondary aim was to characterize the RNA expression of the identified DMR, which contained the nc886 non-coding RNA. METHODS: To identify DMRs, we employed the bump hunter method in samples from young (9-16 yr, n = 92) offspring of women with GDM (O-GDM) and control offspring (n = 94). Validation by pyrosequencing was performed in an adult offspring cohort (age 28-33 years) consisting of O-GDM (n = 82), offspring exposed to maternal type 1 diabetes (O-T1D, n = 67) and control offspring (O-BP, n = 57). RNA-expression was measured using RT-qPCR in subcutaneous adipose tissue and skeletal muscle. RESULTS: One significant DMR represented by 10 CpGs with a bimodal methylation pattern was identified, located in the nc886/VTRNA2-1 non-coding RNA gene. Low methylation status across all CpGs of the nc886 in the young offspring was associated with maternal GDM. While low methylation degree in adult offspring in blood, adipose tissue, and skeletal muscle was not associated with maternal GDM, adipose tissue nc886 expression was increased in O-GDM compared to O-BP, but not in O-T1D. In addition, adipose tissue nc886 expression levels were positively associated with maternal pre-pregnancy BMI (p = 0.006), but not with the offspring's own adiposity. CONCLUSIONS: Our results highlight that nc886 is a metastable epiallele, whose methylation in young offspring is negatively correlated with maternal obesity and GDM status. The physiological effect of nc886 may be more important in adipose tissue than in skeletal muscle. Further research should aim to investigate how nc886 regulation in adipose tissue by exposure to GDM may contribute to development of metabolic disease.

Cord Blood FGF-21 and GDF-15 Levels Are Affected by Maternal Exposure to Moderate to Severe Anemia and Malaria.

Context: Anemia and malaria are global health problems affecting >50% of pregnant women in sub-Saharan Africa and are associated with intrauterine growth restriction. The hormones fibroblast growth factor 21 (FGF-21) and growth differentiation factor 15 (GDF-15) are involved in metabolic regulation and are expressed in the placenta. No studies exist on FGF-21 and GDF-15 responses to exposures of malaria and anemia in pregnancy. Objective and Methods: Using a prospective, longitudinal pregnancy and birth cohort of women with an average age of 26 years from a rural region in northeastern Tanzania, we examined if FGF-21 and GDF-15 levels in maternal blood at week 33 ± 2 (n = 301) and in cord blood at birth (n = 353), were associated with anemia and malaria exposure at different time points in pregnancy and with neonatal anthropometry. Results: Among mothers at gestation week 33 ± 2, lower FGF-21 levels were observed after exposure to malaria in the first trimester, but not anemia, whereas GDF-15 levels at week 33 ± 2 were not associated with malaria nor anemia. In cord blood, moderate to severe anemia at any time point in pregnancy was associated with higher levels of FGF-21, whereas malaria exposure in the third trimester was associated with lower FGF-21 levels in cord blood. Negative associations were observed between cord blood FGF-21 and GDF-15 levels and neonatal skinfold thicknesses and birthweight. Conclusion: Our results suggest that moderate to severe anemia throughout pregnancy associates with higher FGF-21 levels, and malaria in last trimester associates with lower FGF-21 levels, in the neonates, thereby potentially affecting the future cardiometabolic health of the child.

High anti-SARS-CoV-2 seroprevalence among unvaccinated mother-child pairs from a rural setting in north-eastern Tanzania during the second wave of COVID-19.

Background: The reported infection rates and burden of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in low- and middle-income countries, including those in sub-Saharan Africa, are relatively low compared to the rates and burden in Europe and America, partly due to limited testing capability. Unlike many countries, Tanzania has implemented neither mass screening nor restrictive measures such as lockdowns to date. The prevalence of SARS-CoV-2 infection in rural mainland Tanzania is largely unknown. Methods: A cross-sectional study was conducted between April and October 2021 to assess the anti-SARS-CoV-2 seroprevalence among mother-child pairs (n = 634 children, n = 518 mothers) in a rural setting in north-eastern Tanzania. Results: A very high prevalence of anti-SARS-CoV-2 antibody titres was found, with seroprevalence rates ranging from 29% among mothers and 40% among children, with a dynamic peak in seropositivity incidence at the end of July/early August being revealed. Significant differences in age, socioeconomic status, and body composition were associated with seropositivity in mothers and children. No significant associations were observed between seropositivity and comorbidities, including anaemia, diabetes, malaria, and HIV. Conclusions: The transmission of SARS-CoV-2 in a rural region of Tanzania during 2021 was high, indicating a much higher infection rate in rural Tanzania compared to that reported in the UK and USA during the same period. Ongoing immune surveillance may be vital to monitoring the burden of viral infection in rural settings without access to molecular genotyping, where the load of communicable diseases may mask COVID-19. Surveillance could be implemented in tandem with the intensification of vaccination strategies.

Placental DNA methylation in pregnancies complicated by maternal diabetes and/or obesity: State of the art and research gaps.

Maternal diabetes and/or obesity in pregnancy are undoubtedly associated with later disease-risk in the offspring. The placenta, interposed between the mother and the foetus, is a potential mediator of this risk through epigenetic mechanisms, including DNA methylation. In recent years, multiple studies have identified differentially methylated CpG sites in the placental tissue DNA in pregnancies complicated by diabetes and obesity. We reviewed all published original research relevant to this topic and analysed our findings with the focus of identifying overlaps, contradictions, and gaps. Most studies focused on the association of gestational diabetes and/or hyperglycaemia in pregnancy and DNA methylation in placental tissue at term. We identified overlaps in results related to specific candidate genes, but also observed a large research gap of pregnancies affected by type 1 diabetes. Other unanswered questions relate to analysis of specific placental cell types and the timing of DNA methylation change in response to diabetes and obesity during pregnancy. Maternal metabolism is altered already in the first trimester involving structural and functional changes in the placenta, but studies into its effects on placental DNA methylation during this period are lacking and urgently needed. Foetal sex is also an important determinant of pregnancy outcome, but only few studies have taken this into account. Collectively, we provide a reference work for researchers working in this large and evolving field. Based on the results of the literature review, we formulate suggestions for future focus of placental DNA methylation studies in pregnancies complicated by diabetes and obesity.

DNA methylation in blood cells is associated with cortisol levels in offspring of mothers who had prenatal post-traumatic stress disorder.

Maternal stress during pregnancy is associated with differential DNA methylation in offspring and disrupted cortisol secretion. This study aimed to determine methylation signatures of cortisol levels in children, and whether associations differ based on maternal post-traumatic stress disorder (PTSD). Blood epigenome-wide methylation and fasting cortisol levels were measured in 118 offspring of mothers recruited from the Kosovo Rehabilitation Centre for Torture Victims. Mothers underwent clinically administered assessment for PTSD using Diagnostic and Statistical Manual of Mental Disorders. Correlations between offspring methylation and cortisol levels were examined using epigenome-wide analysis, adjusting for covariates. Subsequent analysis focussed on a priori selected genes involved in the hypothalamic-pituitary-adrenal (HPA) axis stress signalling. Methylation at four sites were correlated with cortisol levels (cg15321696, r = -0.33, cg18105800, r = +0.33, cg00986889, r = -0.25, and cg15920527, r = -0.27). In adjusted multivariable regression, when stratifying based on prenatal PTSD status, significant associations were only found for children born to mothers with prenatal PTSD (p < 0.001). Several sites within HPA axis genes were also associated with cortisol levels in the maternal PTSD group specifically. There is evidence that methylation is associated with cortisol levels, particularly in offspring born to mothers with prenatal PTSD. However, larger studies need to be carried out to independently validate these findings.

DNA Methylation and Gene Expression in Blood and Adipose Tissue of Adult Offspring of Women with Diabetes in Pregnancy-A Validation Study of DNA Methylation Changes Identified in Adolescent Offspring.

Maternal gestational diabetes and obesity are associated with adverse outcomes in offspring, including increased risk of diabetes and cardiovascular diseases. Previously, we identified a lower DNA methylation degree at genomic sites near the genes ESM1, MS4A3, and TSPAN14 in the blood cells of adolescent offspring exposed to gestational diabetes and/or maternal obesity in utero. In the present study, we aimed to investigate if altered methylation and expression of these genes were detectable in blood, as well in the metabolically relevant subcutaneous adipose tissue, in a separate cohort of adult offspring exposed to gestational diabetes and obesity (O-GDM) or type 1 diabetes (O-T1D) in utero, compared with the offspring of women from the background population (O-BP). We did not replicate the findings of lower methylation of ESM1, MS4A3, and TSPAN14 in blood from adults, either in O-GDM or O-T1D. In contrast, in adipose tissue of O-T1D, we found higher MS4A3 DNA methylation, which will require further validation. The adipose tissue ESM1 expression was lower in O-GDM compared to O-BP, which in turn was not associated with maternal pre-pregnancy BMI nor the offspring's own adiposity. Adipose tissue TSPAN14 expression was slightly lower in O-GDM compared with O-BP, but also positively associated with maternal pre-pregnancy BMI, as well as offspring's own adiposity and HbA1c levels. In conclusion, the lower DNA methylation in blood from adolescent offspring exposed to GDM could not be confirmed in the present cohort of adult offspring, potentially due to methylation remodeling with increased aging. In offspring adipose tissue, ESM1 expression was associated with maternal GDM, and TSPAN14 expression was associated with both maternal GDM, as well as pre-pregnancy BMI. These altered expression patterns are potentially relevant to the concept of developmental programming of cardiometabolic diseases and require further studies.

Mapping the Cord Blood Transcriptome of Pregnancies Affected by Early Maternal Anemia to Identify Signatures of Fetal Programming.

CONTEXT: Anemia during early pregnancy (EP) is common in developing countries and is associated with adverse health consequences for both mothers and children. Offspring of women with EP anemia often have low birth weight, which increases risk for cardiometabolic diseases, including type 2 diabetes (T2D), later in life. OBJECTIVE: We aimed to elucidate mechanisms underlying developmental programming of adult cardiometabolic disease, including epigenetic and transcriptional alterations potentially detectable in umbilical cord blood (UCB) at time of birth. METHODS: We leveraged global transcriptome- and accompanying epigenome-wide changes in 48 UCB from newborns of EP anemic Tanzanian mothers and 50 controls to identify differentially expressed genes (DEGs) in UCB exposed to maternal EP anemia. DEGs were assessed for association with neonatal anthropometry and cord insulin levels. These genes were further studied in expression data from human fetal pancreas and adult islets to understand their role in beta-cell development and/or function. RESULTS: The expression of 137 genes was altered in UCB of newborns exposed to maternal EP anemia. These putative signatures of fetal programming, which included the birth weight locus LCORL, were potentially mediated by epigenetic changes in 27 genes and associated with neonatal anthropometry. Among the DEGs were P2RX7, PIK3C2B, and NUMBL, which potentially influence beta-cell development. Insulin levels were lower in EP anemia-exposed UCB, supporting the notion of developmental programming of pancreatic beta-cell dysfunction and subsequently increased risk of T2D in offspring of mothers with EP anemia. CONCLUSIONS: Our data provide proof-of-concept on distinct transcriptional and epigenetic changes detectable in UCB from newborns exposed to maternal EP anemia.