Adiposity and Chronic Inflammation in Young Women Predict Inflammation during Normal Pregnancy in the Philippines

Maternal plasma transforming growth factor-β1 (TGF-β1) and newborn size: the Araraquara Cohort Study

OBJECTIVE

To investigate associations of maternal and cord blood cytokine patterns with newborn size and body composition.

METHODS

This cross-sectional study involved 70 pregnant women and their healthy newborns selected from the "Araraquara Cohort Study". Newborn anthropometric measurements were recorded at birth. Body composition was evaluated by air displacement plethysmography. Maternal blood samples were collected from pregnant women between 30 and 36 weeks of gestation, and umbilical cord blood samples were collected immediately after placenta discharge. The concentrations of the cytokines were determined in plasma by ELISA. Multiple linear regression models were used to assess associations between maternal and cord blood cytokine concentrations and newborn anthropometry and body composition measurements.

RESULTS

Maternal plasma TGF-β1 concentration was inversely associated with newborn weight (β = -43.0; p = 0.012), length (β = -0.16, p = 0.028), head circumference (β = -0.13, p = 0.004), ponderal index (β = -0.32, p = 0.011) and fat-free mass (β = -0.05, p = 0.005). However, the association persisted just for head circumference (β = -0.26; p = 0.030) and ponderal index (β = - 0.28; p = 0.028), after adjusting for pre-gestational BMI, gestational weight gain, gestational age, hours after delivery, newborn sex, smoking and alcohol consumption.

CONCLUSIONS

Maternal plasma TGF-β1 concentration may be involved in the regulation of newborn size, mainly head circumference and ponderal index. Further cohort studies are necessary to investigate the role of TGF-β1 in different trimesters of pregnancy and its effect during the early stages of fetal development.

Markers of inflammation in obese pregnant women: Adenosine deaminase and high sensitive C - reactive protein

Introduction

The worldwide increase in the prevalence of obesity over the years has emerged as a global health concern. The growing rate of obesity in women of child bearing age is particularly a matter of concern. Obesity is considered a risk factor that predisposes an individual to a proinflammatory state through the release of the inflammatory mediators. Recent studies have shown a positive correlation between the severity of inflammation and an increase in adenosine deaminase (ADA) and high sensitivity C- reactive protein (hs-CRP). Obese pregnancy women are at a higher risk for developing inflammation-mediated pregnancy complications like gestational diabetes, preeclampsia, and preterm delivery. Considering the fact that pregnancy, obesity and inflammation are closely linked, this study evaluated the inflammation associated with obesity during pregnancy by estimating changes in ADA and hs-CRP.

Materials and methods

The current study aimed to evaluate the levels of inflammation in obese pregnant women compared to non-obese pregnant women by correlating BMI with levels of ADA / hs-CRP. The study also aimed to examine the change in ADA and hs-CRP levels with gestational age (between the 1^st and the 3^rd trimester) in obese pregnant women as compared to non-obese pregnant women. We also examined whether changes in the levels of ADA correlate with changes in the levels of hs-CRP particularly in obese pregnant women.Blood samples were collected from obese and non-obese pregnant women. ADA activity and hs-CRP levels were estimated by biochemical assays. BMI was evaluated in the 1^st trimester and those women with BMI > 30 kg/m²were considered as obese. Thirty subjects were included in each of the two groups.

Results

ADA and hs-CRP levels were significantly higher in obese pregnant women in both the 1^st and 3^rd trimesters compared to non-obese participants (P value<0.05). Statistically significant higher values of ADA and hs-CRP were seen in obese participants in the 3^rd trimester compared to the 1^st trimester.A significant linear positive correlation was found between BMI and 3^rd trimester ADA, and a linear positive correlation between BMI and hs-CRP both in the 1^st and 3^rd trimester. The relationship between ∆ ADA and ∆ hs-CRP was non- significant.

Conclusions

The observations of this study reveal increased inflammatory responses in obese pregnant women and suggests the importance of ADA and hs-CRP as early indicators of obesity-related complications prevailing thereafter, these markers can be useful for clinical diagnosis of impending maternal and neonatal complications.

Association between Pre-Pregnancy BMI and Inflammatory Profile Trajectories during Pregnancy and Postpartum in Brazilian Women with Periodontitis: The IMPROVE Trial

This study aimed to explore the association between pre-pregnancy BMI and longitudinal changes in inflammatory markers from the second trimester of pregnancy to 6-8 weeks postpartum in women with periodontitis. This is a secondary exploratory analysis of 68 women who took part in a feasibility clinical trial in Rio de Janeiro, Brazil. Inflammatory markers included C-reactive protein (CRP), interleukin-6 (IL-6), interleukin-10 (IL-10), and matrix metalloproteinase-9 (MMP-9) blood concentrations at 11-22 (T0) and 30-36 gestational weeks (T1), and 6-8 weeks postpartum (T3). Longitudinal generalised linear mixed-effects models were used to identify possible associations between pre-pregnancy BMI and changes in concentrations of inflammatory markers. Pre-pregnancy excess weight (β = 4.39; 95% CI, 2.12-6.65) was significantly associated with increased CRP levels from pregnancy to postpartum. There were no significant associations between pre-pregnancy BMI and longitudinal changes in IL-6, IL-10 and MMP-9. Our findings provide evidence that a higher pre-pregnancy BMI may lead to increases in CRP levels during pregnancy in women with periodontitis, irrespective of the severity of clinical periodontal parameters. Further studies need to investigate if predictors of changes in inflammatory markers can be used as prognostic factors for gestational outcomes.

Dietary β-Carotene on Postpartum Uterine Recovery in Mice: Crosstalk Between Gut Microbiota and Inflammation

As the precursor of vitamin A, β-carotene has a positive effect on reproductive performance. Our previous study has shown that β-carotene can increase antioxidant enzyme activity potentially through regulating gut microbiota in pregnant sows. This study aimed to clarify the effect of β-carotene on reproductive performance and postpartum uterine recovery from the aspect of inflammation and gut microbiota by using a mouse model. Twenty-seven 6 weeks old female Kunming mice were randomly assigned into 3 groups (n=9), and fed with a diet containing 0, 30 or 90 mg/kg β-carotene, respectively. The results showed that dietary supplementation of β-carotene reduced postpartum uterine hyperemia and uterine mass index (P<0.05), improved intestinal villus height and villus height to crypt depth ratio, decreased serum TNF-α and IL-4 concentration (P<0.05), while no differences were observed in litter size and litter weight among three treatments. Characterization of gut microbiota revealed that β-carotene up-regulated the relative abundance of genera Akkermansia, Candidatus Stoquefichus and Faecalibaculum, but down-regulated the relative abundance of Alloprevotella and Helicobacter. Correlation analysis revealed that Akkermansia was negatively correlated with the IL-4 concentration, while Candidatus Stoquefichus and Faecalibaculum had a negative linear correlation with both TNF-α and IL-4 concentration. On the other hand, Alloprevotella was positively correlated with the TNF-α, and Helicobacter had a positive correlation with both TNF-α and IL-4 concentration. These data demonstrated that dietary supplementation of β-carotene contributes to postpartum uterine recovery by decreasing postpartum uterine hemorrhage and inhibiting the production of inflammatory cytokines potentially through modulating gut microbiota.

Non-linear and non-additive associations between the pregnancy metabolome and birthweight

BACKGROUND

Birthweight is an indicator of fetal growth and environmental-related alterations of birthweight have been linked with multiple disorders and conditions progressing into adulthood. Although a few studies have assessed the association between birthweight and the totality of exogenous exposures and their downstream molecular responses in maternal urine and cord blood; no prior research has considered a) the maternal serum prenatal metabolome, which is enriched for hormones, and b) non-linear and synergistic associations among exposures.

METHODS

We measured the maternal serum metabolome during pregnancy using an untargeted metabolomics approach and birthweight for gestational age (BWGA) z-score in 410 mother-child dyads enrolled in the PRogramming of Intergenerational Stress Mechanisms (PRISM) cohort. We leveraged a Bayesian factor analysis for interaction to select the most important metabolites associated with BWGA z-score and to evaluate their linear, non-linear and non-additive associations. We also assessed the primary biological functions of the identified proteins using the MetaboAnalyst, a centralized repository of curated functional information. We compared our findings with those of a traditional metabolite-wide association study (MWAS) in which metabolites are individually associated with BWGA z-score.

RESULTS

Among 1110 metabolites, 46 showed evidence of U-shape associations with BWGA z-score. Most of the identified metabolites (85%) were lipids primarily enriched for pathways central to energy production, immune function, and androgen and estrogen metabolism, which are essential for pregnancy and parturition processes. Metabolites within the same class, i.e. steroids and phospholipids, showed synergistic relationships with each other.

CONCLUSIONS

Our results support that the aspects of the maternal metabolome during pregnancy contribute linearly, non-linearly and synergistically to variation in newborn birthweight.

The Impact of Early-Life Exposures on Women's Reproductive Health in Adulthood

Purpose of Review

To review the effects of early-life, preconception, and prior-generation exposures on reproductive health in women.

Recent Findings

Women’s early-life factors can affect reproductive health by contributing to health status or exposure level on entering pregnancy. Alternately, they can have permanent effects, regardless of later-life experience. Nutrition, social class, parental smoking, other adverse childhood experiences, environmental pollutants, infectious agents, and racism and discrimination all affect reproductive health, even if experienced in childhood or in utero. Possible transgenerational effects are now being investigated through three- or more-generation studies. These effects occur with mechanisms that may include direct exposure, behavioral, endocrine, inflammatory, and epigenetic pathways.

Summary

Pregnancy is increasingly understood in a life course perspective, but rigorously testing hypotheses on early-life effects is still difficult. In order to improve the health outcomes of all women, we need to expand our toolkit of methods and theory.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40471-021-00279-0.

Mediating role of C-reactive protein in associations between pre-pregnancy BMI and adverse maternal and neonatal outcomes: the ABCD-study cohort

OBJECTIVES

Increased body mass index (BMI) is associated with several adverse pregnancy outcomes, though the underlying mechanism of this association has not been fully elucidated. A mediating role of low-grade systemic inflammation in these associations is suspected but has been understudied. Our objective was to examine the effect of pre-pregnancy BMI (pBMI) on maternal and neonatal pregnancy outcomes and to explore potential mediation of these effects by C-reactive protein (CRP), a first trimester peripheral marker of inflammation.

METHODS

Data from the prospective community-based ABCD-study cohort (n = 3547) was used to assess associations between self-reported continuous and categorized pBMI and outcome measures gestational hypertension (GH) and preeclampsia (PE), preterm birth (PTB) and small for gestational age (SGA) based on national perinatal registration linkage data. High-sensitivity CRP concentrations determined in serum were used to explore potential mediation of these associations by inflammation.

RESULTS

Multivariable logistic regression analyses, adjusted for confounders, showed that pBMI was significantly related to gestational hypertensive disorders (odds ratio (OR) per standard deviation (SD) 1.66, 95% confidence interval (CI) 1.51-1.83) and PTB (OR 1.20, 95% CI 1.05-1.37). Dose-response relationships between categorical pBMI and gestational hypertensive disorders (overweight OR 2.37, 95% CI 1.85-3.03 and obese OR 4.45, 95% CI 2.93-6.72) and PTB (obese OR 2.12, 95% CI 1.16-3.87) were found as well. SGA was only significantly more prevalent in the underweight BMI category (OR 2.06, 95% CI 1.33-3.19). Mediation analyses revealed small but significant indirect effects of pBMI on overall PTB (0.037, bootstrapped 95% CI 0.005-0.065) and spontaneous PTB (0.038, bootstrapped 95% CI 0.002-0.069) through higher CRP. CRP was not a significant mediator of associations between BMI and gestational hypertensive disorders although larger mediation was found for GH than for PE.

CONCLUSION

Our findings provide additional evidence that high(er) pBMI increases the risk of adverse maternal and neonatal outcomes and that systemic inflammation mediates some of these risks. Further research in large cohorts including (morbidly) obese women is warranted to identify pathways that may be incorporated in future interventions to reduce the risk of adverse pregnancy outcomes due to maternal obesity.

Association of maternal sleep before and during pregnancy with preterm birth and early infant sleep and temperament

This study aimed to investigate the association of maternal sleep before and during pregnancy with preterm birth, infant sleep and temperament at 1 month of age. We used the data of the Japan Environment and Children’s Study, a cohort study in Japan, which registered 103,099 pregnancies between 2011 and 2014. Participants were asked about their sleep before and during pregnancy, and the sleep and temperament of their newborns at 1 month of age. Preterm birth data were collected from medical records. Maternal sleep was not associated with preterm birth, but subjective sleep quality during pregnancy was associated with late preterm birth (birth at 34–36 weeks of gestation). For example, participants with extremely light subjective depth of sleep were more likely to experience preterm birth (RR = 1.19; 95% confidence interval [CI] = 1.04–1.35). Maternal sleep both before and during pregnancy seemed to be associated with infant sleep and temperament at 1 month of age. Infants, whose mothers slept for less than 6 hours before pregnancy, tended to cry intensely (RR = 1.15; 95% CI = 1.09–1.20). Maternal sleep problems before and during pregnancy were associated with preterm birth and child sleep problems and temperament.

The Preconception Period analysis of Risks and Exposures Influencing health and Development (PrePARED) consortium

BACKGROUND

Preconception health may have intergenerational influences. We have formed the PrePARED (Preconception Period Analysis of Risks and Exposures influencing health and Development) research consortium to address methodological, conceptual, and generalisability gaps in the literature.

OBJECTIVES

The consortium will investigate the effects of preconception exposures on four sets of outcomes: (1) fertility and miscarriage; (2) pregnancy-related conditions; (3) perinatal and child health; and (4) adult health outcomes.

POPULATION

A study is eligible if it has data measured for at least one preconception time point, has a minimum of selected core data, and is open to collaboration and data harmonisation.

DESIGN

The included studies are a mix of studies following women or couples intending to conceive, general-health cohorts that cover the reproductive years, and pregnancy/child cohort studies that have been linked with preconception data. The majority of the participating studies are prospective cohorts, but a few are clinical trials or record linkages.

METHODS

Data analysis will begin with harmonisation of data collected across cohorts. Initial areas of interest include nutrition and obesity; tobacco, marijuana, and other substance use; and cardiovascular risk factors.

PRELIMINARY RESULTS

Twenty-three cohorts with data on almost 200 000 women have combined to form this consortium, begun in 2018. Twelve studies are of women or couples actively planning pregnancy, and six are general-population cohorts that cover the reproductive years; the remainder have some other design. The primary focus for four was cardiovascular health, eight was fertility, one was environmental exposures, three was child health, and the remainder general women's health. Among other cohorts assessed for inclusion, the most common reason for ineligibility was lack of prospectively collected preconception data.

CONCLUSIONS

The consortium will serve as a resource for research in many subject areas related to preconception health, with implications for science, practice, and policy.

Profiles of gene expression in maternal blood predict offspring birth weight in normal pregnancy

The association between lower birth weight and increased disease risk in adulthood has drawn attention to the physiological processes that shape the gestational environment. We implement genome-wide transcriptional profiling of maternal blood samples to identify subsets of genes and associated transcription control pathways that predict offspring birth weight. Female participants (N = 178, mean = 27.0 years) in a prospective observational birth cohort study were contacted between 2009 and 2014 to identify new pregnancies. An in-home interview was scheduled for early in the third trimester (mean = 30.3 weeks) to collect pregnancy-related information and a blood sample, and birth weight was measured shortly after delivery. Transcriptional activity in white blood cells was determined with a whole-genome gene expression direct hybridization assay. Fifty transcripts were differentially expressed in association with offspring birth weight, with 18 up-regulated in relation to lower birth weight, and 32 down-regulated. Examination of transcription control pathways identified increased activity of NF-κB, AP-1, EGR1, EGR4, and Gfi families, and reduced the activity of CEBP, in association with lower birth weight. Transcript origin analyses identified non-classical CD16+ monocytes, CD1c+ myeloid dendritic cells, and neutrophils as the primary cellular mediators of differential gene expression. These results point toward a systematic regulatory shift in maternal white blood cell activity in association with lower offspring birth weight, and they suggest that analyses of gene expression during gestation may provide insight into regulatory and cellular mechanisms that influence birth outcomes.

Regulation of inflammation during gestation and birth outcomes: Inflammatory cytokine balance predicts birth weight and length

OBJECTIVES

The maternal environment during gestation influences offspring health at birth and throughout the life course. Recent research has demonstrated that endogenous immune processes such as dysregulated inflammation adversely impact birth outcomes, increasing the risk for preterm birth and restricted fetal growth. Prior analyses examining this association suggest a relationship between maternal C-reactive protein (CRP), a summary measure of inflammation, and offspring anthropometric outcomes. This study investigates pro- and anti-inflammatory cytokines, and their ratio, to gain deeper insight into the regulation of inflammation during pregnancy.

METHODS

IL6, IL10, TNFɑ, and CRP were quantified in dried blood spots collected in the early third trimester (mean = 29.9 weeks) of 407 pregnancies in Metropolitan Cebu, Philippines. Relationships between these immune markers and offspring anthropometrics (birth weight, length, head circumference, and sum of skinfold thicknesses) were evaluated using multivariate regression analyses. Ratios of pro- to anti-inflammatory cytokines were generated.

RESULTS

Higher maternal IL6 relative to IL10 was associated with reduced offspring weight and length at birth. Individual cytokines did not predict birth outcomes.

CONCLUSIONS

Consistent with the idea that the relative balance of cytokines with pro- and anti-inflammatory effects is a key regulator of inflammation in pregnancy, the IL6:IL10 ratio, but neither cytokine on its own, predicted offspring birth outcomes. Our findings suggest that prior reports of association between CRP and fetal growth may reflect, in part, the balance between pro- and anti-inflammatory cytokines, and that the gestational environment is significantly shaped by cytokine imbalance.

Genome-wide analysis of DNA methylation in relation to socioeconomic status during development and early adulthood

OBJECTIVES

Socioeconomic status (SES) is a powerful determinant of health, but the underlying biological mechanisms are poorly understood. This study investigates whether levels of DNA methylation at CpG sites across the genome are associated with SES in a cohort of young adults in the Philippines.

METHODS

DNA methylation was assayed with the Illumina HumanMethylation450 Bead Chip, in leukocytes from 489 participants in the Cebu Longitudinal Health and Nutrition Survey (mean age = 20.9 years). SES was measured in infancy/childhood and adulthood, and was based on composite measures of income, assets, and education. Genome-wide analysis of variable probes identified CpG sites significantly associated with SES after adjustment for multiple comparisons. Functional enrichment analysis was used to identify biological pathways associated with these sites.

RESULTS

A total of 2,546 CpG sites, across 1,537 annotated genes, were differentially methylated in association with SES. In comparison with high SES, low SES was associated with increased methylation at 1,777 sites, and decreased methylation at 769 sites. Functional enrichment analysis identified over-representation of biological pathways related to immune function, skeletal development, and development of the nervous system.

CONCLUSIONS

Socioeconomic status predicts DNA methylation at a large number of CpG sites across the genome. The scope of these associations is commensurate with the wide range of biological systems and health outcomes that are shaped by SES, and these findings suggest that DNA methylation may play an important role.

Pre-pregnancy cardiovascular risk factors and racial disparities in birth outcomes: the Bogalusa Heart Study

BACKGROUND

Racial disparities in birth outcomes are mirrored in cardiovascular health. Recently there have been calls for more attention to preconception and interconceptional health in order to improve birth outcomes, including as a strategy to reduce black-white disparities.

METHODS

As part of a larger study of cardiovascular and reproductive health ("Bogalusa Babies"), female participants were linked to their children's birth certificates for Louisiana, Mississippi, and Texas births from 1982 to 2009. Three thousand and ninety-five women were linked to birth certificate data. Birth outcomes were defined as low birthweight (LBW) birthweight < 2500 g; preterm birth (PTB), > 3 weeks early; small for gestational age (SGA), <10th percentile for gestational age (percentiles based on study population); large for gestational age (LGA) >90th percentile for gestational age]. Cardiovascular measures (blood pressure, lipids, glucose, insulin) at the visit closest in time but prior to the pregnancy was examined as predictors of birth outcomes using logistic models adjusted for covariates.

RESULTS

Only a few cardiovascular risk factors were associated with birth outcomes. Triglycerides were associated with higher risk of LBW among whites (aOR 1.05, 95% 1.01-1.10). Higher glucose was associated with a reduction in risk of SGA for black women (aOR 0.85, 95% CI 0.76-0.95), but not whites (p for interaction = 0.02). Clear racial disparities were found, but they were reduced modestly (LBW/SGA) or not at all (PTB/LGA) after CVD risk factors were adjusted for.

CONCLUSIONS

This analysis does not provide evidence for preconception cardiovascular risk being a strong contributor to racial disparities.

Rethinking IL-6 and CRP: Why they are more than inflammatory biomarkers, and why it matters

Behavioral researchers have increasingly become interested in the idea that chronic, low-grade inflammation is a pathway through which social and behavioral variables exert long-term effects on health. Much research in the area employs putative inflammatory biomarkers to infer an underlying state of inflammation. Interleukin 6 (IL-6) and C-reactive protein (CRP, whose production is stimulated by IL-6) are arguably the two most commonly assayed biomarkers. Yet, in contrast with near-universal assumptions in the field, discoveries in immunology over the past two decades show that neither IL-6 nor CRP are unambiguous inflammatory markers. IL-6 operates through two distinct signaling pathways, only one of which is specifically upregulated during inflammation; both pathways have a complex range of effects and influence multiple physiological processes even in absence of inflammation. Similarly, CRP has two isoforms, one of which is produced locally in inflamed or damaged tissues. The other isoform is routinely produced in absence of inflammation and may have net anti-inflammatory effects. We propose a functional framework to account for the multiple actions of IL-6 and CRP. Specifically, we argue that both molecules participate in somatic maintenance efforts; hence elevated levels indicate that an organism is investing in protection, preservation, and/or repair of somatic tissue. Depending on the state of the organism, maintenance may be channeled into resistance against pathogens (including inflammation), pathogen tolerance and harm reduction, or tissue repair. The findings and framework we present have a range of potential implications for the interpretation of empirical findings in this area-a point we illustrate with alternative interpretations of research on socioeconomic status, stress, and depression.

Cardiac Biomarkers in Youth with Type 2 Diabetes Mellitus: Results from the TODAY Study

OBJECTIVES

To examine cardiac biomarkers over time in youth-onset type 2 diabetes, and relate serum concentrations to cardiovascular disease risk factors, and left ventricular structure and function.

STUDY DESIGN

TODAY (Treatment Options for type 2 Diabetes in Adolescents and Youth) was a multicenter randomized trial of 3 treatments including 521 participants with type 2 diabetes, aged 10-17 years, and with 2-6 years of follow-up. Participants were 36% male, obese, and ethnically diverse. Annual serum concentrations of brain natriuretic peptide, troponin, tumor necrosis factor (TNF)-α, receptors 1 and 2 were related to blood pressure, body mass index, hemoglobin A1c, and left ventricular ejection fraction, diastolic function, relative wall thickness, and mass.

RESULTS

Elevated concentrations of brain natriuretic peptide (≥100 pg/mL), TNF-α (≥5.6 pg/mL) and troponin (≥0.01 ng/mL), were present in 17.8%, 18.3%, and 34.2% of the cohort, respectively, at baseline, and in 15.4%, 17.1%, and 31.1% at the end of the study, with wide variability over time, without persistence in individuals or clear relationship to glycemia or cardiovascular structure/function. TNF receptors concentrations were increased at baseline and not significantly different from end-of-study concentrations. Adverse echocardiographic measures were more likely in the highest TNF receptor tertile (all P < .05): higher left ventricular mass (39.3 ± 9.0 g/m^2.7), left atrial internal dimension (3.7 ± 0.4 cm) and E/Em ratio, a measure of diastolic dysfunction (6.2 ± 1.9). After adjustment for body mass index, these relationships were no longer significant.

CONCLUSIONS

Elevated serum concentrations of cardiac biomarkers were common in youth with type 2 diabetes, but their clinical significance is unclear and will require further long-term study.

TRIAL REGISTRATION

ClinicalTrials.govNCT00081328.

Birth weight and postnatal microbial exposures predict the distribution of peripheral blood leukocyte subsets in young adults in the Philippines

The immune system not only provides protection against infectious disease but also contributes to the etiology of neoplastic, atopic, and cardiovascular and metabolic diseases. Prenatal and postnatal nutritional and microbial environments have lasting effects on multiple aspects of immunity, indicating that immune processes may play important roles in the developmental origins of disease. The objective of this study is to evaluate the association between birth weight and the distribution of leukocyte (white blood cell) subsets in peripheral blood in young adulthood. Postnatal microbial exposures were also considered as predictors of leukocyte distribution. Participants (n=486; mean age=20.9 years) were drawn from a prospective birth cohort study in the Philippines, and analyses focused on the following cell types: CD4 T lymphocytes, CD8 T lymphocytes, B lymphocytes, natural killer cells, monocytes, granulocytes. Higher birth weight was a strong predictor of higher proportion of CD4 T lymphocytes (B=0.12, s.e.=0.041, P=0.003), lower proportion of CD8 T lymphocytes (B=-0.874, s.e.=0.364, P=0.016), higher CD4:CD8 ratio (B=1.964, s.e.=0.658, P=0.003), and higher B lymphocytes (B=0.062, s.e.=0.031, P=0.047). Measures of microbial exposure in infancy were negatively associated with proportions of B lymphocytes and granulocytes, and lower CD4:CD8 ratio. Leukocytes are the key regulators and effectors of innate and specific immunity, but the origins of variation in the distribution of cell type across individuals are not known. Our findings point toward nutritional and microbial exposures in infancy as potentially important determinants of immune-phenotypes in adulthood, and they suggest that leukocyte distribution is a plausible mechanism through which developmental environments have lasting effects on disease risk in adulthood.

Maternal pregnancy C-reactive protein predicts offspring birth size and body composition in metropolitan Cebu, Philippines

The gestational milieu is an important influence on fetal development and long-term disease risk. Here we assess relationships between maternal pregnancy inflammation, indicated by C-reactive protein (CRP), and offspring anthropometric outcomes measured soon after birth. Data come from female participants (n=327, age 24.4-30.2 years) in a longitudinal study located in Metropolitan Cebu, Philippines. Between 2009 and 2014, pregnancy interviews (n=429) were conducted during which questionnaire and anthropometric data were obtained along with dried blood spot cards for CRP measurement. Offspring body weight, length, head circumference and five skinfold thickness measures were obtained soon after birth. Maternal pregnancy CRP was borderline (-1.11±0.64 days/log-mg/l; P<0.1) inversely related to gestational age at delivery, but did not increase the likelihood of preterm delivery. After adjusting for maternal pre-pregnancy body mass index, height, pregnancy adiposity, age, parity and other covariates, CRP was significantly, inversely related to offspring body weight (-0.047±0.017 kg/log-mg/l), length (-0.259±0.092 cm/log-mg/l) and sum of skinfolds (-0.520±0.190 mm/log-mg/l) (all P<0.05), and borderline inversely related to offspring head circumference (-0.102±0.068 cm/log-mg/l; P<0.1). Notably, relationships were continuous across the full CRP range, and not limited to unusually high levels of inflammation. These findings point to an important role of maternal non-specific immune activation as a predictor of offspring birth outcomes. In light of evidence that early life microbial, nutritional and stress experiences influence adult inflammatory regulation, these findings point to inflammation as a potential pathway for the intergenerational transmission of maternal experience to offspring health.

Social and physical environments early in development predict DNA methylation of inflammatory genes in young adulthood

Chronic inflammation contributes to a wide range of human diseases, and environments in infancy and childhood are important determinants of inflammatory phenotypes. The underlying biological mechanisms connecting early environments with the regulation of inflammation in adulthood are not known, but epigenetic processes are plausible candidates. We tested the hypothesis that patterns of DNA methylation (DNAm) in inflammatory genes in young adulthood would be predicted by early life nutritional, microbial, and psychosocial exposures previously associated with levels of inflammation. Data come from a population-based longitudinal birth cohort study in metropolitan Cebu, the Philippines, and DNAm was characterized in whole blood samples from 494 participants (age 20-22 y). Analyses focused on probes in 114 target genes involved in the regulation of inflammation, and we identified 10 sites across nine genes where the level of DNAm was significantly predicted by the following variables: household socioeconomic status in childhood, extended absence of a parent in childhood, exposure to animal feces in infancy, birth in the dry season, or duration of exclusive breastfeeding. To evaluate the biological significance of these sites, we tested for associations with a panel of inflammatory biomarkers measured in plasma obtained at the same age as DNAm assessment. Three sites predicted elevated inflammation, and one site predicted lower inflammation, consistent with the interpretation that levels of DNAm at these sites are functionally relevant. This pattern of results points toward DNAm as a potentially important biological mechanism through which developmental environments shape inflammatory phenotypes across the life course.

In vivo immune signatures of healthy human pregnancy: Inherently inflammatory or anti-inflammatory?

Changes in maternal innate immunity during healthy human pregnancy are not well understood. Whether basal immune status in vivo is largely unaffected by pregnancy, is constitutively biased towards an inflammatory phenotype (transiently enhancing host defense) or exhibits anti-inflammatory bias (reducing potential responsiveness to the fetus) is unclear. Here, in a longitudinal study of healthy women who gave birth to healthy infants following uncomplicated pregnancies within the Canadian Healthy Infant Longitudinal Development (CHILD) cohort, we test the hypothesis that a progressively altered bias in resting innate immune status develops. Women were examined during pregnancy and again, one and/or three years postpartum. Most pro-inflammatory cytokine expression, including CCL2, CXCL10, IL-18 and TNFα, was reduced in vivo during pregnancy (20-57%, p<0.0001). Anti-inflammatory biomarkers (sTNF-RI, sTNF-RII, and IL-1Ra) were elevated by ~50-100% (p<0.0001). Systemic IL-10 levels were unaltered during vs. post-pregnancy. Kinetic studies demonstrate that while decreased pro-inflammatory biomarker expression (CCL2, CXCL10, IL-18, and TNFα) was constant, anti-inflammatory expression increased progressively with increasing gestational age (p<0.0001). We conclude that healthy resting maternal immune status is characterized by an increasingly pronounced bias towards a systemic anti-inflammatory innate phenotype during the last two trimesters of pregnancy. This is resolved by one year postpartum in the absence of repeat pregnancy. The findings provide enhanced understanding of immunological changes that occur in vivo during healthy human pregnancy.

Maternal diet, gestational weight gain, and inflammatory markers during pregnancy

OBJECTIVE

To examine the associations of gestational weight gain (GWG) and diet with low-grade inflammation in pregnancy.

METHODS

A cross-sectional analysis of 671 pregnant women was performed, and diet was assessed in gestational week 30. GWG was recorded in weeks 30 and ∼37 (difference between the weight recorded at these time points and pre-pregnancy weight). Markers of inflammation, high-sensitivity C-reactive protein (hsCRP), serum amyloid A (SAA), interleukin (IL)-6, IL-8, IL-1β, and tumor necrosis factor-α were quantified in serum from week 30.

RESULTS

After adjusting for age, pre-pregnancy BMI, parity, smoking status, and education, each 1 kg increase in GWG was associated with 3% (95% CI: 1-5) higher hsCRP and 3% (95% CI: 1-4) higher SAA concentrations, which corresponded to ∼18% to 25% increase in these biomarkers among those with excessive weight gain. GWG was inversely associated with IL-8 while no associations were found for the other inflammatory markers. With respect to diet, women in the highest compared with lowest quintile of protein intake had 26% (95% CI: 3-54) higher hsCRP concentrations. This increase appeared to be driven by intake of animal protein. A similar pattern was observed for SAA.

CONCLUSIONS

Excessive GWG, as well as high intake of animal protein, was associated with higher concentrations of inflammatory factors.

Patterns of peripheral cytokine expression during pregnancy in two cohorts and associations with inflammatory markers in cord blood

PROBLEM

Maternal inflammation undergoes adaptations during pregnancy, and excessive inflammation has been associated with adverse outcomes. One mechanism may be maternal inflammation transmission to the fetal compartment. Links between maternal pregnancy inflammation and fetal inflammation are poorly characterized.

METHOD

Principal components analysis was used to extract underlying inflammation components across cytokines (IFN-γ, IL-10, IL-13, IL-6, IL-8, TNF-α) in two pregnancy cohorts (SPAH N=87, MOMS N=539) assessed during the second and third trimesters. Links between maternal inflammation over pregnancy and fetal (cord blood) inflammation were assessed.

RESULTS

Substantial cytokine rank-order stability was observed in both cohorts, β's range .47-.96, P's <.001. Two consistent inflammatory components were extracted: a pro-inflammatory (IL-10, IL-6, IL-8, TNF-α, IFN-γ) component and anti-inflammatory (IL-13) component. Higher maternal pro-inflammatory and lower anti-inflammatory indices during pregnancy were associated with higher cord blood inflammation, P's>.04.

CONCLUSION

Maternal inflammation indices over pregnancy were associated with inflammation in cord blood at birth. Results have implications for understanding pregnancy inflammatory processes and how maternal inflammation may be transmitted to fetal circulation.

Early developmental exposures shape trade-offs between acquired and innate immunity in humans

BACKGROUND AND OBJECTIVES

Life history theory predicts resource allocation trade-offs between competing functions and processes. We test the hypothesis that relative investment towards innate versus acquired immunity in humans is subject to such trade-offs and that three types of early developmental exposures are particularly salient in shaping adult immunophenotype: (i) pathogen exposure, (ii) nutritional resources; and (iii) extrinsic mortality cues.

METHODOLOGY

We quantified one aspect each of innate and acquired immune function, via C-reactive protein and Epstein-Barr virus antibodies, respectively, in a sample of 1248 men and women from the Philippines (ca. 21.5 years old). Early developmental exposures were assessed via long-term data collected prospectively since participants' birth (1983-4). We calculated a standardized ratio to assess relative bias towards acquired versus innate immune function and examined its relationship to a suite of predictors via multiple regression.

RESULTS

In partial support of our predictions, some of the measures of higher pathogen exposure, greater availability of nutritional resources, and lower extrinsic mortality cues in early life were associated with a bias toward acquired immunity in both men and women. The immune profile of women, in particular, appeared to be more sensitive to early life pathogen exposures than those of men. Finally, contrary to prediction, women exhibited a greater relative investment toward innate, not acquired, immunity.

CONCLUSIONS AND IMPLICATIONS

Early environments can exert considerable influence on the development of immunity. They affect trade-offs between innate and acquired immunity, which show adaptive plasticity and may differ in their influence in men and women.