First trimester maternal tryptophan metabolism and embryonic and fetal growth: the Rotterdam Periconceptional Cohort (Predict Study)

STUDY QUESTION

What is the association between first trimester maternal tryptophan (TRP) metabolites and embryonic and fetal growth?

SUMMARY ANSWER

Higher 5-hydroxytryptophan (5-HTP) concentrations are associated with reduced embryonic growth and fetal growth and with an increased risk of small-for-gestational age (SGA), while higher kynurenine (KYN) concentrations are associated with a reduced risk of SGA.

WHAT IS KNOWN ALREADY

The maternal TRP metabolism is involved in many critical processes for embryonic and fetal growth, including immune modulation and regulation of vascular tone. Disturbances in TRP metabolism are associated with adverse maternal and fetal outcomes.

STUDY DESIGN, SIZE, DURATION

This study was embedded within the Rotterdam Periconceptional Cohort (Predict Study), an ongoing prospective observational cohort conducted at a tertiary hospital from November 2010 onwards.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 1115 women were included before 11 weeks of gestation between November 2010 and December 2020. Maternal serum samples were collected between 7 and 11 weeks of gestation, and TRP metabolites (TRP, KYN, 5-HTP, 5-hydroxytryptamine, and 5-hydroxyindoleacetic acid) were determined using a validated liquid chromatography (tandem) mass spectrometry method. Serial 3D ultrasound scans were performed at 7, 9, and 11 weeks of gestation to accurately assess features of embryonic growth, including crown-rump length (CRL) and embryonic volume (EV) offline using virtual reality systems. Fetal growth parameters were retrieved from medical records and standardized according to Dutch reference curves. Mixed models were used to assess associations between maternal TRP metabolites and CRL and EV trajectories. Linear and logistic regression models were utilized to investigate associations with estimated fetal weight (EFW) and birthweight, and with SGA, respectively. All analyses were adjusted for potential confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

Maternal 5-HTP concentrations and the maternal 5-HTP/TRP ratio were inversely associated with embryonic growth (5-HTP, √CRL: β = -0.015, 95% CI = -0.028 to -0.001; 5-HTP 3√EV: β = -0.009, 95% CI = -0.016 to -0.003). An increased maternal 5-HTP/TRP ratio was also associated with lower EFW and birthweight, and with an increased risk of SGA (odds ratio (OR) = 1.006, 95% CI = 1.00-1.013). In contrast, higher maternal KYN concentrations were associated with a reduced risk of SGA in the unadjusted models (OR = 0.548, 95% CI = 0.320-0.921).

LIMITATIONS, REASONS FOR CAUTION

Residual confounding cannot be ruled out because of the observational design of this study. Moreover, this study was conducted in a single tertiary hospital, which assures high internal validity but may limit external validity.

WIDER IMPLICATIONS OF THE FINDINGS

The novel finding that maternal 5-HTP concentrations are associated with a smaller embryo and fetus implies that disturbances of the maternal serotonin pathway in the first trimester of pregnancy are potentially involved in the pathophysiology of fetal growth restriction. The association between higher maternal KYN concentrations and a reduced risk of SGA substantiate the evidence that the KYN pathway has an important role in fetal growth. More research is needed to delve deeper into the potential role of the maternal TRP metabolism during the periconception period and pregnancy outcome for mother and offspring.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the Department of Obstetrics and Gynecology and the Department of Clinical Chemistry of the Erasmus MC, University Medical Center, Rotterdam, the Netherlands. The authors have no competing interests to disclose.

TRIAL REGISTRATION NUMBER

N/A.

The intake of ultra-processed foods and homocysteine levels in women with(out) overweight and obesity: The Rotterdam Periconceptional Cohort

PURPOSE

Today's diet consists of a substantial proportion of ultra-processed foods (UPF), especially in women with overweight and obesity in the reproductive period. High UPF intake results in an inadequate and unbalanced diet leading to derangements of several metabolic pathways detrimental to pregnancy and birth outcomes. Therefore, we aim to investigate whether UPF intake in the periconceptional period affects total homocysteine plasma levels (tHcy).

METHODS

1532 participants were included from the prospective Rotterdam Periconceptional Cohort. UPF intake was calculated using Food Frequency Questionnaires including items classified as 4 in the Nova classification, and tHcy was measured by using liquid chromatography-tandem mass spectrometry system, with an interassay coefficient of variation of < 5.5%. Multivariable linear regression modeling was used and adjusted for covariates and significant interaction terms.

RESULTS

Women with overweight or obesity showed significantly higher percentage of UPF intake (respectively, 50.3 and 51.3%) and higher tHcy (respectively, 6.6 and 6.3 µmol/L, Kruskal-Wallis test; respectively, p < 0.001 and p = 0.04) compared to women with normal BMI (UPF intake: 46.8%, tHcy: 6.1 µmol/L). A 10% higher intake of UPF was associated with an increase in tHcy (adjusted: β = 1.31, 95% CI = 0.38-2.23). Analysis stratified for BMI classification showed comparable associations in normal weight participants (adjusted: β = 1.07, 95% CI = 0.06-2.07); however, no significant association in participants with overweight (adjusted: β = 0.06, 95% CI = - 0.95-1.07) and obesity (adjusted: β = 1.70, 95% CI = - 0.52-3.92) was shown.

CONCLUSION

This study showed that a higher intake of UPF is associated with increased tHcy. Better knowledge and awareness of the nutritional quality of the diet in the periconceptional period may contribute to 1-CM and subsequently improve pregnancy course and outcome.

TRIAL REGISTRATION NUMBER AND DATE

NTR4356, November 2010.

Global variation in diabetes diagnosis and prevalence based on fasting glucose and hemoglobin A1c

Fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) are both used to diagnose diabetes, but these measurements can identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening, had elevated FPG, HbA1c or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardized proportion of diabetes that was previously undiagnosed and detected in survey screening ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the age-standardized proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c was more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global shortfall in diabetes diagnosis and surveillance.

Simultaneous quantification of tryptophan metabolites by liquid chromatography tandem mass spectrometry during early human pregnancy

OBJECTIVES

In this study we describe the development and validation of a liquid chromatography mass spectrometry method (LC-MS/MS) to quantify five tryptophan (TRP) metabolites within the kynurenine- and serotonin pathway and apply the method to serum samples of women in the first trimester of pregnancy. A secondary aim was to investigate the correlation between body mass index (BMI) and the five analytes.

METHODS

A LC-MS/MS was developed for the analysis of TRP, kynurenine (KYN), 5-hydroxytryptophan (5-HTP), hydroxytryptamine (5-HT), and 5-hydroxyindole acetic acid (5-HIAA). Serum samples (n=374) were analyzed of pregnant women (median gestational age: 8 ± 2 weeks) participating in a subcohort of the Rotterdam Periconceptional Cohort (Predict study).

RESULTS

The LC-MS/MS method provided satisfactory separation of the five analytes (7 min run). For all analytes R² was >0.995. Within- and between-run accuracies were 72-97% and 79-104%, and the precisions were all <15% except for the between-run precisions of the low QC-samples of 5-HTP and 5-HT (both 16%). Analyte concentrations were determined in serum samples of pregnant women (median (IQR)); TRP (µmol/L): 57.5 (13.4), KYN (µmol/L): 1.4 (0.4), 5-HTP (nmol/L): 4.1 (1.2), 5-HT (nmol/L): 615 (323.1), and 5-HIAA (nmol/L): 39.9 (17.0). BMI was negatively correlated with TRP, 5-HTP, and 5-HIAA (TRP: r=-0.18, p<0.001; 5-HTP: r=-0.13, p=0.02; natural log of 5-HIAA: r=-0.11, p=0.04), and positively with KYN (r=0.11, p=0.04).

CONCLUSIONS

The LC-MS/MS method is able to accurately quantify kynurenine- and serotonin pathway metabolites in pregnant women, providing an opportunity to investigate the role of the TRP metabolism in the (patho)physiology of pregnancy.

The Effect of an eHealth Coaching Program (Smarter Pregnancy) on Attitudes and Practices Toward Periconception Lifestyle Behaviors in Women Attempting Pregnancy: Prospective Study

BACKGROUND

Lifestyle behaviors during the periconception period contribute to achievement of a successful pregnancy. Assessment of attitudes and practices toward these modifiable behaviors can aid in identifying gaps in unhealthy lifestyle behaviors with impact on intervention effectiveness.

OBJECTIVE

This study investigates the effectiveness of coaching by the eHealth program Smarter Pregnancy during the periconception period on improvement of attitudes and practices toward fruit and vegetable intake and smoking in women attempting pregnancy through assisted reproductive technology (ART) or natural conception.

METHODS

Women attempting pregnancy through ART (n=1060) or natural conception (n=631) were selected during the periconception period. The intervention groups, conceived through ART or naturally, received Smarter Pregnancy coaching for 24 weeks, whereas the control group conceived through ART and did not receive coaching. Attitudes and practices at baseline and follow-up periods were obtained from self-administered online questionnaire provided by the program. Attitudes were assessed in women with unhealthy behaviors as their intention to increase their fruit and vegetable intake and to quit smoking using a yes/no question. Outcomes on practices, suggesting effectiveness, included daily fruit (pieces) and vegetable (grams) intake, and if women smoked (yes/no). Changes in attitudes and practices were compared at 12 and 24 weeks with baseline between the ART intervention and ART control groups, and within the intervention groups between ART and natural conception. Changes in practices at 12 and 24 weeks were also compared with baseline between women with negative attitude and positive attitude within the intervention groups: ART and natural conception. Analysis was performed using linear and logistic regression models adjusted for maternal confounders and baseline attitudes and practices.

RESULTS

The ART intervention group showed higher vegetable intake and lower odds for negative attitudes toward vegetable intake after 12 weeks (β_adj=25.72 g, P<.001; adjusted odds ratio [OR_adj] 0.24, P<.001) and 24 weeks of coaching (β_adj=23.84 g, P<.001; OR_adj 0.28, P<.001) compared with ART controls. No statistically significant effect was observed on attitudes and practices toward fruit intake (12 weeks: P=.16 and .08, respectively; 24 weeks: P=.16 and .08, respectively) and smoking behavior (12 weeks: P=.87; 24 weeks: P=.92). No difference was observed for the studied attitudes and practices between the ART intervention and natural conception intervention groups. Women with persistent negative attitude toward fruit and vegetable intake at week 12 showed lower fruit and vegetable intake at week 24 compared with women with positive attitude (β_adj=-.49, P<.001; β_adj=-30.07, P<.001, respectively).

CONCLUSIONS

The eHealth Smarter Pregnancy program may improve vegetable intake-related attitudes and practices in women undergoing ART treatment. Women with no intention to increase fruit and vegetable intake had less improvement in their intakes. Despite small changes, this study demonstrates again that Smarter Pregnancy can be used to improve vegetable intake, which can complemented by blended care that combines face-to-face and online care to also improve fruit intake and smoking behavior.

Prototyping of a Digital Life Course Care Platform for Preconception and Pregnancy Care: Pilot Feasibility and Acceptability Study

BACKGROUND

A healthy lifestyle plays a key role in the prevention of lifestyle-related diseases, including subfertility and pregnancy complications. Although the benefits of a healthy lifestyle are well-known, long-term adherence is limited. Moreover, memory for lifestyle-related information as well as medical information provided by the medical professional is often poor and insufficient. In order to innovate and improve health care for both the patients and health care professionals, we developed a prototype of a digital life course care platform (Smarter Health app), providing personalized lifestyle care trajectories integrated in medical care journeys.

OBJECTIVE

This pilot study aimed to evaluate the feasibility, defined as the actual app use, and the acceptability, which included patient satisfaction and appreciation, of the Smarter Health app.

METHODS

Between March 17, 2021, and September 30, 2021, pregnant women familiar with the Dutch language seeking tertiary preconception and pregnancy care were offered the app as part of standard medical care at the outpatient clinic Healthy Pregnancy of the Department of Obstetrics and Gynecology of the Erasmus University Medical Center. Three months after activation of the app, patients received a digital questionnaire consisting of aspects of feasibility and acceptability.

RESULTS

During this pilot study, 440 patients visited the outpatient clinic Healthy Pregnancy. Of the 440 patients, 293 (66.6%) activated the app. Of the 293 patients who activated the app, 125 (42.7%) filled out the questionnaire. Of these 125 patients, 48 (38.4%) used the app. Most app users used it occasionally and logged in 8 times during their medical care trajectory. Overall, app users were satisfied with the app (median 5-point Likert scale=2.4, IQR 2.0-3.3).

CONCLUSIONS

Our findings showed that the Smarter Health app, which integrates lifestyle care in medical care, is a feasible health care innovation, and that patients were satisfied with the app. Follow-up and evaluation of pregnancy outcomes should be performed to further substantiate wider clinical implementation.

Periconceptional Maternal Protein Intake from Animal and Plant Sources and the Impact on Early and Late Prenatal Growth and Birthweight: The Rotterdam Periconceptional Cohort

Plant-based diets continue to rise in popularity, including among women of reproductive age, while consequences for pregnancy outcomes have hardly been studied. During pregnancy, maternal diet is the only source of proteins for the developing fetus. Hence, we investigated the effects of periconceptional maternal animal and plant protein intake on prenatal growth and birthweight. 501 pregnancies were included from the prospective Rotterdam Periconceptional Cohort. Embryonic growth was depicted by crown-rump length (CRL) and embryonic volume (EV) at 7, 9 and 11 weeks using 3D ultrasound scans. Estimated fetal weight (EFW) at 20 weeks and birthweight were retrieved from medical records and standardized. Multivariable mixed models were used for CRL and EV trajectories, and linear regression for EFW and birthweight. A 10 g/day higher maternal animal protein intake was positively associated with increased embryonic growth (CRL: β = 0.023 √mm, p = 0.052; EV: β = 0.015 ∛cm, p = 0.012). A positive association, albeit non-significant, was found between maternal animal protein intake and EFW, and birthweight. No clear associations emerged between maternal plant protein intake and prenatal growth and birthweight, with effect estimates close to zero. In conclusion, maternal animal protein intake during the periconception period was positively associated with early and late prenatal growth and birthweight, while no associations were found between maternal plant protein intake and prenatal growth and birthweight.

Implementation of effective blended periconception lifestyle care in a tertiary hospital in the Netherlands: a cross-sectional study on determinants and patient satisfaction

OBJECTIVE

To identify implementation determinants of blended periconception lifestyle care, and to evaluate patient satisfaction.

DESIGN

Cross-sectional study.

SETTING

The outpatient clinic of the department of Obstetrics and Gynaecology of the Erasmus MC.

PARTICIPANTS

Implementation part: counsellors providing blended periconception lifestyle care. Patient satisfaction part: women who received blended periconception lifestyle care.

METHODS

Blended periconception lifestyle care, including face-to-face counselling and 26 weeks of lifestyle coaching via the online platform 'Smarter Pregnancy', was implemented between June-December 2018. The Measurement Instrument for Determinants of Innovations questionnaire was used as input for the consolidated framework for implementation research to assess determinants of implementation. To evaluate patient satisfaction, patients receiving lifestyle care filled out an evaluation questionnaire, including questions on the needs for lifestyle counselling, information provision during counselling, and motivation and lifestyle change after counselling.

PRIMARY AND SECONDARY OUTCOME MEASURES

Identification of implementation determinants and the level of patient satisfaction.

RESULTS

Facilitators were reported in the implementation domains 'characteristics of the intervention' and 'characteristics of the individuals'. Barriers were in the implementation domains 'inner setting' and 'implementation process'. Regarding patient satisfaction on nutrition counselling, 31% of the respondents wanted information prior to the counselling session, 22% received new information after consultation, 51% got motivated to change and 40% changed their nutritional behaviour.

CONCLUSIONS

A considerable number of patients improved lifestyle after counselling, although, a relatively small number wanted lifestyle counselling prior to consultation.This study underlines the importance of implementation science and the information it provides for improving the implementation process.

The Role of the Kynurenine Pathway in the (Patho) physiology of Maternal Pregnancy and Fetal Outcomes: A Systematic Review

INTRODUCTION

Tryptophan is the precursor of kynurenine pathway (KP) metabolites which regulate immune tolerance, energy metabolism, and vascular tone. Since these processes are important during pregnancy, changes in KP metabolite concentrations may play a role in the pathophysiology of pregnancy complications. We hypothesize that KP metabolites can serve as novel biomarkers and preventive therapeutic targets. This review aimed to provide more insight into associations between KP metabolite concentrations in maternal and fetal blood, and in the placenta, and adverse maternal pregnancy and fetal outcomes.

METHODS

A systematic search was performed on 18 February 2022 comprising all KP metabolites, and keywords related to maternal pregnancy and fetal outcomes. English-written human studies measuring KP metabolite(s) in maternal or fetal blood or in the placenta in relation to pregnancy complications, were included. Methodological quality was assessed using the ErasmusAGE quality score (QS) (range: 0-10). A meta-analysis of the mean maternal tryptophan and kynurenine concentrations in uncomplicated pregnancies was conducted.

RESULTS

Of the 6262 unique records, 37 were included (median QS = 5). Tryptophan was investigated in most studies, followed by kynurenine, predominantly in maternal blood (n = 28/37), and in the second and third trimester of pregnancy (n = 29/37). Compared to uncomplicated pregnancies, decreased tryptophan in maternal blood was associated with an increased prevalence of depression, gestational diabetes mellitus, fetal growth restriction, spontaneous abortion, and preterm birth. Elevated tryptophan was only observed in women with pregnancy-induced hypertension compared to normotensive pregnant women. In women with preeclampsia, only kynurenic acid was altered; elevated in the first trimester of pregnancy, and positively associated with proteinuria in the third trimester of pregnancy.

CONCLUSIONS

KP metabolite concentrations were altered in a variety of maternal pregnancy and fetal complications. This review implies that physiological pregnancy requires a tight balance of KP metabolites, and that disturbances in either direction are associated with adverse maternal pregnancy and fetal outcomes.

Corpus luteum number and the maternal renin-angiotensin-aldosterone system as determinants of utero-placental (vascular) development: the Rotterdam Periconceptional Cohort

BACKGROUND

Pregnancies with > 1 corpus luteum (CL) display a hyperdynamic circulation and an increased risk of small-for-gestational age deliveries. Among the factors released by the CL is prorenin, the inactive precursor of renin. Since the renin-angiotensin-aldosterone system (RAAS) is involved in early hemodynamic pregnancy adaptation, we linked both CL number and first-trimester concentrations of prorenin (as an indicator of RAAS activity) and the aldosterone/renin ratio (as an indicator of angiotensin-independent aldosterone effectiveness) to non-invasive markers of utero-placental (vascular) development, measured longitudinally from the first trimester onwards.

METHODS

A total of 201 women, who conceived naturally or after in-vitro fertilization treatment (with 0 (n = 8), 1 (n = 143), or > 1 (n = 51) CL), were selected from the Rotterdam Periconceptional Cohort. Maternal RAAS components were determined at 11 weeks gestation. Placental volume and utero-placental vascular volume were measured from transvaginal 3D ultrasound scans at 7, 9 and 11 weeks gestation, pulsatility and resistance indices of the uterine arteries were assessed by pulsed wave Doppler ultrasounds at 7, 9, 11, 13, 22 and 32 weeks gestation. At birth placental weight was obtained using standardized procedures.

RESULTS

Pregnancies without a CL show lower uterine artery indices throughout gestation than 1 CL and > 1 CL pregnancies, while parameters of placental development are comparable among the CL groups. After adjustment for patient- and treatment-related factors, first-trimester prorenin concentrations are positively associated with uterine artery pulsatility and resistance indices (β 0.06, 95% CI 0.01;0.12, p = 0.04 and β 0.10, 95% CI 0.01;0.20, p = 0.04, respectively), while high prorenin concentrations are negatively associated with first-trimester utero-placental vascular volume (β -0.23, 95% CI -0.44;-0.02, p = 0.04) and placental weight (β -93.8, 95%CI -160.3;-27.4, p = 0.006). In contrast, the aldosterone/renin ratio is positively associated with first-trimester placental volume (β 0.12, 95% CI 0.01;0.24, p = 0.04).

CONCLUSIONS

The absence of a CL, resulting in low prorenin concentrations, associates with low uterine artery pulsatility and resistance, while high prorenin concentrations associate with a low utero-placental vascular volume and weight. These data support a scenario in which excess prorenin, by upregulating angiotensin II, increases uterine resistance, thereby preventing normal placental (vascular) development, and increasing the risk of small-for-gestational age deliveries. Simultaneously, high aldosterone concentrations, by ensuring volume expansion, exert the opposite.

A prospective population-based multicentre study on the impact of maternal body mass index on adverse pregnancy outcomes: Focus on normal weight

Background

Maternal body mass index (BMI) below or above the reference interval (18.5–24.9 kg/m²) is associated with adverse pregnancy outcomes. Whether BMI exerts an effect within the reference interval is unclear. Therefore, we assessed the association between adverse pregnancy outcomes and BMI, in particular within the reference interval, in a general unselected pregnant population.

Methods

Data was extracted from a prospective population-based multicentre cohort (Risk Estimation for PrEgnancy Complications to provide Tailored care (RESPECT) study) conducted between December 2012 to January 2014. BMI was studied in categories (I: <18.5, II: 18.5–19.9, III: 20.0–22.9, IV: 23.0–24.9, V: 25.0–27.4, VI: 27.5–29.9, VII: >30.0 kg/m²) and as a continuous variable within the reference interval. Adverse pregnancy outcomes were defined as composite endpoints for maternal, neonatal or any pregnancy complication, and for adverse pregnancy outcomes individually. Linear trends were assessed using linear-by-linear association analysis and (adjusted) relative risks by regression analysis.

Results

The median BMI of the 3671 included women was 23.2 kg/m² (IQR 21.1–26.2). Adverse pregnancy outcomes were reported in 1256 (34.2%). Linear associations were observed between BMI categories and all three composite endpoints, and individually for pregnancy-induced hypertension (PIH), preeclampsia, gestational diabetes mellitus (GDM), large-for-gestational-age (LGA) neonates; but not for small-for-gestational-age neonates and preterm birth. Within the reference interval, BMI was associated with the composite maternal endpoint, PIH, GDM and LGA, with adjusted relative risks of 1.15 (95%CI 1.06–1.26), 1.12 (95%CI 1.00–1.26), 1.31 (95%CI 1.11–1.55) and 1.09 (95%CI 1.01–1.17).

Conclusions

Graded increase in maternal BMI appears to be an indicator of risk for adverse pregnancy outcomes even among women with a BMI within the reference interval. The extent to which BMI directly contributes to the increased risk in this group should be evaluated in order to determine strategies most valuable for promoting safety and long-term health for mothers and their offspring.

Optimizing the Periconception Lifestyle of Women With Overweight Using a Blended Personalized Care Intervention Combining eHealth and Face-to-face Counseling (eFUSE): Protocol for a Randomized Controlled Trial

Background

Maternal overweight has a substantial impact on reproductive, maternal, pregnancy, and neonatal outcomes with long-term and transgenerational health consequences. Interventions that aim to optimize periconception maternal lifestyle can improve maternal and fetal health during pregnancy and throughout the life course. However, it remains difficult to change and adopt adequate lifestyle behaviors. We hypothesize that additional psychological therapy targeting cognitive and affective factors substantially contribute to the effectiveness of these interventions.

Objective

The proposed study aims to examine the feasibility and effectiveness of a blended personalized periconception lifestyle care intervention with additional psychological therapy aimed at women with a BMI≥25 and who are contemplating pregnancy or are already pregnant (≤12 weeks) in reducing inadequate lifestyle behaviors and improving early and late pregnancy outcome.

Methods

The eHealth and Face-to-face Counseling (eFUSE) study follows a single-center two-arm randomized controlled trial design at the Erasmus MC, University Medical Center, with a multicenter regional referral. The female patients with overweight (BMI≥25), together with their male partner, will be stratified by pregnancy status (preconception vs pregnant) and randomized to receive either the blended personalized periconception lifestyle care intervention with additional psychological therapy (n=313) or usual care (n=313). The primary outcome is a change in the lifestyle risk score (between baseline and 24 weeks) between the randomization arms (difference in differences). Secondary outcomes include measurements defined as most relevant by the International Consortium for Health Outcomes Measurement, including behavioral determinants, patient satisfaction, provider feasibility, and maternal pregnancy and neonatal complications.

Results

The study will be open for recruitment from Fall 2021 onward. Data collection is expected to be completed by the beginning of 2023, and the results are expected to be published by Fall 2023.

Conclusions

This study will evaluate the feasibility and effectiveness of a blended periconception lifestyle intervention with additional psychological therapy, aimed at women with a BMI≥25. Positive results of this innovative care approach will be used for implementation in routine medical care of all women with overweight, with the ultimate aim to improve clinical outcomes of these high-risk pregnancies.

Trial Registration

Netherlands Trial Register NL9264; https://www.trialregister.nl/trial/9264

International Registered Report Identifier (IRRID)

PRR1-10.2196/28600

Early childhood infections and body mass index in adolescence

BACKGROUND

The incidence of childhood overweight and obesity is rising. It is hypothesized that infections in early childhood are associated with being overweight. This study investigated the association between the number of symptomatic infections or antibiotic prescriptions in the first 3 years of life and body mass index (BMI) in adolescence.

SUBJECTS

The current study is part of the Prevention and Incidence of Asthma and Mite Allergy population-based birth cohort study. Weight and height were measured by trained research staff at ages 12 and 16 years. The 3015 active participants at age 18 years were asked for informed consent for general practitioner (GP) data collection and 1519 gave written informed consent. Studied exposures include (1) GP-diagnosed infections, (2) antibiotic prescriptions, and (3) parent-reported infections in the first 3 years of life. Generalized estimating equation analysis was used to determine the association between each of these exposures and BMI z-score.

RESULTS

Exposure data and BMI measurement in adolescence were available for 622 participants. The frequencies of GP-diagnosed infections and antibiotic prescriptions were not associated with BMI z-score in adolescence with estimates being 0.14 (95% CI -0.09-0.37) and 0.10 (95% CI -0.14-0.34) for the highest exposure categories, respectively. Having ≥6 parent-reported infections up to age 3 years was associated with a 0.23 (95% CI 0.01-0.44) higher BMI z-score compared to <2 parent-reported infections.

CONCLUSIONS

For all infectious disease measures an increase in BMI z-score for the highest childhood exposure to infectious disease was observed, although only statistically significant for parent-reported infections. These results do not show an evident link with infection severity, but suggest a possible cumulative effect of repeated symptomatic infections on overweight development.

Ambient Particle Components and Newborn Blood Pressure in Project Viva

Background

Both elemental metals and particulate air pollution have been reported to influence adult blood pressure (BP). The aim of this study is to examine which elemental components of particle mass with diameter ≤2.5 μm (PM_2.5) are responsible for previously reported associations between PM_2.5 and neonatal BP.

Methods and Results

We studied 1131 mother‐infant pairs in Project Viva, a Boston‐area prebirth cohort. We measured systolic BP (SBP) and diastolic BP (DBP) at a mean age of 30 hours. We calculated average exposures during the 2 to 7 days before birth for the PM_2.5 components—aluminum, arsenic, bromine, sulfur, copper, iron, zinc, nickel, vanadium, titanium, magnesium, potassium, silicon, sodium, chlorine, calcium, and lead—measured at the Harvard supersite. Adjusting for covariates and PM_2.5, we applied regression models to examine associations between PM_2.5 components and median SBP and DBP, and used variable selection methods to select which components were more strongly associated with each BP outcome. We found consistent results with higher nickel associated with significantly higher SBP and DBP, and higher zinc associated with lower SBP and DBP. For an interquartile range increase in the log Z score (1.4) of nickel, we found a 1.78 mm Hg (95% CI, 0.72–2.84) increase in SBP and a 1.30 (95% CI, 0.54–2.06) increase in DBP. Increased zinc (interquartile range log Z score 1.2) was associated with decreased SBP (−1.29 mm Hg; 95% CI, −2.09 to −0.50) and DBP (−0.85 mm Hg; 95% CI: −1.42 to −0.29).

Conclusions

Our findings suggest that prenatal exposures to particulate matter components, and particularly nickel, may increase newborn BP.

Breast milk n-3 long-chain polyunsaturated fatty acids and blood pressure: an individual participant meta-analysis

Purpose

It is controversial whether a higher intake of n-3 long-chain polyunsaturated fatty acids (n-3 LC PUFA) through breastfeeding is associated or not to a lower blood pressure (BP) during childhood. We aimed to clarify this point by undertaking a meta-analysis involving the data from seven European birth cohorts.

Methods

We searched https://www.birthcohort.net for studies that had collected breast milk samples, and had at least one BP measurement in childhood. Principal investigators were contacted, and all agreed to share data. One additional study was identified by contacts with the principal investigators. For each cohort, we analyzed the association of breast milk n-3 LC PUFAs with systolic and diastolic BP with linear mixed effects models or linear regression, and pooled the estimates with a random effects model. We also investigated age-specific and sex-specific associations.

Results

A total of 2188 participants from 7 cohorts were included. Overall, no associations between breast milk n-3 LC PUFAs and BP were observed. In the pooled analysis, each 0.1 wt% increment in breast milk docosahexaenoic acid (DHA) was associated with a 1.19 (95% CI − 3.31, 0.94) mmHg lower systolic BP. Associations were similar for boys and girls and at different ages.

Conclusion

In this individual participant meta-analysis, we found no evidence for an association between breast milk n-3 LC PUFAs and BP.

Electronic supplementary material

The online version of this article (10.1007/s00394-020-02310-4) contains supplementary material, which is available to authorized users.

Repositioning of the global epicentre of non-optimal cholesterol

High blood cholesterol is typically considered a feature of wealthy western countries1,2. However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world3 and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health4,5. However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol-which is a marker of cardiovascular risk-changed from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million-4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.

The joint effect of maternal smoking during pregnancy and maternal pre-pregnancy overweight on infants' term birth weight

Background

It is well known that maternal smoking during pregnancy and maternal pre-pregnancy overweight have opposite effects on the infants’ birth weight. We report on the association of the combination between both risk factors and the infants’ birth weight.

Methods

We studied 3241 infants born at term in the PIAMA birth cohort. Maternal smoking during pregnancy and pre-pregnancy height and weight were self-reported. Multivariable regression analysis was performed to assess the associations between infants of mothers who only smoked during pregnancy, who only had pre-pregnancy overweight and who had both risk factors simultaneously, on term birth weight and the risk of being SGA or LGA.

Results

Of 3241 infants, 421 infants (13%) were born to smoking, non-overweight mothers, 514 (15.8%) to non-smoking, overweight mothers, 129 (4%) to smoking and overweight mothers and 2177 (67%) to non-smoking, non-overweight mothers (reference group). Infants of mothers who smoked and also had pre-pregnancy overweight had similar term birth weight (− 26.6 g, 95%CI: − 113.0, 59.8), SGA risk (OR = 1.06, 95%CI: 0.56, 2.04), and LGA risk (OR = 1.09, 95%CI: 0.61, 1.96) as the reference group.

Conclusions

Our findings suggested that the effects of maternal smoking during pregnancy and maternal pre-pregnancy overweight on infants’ birth weight cancel each other out. Therefore, birth weight may not be a good indicator of an infant’s health status in perinatal practice because it may mask potential health risks due to these maternal risk factors when both present together.

Hypertensive disorders of pregnancy and cardiometabolic outcomes in childhood: A systematic review

Background

Hypertensive disorders of pregnancy (HDPs) are among the leading causes of maternal and perinatal morbidity and mortality worldwide and have been suggested to increase long-term cardiovascular disease risk in the offspring.

Objective

The objective of this study was to investigate whether HDPs are associated with cardiometabolic markers in childhood.

Search strategy

PubMed, The Cochrane Library and reference lists of included studies up to January 2019.

Selection criteria

Studies comparing cardiometabolic markers in 2–18-year-old children of mothers with HDP in utero, to children of mothers without HDP.

Data collection and analysis

Sixteen studies reported in 25 publications were included in this systematic review, of which three were considered as having high risk of bias. Thus 13 studies were included in the evidence synthesis: respectively two and eight reported pregnancy induced hypertension and preeclampsia, and three studies reported on both HDPs.

Main results

Most studies (n = 4/5) found a higher blood pressure in children exposed to pregnancy induced hypertension. Most studies (n = 7/10) found no statistically significantly higher blood pressure in children exposed to preeclampsia. No association was found between exposure to HDP and levels of cholesterol, triglycerides or glucose (n = 5/5). No studies investigated an association with (carotid) intima-media thickness, glycated haemoglobin or diabetes mellitus type 2.

Conclusions

Most studies showed that exposure to pregnancy induced hypertension is associated with a higher offspring blood pressure. There is no convincing evidence for an association between exposure to preeclampsia and blood pressure in childhood. Based on current evidence, exposure to HDP is not associated with blood levels of cholesterol, triglycerides and glucose in childhood.

Association of Gestational Weight Gain With Adverse Maternal and Infant Outcomes

Importance

Both low and high gestational weight gain have been associated with adverse maternal and infant outcomes, but optimal gestational weight gain remains uncertain and not well defined for all prepregnancy weight ranges.

Objectives

To examine the association of ranges of gestational weight gain with risk of adverse maternal and infant outcomes and estimate optimal gestational weight gain ranges across prepregnancy body mass index categories.

Design, Setting, and Participants

Individual participant-level meta-analysis using data from 196 670 participants within 25 cohort studies from Europe and North America (main study sample). Optimal gestational weight gain ranges were estimated for each prepregnancy body mass index (BMI) category by selecting the range of gestational weight gain that was associated with lower risk for any adverse outcome. Individual participant-level data from 3505 participants within 4 separate hospital-based cohorts were used as a validation sample. Data were collected between 1989 and 2015. The final date of follow-up was December 2015.

Exposures

Gestational weight gain.

Main Outcomes and Measures

The main outcome termed any adverse outcome was defined as the presence of 1 or more of the following outcomes: preeclampsia, gestational hypertension, gestational diabetes, cesarean delivery, preterm birth, and small or large size for gestational age at birth.

Results

Of the 196 670 women (median age, 30.0 years [quartile 1 and 3, 27.0 and 33.0 years] and 40 937 were white) included in the main sample, 7809 (4.0%) were categorized at baseline as underweight (BMI <18.5); 133 788 (68.0%), normal weight (BMI, 18.5-24.9); 38 828 (19.7%), overweight (BMI, 25.0-29.9); 11 992 (6.1%), obesity grade 1 (BMI, 30.0-34.9); 3284 (1.7%), obesity grade 2 (BMI, 35.0-39.9); and 969 (0.5%), obesity grade 3 (BMI, ≥40.0). Overall, any adverse outcome occurred in 37.2% (n = 73 161) of women, ranging from 34.7% (2706 of 7809) among women categorized as underweight to 61.1% (592 of 969) among women categorized as obesity grade 3. Optimal gestational weight gain ranges were 14.0 kg to less than 16.0 kg for women categorized as underweight; 10.0 kg to less than 18.0 kg for normal weight; 2.0 kg to less than 16.0 kg for overweight; 2.0 kg to less than 6.0 kg for obesity grade 1; weight loss or gain of 0 kg to less than 4.0 kg for obesity grade 2; and weight gain of 0 kg to less than 6.0 kg for obesity grade 3. These gestational weight gain ranges were associated with low to moderate discrimination between those with and those without adverse outcomes (range for area under the receiver operating characteristic curve, 0.55-0.76). Results for discriminative performance in the validation sample were similar to the corresponding results in the main study sample (range for area under the receiver operating characteristic curve, 0.51-0.79).

Conclusions and Relevance

In this meta-analysis of pooled individual participant data from 25 cohort studies, the risk for adverse maternal and infant outcomes varied by gestational weight gain and across the range of prepregnancy weights. The estimates of optimal gestational weight gain may inform prenatal counseling; however, the optimal gestational weight gain ranges had limited predictive value for the outcomes assessed.

Gestational weight gain charts for different body mass index groups for women in Europe, North America, and Oceania

BACKGROUND

Gestational weight gain differs according to pre-pregnancy body mass index and is related to the risks of adverse maternal and child health outcomes. Gestational weight gain charts for women in different pre-pregnancy body mass index groups enable identification of women and offspring at risk for adverse health outcomes. We aimed to construct gestational weight gain reference charts for underweight, normal weight, overweight, and grades 1, 2 and 3 obese women and to compare these charts with those obtained in women with uncomplicated term pregnancies.

METHODS

We used individual participant data from 218,216 pregnant women participating in 33 cohorts from Europe, North America, and Oceania. Of these women, 9065 (4.2%), 148,697 (68.1%), 42,678 (19.6%), 13,084 (6.0%), 3597 (1.6%), and 1095 (0.5%) were underweight, normal weight, overweight, and grades 1, 2, and 3 obese women, respectively. A total of 138, 517 women from 26 cohorts had pregnancies with no hypertensive or diabetic disorders and with term deliveries of appropriate for gestational age at birth infants. Gestational weight gain charts for underweight, normal weight, overweight, and grade 1, 2, and 3 obese women were derived by the Box-Cox t method using the generalized additive model for location, scale, and shape.

RESULTS

We observed that gestational weight gain strongly differed per maternal pre-pregnancy body mass index group. The median (interquartile range) gestational weight gain at 40 weeks was 14.2 kg (11.4-17.4) for underweight women, 14.5 kg (11.5-17.7) for normal weight women, 13.9 kg (10.1-17.9) for overweight women, and 11.2 kg (7.0-15.7), 8.7 kg (4.3-13.4) and 6.3 kg (1.9-11.1) for grades 1, 2, and 3 obese women, respectively. The rate of weight gain was lower in the first half than in the second half of pregnancy. No differences in the patterns of weight gain were observed between cohorts or countries. Similar weight gain patterns were observed in mothers without pregnancy complications.

CONCLUSIONS

Gestational weight gain patterns are strongly related to pre-pregnancy body mass index. The derived charts can be used to assess gestational weight gain in etiological research and as a monitoring tool for weight gain during pregnancy in clinical practice.

Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: a pooled analysis of 1018 population-based measurement studies with 88.6 million participants

BACKGROUND

Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure.

METHODS

We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probit-transformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure.

RESULTS

In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the high-income Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association.

CONCLUSIONS

Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups.

Long-term BMI and growth profiles in offspring of women with gestational diabetes

AIMS/HYPOTHESIS

Gestational diabetes mellitus (GDM) is reported to be associated with childhood obesity, however the magnitude of this association and relation to intrauterine growth is uncertain. We, therefore, aimed to assess whether the growth trajectories of large for gestational age (LGA) and non-LGA offspring of mothers with GDM (OGDM) are different until early adolescence. We also aimed to explore whether growth trajectories of OGDM differ from those of offspring of mothers with type 1 or 2 diabetes (ODM1, ODM2).

METHODS

We studied height and BMI standard deviation score (SDS) of the OGDM group, up to the age of 14 years, with subgroup analysis comparing LGA with non-LGA at birth as a reflection of the intrauterine environment. All mothers with GDM who delivered at the University Medical Center Utrecht between 1990 and 2006 were contacted to participate; informed consent was received for 104 OGDM of 93 mothers. Offspring data were collected through Dutch infant welfare centres. Recorded height and weight were converted to BMI and age- and sex-specific SDS values for Dutch children. Additionally, we compared the OGDM group with ODM1 and ODM2 groups in order to identify those offspring with the highest risk of becoming overweight. Growth trajectories were compared between non-LGA and LGA OGDM and between OGDM, ODM1 and ODM2, using a random-effects model. In the longitudinal follow-up a mean of 7.4 ± 2 measurements per infant were available.

RESULTS

Mothers had a prepregnancy BMI of 25.8 kg/m² and 24% of their infants were LGA at birth. Heights of OGDM were no different from those of the Dutch Growth Study. Non-LGA OGDM showed a BMI SDS comparable with that of the reference population, with a slight increase in early adolescence. LGA OGDM had a higher BMI SDS trajectory than non-LGA OGDM and the reference population, which plateaued at around 10 years of age. Comparison of growth trajectories of OGDM, ODM1 and ODM2 showed ODM2 to have the highest trajectory followed by ODM1 and OGDM, with the LGA counterparts of all three offspring groups in the highest BMI SDS ranges.

CONCLUSIONS/INTERPRETATION

Until early adolescence, OGDM have a BMI that is 0.5 SDS higher than that of the Dutch background population. LGA OGDM appear to be at particularly higher risk of being overweight in adolescence compared with non-LGA OGDM, putting them also at a higher lifetime risk of being overweight and developing obesity. ODM2 showed the highest BMI SDS values and had an average BMI SDS of +1.6 until the age of 14, when it became +2 SD. These results emphasize the importance of adequate recognition and timely treatment of maternal gestational diabetes to prevent fetal macrosomia in obstetrics.

Worldwide trends in body-mass index, underweight, overweight, and obesity from 1975 to 2016: a pooled analysis of 2416 population-based measurement studies in 128·9 million children, adolescents, and adults

BACKGROUND

Underweight, overweight, and obesity in childhood and adolescence are associated with adverse health consequences throughout the life-course. Our aim was to estimate worldwide trends in mean body-mass index (BMI) and a comprehensive set of BMI categories that cover underweight to obesity in children and adolescents, and to compare trends with those of adults.

METHODS

We pooled 2416 population-based studies with measurements of height and weight on 128·9 million participants aged 5 years and older, including 31·5 million aged 5-19 years. We used a Bayesian hierarchical model to estimate trends from 1975 to 2016 in 200 countries for mean BMI and for prevalence of BMI in the following categories for children and adolescents aged 5-19 years: more than 2 SD below the median of the WHO growth reference for children and adolescents (referred to as moderate and severe underweight hereafter), 2 SD to more than 1 SD below the median (mild underweight), 1 SD below the median to 1 SD above the median (healthy weight), more than 1 SD to 2 SD above the median (overweight but not obese), and more than 2 SD above the median (obesity).

FINDINGS

Regional change in age-standardised mean BMI in girls from 1975 to 2016 ranged from virtually no change (-0·01 kg/m2 per decade; 95% credible interval -0·42 to 0·39, posterior probability [PP] of the observed decrease being a true decrease=0·5098) in eastern Europe to an increase of 1·00 kg/m2 per decade (0·69-1·35, PP>0·9999) in central Latin America and an increase of 0·95 kg/m2 per decade (0·64-1·25, PP>0·9999) in Polynesia and Micronesia. The range for boys was from a non-significant increase of 0·09 kg/m2 per decade (-0·33 to 0·49, PP=0·6926) in eastern Europe to an increase of 0·77 kg/m2 per decade (0·50-1·06, PP>0·9999) in Polynesia and Micronesia. Trends in mean BMI have recently flattened in northwestern Europe and the high-income English-speaking and Asia-Pacific regions for both sexes, southwestern Europe for boys, and central and Andean Latin America for girls. By contrast, the rise in BMI has accelerated in east and south Asia for both sexes, and southeast Asia for boys. Global age-standardised prevalence of obesity increased from 0·7% (0·4-1·2) in 1975 to 5·6% (4·8-6·5) in 2016 in girls, and from 0·9% (0·5-1·3) in 1975 to 7·8% (6·7-9·1) in 2016 in boys; the prevalence of moderate and severe underweight decreased from 9·2% (6·0-12·9) in 1975 to 8·4% (6·8-10·1) in 2016 in girls and from 14·8% (10·4-19·5) in 1975 to 12·4% (10·3-14·5) in 2016 in boys. Prevalence of moderate and severe underweight was highest in India, at 22·7% (16·7-29·6) among girls and 30·7% (23·5-38·0) among boys. Prevalence of obesity was more than 30% in girls in Nauru, the Cook Islands, and Palau; and boys in the Cook Islands, Nauru, Palau, Niue, and American Samoa in 2016. Prevalence of obesity was about 20% or more in several countries in Polynesia and Micronesia, the Middle East and north Africa, the Caribbean, and the USA. In 2016, 75 (44-117) million girls and 117 (70-178) million boys worldwide were moderately or severely underweight. In the same year, 50 (24-89) million girls and 74 (39-125) million boys worldwide were obese.

INTERPRETATION

The rising trends in children's and adolescents' BMI have plateaued in many high-income countries, albeit at high levels, but have accelerated in parts of Asia, with trends no longer correlated with those of adults.

FUNDING

Wellcome Trust, AstraZeneca Young Health Programme.

Proximity to agricultural fields as proxy for environmental exposure to pesticides among children: The PIAMA birth cohort

BACKGROUND

Agricultural pesticides are frequently used for crop protection. Residents living in close proximity to treated fields may be exposed to these pesticides. There is some indication that children living near agricultural fields have an increased risk of developing asthma and decreased lung function.

OBJECTIVES

The aim of this study was to assess the proximity of participants' homes to fields likely treated with pesticides as proxy for environmental exposure to agricultural pesticides among participants of a Dutch birth cohort study, and to combine acreage of fields with farmer-reported pesticide use.

METHODS

Potential pesticide exposure at the home address at the time of the 14-year follow-up was estimated for 2291 participants of the Dutch PIAMA birth cohort study. We used spatial data on the presence of crops during the year 2012 to calculate the surface area of specific crops relevant for pesticide use in The Netherlands cultivated within 50, 100, 500 and 1000m of the study homes. Farmer-reported pesticides use on specific crops from a national survey performed in 2012 was used to estimate the amount of all pesticides and pesticides with known irritant properties for the respiratory system applied within the aforementioned distances of the study homes.

RESULTS

For 3%, 7%, 40%, and 65% of the homes, any relevant crops were present within 50, 100, 500 and 1000m, respectively. Among these, the most frequent crops were corn, cereals, and potatoes. For almost the same percentages of homes, it was estimated that pesticides with known irritant properties for the respiratory system were potentially applied within these distances.

CONCLUSIONS

We observed that a small proportion of the study participants lived in close proximity (<50 or <100m) to agricultural fields with crops relevant for pesticide use in The Netherlands. The percentage of study homes within 500 or 1000m of agricultural fields with these crops was much larger.

Long-chain polyunsaturated fatty acids in infant formula and cardiovascular markers in childhood

To investigate whether children who consumed infant formula supplemented with long-chain polyunsaturated fatty acids (LCPUFAs) had a more favourable cardiovascular profile than children who consumed formula without these fatty acids, we used the Wheezing Illnesses Study Leidsche Rijn, a birth cohort that included 2,468 newborns between 2001 and 2014. Data on infant feeding were obtained by questionnaires. At age 5, blood pressure, carotid intima-media thickness (CIMT), and carotid distension were measured. We used multivariable linear regression analysis to compare levels of cardiovascular markers in formula-fed children born before and after the LCPUFA supplementation. To account for secular trends, we compared levels of cardiovascular markers in a control group of breastfed children from the same cohort born before and after the supplementation. Formula-fed children born after the LCPUFA supplementation (n = 48) had no different systolic blood pressure (-2.58 mmHg, 95% confidence interval, CI [-5.5, 0.30]), diastolic blood pressure (-0.13 mmHg, 95% CI [-2.3, 2.1]), or carotid distension (24.8 MPa^-1 , 95% CI [-47.1, 96.6]) and had a higher CIMT (18.6 μm, 95% CI [3.7, 33.5]) than formula-fed children born before the supplementation (n = 163). In the control group, children born after the LCPUFA supplementation (n = 98) had no different systolic- or diastolic-blood pressure, or CIMT, and a higher carotid distension than children born before the supplementation (n = 142). In conclusion, children who consumed infant formula supplemented with LCPUFAs did not have a more favourable cardiovascular profile in early childhood than children who consumed formula without LCPUFAs.

Pubertal Timing and Cardiometabolic Markers at Age 16 Years

OBJECTIVE

To examine the association between pubertal timing and cardiometabolic markers among adolescents.

STUDY DESIGN

We used data from Dutch adolescents participating in a birth cohort study. The study population for the current study consisted of 799 adolescents of whom data were available for at least 1 of the exposure variables (pubertal timing and/or age at menarche) and any of the cardiometabolic markers (waist circumference, cholesterol, blood pressure [BP], glycated hemoglobin) measured at age 16 years. Adolescents self-reported pubertal development at ages 11, 14, and 16 years. We categorized participants with early (84 girls, 88 boys), intermediate (240 girls, 211 boys), or late pubertal timing (89 girls, 85 boys). We estimated differences in cardiometabolic markers using linear regression analysis.

RESULTS

Girls with early pubertal timing had 1.54 cm larger waist circumference (95% CI .05; 3.03) and 3.98 mm Hg higher systolic BP (95% CI 1.69; 6.27) at age 16 years than girls with intermediate pubertal timing. The association with systolic BP remained after adjusting for childhood body mass index (BMI) (age 8 years) but attenuated after adjusting for BMI in adolescence (age 16 years). Boys with early pubertal timing had 0.79 mmol/mol lower glycated hemoglobin (95%CI -1.38; -0.20) than boys with intermediate pubertal timing.

CONCLUSIONS

Girls with early pubertal timing had unfavorable BP levels at age 16 years, independent of BMI in childhood. Girls and boys with late pubertal timing had a tendency for lower waist circumference, but no differences in other cardiometabolic markers. Late pubertal timing does not appear to be a risk factor for unfavorable cardiometabolic markers in adolescence.

Lifetime secondhand smoke exposure and childhood and adolescent asthma: findings from the PIAMA cohort

BACKGROUND

Secondhand smoke (SHS) exposure is a modifiable risk factor associated with childhood asthma. Associations with adolescent asthma and the relevance of the timing and patterns of exposure are unclear. Knowledge of critical windows of exposure is important for targeted interventions.

METHODS

We used data until age 17 from 1454 children of the Dutch population-based PIAMA birth cohort. Residential SHS exposure was assessed through parental questionnaires completed at ages 3 months, 1-8 (yearly), 11, 14, and 17 years. Lifetime exposure was determined as; a) time window-specific exposure (prenatal, infancy, preschool, primary school, and secondary school); b) lifetime cumulative exposure; c) longitudinal exposure patterns using latent class growth modeling (LCGM). Generalized estimation equations and logistic regression were used to analyze associations between exposure and asthma at ages 4 to 17 years, adjusting for potential confounders.

RESULTS

With all three methods, we consistently found no association between SHS exposure and asthma at ages 4 to 17 years e.g. adjusted overall odds ratio (95% confidence interval) 0.67 (0.41-1.12), 1.00 (0.66-1.51) and 0.67 (0.41-1.11) for prenatal maternal active smoking, infancy, and preschool school time window exposures, respectively.

CONCLUSION

We assessed lifetime SHS exposure using different methods. Different timing and patterns of SHS exposure were not associated with an increased risk of asthma in childhood and adolescence in our study. More longitudinal studies could investigate effects of lifetime SHS exposure on asthma in adolescence and later life.

Family history of myocardial infarction, stroke and diabetes and cardiometabolic markers in children

AIMS/HYPOTHESIS

Despite the overlap in occurrence of cardiovascular disease (CVD) and type 2 diabetes and their risk factors, family history of these diseases has not yet been investigated simultaneously in relation to cardiometabolic markers in offspring. We examined how a family history of CVD and/or diabetes relates to cardiometabolic markers in offspring, and to what extent these diseases independently contribute to cardiometabolic markers.

METHODS

We used data from 1,374 12-year-old children and their parents participating in a birth cohort study in the Netherlands. Family history of CVD (myocardial infarction [MI] and stroke) and diabetes were reported by the parents. Children were classified as 'no', 'moderate' or 'strong' family history, based on early/late onset of disease in parents and grandparents. Cardiometabolic markers were measured at 12 years of age: waist circumference, cholesterol, blood pressure and HbA1c.

RESULTS

Compared with those with no family history, children with a strong family history of MI and/or stroke and/or diabetes (29% of the study population) had 0.13 mmol/l higher total cholesterol (TC) (95% CI 0.03, 0.23) and 0.18 higher TC/HDL-cholesterol (HDLC) ratio (95% CI 0.04, 0.32). A strong family history of MI or diabetes was independently associated with unfavourable cardiometabolic markers specific to those diseases. These associations remained after adjusting for BMI. Children with a moderate family history had no unfavourable cardiometabolic markers.

CONCLUSIONS/INTERPRETATION

One-third of the children had a strong family history of CVD and/or diabetes. These children had higher TC levels and TC/HDLC ratios than children with no family history. A strong family history of MI or diabetes was independently associated with unfavourable cardiometabolic markers specific to those diseases.

Elemental Constituents of Particulate Matter and Newborn's Size in Eight European Cohorts

BACKGROUND

The health effects of suspended particulate matter (PM) may depend on its chemical composition. Associations between maternal exposure to chemical constituents of PM and newborn's size have been little examined.

OBJECTIVE

We aimed to investigate the associations of exposure to elemental constituents of PM with term low birth weight (LBW; weight < 2,500 g among births after 37 weeks of gestation), mean birth weight, and head circumference, relying on standardized fine-scale exposure assessment and with extensive control for potential confounders.

METHODS

We pooled data from eight European cohorts comprising 34,923 singleton births in 1994-2008. Annual average concentrations of elemental constituents of PM ≤ 2.5 and ≤ 10 μm (PM2.5 and PM10) at maternal home addresses during pregnancy were estimated using land-use regression models. Adjusted associations between each birth measurement and concentrations of eight elements (copper, iron, potassium, nickel, sulfur, silicon, vanadium, and zinc) were calculated using random-effects regression on pooled data.

RESULTS

A 200-ng/m3 increase in sulfur in PM2.5 was associated with an increased risk of LBW (adjusted odds ratio = 1.36; 95% confidence interval: 1.17, 1.58). Increased nickel and zinc in PM2.5 concentrations were also associated with an increased risk of LBW. Head circumference was reduced at higher exposure to all elements except potassium. All associations with sulfur were most robust to adjustment for PM2.5 mass concentration. All results were similar for PM10.

CONCLUSION

Sulfur, reflecting secondary combustion particles in this study, may adversely affect LBW and head circumference, independently of particle mass.

CITATION

Pedersen M, Gehring U, Beelen R, Wang M, Giorgis-Allemand L, Andersen AM, Basagaña X, Bernard C, Cirach M, Forastiere F, de Hoogh K, Gražulevičienė R, Gruzieva O, Hoek G, Jedynska A, Klümper C, Kooter IM, Krämer U, Kukkonen J, Porta D, Postma DS, Raaschou-Nielsen O, van Rossem L, Sunyer J, Sørensen M, Tsai MY, Vrijkotte TG, Wilhelm M, Nieuwenhuijsen MJ, Pershagen G, Brunekreef B, Kogevinas M, Slama R. 2016. Elemental constituents of particulate matter and newborn's size in eight European cohorts. Environ Health Perspect 124:141-150; http://dx.doi.org/10.1289/ehp.1409546.

Associations between particulate matter composition and childhood blood pressure--The PIAMA study

BACKGROUND

Childhood blood pressure is an important predictor of hypertension and cardiovascular disease in adulthood. Evidence for an association between ambient particulate matter (PM) exposure and blood pressure is increasing, but little is known about the relevance of different PM constituents.

OBJECTIVES

We investigated the association between particulate matter composition and blood pressure at age 12 years.

METHODS

Annual average concentrations of copper, iron, potassium, nickel, sulfur, silicon, vanadium, and zinc in particles with diameters of less than 2.5μm (PM2.5) and 10μm (PM10) were estimated by land-use regression modeling for the home addresses of the participants of the prospective PIAMA birth cohort study. Associations between element concentrations and blood pressure measurements performed at age 12 years were investigated by linear regression with and without adjustment for confounders.

RESULTS

After adjustment for potential confounders we found statistically significant positive associations of diastolic blood pressure with iron, silicon, and potassium in PM10 in children who lived at the same address since birth [mean difference (95% confidence interval) 0.67 (0.02;1.31) mmHg, 0.85 (0.18;1.52) mmHg, and 0.75 (0.09;1.41) mmHg, respectively, per interquartile range increase in exposure]. Also, we found marginally significant (p<0.1) positive associations between iron and silicon in PM2.5 and diastolic blood pressure. Part of the observed effects was found to be attributable to NO2, a marker of exhaust traffic emissions.

CONCLUSIONS

Exposure to particulate matter constituents, in particular iron may increase blood pressure in children. The possible association with iron may indicate the health relevance of non-exhaust emissions of traffic.

Maternal Gestational and Postdelivery Weight Gain and Child Weight

BACKGROUND

Maternal gestational weight gain (GWG) is a risk factor for the development of overweight in her child. It is unknown whether GWG programs the child's health or whether GWG indicates a shared familial lifestyle during childhood. To disentangle these influences, we studied the association of GWG and postdelivery maternal weight change simultaneously with child's weight development.

METHODS

We used data from 3367 children participating in a birth cohort that started in 1996 in the Netherlands. Weight and height were self-reported. GWG was categorized as "inadequate," "adequate," and "excessive." Multivariable regression and mixed models were used to study maternal and child weight changes.

RESULTS

Children of mothers with excessive GWG had a higher BMI z score and overweight prevalence (odds ratio [OR] 1.20; 95% confidence interval [CI], 0.99 to 1.46) throughout childhood. Children of mothers with a high (≥1 kg/year) postdelivery weight gain had a 0.14 (95% CI, -0.08 to 0.36) higher change in BMI z score between age 1 and 14 years than children of mothers with a low (<0.5 kg/year) postdelivery weight gain. Children of mothers with excessive GWG in combination with a high postdelivery weight gain had the highest BMI z score and overweight risk at age 14 years (OR 3.53; 95% CI, 1.70 to 7.33).

CONCLUSIONS

Maternal GWG and postdelivery weight gain contribute to child's weight development up to adolescence independently.

Fatty acid composition in breastfeeding and school performance in children aged 12 years

Purpose

Breastfeeding has been associated with improved cognition. It remains unclear whether long-chain polyunsaturated fatty acids (LC-PUFAs) play a role in this association. We assessed the association between LC-PUFA concentrations in infant feeding and school performance at age 12.

Methods

Within a population-based birth cohort, we compared school performance of 277 non-breastfed children and 157 children who had fatty acid composition of their mothers’ breast milk measured. Two indicators of school performance were: (1) the score on a standardized achievement test and (2) the teacher’s advice regarding a child’s potential performance level in secondary education. Linear regression and multinomial logistic regression analyses were performed to assess the independent association between LC-PUFA content of breast milk and school performance.

Results

Girls, who received breast milk with a relative high content (above the median) of docosahexaenoic acid (DHA), had a higher Cito-test score (β = 2.96 points, 95 % CI 0.24; 5.69) than non-breastfed girls. Among the breastfed girls, each percentage point of higher content of total n-3 LC-PUFA (β = 4.55, 95 % CI 0.43; 8.66) and DHA (β = 7.09, 95 % CI 0.9; 13.3) was associated with a higher Cito-test score. The association between LC-PUFA content and teacher school advice showed a similar pattern. There was no association between LC-PUFA content and school performance in boys.

Conclusion

Although a large part of the association between infant milk feeding and cognition seems to be explained by sociodemographic and lifestyle-related factors, a relative high content of n-3 PUFAs, especially DHA, in breast milk is associated with better school performance in 12-year-old girls but not in boys.

Electronic supplementary material

The online version of this article (doi:10.1007/s00394-015-1030-y) contains supplementary material, which is available to authorized users.

Prenatal air pollution exposure and newborn blood pressure

BACKGROUND

Air pollution exposure has been associated with increased blood pressure in adults.

OBJECTIVE

We examined associations of antenatal exposure to ambient air pollution with newborn systolic blood pressure (SBP).

METHODS

We studied 1,131 mother-infant pairs in a Boston, Massachusetts, area pre-birth cohort. We calculated average exposures by trimester and during the 2 to 90 days before birth for temporally resolved fine particulate matter (≤ 2.5 μm; PM2.5), black carbon (BC), nitrogen oxides, nitrogen dioxide, ozone (O3), and carbon monoxide measured at stationary monitoring sites, and for spatiotemporally resolved estimates of PM2.5 and BC at the residence level. We measured SBP at a mean age of 30 ± 18 hr with an automated device. We used mixed-effects models to examine associations between air pollutant exposures and SBP, taking into account measurement circumstances; child's birth weight; mother's age, race/ethnicity, socioeconomic position, and third-trimester BP; and time trend. Estimates represent differences in SBP associated with an interquartile range (IQR) increase in each pollutant.

RESULTS

Higher mean PM2.5 and BC exposures during the third trimester were associated with higher SBP (e.g., 1.0 mmHg; 95% CI: 0.1, 1.8 for a 0.32-μg/m3 increase in mean 90-day residential BC). In contrast, O3 was negatively associated with SBP (e.g., -2.3 mmHg; 95% CI: -4.4, -0.2 for a 13.5-ppb increase during the 90 days before birth).

CONCLUSIONS

Exposures to PM2.5 and BC in late pregnancy were positively associated with newborn SBP, whereas O3 was negatively associated with SBP. Longitudinal follow-up will enable us to assess the implications of these findings for health during later childhood and adulthood.

Overweight in infancy: which pre- and perinatal factors determine overweight persistence or reduction? A birth cohort followed for 11 years

BACKGROUND

A considerable proportion of children with early-life overweight attain a normal weight. To recognize infants at risk of persistent overweight, we compared early-life factors of children with a longitudinal pattern of persistent overweight to children with a pattern of overweight in early but not in later childhood.

METHODS

In 3,550 children participating in a birth cohort that started in 1996/1997 in the Netherlands, body mass index was repeatedly assessed until age 11 and dichotomized into with/without overweight. Latent class growth modeling was used to distinguish trajectories. Our analysis was focused on the comparison of early-life factors in children in a persistent overweight pattern with those in an overweight reduction pattern using multivariable log-binomial regression analyses.

RESULTS

Children (n = 133) in the persistent overweight pattern were more likely to have overweight parents [relative risk (RR)mother: 1.85, 95% CI: 1.37-2.49: RRfather: 1.75, 95% CI: 1.21-2.55] than children in the overweight reduction pattern (n = 303). Maternal education, child's gender, ethnicity, birth weight, breast-feeding and maternal smoking during pregnancy did not differ between the trajectories.

CONCLUSION

Health care practitioners should focus on high-weight infants with overweight parents, as these children are less likely to resolve their overweight.

Plasma-serum cholesterol differences in children and use of measurements from different specimens

BACKGROUND

We aimed to assess absolute plasma-serum differences and differences in ranking of total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), and TC/HDLC ratio in children.

METHODS

We analysed data of 412 children participating in a Dutch birth cohort. TC, HDLC, and TC/HDLC ratio were determined in plasma at age 8 and 12 years and in serum at age 12 years.

RESULTS

Compared to serum, plasma TC at age 12 years was 0.07 mmol/l lower (95% CI -0.08 to -0.06), plasma HDLC was 0.06 mmol/l higher (95% CI 0.05-0.07), and plasma TC/HDLC ratio was 0.19 lower (95% CI -0.20 to -0.17) (p < 0.0001). Intraclass correlation coefficients (ICCs) for ranking of TC, HDLC, and TC/HDLC ratio at age 12 years were 0.970, 0.745, and 0.979, respectively. ICCs for ranking of 8- to 12-year change of TC, HDLC, and TC/HDLC ratio were 0.971, 0.957, and 0.955, respectively.

CONCLUSIONS

Cholesterol was systematically different in plasma and serum, and use of plasma would result in a more favourable lipid profile of children (lower TC, higher HDLC, and lower TC/HDLC ratio). Nevertheless, consistency in ranking of children according to plasma or serum cholesterol concentrations was very high. Age-related change in cholesterol can be validly assessed by ranking the difference between serum concentrations at one age and plasma concentrations at another age.

Traffic-related air pollution and noise and children's blood pressure: results from the PIAMA birth cohort study

AIMS

Elevation of a child's blood pressure may cause possible health risks in later life. There is evidence for adverse effects of exposure to air pollution and noise on blood pressure in adults. Little is known about these associations in children. We investigated the associations of air pollution and noise exposure with blood pressure in 12-year-olds.

METHODS

Blood pressure was measured at age 12 years in 1432 participants of the PIAMA birth cohort study. Annual average exposure to traffic-related air pollution [NO2, mass concentrations of particulate matter with diameters of less than 2.5 µm (PM2.5) and less than 10 µm (PM10), and PM2.5 absorbance] at the participants' home and school addresses at the time of blood pressure measurements was estimated by land-use regression models. Air pollution exposure on the days preceding blood pressure measurements was estimated from routine air monitoring data. Long-term noise exposure was assessed by linking addresses to modelled equivalent road traffic noise levels. Associations of exposures with blood pressure were analysed by linear regression. Effects are presented for an interquartile range increase in exposure.

RESULTS

Long-term exposure to NO2 and PM2.5 absorbance were associated with increased diastolic blood pressure, in children who lived at the same address since birth [adjusted mean difference (95% confidence interval) [mmHg] 0.83 (0.06 to 1.61) and 0.75 (-0.08 to 1.58), respectively], but not with systolic blood pressure. We found no association of blood pressure with short-term air pollution or noise exposure.

CONCLUSIONS

Long-term exposure to traffic-related air pollution may increase diastolic blood pressure in children.

Blood pressure in 12-year-old children is associated with fatty acid composition of human milk: the prevention and incidence of asthma and mite allergy birth cohort

Breastfed individuals have a lower blood pressure than formula-fed individuals. Supplementation with n-3 long-chain polyunsaturated fatty acids in adults is also associated with a lower blood pressure. We studied whether children receiving human milk with a relatively high content of n-3 long-chain polyunsaturated fatty acids have a lower blood pressure at age 12 years, and, if so, whether this association is explained by the n-3 long-chain polyunsaturated fatty acids content in erythrocyte membranes at age 12 years. Within a 12-year follow-up of a population-based birth cohort, we compared blood pressure of 205 never-breastfed children and 109 children who had fatty acid composition of their mothers' breast milk measured during lactation. In addition, 973 children had information on erythrocyte fatty acid composition and blood pressure at age 12 years. Children who received human milk with an n-3 long-chain polyunsaturated fatty acids content above the median (ie, 0.51 weight percentage) had a 4.79-mm Hg lower systolic (95% CI, -7.64 to -1.94) and a 2.47-mm Hg lower diastolic (95% CI, -4.45 to -0.49) blood pressure at age 12 years than never-breastfed children. N-3 long-chain polyunsaturated fatty acids levels in human milk below the median value and current n-3 long-chain polyunsaturated fatty acid status were not associated with blood pressure at age 12 years. Thus, a relatively high content of n-3 long-chain polyunsaturated fatty acids in human milk is associated with a lower blood pressure in children at age 12 years, a finding not explained by current n-3 long-chain polyunsaturated fatty acids status.

Neighbourhood socioeconomic inequalities in incidence of acute myocardial infarction: a cohort study quantifying age- and gender-specific differences in relative and absolute terms

Background

Socioeconomic status has a profound effect on the risk of having a first acute myocardial infarction (AMI). Information on socioeconomic inequalities in AMI incidence across age- gender-groups is lacking. Our objective was to examine socioeconomic inequalities in the incidence of AMI considering both relative and absolute measures of risk differences, with a particular focus on age and gender.

Methods

We identified all patients with a first AMI from 1997 to 2007 through linked hospital discharge and death records covering the Dutch population. Relative risks (RR) of AMI incidence were estimated by mean equivalent household income at neighbourhood-level for strata of age and gender using Poisson regression models. Socioeconomic inequalities were also shown within the stratified age-gender groups by calculating the total number of events attributable to socioeconomic disadvantage.

Results

Between 1997 and 2007, 317,564 people had a first AMI. When comparing the most deprived socioeconomic quintile with the most affluent quintile, the overall RR for AMI was 1.34 (95 % confidence interval (CI): 1.32 – 1.36) in men and 1.44 (95 % CI: 1.42 – 1.47) in women. The socioeconomic gradient decreased with age. Relative socioeconomic inequalities were most apparent in men under 35 years and in women under 65 years. The largest number of events attributable to socioeconomic inequalities was found in men aged 45–74 years and in women aged 65–84 years. The total proportion of AMIs that was attributable to socioeconomic inequalities in the Dutch population of 1997 to 2007 was 14 % in men and 18 % in women.

Conclusions

Neighbourhood socioeconomic inequalities were observed in AMI incidence in the Netherlands, but the magnitude across age-gender groups depended on whether inequality was expressed in relative or absolute terms. Relative socioeconomic inequalities were high in young persons and women, where the absolute burden of AMI was low. Absolute socioeconomic inequalities in AMI were highest in the age-gender groups of middle-aged men and elderly women, where the number of cases was largest.

Behavioral risk factors for overweight in early childhood; the 'Be active, eat right' study

Background

The lifestyle-related behaviors having breakfast, drinking sweet beverages, playing outside and watching TV have been indicated to have an association with childhood overweight, but research among young children (below 6 years old) is limited. The aim of the present study was to assess the associations between these four behaviors and overweight among young children.

Methods

This cross-sectional study used baseline data on 5-year-old children (n = 7505) collected for the study ‘Be active, eat right’. Age and sex-specific cut-off points for body mass index of the International Obesity Task Force were used to assess overweight/obesity. Multivariable logistic regression analyses were applied.

Results

For children whom had breakfast <7 days/week and watched TV >2 hours/day, the odds ratio (OR) for having overweight (obesity included) was, respectively, 1.49 (95% confidence interval (CI): 1.13-1.95), and 1.25 (95% CI: 1.03-1.51). There was a positive association between the number of risk behaviors present and the risk for having overweight. For children with 3 or all of the risk behaviors having breakfast <7 days/week, drinking sweet beverages >2 glasses/day, playing outside <1 h/day, watching TV >2 hs/day, the OR for overweight was 1.73 (95% CI: 1.11-2.71) (all models adjusted for children’s sex and sociodemographic characteristics).

Conclusion

Given the positive association between the number of behavioral risk factors and overweight, further studies are needed to evaluate the effectiveness of behavioral counseling of parents of toddlers in preventing childhood overweight. In the meantime we recommend physicians to target all four behaviors for counseling during well-child visits.

Children of low socioeconomic status show accelerated linear growth in early childhood; results from the Generation R Study

OBJECTIVES

People of low socioeconomic status are shorter than those of high socioeconomic status. The first two years of life being critical for height development, we hypothesized that a low socioeconomic status is associated with a slower linear growth in early childhood. We studied maternal educational level (high, mid-high, mid-low, and low) as a measure of socioeconomic status and its association with repeatedly measured height in children aged 0-2 years, and also examined to what extent known determinants of postnatal growth contribute to this association.

METHODS

This study was based on data from 2972 mothers with a Dutch ethnicity, and their children participating in The Generation R Study, a population-based cohort study in Rotterdam, The Netherlands (participation rate 61%). All children were born between April 2002 and January 2006. Height was measured at 2 months (mid-90% range 1.0-3.9), 6 months (mid-90% range 5.6-11.4), 14 months (mid-90% range 13.7-17.9) and 25 months of age (mid-90% range 23.6-29.6).

RESULTS

At 2 months, children in the lowest educational subgroup were shorter than those in the highest (difference: -0.87 cm; 95% CI: -1.16, -0.58). Between 1 and 18 months, they grew faster than their counterparts. By 14 months, children in the lowest educational subgroup were taller than those in the highest (difference at 14 months: 0.40 cm; 95% CI: 0.08,0.72). Adjustment for other determinants of postnatal growth did not explain the taller height. On the contrary, the differences became even larger (difference at 14 months: 0.61 cm; 95% CI: 0.26,0.95; and at 25 months: 1.00 cm; 95% CI: 0.57,1.43)

CONCLUSIONS

Compared with children of high socioeconomic status, those of low socioeconomic status show an accelerated linear growth until the 18th month of life, leading to an overcompensation of their initial height deficit. The long-term consequences of these findings remain unclear and require further study.

The role of prenatal, perinatal and postnatal factors in the explanation of socioeconomic inequalities in preschool asthma symptoms: the Generation R Study

BACKGROUND

The authors assessed whether socioeconomic inequalities in asthma symptoms were already present in preschool children and to what extent prenatal, perinatal and postnatal risk factors for asthma symptoms mediate the effect of socioeconomic status (SES).

METHODS

The study included 3136 Dutch children participating in the Generation R Study, a prospective cohort study. Adjusted ORs of asthma symptoms for low and middle SES (household income and maternal education) compared to high SES were calculated after adjustment for potential confounders and also adjusted for prenatal, perinatal and postnatal mediators at preschool age.

RESULTS

At age 1 year, low-SES children had a 40% lower risk of asthma symptoms compared to high-SES children (p<0.01). However, the risk of asthma symptoms in 3- and 4-year-old low-SES children was 1.5 times higher compared to their high-SES age mates (p<0.05). The positive associations at age 1 year were particularly modified by postnatal factors (up to 38%). In toddlers, prenatal factors explained up to 58% of the negative associations between SES and asthma symptoms.

CONCLUSIONS

SES indirectly affects asthma symptoms at preschool age. The inverse association between SES and asthma symptoms emerges at age 3 years. This is particularly due to a high level of adverse prenatal circumstances in low-SES toddlers. Future research should evaluate public health programs (during pregnancy) to reduce socioeconomic inequalities in childhood asthma.

An observational study on socio-economic and ethnic differences in indicators of sedentary behavior and physical activity in preschool children

OBJECTIVE

We studied associations between social disadvantage and indicators of sedentary behavior and physical activity at preschool age.

METHODS

Data from 4688 children enrolled in a birth cohort in Rotterdam, the Netherlands, between 2002 and 2006 were analyzed. Indicators of sedentary behavior (watching television ≥ 2 h/day and sitting in a buggy ≥ 0.5 h/day) and physical inactivity (playing outside < 3 h/day) were measured by a parent-reported questionnaire at age 3. Adjustments were made for social circumstances and indicators of health behaviors. Logistic regression was used to obtain odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Children with low-educated mothers (OR: 3.27, 95% CI 2.12-5.05) and non-Dutch children (OR(nonWestern): 2.67, 95% CI 2.04-3.49, OR(Western): 2.09, 95% CI 1.42-3.0) were more likely to watch television for at least 2 h/day. Similar results were seen for sitting in a buggy for at least 0.5h/day. Non western children were more likely to play outside for less than 3 h/day (OR: 1.95, 95% CI: 1.39-2.73) than native Dutch children, while no differences were seen for other western children or children from mothers with a low educational level.

CONCLUSIONS

Socio-economic status and ethnicity are already associated with indicators of sedentary lifestyles at preschool age.

Is the association of breastfeeding with child obesity explained by infant weight change?

OBJECTIVE

Breastfeeding and infant weight change are both associated with adiposity. We examined the extent to which infant weight change mediates the association between breastfeeding and adiposity at age 3 years.

METHODS

We studied 884 children in a prospective cohort study. We determined breastfeeding status in the first 6 months. Our primary outcomes at 3 years were body mass index (BMI) z score and the sum of subscapular and triceps skinfold thicknesses (SS + TR); we also assessed obesity. We defined infant weight change as change in weight-for-age z score between birth and 6 months. We performed multivariable regression analyses.

RESULTS

At age 6 months, 25.0% of infants were fully breastfed. At age 3 years, mean (standard deviation) BMI z score was 0.45 (1.03). In linear regression analyses adjusted for mother's educational level, race/ethnicity, smoking, BMI, pregnancy weight gain and birth weight (adjusted for gestational age), the BMI z score of fully breastfed children was 0.17 (95% CI: -0.43, 0.09) units lower than never breastfed children. After additional adjustment for infant weight change, the estimate was attenuated (-0.03, 95% CI: -0.27, 0.20). Adjustment for infant weight change only modestly attenuated estimates for SS + TR (from -1.48 mm [95% CI: -2.52, -0.44] to -1.16 mm [95% CI: -2.18, -0.14]), and for the odds of being obese (from 0.21 [95% CI: 0.07, 0.68] to 0.29 [95% CI: 0.08, 1.05]).

CONCLUSION

Infant weight change between birth and 6 months mediates associations of breastfeeding with BMI, but only partially with indicators of child adiposity.