Periconceptional maternal micronutrient supplementation is associated with widespread gender related changes in the epigenome: a study of a unique resource in the Gambia

Type 1 diabetes mellitus in the context of high levels of rural deprivation: differences in demographic and anthropometric characteristics between urban and rural cases in NW Ethiopia

Background

While there is increasing evidence for an altered clinical phenotype of Type 1 diabetes in several low-and middle-income countries, little is known about urban-rural differences and how the greater poverty of rural environments may alter the pattern of disease.

Objective

Investigation of urban-rural differences in demographic and anthropometric characteristics of type 1 diabetes in a resource-poor setting.

Research design and methods

Analysis of a unique case register, comprising all patients (rural and urban) presenting with Type 1 diabetes over a 20 yr. period in a poor, geographically defined area in northwest Ethiopia. The records included age, sex, place of residence, together with height and weight at the clinical onset.

Results

A total of 1682 new cases of Type 1 diabetes were registered with a mean age of onset of 31.2 (SD 13.4) yr. The patients were thin with 1/3 presenting with a body mass index (BMI) <17kg/m2. There was a striking male predominance of cases when clinical onset was between 20 and 35 yr., this was more marked in the very poor rural dwellers compared to the urban population. While most patients with Type 1 diabetes presented with low BMIs and reduced height, stunting preferentially affected rural men.

Conclusions

These data have led to the hypothesis that complex interactions among poor socioeconomic conditions in early life affect both pancreatic function and the development of autoimmunity and provide a possible explanation of the unusual phenotype of Type 1 diabetes in this very poor community.

The influence of early environment and micronutrient availability on developmental epigenetic programming: lessons from the placenta

DNA methylation is the most commonly studied epigenetic mark in humans, as it is well recognised as a stable, heritable mark that can affect genome function and influence gene expression. Somatic DNA methylation patterns that can persist throughout life are established shortly after fertilisation when the majority of epigenetic marks, including DNA methylation, are erased from the pre-implantation embryo. Therefore, the period around conception is potentially critical for influencing DNA methylation, including methylation at imprinted alleles and metastable epialleles (MEs), loci where methylation varies between individuals but is correlated across tissues. Exposures before and during conception can affect pregnancy outcomes and health throughout life. Retrospective studies of the survivors of famines, such as those exposed to the Dutch Hunger Winter of 1944-45, have linked exposures around conception to later disease outcomes, some of which correlate with DNA methylation changes at certain genes. Animal models have shown more directly that DNA methylation can be affected by dietary supplements that act as cofactors in one-carbon metabolism, and in humans, methylation at birth has been associated with peri-conceptional micronutrient supplementation. However, directly showing a role of micronutrients in shaping the epigenome has proven difficult. Recently, the placenta, a tissue with a unique hypomethylated methylome, has been shown to possess great inter-individual variability, which we highlight as a promising target tissue for studying MEs and mixed environmental exposures. The placenta has a critical role shaping the health of the fetus. Placenta-associated pregnancy complications, such as preeclampsia and intrauterine growth restriction, are all associated with aberrant patterns of DNA methylation and expression which are only now being linked to disease risk later in life.

Differential expression of genes influencing mitotic processes in cord blood mononuclear cells after a pre-conceptional micronutrient-based randomised controlled trial: Pune Rural Intervention in Young Adolescents (PRIYA)

In The Pune Maternal Nutrition Study, vitamin B12 deficiency was seen in 65% of pregnant women, folate deficiency was rare. Maternal total homocysteine concentrations were inversely associated with offspring birthweight, and low vitamin B12 and high folate concentrations predicted higher offspring adiposity and insulin resistance. These findings guided a nested pre-conceptional randomised controlled trial 'Pune Rural Intervention in Young Adolescents'. The interventions included: (1) vitamin B12+multi-micronutrients as per the United Nations International Multiple Micronutrient Antenatal Preparation, and proteins (B12+MMN), (2) vitamin B12 (B12 alone), and (3) placebo. Intervention improved maternal pre-conceptional and in-pregnancy micronutrient nutrition. Gene expression analysis in cord blood mononuclear cells in 88 pregnancies revealed 75 differentially expressed genes between the B12+MMN and placebo groups. The enriched biological processes included G2/M phase transition, chromosome segregation, and nuclear division. Enriched pathways included, mitotic spindle checkpoint and DNA damage response while enriched human phenotypes were sloping forehead and decreased head circumference. Fructose-bisphosphatase 2 (FBP2) and Cell Division Cycle Associated 2 (CDCA2) genes were under-expressed in the B12 alone group. The latter, involved in chromosome segregation was under-expressed in both intervention groups. Based on the role of B-complex vitamins in the synthesis of nucleotides and S-adenosyl methionine, and the roles of vitamins A and D on gene expression, we propose that the multi-micronutrient intervention epigenetically affected cell cycle dynamics. Neonates in the B12+MMN group had the highest ponderal index. Follow-up studies will reveal if the intervention and the altered biological processes influence offspring diabesity.

The impact of early-life environment on absence epilepsy and neuropsychiatric comorbidities

This review discusses the long-term effects of early-life environment on epileptogenesis, epilepsy, and neuropsychiatric comorbidities with an emphasis on the absence epilepsy. The WAG/Rij rat strain is a well-validated genetic model of absence epilepsy with mild depression-like (dysthymia) comorbidity. Although pathologic phenotype in WAG/Rij rats is genetically determined, convincing evidence presented in this review suggests that the absence epilepsy and depression-like comorbidity in WAG/Rij rats may be governed by early-life events, such as prenatal drug exposure, early-life stress, neonatal maternal separation, neonatal handling, maternal care, environmental enrichment, neonatal sensory impairments, neonatal tactile stimulation, and maternal diet. The data, as presented here, indicate that some early environmental events can promote and accelerate the development of absence seizures and their neuropsychiatric comorbidities, while others may exert anti-epileptogenic and disease-modifying effects. The early environment can lead to phenotypic alterations in offspring due to epigenetic modifications of gene expression, which may have maladaptive consequences or represent a therapeutic value. Targeting DNA methylation with a maternal methyl-enriched diet during the perinatal period appears to be a new preventive epigenetic anti-absence therapy. A number of caveats related to the maternal methyl-enriched diet and prospects for future research are discussed.

The Influence of Parental Environmental Exposure and Nutrient Restriction on the Early Life of Offspring Growth in Gambia-A Pilot Study

BACKGROUND

The role of the germline in epigenetic transgenerational inheritance starts with environmental factors, acting on the first generation of a gestating mother. These factors influence the developing second-generation fetus by altering gonadal development, thereby reprogramming the primordial germ cell DNA methylation and leading to consequences that might be seen along generations.

OBJECTIVE

Despite these epigenetic factors now surfacing, the few available studies are on animal-based experiments, and conducting a follow-up on human intergenerational trials might take decades. To this response, this study aimed to determine the influence of parental energy, toxicant exposure, age, and nutrient restriction on the early life of offspring growth in Gambia.

METHOD

This pilot study was based on population observation and combined both maternal and paternal factors across the country between August and October 2021. It captures the lifestyle and health detailed account of 339 reproductive parents and their last born (child under 5 years) using a structured interview questionnaire performed by nurses and public health officers.

RESULTS

This study showed that parents who worked in industrial areas were more likely to have offspring with poor psychosocial skills. In addition, mothers who are exposed to oxidative stress and high temperatures are more likely to have offspring with poor psychosocial skills. Mothers who consume a high-protein diet were almost three times more likely to have infants with good psychosocial skills in their offspring. Furthermore, there was a negative correlation between maternal stress during pregnancy and the psychosocial skills of offspring.

CONCLUSION

This study was able to ascertain if the maternal diet during gestation, toxicant exposure, maternal stress, and parental smoking habits have an influence on the early life of offspring. While the study recommends a large sample size study to eliminate selection bias, there should be an increased level of awareness of mothers of their offspring's health and their husbands' lifestyles that might influence the adulthood health of their offspring.

Sex disparities in influenza: A multiscale network analysis

Sex differences in the pathogenesis of infectious diseases because of differential immune responses between females and males have been well-documented for multiple pathogens. However, the molecular mechanism underlying the observed sex differences in influenza virus infection remains poorly understood. In this study, we used a network-based approach to characterize the blood transcriptome collected over the course of infection with influenza A virus from female and male ferrets to dissect sex-biased gene expression. We identified significant differences in the temporal dynamics and regulation of immune responses between females and males. Our results elucidate sex-differentiated pathways involved in the unfolded protein response (UPR), lipid metabolism, and inflammatory responses, including a female-biased IRE1/XBP1 activation and male-biased crosstalk between metabolic reprogramming and IL-1 and AP-1 pathways. Overall, our study provides molecular insights into sex differences in transcriptional regulation of immune responses and contributes to a better understanding of sex biases in influenza pathogenesis.

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Regulation of immune responses between females and males is significantly different

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Rapid activation of UPR in females triggers potent immune and inflammatory responses

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Male-specific regulatory pattern in the AP1 pathway indicate a bias in immune response

Sex differences in the intergenerational inheritance of metabolic traits

Strong evidence suggests that early-life exposures to suboptimal environmental factors, including those in utero, influence our long-term metabolic health. This has been termed developmental programming. Mounting evidence suggests that the growth and metabolism of male and female fetuses differ. Therefore, sexual dimorphism in response to pre-conception or early-life exposures could contribute to known sex differences in susceptibility to poor metabolic health in adulthood. However, until recently, many studies, especially those in animal models, focused on a single sex, or, often in the case of studies performed during intrauterine development, did not report the sex of the animal at all. In this review, we (a) summarize the evidence that male and females respond differently to a suboptimal pre-conceptional or in utero environment, (b) explore the potential biological mechanisms that underlie these differences and (c) review the consequences of these differences for long-term metabolic health, including that of subsequent generations.

The association between micronutrients and the SARS-CoV-2-specific antibodies in convalescent patients

BACKGROUND

Various micronutrients play key roles in the immune responses to viral infection, antibody synthesis, and susceptibility to infection. This study aimed to investigate the role of micronutrients on the immune responses following SARS-CoV-2 infection.

METHODS

To evaluate humoral immunity following SARS-CoV-2 infection, the levels of SARS-CoV-2-specific IgM and IgG, as well as the concentrations of different micronutrients, were determined in 36 convalescent COVID-19 patients 60 days after infection. Furthermore, the correlation between biochemical and hematological parameters, clinical features, and the changes in adiposity with SARS-CoV-2 antibodies was evaluated.

RESULTS

Serum IgM and IgG antibodies were detected in 38.8% and 83.3% of recovered patients after 60 days of COVID-19 infection, respectively. The values of SARS-CoV-2-specific IgG were negatively correlated with the number of the platelet. Moreover, the values of SARS-CoV-2-specific IgM were positively correlated with LDH and the vitamin B₁₂ concentration. Furthermore, a gender-specific association of SARS-CoV-2-specific IgG and IgM with vitamins D as well as with B₉ and zinc was observed. A significant negative correlation was observed between the values of IgG with vitamin D in male participants and a positive correlation was detected between IgG values and B₉ in female participants. Moreover, IgM levels with serum zinc values in females were negatively correlated.

CONCLUSION

Our study suggests the potential role of micronutrients in gender-specific humoral immunity following SARS-CoV-2 infection. Further studies are required with a greater sample of subjects to substantiate the validity and robustness of our findings.

Epigenetics in the Uterine Environment: How Maternal Diet and ART May Influence the Epigenome in the Offspring with Long-Term Health Consequences

The societal burden of non-communicable disease is closely linked with environmental exposures and lifestyle behaviours, including the adherence to a poor maternal diet from the earliest preimplantation period of the life course onwards. Epigenetic variations caused by a compromised maternal nutritional status can affect embryonic development. This review summarises the main epigenetic modifications in mammals, especially DNA methylation, histone modifications, and ncRNA. These epigenetic changes can compromise the health of the offspring later in life. We discuss different types of nutritional stressors in human and animal models, such as maternal undernutrition, seasonal diets, low-protein diet, high-fat diet, and synthetic folic acid supplement use, and how these nutritional exposures epigenetically affect target genes and their outcomes. In addition, we review the concept of thrifty genes during the preimplantation period, and some examples that relate to epigenetic change and diet. Finally, we discuss different examples of maternal diets, their effect on outcomes, and their relationship with assisted reproductive technology (ART), including their implications on epigenetic modifications.

Self-Protection as an Adaptive Female Strategy

Many male traits are well explained by sexual selection theory as adaptations to mating competition and mate choice, whereas no unifying theory explains traits expressed more in females. Anne Campbell's "staying alive" theory proposed that human females produce stronger self-protective reactions than males to aggressive threats because self-protection tends to have higher fitness value for females than males. We examined whether Campbell's theory has more general applicability by considering whether human females respond with greater self-protectiveness than males to other threats beyond aggression. We searched the literature for physiological, behavioral, and emotional responses to major physical and social threats, and found consistent support for females' responding with greater self-protectiveness than males. Females mount stronger immune responses to many pathogens; experience a lower threshold to detect, and lesser tolerance of, pain; awaken more frequently at night; express greater concern about physically dangerous stimuli; exert more effort to avoid social conflicts; exhibit a personality style more focused on life's dangers; react to threats with greater fear, disgust and sadness; and develop more threat-based clinical conditions than males. Our findings suggest that in relation to threat human females have relatively heightened protective reactions compared to males. The pervasiveness of this result across multiple domains suggests that general mechanisms might exist underlying females' unique adaptations. An understanding of such processes would enhance knowledge of female health and well-being.

Sex Differences in Immunity to Viral Infections

The ongoing COVID-19 pandemic has increased awareness about sex-specific differences in immunity and outcomes following SARS-CoV-2 infection. Strong evidence of a male bias in COVID-19 disease severity is hypothesized to be mediated by sex differential immune responses against SARS-CoV-2. This hypothesis is based on data from other viral infections, including influenza viruses, HIV, hepatitis viruses, and others that have demonstrated sex-specific immunity to viral infections. Although males are more susceptible to most viral infections, females possess immunological features that render them more vulnerable to distinct immune-related disease outcomes. Both sex chromosome complement and related genes as well as sex steroids play important roles in mediating the development of sex differences in immunity to viral infections.

Identification of methylation changes associated with positive and negative growth deviance in Gambian infants using a targeted methyl sequencing approach of genomic DNA

Low birthweight and reduced height gain during infancy (stunting) may arise at least in part from adverse early life environments that trigger epigenetic reprogramming that may favor survival. We examined differential DNA methylation patterns using targeted methyl sequencing of regions regulating gene activity in groups of rural Gambian infants: (a) low and high birthweight (DNA from cord blood (n = 16 and n = 20, respectively), from placental trophoblast tissue (n = 21 and n = 20, respectively), and DNA from peripheral blood collected from infants at 12 months of age (n = 23 and n = 17, respectively)), and, (b) the top 10% showing rapid postnatal length gain (high, n = 20) and the bottom 10% showing slow postnatal length gain (low, n = 20) based on z score change between birth and 12 months of age (LAZ) (DNA from peripheral blood collected from infants at 12 months of age). Using BiSeq analysis to identify significant methylation marks, for birthweight, four differentially methylated regions (DMRs) were identified in trophoblast DNA, compared to 68 DMRs in cord blood DNA, and 54 DMRs in 12‐month peripheral blood DNA. Twenty‐five DMRs were observed to be associated with high and low length for age (LAZ) at 12 months. With the exception of five loci (associated with two different genes), there was no overlap between these groups of methylation marks. Of the 194 CpG methylation marks contained within DMRs, 106 were located to defined gene regulatory elements (promoters, CTCF‐binding sites, transcription factor‐binding sites, and enhancers), 58 to gene bodies (introns or exons), and 30 to intergenic DNA. Distinct methylation patterns associated with birthweight between comparison groups were observed in DNA collected at birth (at the end of intrauterine growth window) compared to those established by 12 months (near the infancy/childhood growth transition). The longitudinal differences in methylation patterns may arise from methylation adjustments, changes in cellular composition of blood or both that continue during the critical postnatal growth period, and in response to early nutritional and infectious environmental exposures with impacts on growth and longer‐term health outcomes.

Sex-specific effects of in utero and adult tobacco smoke exposure

Tobacco smoke has harmful effects on a multiorgan level. Exposure to smoke, whether in utero or environmental, significantly increases susceptibility. This susceptibility has been identified to be divergent between males and females. However, there remains a distinct lack of thorough research into the relationship between sex and exposure to tobacco. Females tend to generate a more significant response than males during adulthood exposure. The intrauterine environment is meticulously controlled, and exposure to tobacco presents a significant factor that contributes to poor health outcomes and susceptibility later in life. Analysis of these effects in relation to the sex of the offspring is yet to be holistically reviewed and summarized. In this review, we will delineate the time-dependent relationship between tobacco smoke exposure and sex-specific disease susceptibility. We further outline possible biological mechanisms that may contribute to the identified pattern.

Type 1 diabetes in Africa: an immunogenetic study in the Amhara of North-West Ethiopia

AIMS/HYPOTHESIS

We aimed to characterise the immunogenic background of insulin-dependent diabetes in a resource-poor rural African community. The study was initiated because reports of low autoantibody prevalence and phenotypic differences from European-origin cases with type 1 diabetes have raised doubts as to the role of autoimmunity in this and similar populations.

METHODS

A study of consecutive, unselected cases of recently diagnosed, insulin-dependent diabetes (n = 236, ≤35 years) and control participants (n = 200) was carried out in the ethnic Amhara of rural North-West Ethiopia. We assessed their demographic and socioeconomic characteristics, and measured non-fasting C-peptide, diabetes-associated autoantibodies and HLA-DRB1 alleles. Leveraging genome-wide genotyping, we performed both a principal component analysis and, given the relatively modest sample size, a provisional genome-wide association study. Type 1 diabetes genetic risk scores were calculated to compare their genetic background with known European type 1 diabetes determinants.

RESULTS

Patients presented with stunted growth and low BMI, and were insulin sensitive; only 15.3% had diabetes onset at ≤15 years. C-peptide levels were low but not absent. With clinical diabetes onset at ≤15, 16-25 and 26-35 years, 86.1%, 59.7% and 50.0% were autoantibody positive, respectively. Most had autoantibodies to GAD (GADA) as a single antibody; the prevalence of positivity for autoantibodies to IA-2 (IA-2A) and ZnT8 (ZnT8A) was low in all age groups. Principal component analysis showed that the Amhara genomes were distinct from modern European and other African genomes. HLA-DRB1*03:01 (p = 0.0014) and HLA-DRB1*04 (p = 0.0001) were positively associated with this form of diabetes, while HLA-DRB1*15 was protective (p < 0.0001). The mean type 1 diabetes genetic risk score (derived from European data) was higher in patients than control participants (p = 1.60 × 10-7). Interestingly, despite the modest sample size, autoantibody-positive patients revealed evidence of association with SNPs in the well-characterised MHC region, already known to explain half of type 1 diabetes heritability in Europeans.

CONCLUSIONS/INTERPRETATION

The majority of patients with insulin-dependent diabetes in rural North-West Ethiopia have the immunogenetic characteristics of autoimmune type 1 diabetes. Phenotypic differences between type 1 diabetes in rural North-West Ethiopia and the industrialised world remain unexplained.

Pre-pregnancy diet quality and its association with offspring behavioral problems

PURPOSE

The maternal diet has a critical role in epigenetic changes in the fetus, which has been associated with fetal brain tissue development and later onset of behavioral disorder. However, pre-pregnancy diet quality has not been examined in relation to offspring behavioral problems.

METHODS

1554 mother-child dyads with mothers from the Australian longitudinal study on women's health (ALSWH) and children from the mothers and their children's health Study (MatCH). The healthy eating index (HEI-2015) score was used to explore maternal diet quality before pregnancy. Childhood total behavioral difficulties, internalizing (emotional and peer) and externalizing problems (hyperactivity and conduct) were assessed using the Strengths and Difficulties Questionnaire (SDQ). Multivariable logistic regression was used.

RESULTS

211 children experienced a greater SDQ-score on total behavioral difficulties (13.6%) among the 1554 children. Better pre-pregnancy diet quality was associated with lower odds of offspring total behavioral difficulties after adjustment for potential confounders, highest vs lowest tertile (AOR = 0.52, 95% CI 0.32, 0.85) at p = 0.009. Greater adherence to the HEI-2015 score before pregnancy was also inversely associated with lower odds of offspring externalizing problems (AOR = 0.64, 95% CI 0.43, 0.94). Among the four subscales, hyperactivity and peer problems were negatively associated with better diet quality, (AOR = 0.67, 95% CI 0.47, 0.96) and (AOR = 0.63, 95% CI 0.42, 0.96), respectively.

CONCLUSIONS

We found that adherence to a diet of better quality in pre-pregnancy was associated with a lower risk of behavioral disorders in the offspring. Large prospective studies are warranted to confirm the findings.

Prepregnancy dietary patterns and risk of preterm birth and low birth weight: findings from the Australian Longitudinal Study on Women's Health

BACKGROUND

Findings from previous studies on associations between prepregnancy dietary patterns and preterm birth and low birth weight (LBW) are limited and inconsistent.

OBJECTIVES

To examine the association between prepregnancy dietary patterns and the risk of preterm birth and LBW.

METHODS

This study included 3422 and 3508 singleton live births from the Australian Longitudinal Study on Women's Health (ALSWH) for the analyses of preterm birth and LBW, respectively. We included women who were nulliparous and nonpregnant at baseline surveys. We used factor analyses and the Healthy Eating Index-2015 (HEI-2015) score to derive maternal dietary patterns. Four dietary patterns were identified with factor analyses: meats and high-fats; prudent diets; sugar, refined grains, and processed foods; and traditional vegetables. Preterm birth and LBW were assessed using maternal reports from ALSWH data between 2003 and 2015. Multivariable logistic regression analyses were used.

RESULTS

Greater adherence to the traditional vegetables pattern before pregnancy was associated with a lower risk of preterm birth and spontaneous preterm birth after adjustments for lifestyle factors and pregnancy complications, highest compared with lowest tertile (adjusted OR = 0.72, 95% CI: 0.53, 0.99) and (RR ratio = 0.62, 95% CI: 0.39, 1.00), respectively. However, these associations were attenuated by the prepregnancy BMI. No significant associations were observed between prepregnancy dietary patterns and LBW.

CONCLUSION

This study suggests that better adherence to the traditional vegetables pattern before pregnancy is associated with a lower risk of preterm birth, particularly spontaneous preterm birth among nulliparous women. This finding warrants further examination.

In Vitro Fertilization Technology and Child Health

BACKGROUND

Just under 3% of children in Germany, and approximately 6% of children in some other countries, such as Denmark, are now being conceived with the aid of in vitro fertilization (IVF) technology. Alongside the increased risk of organ malformation, there is now evidence for functional abnormalities due to epigenetic modifications.

METHODS

This review is based on pertinent publications retrieved by a literature search on currently known associations of IVF therapy with malformations and functional abnormalities. The potential implications for the treatment of infertility are discussed.

RESULTS

The risk of congenital malformations is approximately one-third higher in children conceived with the aid of IVF technology than in other children; specifically, there is an odds ratio (OR) of 1.29 (95% confidence interval, [1.03; 1.60]) for cardiac malformations, and there is a relative risk (RR) of 1.35 ([1.12; 1.64]) for musculo- skeletal malformations and 1.58 ([1.28; 1.94]) for genitourinary malformations. The risks of preterm birth and low birth weight are, respectively, 1.7 and 1.5 times higher in IVF singleton pregnancies than in non-IVF pregnancies. Cardiovascular changes are the main type of functional disturbance. Some of the risks associated with IVF have decreased in recent years. An association has been revealed between cardiovascular abnormalities and epigenetic modifications; the causes are thought to include not only maternal and paternal factors, but also the IVF techniques that are used. A modification of IVF therapies might lower the risks, but might also lower the success rate.

CONCLUSION

For the well-being of the children to be conceived, IVF therapy should hat cannot be treated by any other means, as the precise causes of the risks of IVF to child health are unclear.

The Maternal Nutritional Buffering Model: an evolutionary framework for pregnancy nutritional intervention

Evidence that fetal nutrition influences adult health has heightened interest in nutritional interventions targeting pregnancy. However, as is true for other placental mammals, human females have evolved mechanisms that help buffer the fetus against short-term fluctuations in maternal diet and energy status. In this review, we first discuss the evolution of increasingly elaborate vertebrate strategies of buffering offspring from environmental fluctuations during development, including the important innovation of the eutherian placenta. We then present the Maternal Nutritional Buffering Model, which argues that, in contrast to many micronutrients that must be derived from dietary sources, the effects of short-term changes in maternal macronutrient intake during pregnancy, whether due to a deficit or supplementation, will be minimized by internal buffering mechanisms that work to ensure a stable supply of essential resources. In contrast to the minimal effects of brief macronutrient supplementation, there is growing evidence that sustained improvements in early life and adult pre-pregnancy nutrition could improve birth outcomes in offspring. Building on these and other observations, we propose that strategies to improve fetal macronutrient delivery will be most effective if they modify the pregnancy metabolism of mothers by targeting nutrition prior to conception and even during early development, as a complement to the conventional focus on bolstering macronutrient intake during pregnancy itself. Our model leads to the prediction that birth weight will be more strongly influenced by the mother’s chronic pre-pregnancy nutrition than by pregnancy diet, and highlights the need for policy solutions aimed at optimizing future, intergenerational health outcomes.

Lay summary: We propose that strategies to improve fetal macronutrient delivery will be most effective if they modify the pregnancy metabolism of mothers by targeting nutrition prior to conception and even during early development, as a complement to the conventional focus on bolstering macronutrient intake during pregnancy itself.

MapReduce-Based Parallel Genetic Algorithm for CpG-Site Selection in Age Prediction

Genomic biomarkers such as DNA methylation (DNAm) are employed for age prediction. In recent years, several studies have suggested the association between changes in DNAm and its effect on human age. The high dimensional nature of this type of data significantly increases the execution time of modeling algorithms. To mitigate this problem, we propose a two-stage parallel algorithm for selection of age related CpG-sites. The algorithm first attempts to cluster the data into similar age ranges. In the next stage, a parallel genetic algorithm (PGA), based on the MapReduce paradigm (MR-based PGA), is used for selecting age-related features of each individual age range. In the proposed method, the execution of the algorithm for each age range (data parallel), the evaluation of chromosomes (task parallel) and the calculation of the fitness function (data parallel) are performed using a novel parallel framework. In this paper, we consider 16 different healthy DNAm datasets that are related to the human blood tissue and that contain the relevant age information. These datasets are combined into a single unioned set, which is in turn randomly divided into two sets of train and test data with a ratio of 7:3, respectively. We build a Gradient Boosting Regressor (GBR) model on the selected CpG-sites from the train set. To evaluate the model accuracy, we compared our results with state-of-the-art approaches that used these datasets, and observed that our method performs better on the unseen test dataset with a Mean Absolute Deviation (MAD) of 3.62 years, and a correlation (R²) of 95.96% between age and DNAm. In the train data, the MAD and R² are 1.27 years and 99.27%, respectively. Finally, we evaluate our method in terms of the effect of parallelization in computation time. The algorithm without parallelization requires 4123 min to complete, whereas the parallelized execution on 3 computing machines having 32 processing cores each, only takes a total of 58 min. This shows that our proposed algorithm is both efficient and scalable.

DNA methylation profile is a quantitative measure of biological aging in children

DNA methylation changes within the genome can be used to predict human age. However, the existing biological age prediction models based on DNA methylation are predominantly adult-oriented. We established a methylation-based age prediction model for children (9-212 months old) using data from 716 blood samples in 11 DNA methylation datasets. Our elastic net model includes 111 CpG sites, mostly in genes associated with development and aging. The model performed well and exhibited high precision, yielding a 98% correlation between the DNA methylation age and the chronological age, with an error of only 6.7 months. When we used the model to assess age acceleration in children based on their methylation data, we observed the following: first, the aging rate appears to be fastest in mid-childhood, and this acceleration is more pronounced in autistic children; second, lead exposure early in life increases the aging rate in boys, but not in girls; third, short-term recombinant human growth hormone treatment has little effect on the aging rate of children. Our child-specific methylation-based age prediction model can effectively detect epigenetic changes and health imbalances early in life. This may thus be a useful model for future studies of epigenetic interventions for age-related diseases.

Maternal diet before and during pregnancy and risk of asthma and allergic rhinitis in children

BACKGROUND

Consumption of certain foods during pregnancy has been shown to have beneficial effects on childhood asthma and allergic disease development and aggravation. However, most studies provide conflicting results and the relationships between maternal preconceptional diet and risks of childhood asthma and allergic disease have not previously been explored. The objective of this study was to assess maternal diet during the year before pregnancy and the last 3 months of pregnancy and investigate their associations with the risks of asthma, wheezing, allergic rhinitis and atopic dermatitis in young children.

METHODS

The study sample consisted of 1140 mother-child pairs from the EDEN cohort. Mothers had responded to the food frequency questionnaires used to assess diet before and during pregnancy. Children were followed up using health questionnaires. The health outcomes studied were: asthma, wheezing, allergic rhinitis and atopic dermatitis by the age of 3 years.

RESULTS

Using multivariable-adjusted logistic regression models, significant inverse associations were observed between cooked green vegetable consumption before pregnancy and childhood asthma; consumption of eggs and raw vegetables before and during pregnancy, consumption of grains before pregnancy, and consumption of cooked green vegetables during pregnancy and allergic rhinitis. For the first time, a significant positive association was found between meat intake during the preconceptional period and a risk of wheezing, allergic rhinitis and atopic dermatitis.

CONCLUSIONS

Based on our findings, preconceptional and prenatal maternal intake of certain type of food groups may be preventive against asthma, wheezing and allergic rhinitis, whereas higher maternal intake of meat before pregnancy may increase the risk of wheezing, allergic rhinitis and atopic dermatitis in young children.

FOETAL for NCD-FOetal Exposure and Epidemiological Transitions: the role of Anaemia in early Life for Non-Communicable Diseases in later life: a prospective preconception study in rural Tanzania

PURPOSE

Low-income and middle-income countries such as Tanzania experience a high prevalence of non-communicable diseases (NCDs), including anaemia. Studying if and how anaemia affects growth, placenta development, epigenetic patterns and newborns' risk of NCDs may provide approaches to prevent NCDs.

PARTICIPANTS

The FOETALforNCD (FOetal Exposure and Epidemiological Transitions: the role of Anaemia in early Life for Non-Communicable Diseases in later life) Study is a population-based preconception, pregnancy and birth cohort study (n=1415, n=538, n=427, respectively), conducted in a rural region of North-East Tanzania. All participants were recruited prior to conception or early in pregnancy and followed throughout pregnancy as well as at birth. Data collection included: maternal blood, screening for NCDs and malaria, ultrasound in each trimester, neonatal anthropometry at birth and at 1 month of age, cord blood, placental and cord biopsies for stereology and epigenetic analyses.

FINDINGS TO DATE

At preconception, the average age, body mass index and blood pressure of the women were 28 years, 23 kg/m² and 117/75 mm Hg, respectively. In total, 458 (36.7%) women had anaemia (haemoglobin Hb <12 g/dL) and 34 (3.6%) women were HIV-positive at preconception. During pregnancy 359 (66.7%) women had anaemia of which 85 (15.8%) women had moderate-to-severe anaemia (Hb ≤9 g/dL) and 33 (6.1%) women had severe anaemia (Hb ≤8 g/dL). In total, 185 (34.4%) women were diagnosed with malaria during pregnancy.

FUTURE PLANS

The project will provide new knowledge on how health, even before conception, might modify the risk of developing NCDs and how to promote better health during pregnancy. The present project ended data collection 1 month after giving birth, but follow-up is continuing through regular monitoring of growth and development and health events according to the National Road Map Strategic Plan in Tanzania. This data will link fetal adverse event to childhood development, and depending on further grant allocation, through a life course follow-up.

Multiple-micronutrient supplementation for women during pregnancy

BACKGROUND

Multiple-micronutrient (MMN) deficiencies often coexist among women of reproductive age in low- and middle-income countries. They are exacerbated in pregnancy due to the increased demands of the developing fetus, leading to potentially adverse effects on the mother and baby. A consensus is yet to be reached regarding the replacement of iron and folic acid supplementation with MMNs. Since the last update of this Cochrane Review in 2017, evidence from several trials has become available. The findings of this review will be critical to inform policy on micronutrient supplementation in pregnancy.

OBJECTIVES

To evaluate the benefits of oral multiple-micronutrient supplementation during pregnancy on maternal, fetal and infant health outcomes.

SEARCH METHODS

For this 2018 update, on 23 February 2018 we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP), and reference lists of retrieved studies. We also contacted experts in the field for additional and ongoing trials.

SELECTION CRITERIA

All prospective randomised controlled trials evaluating MMN supplementation with iron and folic acid during pregnancy and its effects on pregnancy outcomes were eligible, irrespective of language or the publication status of the trials. We included cluster-randomised trials, but excluded quasi-randomised trials. Trial reports that were published as abstracts were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We assessed the quality of the evidence using the GRADE approach.

MAIN RESULTS

We identified 21 trials (involving 142,496 women) as eligible for inclusion in this review, but only 20 trials (involving 141,849 women) contributed data. Of these 20 trials, 19 were conducted in low- and middle-income countries and compared MMN supplements with iron and folic acid to iron, with or without folic acid. One trial conducted in the UK compared MMN supplementation with placebo. In total, eight trials were cluster-randomised.MMN with iron and folic acid versus iron, with or without folic acid (19 trials)MMN supplementation probably led to a slight reduction in preterm births (average risk ratio (RR) 0.95, 95% confidence interval (CI) 0.90 to 1.01; 18 trials, 91,425 participants; moderate-quality evidence), and babies considered small-for-gestational age (SGA) (average RR 0.92, 95% CI 0.88 to 0.97; 17 trials; 57,348 participants; moderate-quality evidence), though the CI for the pooled effect for preterm births just crossed the line of no effect. MMN reduced the number of newborn infants identified as low birthweight (LBW) (average RR 0.88, 95% CI 0.85 to 0.91; 18 trials, 68,801 participants; high-quality evidence). We did not observe any differences between groups for perinatal mortality (average RR 1.00, 95% CI 0.90 to 1.11; 15 trials, 63,922 participants; high-quality evidence). MMN supplementation led to slightly fewer stillbirths (average RR 0.95, 95% CI 0.86 to 1.04; 17 trials, 97,927 participants; high-quality evidence) but, again, the CI for the pooled effect just crossed the line of no effect. MMN supplementation did not have an important effect on neonatal mortality (average RR 1.00, 95% CI 0.89 to 1.12; 14 trials, 80,964 participants; high-quality evidence). We observed little or no difference between groups for the other maternal and pregnancy outcomes: maternal anaemia in the third trimester (average RR 1.04, 95% CI 0.94 to 1.15; 9 trials, 5912 participants), maternal mortality (average RR 1.06, 95% CI 0.72 to 1.54; 6 trials, 106,275 participants), miscarriage (average RR 0.99, 95% CI 0.94 to 1.04; 12 trials, 100,565 participants), delivery via a caesarean section (average RR 1.13, 95% CI 0.99 to 1.29; 5 trials, 12,836 participants), and congenital anomalies (average RR 1.34, 95% CI 0.25 to 7.12; 2 trials, 1958 participants). However, MMN supplementation probably led to a reduction in very preterm births (average RR 0.81, 95% CI 0.71 to 0.93; 4 trials, 37,701 participants). We were unable to assess a number of prespecified, clinically important outcomes due to insufficient or non-available data.When we assessed primary outcomes according to GRADE criteria, the quality of evidence for the review overall was moderate to high. We graded the following outcomes as high quality: LBW, perinatal mortality, stillbirth, and neonatal mortality. The outcomes of preterm birth and SGA we graded as moderate quality; both were downgraded for funnel plot asymmetry, indicating possible publication bias.We carried out sensitivity analyses excluding trials with high levels of sample attrition (> 20%). We found that results were consistent with the main analyses for all outcomes. We explored heterogeneity through subgroup analyses by maternal height, maternal body mass index (BMI), timing of supplementation, dose of iron, and MMN supplement formulation (UNIMMAP versus non-UNIMMAP). There was a greater reduction in preterm births for women with low BMI and among those who took non-UNIMMAP supplements. We also observed subgroup differences for maternal BMI and maternal height for SGA, indicating greater impact among women with greater BMI and height. Though we found that MMN supplementation made little or no difference to perinatal mortality, the analysis demonstrated substantial statistical heterogeneity. We explored this heterogeneity using subgroup analysis and found differences for timing of supplementation, whereby higher impact was observed with later initiation of supplementation. For all other subgroup analyses, the findings were inconclusive.MMN versus placebo (1 trial)A single trial in the UK found little or no important effect of MMN supplementation on preterm births, SGA, or LBW but did find a reduction in maternal anaemia in the third trimester (RR 0.66, 95% CI 0.51 to 0.85), when compared to placebo. This trial did not measure our other outcomes.

AUTHORS' CONCLUSIONS

Our findings suggest a positive impact of MMN supplementation with iron and folic acid on several birth outcomes. MMN supplementation in pregnancy led to a reduction in babies considered LBW, and probably led to a reduction in babies considered SGA. In addition, MMN probably reduced preterm births. No important benefits or harms of MMN supplementation were found for mortality outcomes (stillbirths, perinatal and neonatal mortality). These findings may provide some basis to guide the replacement of iron and folic acid supplements with MMN supplements for pregnant women residing in low- and middle-income countries.

Maternal betaine status, but not that of choline or methionine, is inversely associated with infant birth weight

Maternal one-carbon metabolism during pregnancy is crucial for fetal development and programming by DNA methylation. However, evidence on one-carbon biomarkers other than folate is lacking. We, therefore, investigated whether maternal plasma methyl donors, that is, choline, betaine and methionine, are associated with birth outcomes. Blood samples were obtained from 115 women during gestation (median 26·3 weeks, 90 % range 22·7-33·0 weeks). Plasma choline, betaine, methionine and dimethylglycine were measured using HPLC-tandem MS. Multivariate linear and logistic regression models were used to estimate the association between plasma biomarkers and birth weight, birth length, the risk of small-for-gestational-age and large-for-gestational-age (LGA). Higher level of maternal betaine was associated with lower birth weight (-130·3 (95 % CI -244·8, -15·9) per 1 sd increment for log-transformed betaine). Higher maternal methionine was associated with lower risk of LGA, and adjusted OR, with 95 % CI for 1 sd increase in methionine concentration was 0·44 (95 % CI 0·21, 0·89). Stratified analyses according to infant sex or maternal plasma homocysteine status showed that reduction in birth weight in relation to maternal betaine was only limited to male infants or to who had higher maternal homocysteine status (≥5·1 µmol/l). Higher maternal betaine status was associated with reduced birth weight. Maternal methionine was inversely associated with LGA risk. These findings are needed to be replicated in future larger studies.

A multicountry randomized controlled trial of comprehensive maternal nutrition supplementation initiated before conception: the Women First trial

Background

Reported benefits of maternal nutrition supplements commenced during pregnancy in low-resource populations have typically been quite limited.

Objectives

This study tested the effects on newborn size, especially length, of commencing nutrition supplements for women in low-resource populations ≥3 mo before conception (Arm 1), compared with the same supplement commenced late in the first trimester of pregnancy (Arm 2) or not at all (control Arm 3).

Methods

Women First was a 3-arm individualized randomized controlled trial (RCT). The intervention was a lipid-based micronutrient supplement; a protein-energy supplement was also provided if maternal body mass index (kg/m2) was <20 or gestational weight gain was less than recommendations. Study sites were in rural locations of the Democratic Republic of the Congo (DRC), Guatemala, India, and Pakistan. The primary outcome was length-for-age z score (LAZ), with all anthropometry obtained <48 h post delivery. Because gestational ages were unavailable in DRC, outcomes were determined for all 4 sites from WHO newborn standards (non-gestational-age-adjusted, NGAA) as well as INTERGROWTH-21st fetal standards (3 sites, gestational age-adjusted, GAA).

Results

A total of 7387 nonpregnant women were randomly assigned, yielding 2451 births with NGAA primary outcomes and 1465 with GAA outcomes. Mean LAZ and other outcomes did not differ between Arm 1 and Arm 2 using either NGAA or GAA. Mean LAZ (NGAA) for Arm 1 was greater than for Arm 3 (effect size: +0.19; 95% CI: 0.08, 0.30, P = 0.0008). For GAA outcomes, rates of stunting and small-for-gestational-age were lower in Arm 1 than in Arm 3 (RR: 0.69; 95% CI: 0.49, 0.98, P = 0.0361 and RR: 0.78; 95% CI: 0.70, 0.88, P < 0.001, respectively). Rates of preterm birth did not differ among arms.

Conclusions

In low-resource populations, benefits on fetal growth-related birth outcomes were derived from nutrition supplements commenced before conception or late in the first trimester. This trial was registered at clinicaltrials.gov as NCT01883193.

Prenatal influences on temperament development: The role of environmental epigenetics

This review summarizes current knowledge and outlines future directions relevant to questions concerning environmental epigenetics and the processes that contribute to temperament development. Links between prenatal adversity, epigenetic programming, and early manifestations of temperament are important in their own right, also informing our understanding of biological foundations for social-emotional development. In addition, infant temperament attributes represent key etiological factors in the onset of developmental psychopathology, and studies elucidating their prenatal foundations expand our understanding of developmental origins of health and disease. Prenatal adversity can take many forms, and this overview is focused on the environmental effects of stress, toxicants, substance use/psychotropic medication, and nutrition. Dysregulation associated with attention-deficit/hyperactivity-disruptive disorders was noted in the context of maternal substance use and toxicant exposures during gestation, as well as stress. Although these links can be made based on the existing literature, currently few studies directly connect environmental influences, epigenetic programming, and changes in brain development/behavior. The chain of events starting with environmental inputs and resulting in alterations to gene expression, physiology, and behavior of the organism is driven by epigenetics. Epigenetics provides the molecular mechanism of how environmental factors impact development and subsequent health and disease, including early brain and temperament development.

Manipulation of the Alternative NF-κB Pathway in Mice Has Sexually Dimorphic Effects on Bone

Alternative NF‐κB signaling promotes osteoclastogenesis and pathological bone loss, but the effect of sex on phenotype has not been explored. We disrupted alternative NF‐κB signaling by deletion of upstream kinase NF‐κB‐inducing kinase (NIK) or NF‐κB subunit RelB and found that both NIK‐deficient and RelB‐deficient female mice possessed more than twofold higher trabecular bone mass compared to controls, whereas no differences were observed in males. In vitro, RelB‐deficient precursors from female mice showed a more severe osteoclast (OC) differentiation defect than male, while WT had no sex bias. Next, we asked whether pharmacologic activation of alternative NF‐κB by inhibitor of apoptosis (IAP) antagonist BV6 has sex‐dependent effects on bone. Unlike male mice that lost bone, female mice on BV6 for 4 weeks showed no changes in either trabecular bone mass or OC number. Because estrogen generally suppresses NF‐κB, we hypothesized that estrogen protects bone from BV6 effects in vivo. Thus, we performed ovariectomy or sham surgery in female mice, then treated with BV6 or vehicle for 4 weeks. Although ovariectomy caused bone loss, BV6 did not have any additional impact, suggesting that direct estrogen effects do not cause resistance to BV6 in vivo. The osteopenic effects of IAP antagonists in males may have implications for their use in cancer therapy. © 2018 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

The Impact of Nutritional Interventions in Pregnant Women on DNA Methylation Patterns of the Offspring: A Systematic Review

Epidemiological studies have consistently demonstrated that environmental exposures in early life are associated with later-life health status and disease susceptibility. Epigenetic modifications, such as DNA methylation, have been suggested as potential mechanisms linking the intrauterine environment with offspring health status. The present systematic review compiles peer-reviewed randomized controlled trials assessing the impact of maternal nutritional interventions on DNA methylation patterns of the offspring. The results of the included trials are consistent with micronutrient supplementation not significantly affecting offspring tissue DNA methylation patterns, yet subgrouping by sex, BMI, and smoking status increased the significance of nutritional supplementation on DNA methylation. Maternal BMI and smoking status as well as offspring sex were factors influencing offspring DNA methylation responsiveness to nutritional interventions during pregnancy. Future research should aim at assessing the impact of nutritional interventions on DNA methylation patterns of neonates comparing single versus multi-micronutrient supplementation, within populations having high versus low baseline nutritional statuses.

The long-term impact of folic acid in pregnancy on offspring DNA methylation: follow-up of the Aberdeen Folic Acid Supplementation Trial (AFAST)

BACKGROUND

It has been proposed that maternal folic-acid supplement use may alter the DNA-methylation patterns of the offspring during the in-utero period, which could influence development and later-life health outcomes. Evidence from human studies suggests a role for prenatal folate levels in influencing DNA methylation in early life, but this has not been extended to consider persistent effects into adulthood.

METHODS

To better elucidate the long-term impact of maternal folic acid in pregnancy on DNA methylation in offspring, we carried out an epigenome-wide association study (EWAS) nested within the Aberdeen Folic Acid Supplementation Trial (AFAST-a trial of two different doses: 0.2 and 5 mg, folic acid vs placebo). Offspring of the AFAST participants were recruited at a mean age of 47 years and saliva samples were profiled on the Illumina Infinium Human Methylation450 array. Both single-site and differentially methylated region analyses were performed.

RESULTS

We found an association at cg09112514 (p = 4.03×10-9), a CpG located in the 5' untranslated region of PDGFRA, in the main analysis comparing the intervention arms [low- (0.2 mg) and high-dose (5 mg) folic acid combined (N = 43)] vs placebo (N = 43). Furthermore, a dose-response reduction in methylation at this site was identified in relation to the intervention. In the regional approach, we identified 46 regions of the genome that were differentially methylated in response to the intervention (Sidak p-value <0.05), including HLA-DPB2, HLA-DPB1, PAX8 and VTRNA2-1. Whereas cg09112514 did not replicate in an independent EWAS of maternal plasma folate, there was suggested replication of differential methylation in PAX8.

CONCLUSIONS

The results of this study suggest that maternal folic-acid supplement use is associated with changes in the DNA methylation of the offspring that persist for many years after exposure in utero. These methylation changes are located in genes implicated in embryonic development, immune response and cellular proliferation. Further work to investigate whether these epigenetic changes translate into detectable phenotypic differences is required.

Sex and Gender Differences in the Outcomes of Vaccination over the Life Course

Both sex (i.e., biological differences) and gender (i.e., social or cultural influences) impact vaccine acceptance, responses, and outcomes. Clinical data illustrate that among children, young adults, and aged individuals, males and females differ in vaccine-induced immune responses, adverse events, and protection. Although males are more likely to receive vaccines, following vaccination, females typically develop higher antibody responses and report more adverse effects of vaccination than do males. Human, nonhuman animal, and in vitro studies reveal numerous immunological, genetic, hormonal, and environmental factors that differ between males and females and contribute to sex- and gender-specific vaccine responses and outcomes. Herein, we address the impact of sex and gender variables that should be considered in preclinical and clinical studies of vaccines.

Does antenatal micronutrient supplementation improve children's cognitive function? Evidence from the follow-up of a double-blind randomised controlled trial in Nepal

Introduction

Multiple Micronutrient (MMN) supplementation during pregnancy can decrease the proportion of infants born low birth weight and small for gestational age. Supplementation could also enhance children's cognitive function by improving access to key nutrients during fetal brain development and increasing birth weight, especially in areas where undernutrition is common. We tested the hypothesis that children whose mothers received MMN supplementation during pregnancy would have higher intelligence in early adolescence compared with those receiving Iron and Folic Acid (IFA) only.

Methods

We followed up children in Nepal, whose mothers took part in a double-blind Randomised Controlled Trial (RCT) that compared the effects on birth weight and gestational duration of antenatal MMN versus IFA supplementation. We assessed children's Full Scale Intelligence Quotient (FSIQ) using the Universal Non-verbal Intelligence Test (UNIT), and their executive function using the counting Stroop test. The parent trial was registered as ISRCTN88625934.

Results

We identified 813 (76%) of the 1069 children whose mothers took part in the parent trial. We found no differences in FSIQ at 12 years between MMN and IFA groups (absolute difference in means (diff): 1.25, 95% CI -0.57 to 3.06). Similarly, there were no differences in mean UNIT memory (diff: 1.41, 95% CI -0.48 to 3.30), reasoning (diff: 1.17, 95% CI -0.72 to 3.06), symbolic (diff: 0.97, 95% CI -0.67 to 2.60) or non-symbolic quotients (diff: 1.39, 95% CI -0.60 to 3.38).

Conclusion

Our follow-up of a double-blind RCT in Nepal found no evidence of benefit from antenatal MMN compared with IFA for children's overall intelligence and executive function at 12 years.

Exploring a causal role of DNA methylation in the relationship between maternal vitamin B12 during pregnancy and child's IQ at age 8, cognitive performance and educational attainment: a two-step Mendelian randomization study

An adequate intake of vitamin B₁₂ during pregnancy plays an important role in offspring neurodevelopment, potentially via epigenetic processes. We used a two-step Mendelian randomization approach to assess whether DNA methylation plays a mediating and causal role in associations between maternal vitamin B₁₂ status and offspring’s cognition. Firstly, we estimated the causal effect of maternal vitamin B₁₂ levels on cord blood DNA methylation using the maternal FUT2 genotypes rs492602:A > G and rs1047781:A > T as proxies for circulating vitamin B₁₂ levels in the Avon Longitudinal Study of Parents and Children (ALSPAC) and we tested the observed associations in a replication cohort. Secondly, we estimated the causal effect of DNA methylation on IQ using the offspring genotype at sites close to the methylated CpG site as a proxy for DNA methylation in ALSPAC and in a replication sample. The first step Mendelian randomization estimated that maternal vitamin B₁₂ had a small causal effect on DNA methylation in offspring at three CpG sites, which was replicated for one of the sites. The second step Mendelian randomization found weak evidence of a causal effect of DNA methylation at two of these sites on childhood performance IQ which was replicated for one of the sites. The findings support a causal effect of maternal vitamin B₁₂ levels on cord blood DNA methylation, and a causal effect of vitamin B₁₂-responsive DNA methylation changes on children’s cognition. Some limitations were identified and future studies using a similar approach should aim to overcome such issues.

Obesity in Pregnancy: Optimizing Outcomes for Mom and Baby

Obesity is common in women of childbearing age, and management of this population around the time of pregnancy involves specific challenges. Weight and medical comorbidities should be optimized both before and during pregnancy. During pregnancy, gestational weight gain should be limited, comorbidities should be appropriately screened for and managed, and fetal health should be monitored. Consideration should be given to the optimal timing of delivery and to reducing surgical and anesthetic complications. In the postpartum period, breastfeeding and weight loss should be promoted. Maternal obesity is associated with adverse metabolic effects in offspring, promoting an intergenerational cycle of obesity.

Protocol for the EMPHASIS study; epigenetic mechanisms linking maternal pre-conceptional nutrition and children's health in India and Sub-Saharan Africa

Background

Animal studies have shown that nutritional exposures during pregnancy can modify epigenetic marks regulating fetal development and susceptibility to later disease, providing a plausible mechanism to explain the developmental origins of health and disease. Human observational studies have shown that maternal peri-conceptional diet predicts DNA methylation in offspring. However, a causal pathway from maternal diet, through changes in DNA methylation, to later health outcomes has yet to be established. The EMPHASIS study (Epigenetic Mechanisms linking Pre-conceptional nutrition and Health Assessed in India and Sub-Saharan Africa, ISRCTN14266771) will investigate epigenetically mediated links between peri-conceptional nutrition and health-related outcomes in children whose mothers participated in two randomized controlled trials of micronutrient supplementation before and during pregnancy.

Methods

The original trials were the Mumbai Maternal Nutrition Project (MMNP, ISRCTN62811278) in which Indian women were offered a daily snack made from micronutrient-rich foods or low-micronutrient foods (controls), and the Peri-conceptional Multiple Micronutrient Supplementation Trial (PMMST, ISRCTN13687662) in rural Gambia, in which women were offered a daily multiple micronutrient (UNIMMAP) tablet or placebo. In the EMPHASIS study, DNA methylation will be analysed in the children of these women (~1100 children aged 5–7 y in MMNP and 298 children aged 7–9 y in PMMST). Cohort-specific and cross-cohort effects will be explored. Differences in DNA methylation between allocation groups will be identified using the Illumina Infinium MethylationEPIC array, and by pyrosequencing top hits and selected candidate loci. Associations will be analysed between DNA methylation and health-related phenotypic outcomes, including size at birth, and children’s post-natal growth, body composition, skeletal development, cardio-metabolic risk markers (blood pressure, serum lipids, plasma glucose and insulin) and cognitive function. Pathways analysis will be used to test for enrichment of nutrition-sensitive loci in biological pathways. Causal mechanisms for nutrition-methylation-phenotype associations will be explored using Mendelian Randomization. Associations between methylation unrelated to supplementation and phenotypes will also be analysed.

Conclusion

The study will increase understanding of the epigenetic mechanisms underpinning the long-term impact of maternal nutrition on offspring health. It will potentially lead to better nutritional interventions for mothers preparing for pregnancy, and to identification of early life biomarkers of later disease risk.

DNA methylation links genetics, fetal environment, and an unhealthy lifestyle to the development of type 2 diabetes

Type 2 diabetes is a complex trait with both environmental and hereditary factors contributing to the overall pathogenesis. One link between genes, environment, and disease is epigenetics influencing gene transcription and, consequently, organ function. Genome-wide studies have shown altered DNA methylation in tissues important for glucose homeostasis including pancreas, liver, skeletal muscle, and adipose tissue from subjects with type 2 diabetes compared with nondiabetic controls. Factors predisposing for type 2 diabetes including an adverse intrauterine environment, increasing age, overweight, physical inactivity, a family history of the disease, and an unhealthy diet have all shown to affect the DNA methylation pattern in target tissues for insulin resistance in humans. Epigenetics including DNA methylation may therefore improve our understanding of the type 2 diabetes pathogenesis, contribute to development of novel treatments, and be a useful tool to identify individuals at risk for developing the disease.

A quadratically regularized functional canonical correlation analysis for identifying the global structure of pleiotropy with NGS data

Investigating the pleiotropic effects of genetic variants can increase statistical power, provide important information to achieve deep understanding of the complex genetic structures of disease, and offer powerful tools for designing effective treatments with fewer side effects. However, the current multiple phenotype association analysis paradigm lacks breadth (number of phenotypes and genetic variants jointly analyzed at the same time) and depth (hierarchical structure of phenotype and genotypes). A key issue for high dimensional pleiotropic analysis is to effectively extract informative internal representation and features from high dimensional genotype and phenotype data. To explore correlation information of genetic variants, effectively reduce data dimensions, and overcome critical barriers in advancing the development of novel statistical methods and computational algorithms for genetic pleiotropic analysis, we proposed a new statistic method referred to as a quadratically regularized functional CCA (QRFCCA) for association analysis which combines three approaches: (1) quadratically regularized matrix factorization, (2) functional data analysis and (3) canonical correlation analysis (CCA). Large-scale simulations show that the QRFCCA has a much higher power than that of the ten competing statistics while retaining the appropriate type 1 errors. To further evaluate performance, the QRFCCA and ten other statistics are applied to the whole genome sequencing dataset from the TwinsUK study. We identify a total of 79 genes with rare variants and 67 genes with common variants significantly associated with the 46 traits using QRFCCA. The results show that the QRFCCA substantially outperforms the ten other statistics.

Epigenetics, nutrition and mental health. Is there a relationship?

Many aspects of human development and disease are influenced by the interaction between genetic and environmental factors. Understanding how our genes respond to the environment is central to managing health and disease, and is one of the major contemporary challenges in human genetics. Various epigenetic processes affect chromosome structure and accessibility of deoxyribonucleic acid (DNA) to the enzymatic machinery that leads to expression of genes. One important epigenetic mechanism that appears to underlie the interaction between environmental factors, including diet, and our genome, is chemical modification of the DNA. The best understood of these modifications is methylation of cytosine residues in DNA. It is now recognized that the pattern of methylated cytosines throughout our genomes (the 'methylome') can change during development and in response to environmental cues, often with profound effects on gene expression. Many dietary constituents may indirectly influence genomic pathways that methylate DNA, and there is evidence for biochemical links between nutritional quality and mental health. Deficiency of both macro- and micronutrients has been associated with increased behavioural problems, and nutritional supplementation has proven efficacious in treatment of certain neuropsychiatric disorders. In this review we examine evidence from the fields of nutrition, developmental biology, and mental health that supports dietary impacts on epigenetic processes, particularly DNA methylation. We then consider whether such processes could underlie the demonstrated efficacy of dietary supplementation in treatment of mental disorders, and whether targeted manipulation of DNA methylation patterns using controlled dietary supplementation may be of wider clinical value.

Multiple-micronutrient supplementation for women during pregnancy

BACKGROUND

Multiple-micronutrient (MMN) deficiencies often coexist among women of reproductive age in low- to middle-income countries. They are exacerbated in pregnancy due to the increased demands, leading to potentially adverse effects on the mother and developing fetus. Though supplementation with MMNs has been recommended earlier because of the evidence of impact on pregnancy outcomes, a consensus is yet to be reached regarding the replacement of iron and folic acid supplementation with MMNs. Since the last update of this Cochrane review, evidence from a few large trials has recently been made available, the inclusion of which is critical to inform policy.

OBJECTIVES

To evaluate the benefits of oral multiple-micronutrient supplementation during pregnancy on maternal, fetal and infant health outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (11 March 2015) and reference lists of retrieved articles and key reviews. We also contacted experts in the field for additional and ongoing trials.

SELECTION CRITERIA

All prospective randomised controlled trials evaluating MMN supplementation with iron and folic acid during pregnancy and its effects on the pregnancy outcome were eligible, irrespective of language or the publication status of the trials. We included cluster-randomised trials, but quasi-randomised trials were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. The quality of the evidence was assessed using the GRADE approach.

MAIN RESULTS

Nineteen trials (involving 138,538 women) were identified as eligible for inclusion in this review but only 17 trials (involving 137,791 women) contributed data to the review. Fifteen of these 17 trials were carried out in low and middle-income countries and compared MMN supplements with iron and folic acid versus iron with or without folic acid. Two trials carried out in the UK compared MMN with a placebo. MMN with iron and folic acid versus iron, with or without folic acid (15 trials): MMN resulted in a significant decrease in the number of newborn infants identified as low birthweight (LBW) (average risk ratio (RR) 0.88, 95% confidence interval (CI) 0.85 to 0.91; high-quality evidence) or small-for-gestational age (SGA) (average RR 0.92, 95% CI 0.86 to 0.98; moderate-quality evidence). No significant differences were shown for other maternal and pregnancy outcomes: preterm births (average RR 0.96, 95% CI 0.90 to 1.03; high-quality evidence), stillbirth (average RR 0.97, 95% CI 0.87, 1.09; high-quality evidence), maternal anaemia in the third trimester (average RR 1.03, 95% CI 0.85 to 1.24), miscarriage (average RR 0.91, 95% CI 0.80 to 1.03), maternal mortality (average RR 0.97, 95% CI 0.63 to 1.48), perinatal mortality (average RR 1.01, 95% CI 0.91 to 1.13; high-quality evidence), neonatal mortality (average RR 1.06, 95% CI 0.92 to 1.22; high-quality evidence), or risk of delivery via a caesarean section (average RR 1.04; 95% CI 0.74 to 1.46).A number of prespecified, clinically important outcomes could not be assessed due to insufficient or non-available data. Single trials reported results for: very preterm birth < 34 weeks, macrosomia, side-effects of supplements, nutritional status of children, and congenital anomalies including neural tube defects and neurodevelopmental outcome: Bayley Scales of Infant Development (BSID) scores. None of these trials reported pre-eclampsia, placental abruption, premature rupture of membranes, cost of supplementation, and maternal well-being or satisfaction.When assessed according to GRADE criteria, the quality of evidence for the review's primary outcomes overall was good. Pooled results for primary outcomes were based on multiple trials with large sample sizes and precise estimates. The following outcomes were graded to be as of high quality: preterm birth, LBW, perinatal mortality, stillbirth and neonatal mortality. The outcome of SGA was graded to be of moderate quality, with evidence downgraded by one for funnel plot asymmetry and potential publication bias.We carried out sensitivity analysis excluding trials with high levels of sample attrition (> 20%); results were consistent with the main analysis except for the findings for SGA (average RR 0.91, 95% CI 0.84 to 1.00). We explored heterogeneity through subgroup analyses by maternal height and body mass index (BMI), timing of supplementation and dose of iron. Subgroup differences were observed for maternal BMI for the outcome preterm birth, with significant findings among women with low BMI. Subgroup differences were also observed for maternal BMI and maternal height for the outcome SGA, indicating a significant impact among women with higher maternal BMI and height. The overall analysis of perinatal mortality, although showed a non-significant effect of MMN supplements versus iron with or without folic acid, was found to have substantial statistical heterogeneity. Subgroup differences were observed for timing of supplementation for this outcome, indicating a significantly higher impact with late initiation of supplementation. The findings between subgroups for other primary outcomes were inconclusive. MMN versus placebo (two trials): A single trial in the UK found no clear differences between groups for preterm birth, SGA, LBW or maternal anaemia in the third trimester. A second trial reported the number of women with pre-eclampsia; there was no evidence of a difference between groups. Other outcomes were not reported.

AUTHORS' CONCLUSIONS

Our findings support the effect of MMN supplements with iron and folic acid in improving some birth outcomes. Overall, pregnant women who received MMN supplementation had fewer low birthweight babies and small-for-gestational-age babies. The findings, consistently observed in several systematic evaluations of evidence, provide a basis to guide the replacement of iron and folic acid with MMN supplements containing iron and folic acid for pregnant women in low and middle-income countries where MMN deficiencies are common among women of reproductive age. Efforts could focus on the integration of this intervention in maternal nutrition and antenatal care programs in low and middle-income countries.

Challenges for epigenetic research in inflammatory bowel diseases

The human epigenome may link environmental exposures and commensal microbiota changes to host pathology in respect to the developmental origins of inflammatory bowel diseases (ulcerative colitis [UC] and Crohn's disease [more appropriately Crohn disease, CD]). Genetic predisposition - prenatal, perinatal and pediatric environmental influences - microbiome aberration (dysbiosis) and immune dysregulation appear to be important elements in disease development, progression and maintenance. The prevalence of combined genetic and epigenetic susceptibility toward UC and CD is calculated herein to be as high as 2%, and approximately 1% for UC and CD in highly developed countries, respectively. This review emphasizes the significant challenges for epigenetic research in inflammatory bowel diseases. Overcoming these challenges, however, could reveal unique opportunities for disease prevention, treatment and possible cure.

Epigenetic memory in response to environmental stressors

Exposure to environmental stressors, toxicants, and nutrient deficiencies can affect DNA in several ways. Some exposures cause damage and alter the structure of DNA, but there is increasing evidence that the same or other environmental exposures, including those that occur during fetal development in utero, can cause epigenetic effects that modulate DNA function and gene expression. Some epigenetic changes to DNA that affect gene transcription are at least partially reversible (i.e., they can be enzymatically reversed after cessation of exposure to environmental agents), but some epigenetic modifications seem to persist, even for decades. To explain the effects of early life experiences (such as famine and exposures to other stressors) on the long-term persistence of specific patterns of epigenetic modifications, such as DNA methylation, we propose an analogy with immune memory. We propose that an epigenetic memory can be established and maintained in self-renewing stem cell compartments. We suggest that the observations on early life effects on adult diseases and the persistence of methylation changes in smokers support our hypothesis, for which a mechanistic basis, however, needs to be further clarified. We outline a new model based on methylation changes. Although these changes seem to be mainly adaptive, they are also implicated in the pathogenesis and onset of diseases, depending on individual genotypic background and types of subsequent exposures. Elucidating the relationships between the adaptive and maladaptive consequences of the epigenetic modifications that result from complex environmental exposures is a major challenge for current and future research in epigenetics.-Vineis, P., Chatziioannou, A., Cunliffe, V. T., Flanagan, J. M., Hanson, M., Kirsch-Volders, M., Kyrtopoulos, S. Epigenetic memory in response to environmental stressors.

Contrasting the effects of intra-uterine smoking and one-carbon micronutrient exposures on offspring DNA methylation

Maternal smoking and micronutrient intake during pregnancy are two strong biological candidates for impacting the developing epigenome. The extent to which DNA methylation in offspring is modified by these intrauterine exposures has not been presented in parallel. In this review, we summarize human studies which have investigated genome-wide DNA methylation in the offspring in relation to maternal smoking and one-carbon micronutrient exposure during pregnancy. We contrast the primarily independent efforts for these two categories of exposure, and potential explanations for these differences. We emphasize methodological considerations such as power to detect methylation signals, exposure assessment, control of sources of variability, causal inference and the role of observed methylation changes in mediating downstream outcomes in the offspring.

Infant's DNA Methylation Age at Birth and Epigenetic Aging Accelerators

Knowing the biological age of the neonates enables us to evaluate and better understand the health and maturity comprehensively. However, because of dearth of biomarkers, it is difficult to quantify the neonatal biological age. Here we sought to quantify and assess the variability in biological age at birth and to better understand how the aging rates before birth are influenced by exposure in intrauterine period by employing a novel epigenetic biomarker of aging (epigenetic clock). We observed that the methylation age at birth was independent of the infant's sex but was significantly influenced by race. Partial correlation analysis showed a significant negative relationship between maternal socioeconomic status and infants' methylation age (r_s = −0.48, P_s = 0.005). A significant association with the risk of fast aging was observed for prenatal exposure to tobacco smoke with OR (95% CI) of 3.17 (1.05–9.56). Both estimated cell abundance measures and lymphocyte subpopulations in cord blood showed that tobacco exposed group exhibit an altered T cell compartment, specifically substantial loss of naive T cells. Present study provides the first evidence that common perinatal exposure (such as maternal smoking and lower socioeconomic status) may be important aging accelerators and substantial loss of naive T cells may play a role in the smoking-related fast aging phenomenon.

Linear growth trajectories in Zimbabwean infants

BACKGROUND

Undernutrition in early life underlies 45% of child deaths globally. Stunting malnutrition (suboptimal linear growth) also has long-term negative effects on childhood development. Linear growth deficits accrue in the first 1000 d of life. Understanding the patterns and timing of linear growth faltering or recovery during this period is critical to inform interventions to improve infant nutritional status.

OBJECTIVE

We aimed to identify the pattern and determinants of linear growth trajectories from birth through 24 mo of age in a cohort of Zimbabwean infants.

DESIGN

We performed a secondary analysis of longitudinal data from a subset of 3338 HIV-unexposed infants in the Zimbabwe Vitamin A for Mothers and Babies trial. We used k-means clustering for longitudinal data to identify linear growth trajectories and multinomial logistic regression to identify covariates that were associated with each trajectory group.

RESULTS

For the entire population, the mean length-for-age z score declined from -0.6 to -1.4 between birth and 24 mo of age. Within the population, 4 growth patterns were identified that were each characterized by worsening linear growth restriction but varied in the timing and severity of growth declines. In our multivariable model, 1-U increments in maternal height and education and infant birth weight and length were associated with greater relative odds of membership in the least-growth restricted groups (A and B) and reduced odds of membership in the more-growth restricted groups (C and D). Male infant sex was associated with reduced odds of membership in groups A and B but with increased odds of membership in groups C and D.

CONCLUSION

In this population, all children were experiencing growth restriction but differences in magnitude were influenced by maternal height and education and infant sex, birth weight, and birth length, which suggest that key determinants of linear growth may already be established by the time of birth. This trial was registered at clinicaltrials.gov as NCT00198718.

Effect of prenatal DHA supplementation on the infant epigenome: results from a randomized controlled trial

BACKGROUND

Evidence is accumulating that nutritional exposures in utero can influence health outcomes in later life. Animal studies and human epidemiological studies have implicated epigenetic modifications as playing a key role in this process, but there are limited data from large well-controlled human intervention trials. This study utilized a large double-blind randomized placebo-controlled trial to test whether a defined nutritional exposure in utero, in this case docosahexaenoic acid (DHA), could alter the infant epigenome. Pregnant mothers consumed DHA-rich fish oil (800 mg DHA/day) or placebo supplements from 20 weeks' gestation to delivery. Blood spots were collected from the children at birth (n = 991) and blood leukocytes at 5 years (n = 667). Global DNA methylation was measured in all samples, and Illumina HumanMethylation450K BeadChip arrays were used for genome-wide methylation profiling in a subset of 369 children at birth and 65 children at 5 years.

RESULTS

There were no differences in global DNA methylation levels between the DHA and control group either at birth or at 5 years, but we identified 21 differentially methylated regions (DMRs) at birth, showing small DNA methylation differences (<5%) between the treatment groups, some of which seemed to persist until 5 years. The number of DMRs at birth was greater in males (127 DMRs) and in females (72 DMRs) separately, indicating a gender-specific effect.

CONCLUSION

Maternal DHA supplementation during the second half of pregnancy had small effects on DNA methylation of infants. While the potential functional significance of these changes remains to be determined, these findings further support the role of epigenetic modifications in developmental programming in humans and point the way for future studies.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR), ACTRN12605000569606 and ACTRN12611001127998.