Associations of Maternal Educational Level, Proximity to Greenspace During Pregnancy, and Gestational Diabetes With Body Mass Index From Infancy to Early Adulthood: A Proof-of-Concept Federated Analysis in 18 Birth Cohorts.

International sharing of cohort data for research is important and challenging. We explored the feasibility of multi-cohort federated analyses by examining associations between three pregnancy exposures (maternal education, exposure to green vegetation and gestational diabetes) with offspring BMI from infancy to 17 years. We used data from 18 cohorts (n=206,180 mother-child pairs) from the EU Child Cohort Network and derived BMI at ages 0-1, 2-3, 4-7, 8-13 and 14-17 years. Associations were estimated using linear regression via one-stage IPD meta-analysis using DataSHIELD. Associations between lower maternal education and higher child BMI emerged from age 4 and increased with age (difference in BMI z-score comparing low with high education age 2-3 years = 0.03 [95% CI 0.00, 0.05], 4-7 years = 0.16 [95% CI 0.14, 0.17], 8-13 years = 0.24 [95% CI 0.22, 0.26]). Gestational diabetes was positively associated with BMI from 8 years (BMI z-score difference = 0.18 [CI 0.12, 0.25]) but not at younger ages; however associations attenuated towards the null when restricted to cohorts which measured GDM via universal screening. Exposure to green vegetation was weakly associated with higher BMI up to age one but not at older ages. Opportunities of cross-cohort federated analyses are discussed.

Measures of Early-life Behavior and Later Psychopathology in the LifeCycle Project - EU Child Cohort Network: A Cohort Description.

BACKGROUND: The EU LifeCycle Project was launched in 2017 to combine, harmonize, and analyze data from more than 250,000 participants across Europe and Australia, involving cohorts participating in the EU-funded LifeCycle Project. The purpose of this cohort description is to provide a detailed overview of the major measures within mental health domains that are available in 17 European and Australian cohorts participating in the LifeCycle Project. METHODS: Data on cognitive, behavioral, and psychological development has been collected on participants from birth until adulthood through questionnaire and medical data. We developed an inventory of the available data by mapping individual instruments, domain types, and age groups, providing the basis for statistical harmonization across mental health measures. RESULTS: The mental health data in LifeCycle contain longitudinal and cross-sectional data from birth throughout the life course, covering domains across a wide range of behavioral and psychopathology indicators and outcomes, including executive function, depression, ADHD, and cognition. These data span a unique combination of qualitative data collected through behavioral/cognitive/mental health questionnaires and examination, as well as data from biological samples and indices in the form of imaging (MRI, fetal ultrasound) and DNA methylation data. Harmonized variables on a subset of mental health domains have been developed, providing statistical equivalence of measures required for longitudinal meta-analyses across instruments and cohorts. CONCLUSION: Mental health data harmonized through the LifeCycle project can be used to study life-course trajectories and exposure-outcome models that examine early life risk factors for mental illness and develop predictive markers for later-life disease.

[Respiratory and allergic diseases of children : Temporal trends, urban-rural differences, and in association with environmental tobacco smoke exposure]. / Atemwegs- und Allergieerkrankungen bei Kindern : Zeitliche Trends, Stadt-Land-Unterschiede und Assoziationen mit einer Tabakrauchexposition.

BACKGROUND/OBJECTIVES: Ten years after the establishment of health monitoring units (GME) in Bavaria, temporal trends and urban-rural differences in parent-reported respiratory and allergic diseases as well as environmental tobacco smoke (ETS) exposure in preschoolers were analyzed in an explorative manner. Furthermore, associations between diseases and ETS exposure were studied. METHODS: Parent questionnaires were used as part of the school entrance examination in two cross sectional studies (S1:2004/2005, n 1 = 6350; S2:2012/2013, n 2 = 5052). Temporal trends and urban-rural-differences were tested by X2 tests. Associations between diseases and exposures were studied using multiple logistic regression analysis. RESULTS: The lifetime prevalence of atopic dermatitis declined from S1-S2 from 12.4 to 11.1 %, whereas those for hay fever, asthma, bronchitis and pseudocroup remained stable. In S1 and S2, bronchitis was less often reported in cities. The other diseases showed no urban-rural differences. The prevalence of children's ETS exposure at home declined from S1-S2 from 14.3 to 7.2 % and was generally higher in cities than in rural regions. There was no positive association between diseases and children's ETS exposure at home. In S2 an association was found between asthma and current parental smoking (OR = 1.60; 95 % CI = (1.10-2.32)). CONCLUSION: The GME provide important data for regional distribution of respiratory and allergic diseases and ETS exposure of preschoolers in Bavaria. The results of the study are important for further development of questionnaires, which will be used in future GME.