Fetal programming: Early-life modulations that affect adult outcomes

Effect of maternal asthma on fetal pulmonary artery Doppler parameters: a case-control study

OBJECTIVES

To compare fetal pulmonary artery Doppler parameters between pregnant women with asthma and healthy pregnant women.

METHODS

This prospective, cross-sectional study was conducted on 50 pregnant women diagnosed with asthma and 61 healthy pregnant women. Fetal pulmonary artery Doppler parameters and the fetal main pulmonary artery acceleration time/ejection time (PATET) ratio were compared between the study and control groups. Thereafter, the study group was divided into two subgroups as non-severe and severe asthma. PATET ratio was compared between the subgroups.

RESULTS

The fetal main pulmonary artery acceleration time was 25 ms in pregnant women with asthma and 33 ms in the healthy group, indicating a statistically significant difference (p=0.001). The acceleration time/ejection time ratio was statistically lower in the asthma group (0.185 vs. 0.240, p<0.001). The acceleration time/ejection time ratio was 0.172 in patients with severe asthma and 0.195 ms in the non-severe study group (p=0.156). In the maternal asthma group, the PATET ratio of those who went to the NICU due to respiratory distress was also 0.188, and the PATET ratio of those who went to the NICU for other reasons was 0.269 (p=0.053).

CONCLUSIONS

Fetal pulmonary artery acceleration time and PATET decreased statistically in pregnant women with severe or non-severe asthma. Maternal asthma is associated with changes in pulmonary Doppler parameters in the fetus.

Surrogate fostering of mice prevents prenatal estradiol-induced insulin resistance via modulation of the microbiota-gut-brain axis

Introduction

Prenatal and early postnatal development are known to influence future health. We previously reported that prenatal high estradiol (HE) exposure induces insulin resistance in male mice by disrupting hypothalamus development. Because a foster dam can modify a pup's gut microbiota and affect its health later in life, we explored whether surrogate fostering could also influence glucose metabolism in HE offspring and examined mechanisms that might be involved.

Methods

We performed a surrogate fostering experiment in mice and examined the relationship between the metabolic markers associated to insulin resistance and the composition of the gut microbiota.

Results

HE pups raised by HE foster dams (HE-HE) developed insulin resistance, but HE pups fostered by negative control dams (NC-HE) did not. The gut microbiota composition of HE-HE mice differed from that of NC mice raised by NC foster dams (NC-NC), whereas the composition in NC-HE mice was similar to that of NC-NC mice. Compared with NC-NC mice, HE-HE mice had decreased levels of fecal short-chain fatty acids and serum intestinal hormones, increased food intake, and increased hypothalamic neuropeptide Y expression. In contrast, none of these indices differed between NC-HE and NC-NC mice. Spearman correlation analysis revealed a significant correlation between the altered gut microbiota composition and the insulin resistance-related metabolic indicators, indicating involvement of the microbiota-gut-brain axis.

Discussion

Our findings suggest that alterations in the early growth environment may prevent fetal-programmed glucose metabolic disorder via modulation of the microbiota-gut-brain axis. These findings offer direction for development of translational solutions for adult diseases associated with aberrant microbial communities in early life.

The role of prenatal vitamin D on the development of childhood asthma and wheeze: An umbrella review of systematic reviews and meta-analyses

BACKGROUND & OBJECTIVE

It has been suggested that prenatal vitamin D plays a role in the development of childhood asthma and wheeze. Several systematic reviews have been conducted, but the results are inconsistent, and the methodological quality has not been studied. Therefore, the objective of this umbrella review was to assess the internal validity of the evidence base and the evidence for an association between prenatal vitamin D and asthma or wheezing in the offspring.

METHODS

We searched the electronic databases Embase, PubMed, and Cochrane Library for studies on prenatal vitamin D using search words such as vitamin D, 25-hydroxyvitamin D, calcidiol, fetal, and neonatal. The search was conducted in June 2020, and the databases were searched from their date of establishment. We included systematic reviews and/or meta-analyses of experimental and observational studies assessing the association between prenatal vitamin D or asthma and wheeze. We excluded narrative reviews, commentaries, and other umbrella reviews. The methodological quality of systematic reviews was assessed using AMSTAR 2 tool. PROSPERO reg. no. CRD42020151329.

RESULTS

We identified 22 eligible systematic reviews (17 on asthma and 20 on wheeze). Using the AMSTAR 2 quality assessment tool, the methodological quality was rated as critically low in 21 out of 22 systematic reviews, suggesting that previous reviews and meta-analyses did not provide accurate and comprehensive summaries of the included studies and that conclusions reached were potentially flawed. The majority of the included reviews reported that prenatal vitamin D reduces the risk of wheeze in the offspring.

CONCLUSION

Prior to informing public guidelines, high-quality systematic reviews of the current evidence are greatly warranted.

The correlation between neonatal vitamin D levels and the risk of childhood asthma attacks

BACKGROUND

To explore the correlation between neonatal vitamin D levels and the risk of asthma in children aged 3-9 years.

METHODS

A total of 1,534 subjects were selected, and clinical and laboratory test data of all subjects were collected at birth, including 25-hydroxyvitamin D3 [25(OH)D3] levels, gender, season of birth, birth weight; whether delivery was premature, cesarean section, or primipara; and parental details including maternal age, ethnicity, level of education, history of smoking, and history of maternal or paternal asthma. The level of 25(OH)D3 was used as a continuous variable to analyze its correlation with the risk of asthma using the Cox proportional regression model. In addition, subjects were divided into four groups according to their 25(OH)D3 quartiles, and the first quantile group was used as a reference to analyze the risk of asthma in the other groups. Further subgroup analysis was conducted according to the patients' gender and birth season.

RESULTS

Among the 1,534 subjects included, there were 107 cases in the asthma-affected group and 1,427 cases in the normal control group. Compared with the control group, the level of 25(OH)D3 in the asthma group was significantly lower (P=0.03), the mother's education level was lower (P=0.002), but the preterm birth rate, cesarean section rate, and parental asthma prevalence rate were significantly higher (all P<0.05). When the neonatal 25(OH)D3 was divided into quartiles to perform a categorical variable analysis, we found that compared with the first quantile (Q1, 0.0-25.1 mmol/L), the risk of asthma in Q4 was reduced by 50% (HR=0.50, 95% CI: 0.38-0.76). The second quantile group (Q2) and the third quantile group (Q3) showed no significant difference in the risk of disease compared with Q1 but showed a trend of decreasing risk as the quantile group increased (the trend P values were both <0.05). This correlation was still valid when a stratified analysis was made based on gender and birth season.

CONCLUSIONS

There is a significant correlation between a reduced vitamin D level in newborns and the subsequent risk of asthma in children aged 3-9 years. Moreover, the level of vitamin D is an independent risk factor for childhood asthma.

Eating fish and fruits are associated with lower prevalence of allergic diseases

BACKGROUND

Allergic diseases are recognized as a burden on the public health. They stand as one of the most common chronic diseases, especially in developed countries. Therefore, the objective of this study is to evaluate the association between the development of atopic allergy and the presence of food allergy in children, and food consumption.

METHODS

This multidisciplinary cross-observational epidemiological study was conducted among 1199 schoolchildren who were recruited in 4th grade and 5th grade (9-11 years old from Marseille). Data were collected by means of a standardized epidemiological questionnaire with a medical assessment focusing on allergic diseases, and questions on lifestyle and child nutrition (FFQ).

RESULTS

During the last 12 months, prevalence of allergic diseases were shown as follows: 41% of children presented allergic rhinitis symptoms, 24% reported having asthma related symptoms, while 28% suffered of eczema and 7% complained of food allergy. There was a significant association between food allergy and asthma symptoms (P-value<0.001, IC=[2.29-7.69]), eczema (P-value<0.001, IC=[2.37-8.32]) and allergic rhinitis (P-value<0.001, IC=[2.32-8.17]). Regarding dietary habits, the multivariate analysis shows that the consumption of vegetables (ORa=0.72 [0.64-0.74]) and fish (ORa=0.74 [0.50-1.09], ORa=0.66 [0.47-0.94] respectively) are associated decreased risk of developing asthma and allergic rhinitis symptoms, while fruit consumption (ORa=0.68 [0.45-1.03]) is associated with a decrease in eczema symptoms.

CONCLUSION

This study shows that the presence of a food allergy is strongly associated with allergic diseases. Indeed, the consumption of vegetables, fruits and fish seems to have a protective effect on the occurrence of these diseases.

Neonatal Vitamin D Status and Risk of Asthma in Childhood: Results from the D-Tect Study

Background: low vitamin D status in pregnancy can influence the offspring’s lung function and contribute to childhood asthma development. The objective of this study was to examine the influence of neonatal vitamin D status on the development of asthma among children age 3–9 years in a large population sample. Method: in a case-cohort study utilizing a Danish biobank and register data we examined the association between neonatal 25-hydroxyvitamin D₃ (25(OH)D₃) concentrations and incidence of asthma among children aged 3–9 years. Cases of asthma (n = 911) were randomly selected among all cases of asthma in the Danish National Patient Register from children born between 1992 and 2002. The sub-cohort (n = 1423) was randomly selected among all children born in the same period. We used a weighted Cox proportional hazard model assessing the hazard of first asthma diagnoses by quintiles of 25(OH)D₃. Results: the median 25(OH)D3 (interquartile range) for asthma cases was 23 nmol/L (14–35) and the sub-cohort 25 nmol/L (14–40). The hazard ratio for developing asthma between ages 3 and 9 years was lower for children in the fifth quintile of neonatal 25(OH)D₃ compared to children in the first quintile, both in the unadjusted (0.61 95% CI: 0.46–0.80) and adjusted (0.55 95% CI: 0.39–0.77) analyses. Conclusion: the results from our study suggest that higher neonatal vitamin D concentration may reduce the risk of developing childhood asthma at ages 3–9 years, indicating that neonatal vitamin D status as a proxy of vitamin D status during the prenatal period is important for normal immune- and lung development.

Vitamin D and Gestational Diabetes Mellitus: Is There a Link?

Gestational diabetes mellitus (GDM) is a very common condition among pregnant women worldwide with important metabolic implications on the mother and the offspring. Vitamin D status has been suggested to potentially play a role in GDM risk with no documented consequences for the offspring. The purpose of this article was to review currently available evidence on the relationship between vitamin D and GDM. Current evidence shows an association between vitamin D blood levels and risk of GDM, despite heterogeneity of results across studies limit the conclusions. Moreover, data from randomized controlled trials is scarce and resulting in null findings. Among the limitations to be noted, improving the standardization of dosages, the characteristics of individuals in the sample, and the appropriate outcome measurement could provide a more effective approach in understanding the relationship between vitamin D and GDM. In conclusions, despite observational studies may suggest that adequate vitamin D levels may decrease the risk of GDM compared to deficiency status, evidence from clinical trials is inadequate to draft any definitive conclusion regarding its supplementation. Future better designed randomized clinical trials taking into account a more integrated approach could provide clearer and definitive data on the outcomes of such a multifactorial condition.

Prenatal vitamin D status and respiratory and allergic outcomes in childhood: A meta-analysis of observational studies

BACKGROUND

Prenatal vitamin D status may influence offspring's respiratory and allergic outcomes; however, evidence is inconclusive. A systematic review and meta-analysis were conducted on the association between 25-hydroxyvitamin D [25(OH)D] levels in maternal blood in pregnancy or cord blood at birth with the risk of offspring's respiratory and allergic conditions.

METHODS

Two independent researchers conducted systematic searches for observational studies published until May 2017 using defined keywords on vitamin D and health outcomes, including respiratory tract infections (RTIs), wheeze, asthma, atopic eczema, allergic rhinitis, allergic sensitization, and lung function. Random-effects meta-analyses were conducted.

RESULTS

A total of 34 from 547 retrieved articles were included. Increased prenatal exposure to 25(OH)D was inversely associated with risk of RTIs. Comparing the highest with the lowest category of 25(OH)D levels, the pooled odds ratio was 0.64 (95% CI 0.47, 0.87). A positive borderline association was found for lung function at school age (FEV1 z-score coefficient 0.07, 95% CI -0.01, 0.15). No associations were found for wheeze, asthma, atopic eczema, allergic rhinitis, and allergic sensitization.

CONCLUSION

The introduction of public health measures to tackle vitamin D status in pregnancy may reduce the burden of RTIs in offspring. Current evidence does not support an impact on asthma and allergy.

Exposure amount and timing of solar irradiation during pregnancy and the risk of sensitization in children

BACKGROUND

Solar irradiation affects sensitization to aeroallergens and the prevalence of allergic diseases. Little is known, however, about how the time and amount of solar irradiation during pregnancy affects such risks in children. We aimed to find out how solar irradiation during pregnancy affects sensitization to aero-allergens and the prevalence of allergic diseases in children.

METHODS

This population-based cross-sectional study involved 7301 aged 6 years and aged 12 years children. Maternal exposure to solar irradiation during pregnancy was evaluated using data from weather stations closest to each child's birthplace. Monthly average solar irradiation during the second and third trimesters was calculated with rank by quartiles. Risks of allergic sensitization and allergic disease were estimated.

RESULTS

Relative to the first (lowest) quartile, the adjusted odds ratio (aOR) for allergic sensitization in the fourth (highest) quartile was lowest within solar irradiation during pregnancy months 5-6 (aOR = 0.823, 95% CI 0.720-0.942, p < 0.05). During months 9-10, the aOR for allergic sensitization for the fourth was higher than the first quartile of solar irradiation (aOR = 1.167, 95% CI 1.022-1.333, p < 0.05). Similar results were observed when solar irradiation was analyzed as a continuous variable during months 5 (aOR = 0.975, 95% CI 0.962-0.989, p < 0.001) and month 9 (aOR = 1.018, 95% CI 1.004-1.031, p = 0.003). Increased solar irradiation during months 7-8 increased the risk of asthma (aOR = 1.309, 95% CI 1.024-1.674, p = 0.032).

CONCLUSIONS

Maternal exposure to solar irradiation during the second trimester of pregnancy associated with reduced aeroallergen sensitization, whereas solar irradiation during the third trimester was related to increased sensitization to aeroallergens.

Prenatal maternal depression related to allergic rhinoconjunctivitis in the first 5 years of life in children of the EDEN mother-child cohort study

Backgroud: Evidence about the relationship between prenatal maternal depression and the development of childhood asthma and allergies in early life is scarce. We aimed to examine this relationship by using data set of EDEN mother-child cohort study. A total of 1139 children were followed-up until the age of 5 years.

METHODS

Prenatal maternal depression was self-reported by using the Centre for Epidemiological Studies-Depression scale (CES-D) questionnaire and was classified into binary variable (maternal depression [CES-D score of ≥16] and no maternal depression [CES-D score of <16]). Asthma and allergies in the first 5 years were assessed by using the questionnaire of the International Study of Asthma and Allergies in Childhood (ISAAC). Adjusted odds ratio (aOR) was estimated for the relationship between prenatal maternal depression and early life asthma and allergies by marginal models through the method of generalized estimating equation (GEE) when adjusting for the confounders.

RESULTS

In our study population, 13.67 % of the mothers had clinical significant depression (the total scores for CES-D ≥16) during pregnancy. For children ages 5 years, the prevalence of wheezing, physician-diagnosed asthma, physician-diagnosed eczema and allergic rhinoconjunctivitis were 46.78, 20.99, 29.17, and 22.54%, respectively. Prenatal maternal depression was associated with ever allergic rhinoconjunctivitis (aOR 1.87 [95% confidence interval {CI}, 1.33-2.62]). No significant relationships were found between prenatal maternal depression and wheezing, physician-diagnosed asthma and physician-diagnosed eczema (aOR 1.12 [95% CI, 0.91-1.39], aOR 1.23 [95% CI, 0.81-1.85] and aOR 1.17 [95% CI, 0.86-1.61], respecitvely).

CONCLUSION

Prenatal maternal depression was related to ever allergic rhinoconjunctivitis in the first 5 years of life in children of EDEN mother-child cohort study.

Impact of perinatal environmental tobacco smoke on the development of childhood allergic diseases

Allergic diseases such as asthma, allergic rhinitis, atopic dermatitis, and food allergy, are most common chronic, noncommunicable diseases in childhood. In the past few decades, the prevalence has increased abruptly worldwide. There are 2 possible explanations for the rising prevalence of allergic diseases worldwide, that an increased disease-awareness of physician, patient, or caregivers, and an abrupt exposure to unknown hazards. Unfortunately, the underlying mechanisms remain largely unknown. Despite the continuing efforts worldwide, the etiologies and rising prevalence remain unclear. Thus, it is important to identify and control risk factors in the susceptible individual for the best prevention and management. Genetic susceptibility or environments may be a potential background for the development of allergic disease, however they alone cannot explain the rising prevalence worldwide. There is growing evidence that epigenetic change depends on the gene, environment, and their interactions, may induce a long-lasting altered gene expression and the consequent development of allergic diseases. In epigenetic mechanisms, environmental tobacco smoke (ETS) exposure during critical period (i.e., during pregnancy and early life) are considered as a potential cause of the development of childhood allergic diseases. However, the causal relationship is still unclear. This review aimed to highlight the impact of ETS exposure during the perinatal period on the development of childhood allergic diseases and to propose a future research direction.

Vitamin D during pregnancy: why observational studies suggest deficiency and interventional studies show no improvement in clinical outcomes? A narrative review

A considerable number of studies have examined vitamin D status during pregnancy. Although data from observational studies denote vitamin D hypovitaminosis (deficiency or insufficiency) during pregnancy is associated with a plethora of adverse maternal and neonatal outcomes, data from interventional (supplementation) trials fail to reveal a significant impact on maternal and offspring health. The aim of this narrative review was to critically appraise the methodology of the most representative published randomized controlled trials in an attempt to explain the difference between observational and supplementation results. We found that this difference could be attributed to a variety of factors, namely: (i) study design (lack of a specific outcome in conjunction with timing of supplementation, enrolment of participants with heterogeneous vitamin D status); (ii) pitfalls in the interpretation of vitamin D equilibrium (lack of determination of plasma half-life); (iii) supplementation regimen (administration of a wide range of regimens, in terms of dose, bolus and form); (iv) geographical characteristics (vitamin D needs could vary significantly within a country, particularly in areas with a wide range of latitude gradient); (v) adaptations of vitamin D metabolism during pregnancy (vitamin D and calcium equilibrium are changed during pregnancy compared with the non-pregnant state) and (vi) supplementation of populations with low baseline 25(OH)D values would likely manifest beneficial effects. All these parameters should be taken into consideration in the design of future vitamin D supplementation trials.

Advanced Aged Women's Needs for Pregnancy and Childbirth Care

PURPOSE

Advanced aged pregnancy may be related with health problems so that more aggressive health care is necessary for these women. This study aimed to provide the basic data for developing nursing intervention programs to enhance the health of pregnant women and their new-born babies and by identifying the advanced aged women's need for pregnancy and childbirth.

METHODS

It is the cross-sectional descriptive study to identify the advanced aged women's need on pregnancy and childbirth. Subjects were pregnant women 35 years or older and postpartum women. Total number of subjects was 95. Measurement tool is self-reporting survey that consisted of 67 items with four-point Likert scale, which was completed during October to November 2014.

RESULTS

Average score was 3.44 out of maximum 4 on the care need on pregnancy and childbirth. Average scores according to category were as follows: baby rearing and parental role, 3.55; preconception care, 3.49; delivery care, 3.47; postpartum care 3.42; and prenatal pregnancy, 3.39. The degree of needs on pregnancy and childbirth was different according to delivery experience (t=-2.49, p=.014).

CONCLUSION

Prenatal and postpartum nursing interventions were completed regardless of pregnant women's age until now; however, new nursing intervention programs are necessary to prevent the risk of advanced aged pregnancy, to provide the preconception care, and to increase the infant care and family support.

Study on Awareness of Preconception Care and Reproductive Health Behaviors in Pre-honeymooners

PURPOSE

The purpose of this study was 1) to examine levels of awareness on preconception care and pregnancy, and reproductive health promoting behavior among pre-honeymooners; and 2) to explore the relationship between awareness levels of preconception care and pregnancy, and reproductive health promoting behavior.

METHODS

This study was a correlation design with a total of 134 participants (67 couples of pre-honeymooners). Data were collected with questionnaire.

RESULTS

Mean score of self-perception of awareness of preconception care and pregnancy was 2.82 out of 4. Content awareness level was 6.83 out of 13, and reproductive health promoting behavior score was 3.02 out of 4, indicating low to mid-level. Women reported higher scores in all variables than those in men. Self-perception awareness and content awareness of care and pregnancy had a weak positive correlation (r=.18, p=.038). Reproductive health promoting behavior was positively related to self-perception awareness of care and pregnancy (r=.33, p<.001) and content awareness of care and pregnancy (r=.23, p=.008).

CONCLUSION

Based on this results, a variety of nursing intervention strategies may need to promote reproductive health behavior such as raising awareness of the preconception care and pregnancy.

Cohort Profile: Swedish Twin Study on Prediction and Prevention of Asthma (STOPPA)

Asthma is a common childhood disease and several risk factors have been identified; however, the impact of genes and environment is not fully understood. The aim of the Swedish Twin study On Prediction and Prevention of Asthma (STOPPA) is to identify environmental (birth characteristics and early life) and genetic (including epigenetic) factors as determinants for asthmatic disease. Based on the Child and Adolescent Twin Study in Sweden (CATSS) (parental interview at 9 or 12 years, N ~23,900) and an asthma and/or wheezing algorithm, we identified a sample of monozygotic (MZ) and dizygotic (DZ) same-sexed twin pairs. The twin pairs were classified as asthma concordant (ACC), asthma discordant (ADC) and healthy concordant (HCC). A sample of 9- to 14-year-old twins and their parents were invited to participate in a clinical examination. Background characteristics were collected in questionnaires and obtained from the National Health Registers. A clinical examination was performed to test lung function and capacity (spirometry with reversibility test and exhaled nitric oxide) and collect blood (serology and DNA), urine (metabolites), feces (microbiota), and saliva (cortisol). In total, 376 twin pairs (752 individual twins) completed the study, response rate 52%. All participating twins answered the questionnaire and >90% participated in lung function testing, blood-, and saliva sampling. This article describes the design, recruitment, data collection, measures, and background characteristics, as well as ongoing and planned analyses in STOPPA. Potential gains of the study include the identification of biomarkers, the emergence of candidates for drug development, and new leads for prevention of asthma and allergic disease.

Prenatal adverse life events increase the risk for atopic diseases in children, which is enhanced in the absence of a maternal atopic predisposition

BACKGROUND

There is evidence to suggest an association between prenatal maternal stress and the development of asthma or other atopic diseases in offspring. Yet, insights on the lasting effect of multiple, common prenatal stressors are rare, and the effects of prenatal timing are poorly understood. Further, it remains elusive if prenatal life events modify the risk for atopic diseases in the context of a parental predisposition to atopy.

OBJECTIVE

We tested whether women's experiences of common, adverse life events during the first or second half of pregnancy predicted the risk of developing atopic diseases in their children and whether a reported parental atopic disease moderated this association.

METHODS

We calculated the odds of a child developing asthma, eczema, and/or allergic rhinitis at ages 6 or 14 years, depending on maternal prenatal exposure to negative life events in a sample of 1587 children from the Western Australian Pregnancy Cohort (Raine) Study by using multivariable logistic regression.

RESULTS

We observed that the likelihood of asthma and eczema at age 14 years was significantly increased in children of mothers who had experienced adverse life events during the second half of gestation (1 life event: adjusted odds ratio for asthma, 2.08 [95% CI, 1.22-3.54]). A stronger increase in the odds to develop asthma upon prenatal life events was present in children of mothers without asthma compared with mothers with asthma.

CONCLUSIONS

Maternal adverse life events during the second half of gestation are linked to an increased risk for the development of atopic disorders, asthma, and eczema, in the case of asthma, particularly in the absence of a maternal asthma.

Severe acute asthma

Asthma is common among women of reproductive age and affects between 4% and 8% of pregnant women. Pregnancy outcomes are correlated to the degree of asthma severity and control. Approximately one-third of pregnant women with asthma remain stable, a third will have improvement of their asthma, and a third will have worsening of the disease. Pregnant women with severe asthma are at markedly increased risk of maternal and perinatal morbidity and mortality, preeclampsia, low-birth weight infants, and preterm delivery. A severe asthma exacerbation in a pregnant woman may be clinically daunting, however immediate intervention with appropriate supplemental oxygenation, medical therapy, and intubation if necessary can be life-saving. A focus on maternal well-being and pulmonary function in a pregnant asthmatic is essential to ensure optimal outcomes for both mother and her fetus. This article will provide an overview of asthma management, particularly in the acute care setting.

Peanut and tree nut consumption during pregnancy and allergic disease in children-should mothers decrease their intake? Longitudinal evidence from the Danish National Birth Cohort

BACKGROUND

The relation between maternal peanut intake during pregnancy and allergic disease development in children has been controversial.

OBJECTIVE

We used data from the Danish National Birth Cohort to examine associations between maternal peanut and tree nut intake during pregnancy and allergic outcomes in children at 18 months and 7 years of age.

METHODS

We estimated maternal peanut and tree nut intake (n = 61,908) using a validated midpregnancy food frequency questionnaire. At 18 months, we used parental report of childhood asthma diagnosis, wheeze symptoms, and recurrent wheeze (>3 episodes). We defined current asthma at 7 years as doctor-diagnosed asthma plus wheeze in the past 12 months and allergic rhinitis as a self-reported doctor's diagnosis. We also used alternative classifications based on registry-based International Classification of Diseases, Tenth Revision, codes and drug dispensary data. We report here odds ratios (ORs) comparing intake of 1 or more times per week versus no intake.

RESULTS

We found that maternal intake of peanuts (OR, 0.79; 95% CI, 0.65-0.97) and tree nuts (OR, 0.75; 95% CI, 0.67-0.84) was inversely associated with asthma in children at 18 months of age. Compared with mothers consuming no peanuts, children whose mothers reported eating peanuts 1 or more times per week were 0.66 (95% CI, 0.44-0.98) and 0.83 (95% CI, 0.70-1.00) times as likely to have a registry-based and medication-related asthma diagnosis, respectively. Higher tree nut intake was inversely associated with a medication-related asthma diagnosis (OR, 0.81; 95% CI, 0.73-0.90) and self-reported allergic rhinitis (OR, 0.80; 95% CI, 0.64-1.01).

CONCLUSIONS

Our results do not suggest that women should decrease peanut and tree nut intake during pregnancy; instead, consumption of peanuts and tree nuts during pregnancy might even decrease the risk of allergic disease development in children.

Analysis of genetic interactions involving maternal and offspring genotypes at different Loci: power simulation and application to testicular cancer

The analyses of genetic interaction between maternal and offspring genotypes are usually conducted considering a single locus. Here, we propose testing maternal × offspring (M×O) and maternal × maternal (M×M) genotype interactions involving two unlinked loci. We reformulate the log-linear approach of analyzing cases and their parents (family trios) to accommodate two loci, fit fuller models to avoid confounding in a first analysis step and propose that the model be reduced to the most prominent effects in a second step. We conduct extensive simulations to assess the validity and power of this approach under various model assumptions. We show that the approach is valid and has good power to detect M×O and M×M interactions. For example, the power to detect a dominant interaction relative risk of 1.5 (both M×O and M×M) is 70% with 300 trios and approaches 100% with 1,000 trios. Unlike the main effects, M×O and M×M interactions are conditionally independent of mating types, and consequently, their power is not affected by missing paternal genotypes. When applied to single-locus M×O interaction, our method is as powerful as other existing methods. Applying the method to testicular cancer, we found a nominally significant M×M interaction between single nucleotide polymorphisms from C-Kit Ligand (KITLG) and Sex Hormone Binding Globulin (SHBG) using 210 families (relative risk 2.2, P = 0.03). This finding supports a role of maternal hormones in offspring testicular cancer and warrants confirmation in a larger dataset.

Early life exposures: impact on asthma and allergic disease

PURPOSE OF REVIEW

To identify and discuss recent studies relating prenatal and early-life environmental exposures to the development of asthma and allergic disease.

RECENT FINDINGS

New studies show that prenatal and early-life stress can alter infant immune profiles, increasing risk for asthma and allergy. Mounting evidence implicates indoor and outdoor air pollution in the origins of allergic disease, while Vitamin D intake and a Mediterranean diet may be protective. The role of early-life fever and infection remain controversial, with recent studies yielding conflicting results and new evidence indicating that previous studies may have been confounded. New studies are increasingly focused on environmental 'imprinting' of the infant gut microbiota, which is a critical determinant of immune system development. Early exposures impacting the intestinal microbiota include mode of delivery, infant diet, and use of antibiotics - factors that are also associated with childhood asthma and allergic disease.

SUMMARY

This overview highlights environmental exposures during the in-utero and ex-utero time periods that are potential stimuli for the early programming of asthma and allergy. Special consideration is given for the potential role of intestinal microbiota. Future studies in this field promise to inform health policy and intervention strategies for the prevention of asthma and allergic disease.

Perinatal programming of asthma: the role of gut microbiota

Perinatal programming, a dominant theory for the origins of cardiovascular disease, proposes that environmental stimuli influence developmental pathways during critical periods of prenatal and postnatal development, inducing permanent changes in metabolism. In this paper, we present evidence for the perinatal programming of asthma via the intestinal microbiome. While epigenetic mechanisms continue to provide new explanations for the programming hypothesis of asthma development, it is increasingly apparent that the intestinal microbiota plays an independent and potentially interactive role. Commensal gut bacteria are essential to immune system development, and exposures disrupting the infant gut microbiota have been linked to asthma. This paper summarizes the recent findings that implicate caesarean delivery, breastfeeding, perinatal stress, probiotics, and antibiotics as modifiers of infant gut microbiota in the development of asthma.

Is there a regulatory role of immunoglobulins on tissue forming cells relevant in chronic inflammatory lung diseases?

Epithelial cells, fibroblasts and smooth muscle cells together form and give structure to the airway wall. These three tissue forming cell types are structure giving elements and participate in the immune response to inhaled particles including allergens and dust. All three cell types actively contribute to the pathogenesis of chronic inflammatory lung diseases such as asthma and chronic obstructive pulmonary disease (COPD). Tissue forming cells respond directly to allergens through activated immunoglobulins which then bind to their corresponding cell surface receptors. It was only recently reported that allergens and particles traffic through epithelial cells without modification and bind to the immunoglobulin receptors on the surface of sub-epithelial mesenchymal cells. In consequence, these cells secrete pro-inflammatory cytokines, thereby extending the local inflammation. Furthermore, activation of the immunoglobulin receptors can induce proliferation and tissue remodeling of the tissue forming cells. New studies using anti-IgE antibody therapy indicate that the inhibition of immunoglobulins reduces the response of tissue forming cells. The unmeasured questions are: (i) why do tissue forming cells express immunoglobulin receptors and (ii) do tissue forming cells process immunoglobulin receptor bound particles? The focus of this review is to provide an overview of the expression and function of various immunoglobulin receptors.