Associations of maternal preterm birth with subsequent risk for type 2 diabetes in women from the women's health initiative

Preterm birth has been associated with insulin resistance and beta-cell dysfunction, a hallmark characteristic of type 2 diabetes. However, studies investigating the relationship between a personal history of being born preterm and type 2 diabetes are sparse. We sought to investigate the potential association between a personal history of being born preterm and risk for type 2 diabetes in a racially and ethnically diverse population. Baseline and incident data (>16 years of follow-up) from the Women's Health Initiative (n = 85,356) were used to examine the association between personal history of being born preterm (born 1910-1940s) and prevalent (baseline enrollment; cross-sectional) or incident (prospective cohort) cases of type 2 diabetes. Logistic and Cox proportional hazards regression models were used to estimate odds and hazards ratios. Being born preterm was significantly, positively associated with odds for prevalent type 2 diabetes at enrollment (adjOR = 1.79, 95% CI 1.43-2.24; P < 0.0001). Stratified regression models suggested the positive associations at baseline were consistent across race and ethnicity groups. However, being born preterm was not significantly associated with risk for incident type 2 diabetes. Regression models stratified by age at enrollment suggest the relationship between being born preterm and type 2 diabetes persists only among younger age groups. Preterm birth was associated with higher risk of type 2 diabetes but only in those diagnosed with type 2 diabetes prior to study enrollment, suggesting the association between preterm birth and type 2 diabetes may exist at earlier age of diagnosis but wane over time.

Advancing human health in the decade ahead: pregnancy as a key window for discovery: A Burroughs Wellcome Fund Pregnancy Think Tank

Recent revolutionary advances at the intersection of medicine, omics, data sciences, computing, epidemiology, and related technologies inspire us to ponder their impact on health. Their potential impact is particularly germane to the biology of pregnancy and perinatal medicine, where limited improvement in health outcomes for women and children has remained a global challenge. We assembled a group of experts to establish a Pregnancy Think Tank to discuss a broad spectrum of major gestational disorders and adverse pregnancy outcomes that affect maternal-infant lifelong health and should serve as targets for leveraging the many recent advances. This report reflects avenues for future effects that hold great potential in 3 major areas: developmental genomics, including the application of methodologies designed to bridge genotypes, physiology, and diseases, addressing vexing questions in early human development; gestational physiology, from immune tolerance to growth and the timing of parturition; and personalized and population medicine, focusing on amalgamating health record data and deep phenotypes to create broad knowledge that can be integrated into healthcare systems and drive discovery to address pregnancy-related disease and promote general health. We propose a series of questions reflecting development, systems biology, diseases, clinical approaches and tools, and population health, and a call for scientific action. Clearly, transdisciplinary science must advance and accelerate to address adverse pregnancy outcomes. Disciplines not traditionally involved in the reproductive sciences, such as computer science, engineering, mathematics, and pharmacology, should be engaged at the study design phase to optimize the information gathered and to identify and further evaluate potentially actionable therapeutic targets. Information sources should include noninvasive personalized sensors and monitors, alongside instructive "liquid biopsies" for noninvasive pregnancy assessment. Future research should also address the diversity of human cohorts in terms of geography, racial and ethnic distributions, and social and health disparities. Modern technologies, for both data-gathering and data-analyzing, make this possible at a scale that was previously unachievable. Finally, the psychosocial and economic environment in which pregnancy takes place must be considered to promote the health and wellness of communities worldwide.

The Effects of Maternal and Postnatal Dietary Methyl Nutrients on Epigenetic Changes that Lead to Non-Communicable Diseases in Adulthood

The risk for non-communicable diseases in adulthood can be programmed by early nutrition. This programming is mediated by changes in expression of key genes in various metabolic pathways during development, which persist into adulthood. These developmental modifications of genes are due to epigenetic alterations in DNA methylation patterns. Recent studies have demonstrated that DNA methylation can be affected by maternal or early postnatal diets. Because methyl groups for methylation reactions come from methionine cycle nutrients (i.e., methionine, choline, betaine, folate), deficiency or supplementation of these methyl nutrients can directly change epigenetic regulation of genes permanently. Although many studies have described the early programming of adult diseases by maternal and infant nutrition, this review discusses studies that have associated early dietary methyl nutrient manipulation with direct effects on epigenetic patterns that could lead to chronic diseases in adulthood. The maternal supply of methyl nutrients during gestation and lactation can alter epigenetics, but programming effects vary depending on the timing of dietary intervention, the type of methyl nutrient manipulated, and the tissue responsible for the phenotype. Moreover, the postnatal manipulation of methyl nutrients can program epigenetics, but more research is needed on whether this approach can rescue maternally programmed offspring.

Associations of early-life growth with health using an allostatic load score in young, urban African adults: Birth to Twenty Plus Cohort

Growth in early life is associated with various individual health outcomes in adulthood, but limited research has been done on associations with a more comprehensive measure of health. Combining information from multiple biological systems, allostatic load (AL) provides such a quantitative measure of overall physiological health. We used longitudinal data from the Birth to Twenty Plus cohort in South Africa to calculate an AL score at age 22 years and examined associations with birth weight and linear growth and weight gain from age 0 to 2 years and 2 to 5 years, as attenuated by trajectories of body mass index and pubertal development in later childhood and adolescence. Differences in total AL score between males and females were small, though levels of individual biological factors contributing to AL differed by sex. Increased weight gain from age 2 to 5 years among males was associated with an increased risk of high AL, but no other early-life measures were associated with AL. Increased adiposity through childhood and adolescence in females was associated with higher AL in early adulthood. These results illustrate that patterns of early-life growth are not consistently associated with higher AL. While more research is needed to link AL in young adulthood to later health outcomes, these results also suggest increased adiposity during childhood and adolescence represents a potential early sign of later physiological risk.

Relationship between early growth and CVD risk factors in adolescents

Low birth weight and a rapid weight gain in early childhood may lead to an increased risk for developing cardiovascular disease later in life, such as hypertension and dyslipidaemia. In this study, we examined the associations between size at birth, relative weight gain in infancy and childhood with specific cardiovascular disease risk factors in early adulthood. Adolescents (n=1935) from the Birth to Twenty plus (BT20+) cohort were included in the analysis. The following were treated as exposure variables: weight at birth, and relative conditional weight gain (CW), independent of height, between ages 0-24 months and 24-48 months. Outcomes were serum lipids and body composition variables at age 18 years. After adjusting for sex and other confounders, early life exposures were not associated with adolescent lipid profile. Following adjustment for sex and height (body size), birth weight [β=0.704 (0.40, 1.01)], CW 0-24 [β=1.918 (1.56, 2.28)] and CW24-48 [β=1.485 (1.14, 1.82)] accounted for 48% of the variance in fat mass. However, birth weight [β=0.773 (0.54, 1.01)], CW 0-24 [β=1.523 (1.24, 1.80)] and CW24-48 [β=1.226 (0.97, 1.49)] were also positively predicted and accounted for 71% of the variance in fat mass in adolescence (P<0.05). Our data suggests that birth weight and weight gain during infancy and early childhood independent of linear growth are related to adolescent body composition but not blood lipid profiles in an urban African population.

Children's Environmental Health: A Brief History

BACKGROUND

Children's environmental health (CEH), the branch of pediatrics that studies the influence of the environment on children's health, has grown substantially in the past 3 decades and become an increasingly visible and important component of pediatric medicine.

GOALS

To trace the historical origins of CEH; to identify factors responsible for its recent growth.

FINDINGS

CEH has historical roots in toxicology, epidemiology, and occupational medicine. It arose in the second half of the 20th century through a melding of insights from pediatric toxicology, nutritional epidemiology, and social science research. Convergent research in these 3 fields has documented children's unique sensitivities to chemical, nutritional, and psychosocial hazards during windows of vulnerability in early development and has shown that early-life exposures can produce disease and disability in childhood and across the life span. Key events in the development of CEH were: 1) formation by the American Academy of Pediatrics in 1957 of a committee on environmental health that has nurtured the growth of the field for 5 decades and evolved into the Council on Environmental Health; 2) observations made in the 1980s that nutritional deficiency in utero increased risk for adult-onset obesity, diabetes, and cardiovascular disease-work that led to the hypothesis of the developmental origins of health and disease; 3) social science research showing that early exposure to psychosocial stress and trauma increases risk for chronic illness; and 4) publication in 1993 by the National Academy of Sciences of a report, Pesticides in the Diets of Infants and Children, which elevated awareness among national policy makers of children's vulnerability to toxic hazards, moved US environmental policy toward protection of children's health, and catalyzed research investment in CEH in the United States and globally.

CONCLUSIONS

CEH has made substantial progress but faces emerging challenges, including new chemicals and pesticides; increasing movement of polluting industries to poor countries where environmental and public health protections are few; and global climate change. In the future, CEH will require continued investment in research and education and will need to adopt an increasingly global perspective.

In utero nicotine exposure epigenetically alters fetal chromatin structure and differentially regulates transcription of the glucocorticoid receptor in a rat model

BACKGROUND

Fetal exposure to nicotine is not limited to maternal tobacco smoke, as electronic cigarettes have an increased prevalence of use among reproductive aged women. Animal models have shown that nicotine exposure in utero is associated with increased risk of asthma and cognitive deficits, as well as increased expression of the hippocampal glucocorticoid receptor. We hypothesized that in utero nicotine exposure is associated with epigenetic changes in the offspring lung and brain which may contribute to a memory of this exposure

METHODS

Sprague-Dawley rat dams received either saline or 2 mg/kg of nicotine by intraperitoneal injection once daily from embryonic day 6 (e6) to e22. Pups were killed on day 1 of life, and brain and lung tissues were harvested (N = 3/ group).

RESULTS

We found that nicotine exposed offspring have altered histone modifications in the brain. Dimethylation of lysine 9 of histone H3 is decreased (0.43-fold; p = 0.03) while acetylation is increased (1.79-fold; p = 0.031). Histone deacetylase activity is significantly decreased with nicotine exposure in brain and lung (0.11-fold; p < 0.001; 0.12-fold; p < 0.001, respectively). Expression of splice variant 1.7 of the glucocorticoid receptor is reduced in the nicotine exposed offspring lung (0.25-fold; p = 0.038).

CONCLUSION

We conclude that nicotine exposure is associated with epigenetic alterations in the offspring and may lead to susceptibility to adult disease,. Our finding that in utero exposure to nicotine is associated with inhibition of histone deacetylase activity in the brain of offspring is of importance as a similar inhibition has been suggested as a mechanism for the potentiation of addiction.

The developmental neurotoxicity of arsenic: cognitive and behavioral consequences of early life exposure

BACKGROUND

More than 200 million people worldwide are chronically exposed to arsenic. Arsenic is a known human carcinogen, and its carcinogenic and systemic toxicity have been extensively studied. By contrast, the developmental neurotoxicity of arsenic has been less well described. The aim of this review was to provide a comprehensive review of the developmental neurotoxicity of arsenic.

METHODS

We reviewed the published epidemiological and toxicological literature on the developmental neurotoxicity of arsenic.

RESULTS

Arsenic is able to gain access to the developing brain and cause neurotoxic effects. Animal models link prenatal and early postnatal exposure to reduction in brain weight, reductions in numbers of glia and neurons, and alterations in neurotransmitter systems. Animal and in vitro studies both suggest that oxidative stress may be a mechanism of arsenic neurotoxicity. Fifteen epidemiological studies indicate that early life exposure is associated with deficits in intelligence and memory. These effects may occur at levels of exposure below current safety guidelines, and some neurocognitive consequences may become manifest only later in life. Sex, concomitant exposures, and timing of exposure appear to modify the developmental neurotoxicity of arsenic. Four epidemiological studies failed to show behavioral outcomes of arsenic exposure.

CONCLUSIONS

The published literature indicates that arsenic is a human developmental neurotoxicant. Ongoing and future prospective birth cohort studies will allow more precise definition of the developmental consequences of arsenic exposure in early life.

Do environments in infancy moderate the association between stress and inflammation in adulthood? Initial evidence from a birth cohort in the Philippines

Chronic inflammation is a potentially important pathway through which psychosocial stressors increase risk for cardiovascular disease. However, prior research on stress and inflammation has been conducted almost exclusively in high income, industrialized populations with low levels of infectious disease. In this study we test the hypothesis that psychosocial stressors are associated with elevated concentrations of C-reactive protein (CRP) among young adults in the Philippines (n=1622), who have grown up in an ecological and epidemiological setting that differs substantially from that of the US. In addition, we apply a developmental, ecological perspective to consider whether microbial and nutritional environments in infancy alter patterns of association between stressors and CRP. Data come from the Cebu Longitudinal Health and Nutrition Survey, a prospective cohort study that began collecting data in 1983-1984 when participants were in utero. A series of regression models indicate trends toward significant interactions between perceived stress and environmental factors in infancy, including exposure to animal feces, season of birth, and birth weight. Parental absence in childhood was a significant predictor of CRP in adulthood in interaction with exposure to animal feces in infancy. Positive associations between stressors and CRP were only evident for individuals with lower levels of microbial exposure in infancy, or lower birth weight. These results suggest that early environments influence the development of inflammatory phenotypes in ways that moderate sensitivity to psychosocial stressors in adulthood, and they underscore the value of a comparative, developmental approach to research on social environments, inflammation, and disease.

Associations between parenting behavior and anxiety in a rodent model and a clinical sample: relationship to peripheral BDNF levels

Adverse early-life environment is associated with anxiety-like behaviors and disorders. Brain-derived neurotrophic factor (BDNF) is sensitive to this environment and could be a marker of underlying brain changes. We aimed at evaluating the development of anxiety-like behaviors in a rat model of early adversity, as well as the possible association with BDNF levels. Similar associations were investigated in a sample of adolescent humans. For the rat study, Wistar rat litters were divided into: early-life stress (ELS, limited access to nesting material) and control groups. Maternal behavior was observed from days 1 to 9 of life and, as adults, rats were subjected to behavioral testing and BDNF measurements in plasma, hippocampus, amygdala and periaqueductal gray. For the human study, 129 adolescents were evaluated for anxiety symptoms and perceived parental care. Serum BDNF levels and the Val66Met polymorphism of the BDNF gene were investigated. We found that ELS dams showed more pure contact, that is, contact with low care and high control, toward pups, and their adult offspring demonstrated higher anxiety-like behaviors and plasma BDNF. Also the pure contact correlated positively with adult peripheral BDNF. Similarly in humans, there was a positive correlation between maternal overprotection and serum BDNF only in Met carriers. We also found negative correlations between maternal warmth and separation anxiety, social phobia and school phobia. Finally, our translational approach revealed that ELS, mediated through variations in maternal care, is associated with anxiety in both rats and humans and increased peripheral BDNF may be marking these phenomena.

Depressive symptoms are not associated with inflammation in younger and older adults in the Philippines

Depression is not associated with inflammation among adults in the Philippines, in contrast to prior research in the US. These results suggest that higher levels of microbial exposure in the Philippines may promote the development of immuno-regulatory pathways that prevent the emergence of a relationship between depression and inflammation.

Depression is positively associated with chronic inflammation in industrialized settings with low burdens of infectious disease, but the pattern of association in environments with higher levels of microbial exposure is not known. We measured C-reactive protein (CRP) and interleukin 6 (IL6) in community-based samples of young adults (20–22 years) and older women (35–69 years) in the Philippines. Concentrations of CRP and IL6 were low, and bivariate and multivariate regression analyses indicated no associations between depressive symptoms and inflammation in either sample. Results are interpreted in light of prior research indicating that higher levels of microbial exposure in infancy have lasting effects on the regulation of inflammation, and may prevent the emergence of a relationship between depression and inflammation in adulthood.

Developmental origins of adult diseases

There is considerable evidence for the fact that early life environment in human beings are associated with future development of various metabolic diseases. Fetal programming and perinatal events appear to exert effects on later life that are independent of environmental risk factors in adults. Our understanding of the underlying mechanisms are limited and remains unclear. However several animal models and epidemiological studies have shown this association, and it is assumed secondary to the penalties of developmental plasticity. In this review, we amalgamate facts from several disciplines to support this hypothesis.

Developmental exposure to polychlorinated biphenyls influences stroke outcome in adult rats

BACKGROUND

The "developmental origins of adult disease" hypothesis was originally derived from evidence linking low birth weight to cardiovascular diseases including stroke. Subsequently, it has been expanded to include developmental exposures to environmental contaminants as risk factors for adult onset disease.

OBJECTIVE

Our goal in this study was to test the hypothesis that developmental exposure to poly-chlorinated biphenyls (PCBs) alters stroke outcome in adults.

METHODS

We exposed rats to the PCB mixture Aroclor 1254 (A1254) at 0.1 or 1 mg/kg/day in the maternal diet throughout gestation and lactation. Focal cerebral ischemia was induced at 6-8 weeks of age via middle cerebral artery occlusion, and infarct size was measured in the cerebral cortex and striatum at 22 hr of reperfusion. PCB congeners were quantified in brain tissue by gas chromatography with microelectron capture detection, and cortical and striatal expression of Bcl2 and Cyp2C11 were quantified by quantitative reverse transcriptase-polymerase chain reaction.

RESULTS

Developmental exposure to A1254 significantly decreased striatal infarct in females and males at 0.1 and 1 mg/kg/day, respectively. Predominantly ortho-substituted PCB congeners were detected above background levels in brains of adult females and males exposed to A1254 at 1 but not 0.1 mg/kg/day. Effects of developmental A1254 exposure on Bcl2 and Cyp2C11 expression did not correlate with effects on infarct volume.

CONCLUSION

Our data provide proof of principle that developmental exposures to environmental contaminants influence the response of the adult brain to ischemic injury and thus represent potentially important determinants of stroke susceptibility.

Maternal genistein alters coat color and protects Avy mouse offspring from obesity by modifying the fetal epigenome

Genistein, the major phytoestrogen in soy, is linked to diminished female reproductive performance and to cancer chemoprevention and decreased adipose deposition. Dietary genistein may also play a role in the decreased incidence of cancer in Asians compared with Westerners, as well as increased cancer incidence in Asians immigrating to the United States. Here, we report that maternal dietary genistein supplementation of mice during gestation, at levels comparable with humans consuming high-soy diets, shifted the coat color of heterozygous viable yellow agouti (A(vy/a) offspring toward pseudoagouti. This marked phenotypic change was significantly associated with increased methylation of six cytosine-guanine sites in a retrotransposon upstream of the transcription start site of the Agouti gene. The extent of this DNA methylation was similar in endodermal, mesodermal, and ectodermal tissues, indicating that genistein acts during early embryonic development. Moreover, this genistein-induced hypermethylation persisted into adulthood, decreasing ectopic Agouti expression and protecting offspring from obesity. Thus, we provide the first evidence that in utero dietary genistein affects gene expression and alters susceptibility to obesity in adulthood by permanently altering the epigenome.