Air pollution and childhood respiratory consultations in primary care:A systematic review

Background: Outdoor air pollution is a known risk factor for respiratory morbidity worldwide. Compared with the adult population, there are fewer studies that analyse the association between short-term exposure to air pollution and respiratory morbidity in children in primary care. Objective: To evaluate whether children in a primary care setting exposed to outdoor air pollutants during short-term intervals are at increased risk of respiratory diagnoses. Methods: A search in Medline, the Cochrane Library, Web of Science and Embase databases throughout March 2023. Percentage change or risk ratios with corresponding 95% CI for the association between air pollutants and respiratory diseases were retrieved from individual studies. Risk of bias assessment was conducted with the Newcastle-Ottawa Scale (NOS) for cohort or case-control studies and an adjusted NOS for time series studies. Results: From 1366 studies, 14 were identified as meeting the inclusion criteria. Most studies had intermediate or high quality. A meta-analysis was not conducted due to heterogeneity in exposure and health outcome. Overall, studies on short-term exposure to air pollutants (carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2) and particulate matter ≤10 μm (PM10)) were associated with increased childhood respiratory consultations in primary care. In general, exposure to ozone was associated with a reduction in respiratory consultations. Conclusions: The evidence suggests CO, SO2, NO2, PM10 and PM2.5 are risk factors for respiratory diseases in children in primary care in the short term. However, given the heterogeneity of the studies, interpretation of these findings must be done with caution. PROSPERO registration number: CRD42022259279.</p

Air pollution and childhood respiratory consultations in primary care:A systematic review

Background: Outdoor air pollution is a known risk factor for respiratory morbidity worldwide. Compared with the adult population, there are fewer studies that analyse the association between short-term exposure to air pollution and respiratory morbidity in children in primary care. Objective: To evaluate whether children in a primary care setting exposed to outdoor air pollutants during short-term intervals are at increased risk of respiratory diagnoses. Methods: A search in Medline, the Cochrane Library, Web of Science and Embase databases throughout March 2023. Percentage change or risk ratios with corresponding 95% CI for the association between air pollutants and respiratory diseases were retrieved from individual studies. Risk of bias assessment was conducted with the Newcastle-Ottawa Scale (NOS) for cohort or case-control studies and an adjusted NOS for time series studies. Results: From 1366 studies, 14 were identified as meeting the inclusion criteria. Most studies had intermediate or high quality. A meta-analysis was not conducted due to heterogeneity in exposure and health outcome. Overall, studies on short-term exposure to air pollutants (carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2) and particulate matter ≤10 μm (PM10)) were associated with increased childhood respiratory consultations in primary care. In general, exposure to ozone was associated with a reduction in respiratory consultations. Conclusions: The evidence suggests CO, SO2, NO2, PM10 and PM2.5 are risk factors for respiratory diseases in children in primary care in the short term. However, given the heterogeneity of the studies, interpretation of these findings must be done with caution. PROSPERO registration number: CRD42022259279.</p

Influence of maternal vomiting during early pregnancy on school-age respiratory health

BACKGROUND: Hyperemesis gravidarum, a clinical entity characterized by severe nausea and excess vomiting, might lead to a suboptimal maternal nutritional status during pregnancy and subsequently to adverse respiratory health in the offspring. The role of common vomiting symptoms on offspring's respiratory health is unclear. We examined the associations of maternal daily vomiting during early pregnancy with childhood respiratory outcomes, and potential explaining factors. METHODS: This study was embedded in a population‐based prospective cohort study from early pregnancy onwards among 4232 mothers and their children. Maternal vomiting during early pregnancy was assessed by a questionnaire. At age 10 years, information on current wheezing and ever asthma was obtained by a questionnaire, and lung function was measured by spirometry at our research center. We used multiple regression analyses to assess the associations of maternal daily vomiting during early pregnancy with childhood respiratory outcomes. RESULTS: Compared to children from mothers without daily vomiting during early pregnancy, children from mothers with daily vomiting during early pregnancy had a higher forced expiratory flow when 75% of the forced vital capacity (FVC) is exhaled (Z‐score difference [95% confidence interval, CI]: 0.13 [0.03, 0.23]), and an increased risk of current wheezing and ever asthma ([odds ratio, OR] [95% CI]: 1.75 [1.10, 2.79] and 1.61 [1.13, 2.31], respectively). These associations were fully explained by sociodemographic factors, but not sex or lifestyle‐, infectious‐, or growth‐related factors. Maternal daily vomiting during early pregnancy was not associated with forced expiratory volume in 1 s (FEV(1)), FVC, and FEV(1)/FVC. CONCLUSION: Only sociodemographic factors explain the associations of maternal daily vomiting during early pregnancy with childhood respiratory outcomes

Maternal hemoglobin and iron status in early pregnancy and risk of respiratory tract infections in childhood:A population-based prospective cohort study

Background: Maternal hemoglobin and iron status measures during pregnancy might affect the developing fetal respiratory system leading to adverse respiratory conditions. Our aim was to assess the associations of maternal hemoglobin and iron status measures during pregnancy with the risk of respiratory tract infections in children until 10 years of age. Methods:In a population-based cohort study among 5134 mother–child pairs, maternal hemoglobin and iron status including ferritin, transferrin, and transferrin saturation were measured during early pregnancy. In children, physician-attended respiratory tract infections from age 6 months until 10 years were assessed by questionnaires. Confounder-adjusted generalized estimating equation modeling was applied. Results: After taking multiple testing into account, high maternal ferritin concentrations and low maternal transferrin saturation during pregnancy were associated with an overall increased risk of upper, not lower, respiratory tract infections until age 10 years of the child [OR (95% CI: 1.23 (1.10, 1.38) and 1.28 (1.12, 1.47), respectively)]. High maternal transferrin saturation during pregnancy was associated with a decreased and increased risk of upper respiratory tract infections at 1 and 6 years, respectively, [OR (95% CI: 0.60 (0.44, 0.83) and 1.54 (1.17, 2.02))]. Observed associations were suggested to be U-shaped (p-values for non-linearity ≤.001). Maternal hemoglobin and iron status measures during pregnancy were not consistently associated with child's gastroenteritis and urinary tract infections, as proxies for general infection effects. Conclusion: High maternal ferritin and low transferrin saturation concentrations during early pregnancy were most consistently associated with an overall increased risk of child's upper, not lower, respiratory tract infections.</p

Early life antibiotic use and the risk of asthma and asthma exacerbations in children

Background: The use of antibiotic therapy early in life might influence the risk of developing asthma. Studies assessing the influence of early life antibiotic use on the risk of asthma exacerbations are limited, and the results are inconsistent. Therefore, the aim of this study was to assess the association between use of antibiotic during the first three years of life and the risk of developing childhood asthma and the occurrence of asthma exacerbations. Methods: Data from four large childhood cohorts were used; two population-based cohorts to study the risk of developing asthma: Generation R (n=7,393, the Netherlands) and SEATON (n=891, Scotland, UK), and two asthma cohorts to assess the risk of asthma exacerbations: PACMAN (n=668, the Netherlands) and BREATHE (n=806, Scotland, UK). Odds ratios (ORs) were derived from logistic regression analysis within each database followed by pooling the results using a fixed- or random-effect model. Results: Antibiotic use in early life was associated with an increased risk of asthma in a meta-analysis of the Generation R and SEATON data (OR: 2.18, 95% CI: 1.04-4.60; I2: 76.3%). There was no association between antibiotic use in early life and risk of asthma exacerbations later in life in a meta-analysis of the PACMAN and BREATHE data (OR: 0.93, 95% CI: 0.65-1.32; I2: 0.0%). Conclusion: Children treated with antibiotic in the first three years of life are more likely to develop asthma, but there is no evidence that the exposure to antibiotic is associated with increase d risk of asthma exacerbations

Early-life respiratory tract infections and the risk of school-age lower lung function and asthma: A meta-analysis of 150 000 European children

BACKGROUND: Early-life respiratory tract infections might affect chronic obstructive respiratory diseases, but conclusive studies from general populations are lacking. Our objective was to examine if children with early-life respiratory tract infections had increased risks of lower lung function and asthma at school age. METHODS: We used individual participant data of 150 090 children primarily from the EU Child Cohort Network to examine the associations of upper and lower respiratory tract infections from age 6 months to 5 years with forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC, forced expiratory flow at 75% of FVC (FEF75%) and asthma at a median (range) age of 7 (4-15) years. RESULTS: Children with early-life lower, not upper, respiratory tract infections had a lower school-age FEV1, FEV1/FVC and FEF75% (z-score range: -0.09 (95% CI -0.14- -0.04) to -0.30 (95% CI -0.36- -0.24)). Children with early-life lower respiratory tract infections had a higher increased risk of school-age asthma than those with upper respiratory tract infections (OR range: 2.10 (95% CI 1.98-2.22) to 6.30 (95% CI 5.64-7.04) and 1.25 (95% CI 1.18-1.32) to 1.55 (95% CI 1.47-1.65), respectively). Adjustment for preceding respiratory tract infections slightly decreased the strength of the effects. Observed associations were similar for those with and without early-life wheezing as a proxy for early-life asthma. CONCLUSIONS: Our findings suggest that early-life respiratory tract infections affect development of chronic obstructive respiratory diseases in later life, with the strongest effects for lower respiratory tract infections

Early-life respiratory tract infections and the risk of school-age lower lung function and asthma: a meta-analysis of 150 000 European children

Background: Early-life respiratory tract infections might affect chronic obstructive respiratory diseases, but conclusive studies from general populations are lacking. Our objective was to examine if children with early-life respiratory tract infections had increased risks of lower lung function and asthma at school age. Methods: We used individual participant data of 150 090 children primarily from the EU Child Cohort Network to examine the associations of upper and lower respiratory tract infections from age 6 months to 5 years with forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC, forced expiratory flow at 75% of FVC (FEF75%) and asthma at a median (range) age of 7 (4-15) years. Results: Children with early-life lower, not upper, respiratory tract infections had a lower school-age FEV1, FEV1/FVC and FEF75% (z-score range: -0.09 (95% CI -0.14- -0.04) to -0.30 (95% CI -0.36- -0.24)). Children with early-life lower respiratory tract infections had a higher increased risk of school-age asthma than those with upper respiratory tract infections (OR range: 2.10 (95% CI 1.98-2.22) to 6.30 (95% CI 5.64-7.04) and 1.25 (95% CI 1.18-1.32) to 1.55 (95% CI 1.47-1.65), respectively). Adjustment for preceding respiratory tract infections slightly decreased the strength of the effects. Observed associations were similar for those with and without early-life wheezing as a proxy for early-life asthma. Conclusions: Our findings suggest that early-life respiratory tract infections affect development of chronic obstructive respiratory diseases in later life, with the strongest effects for lower respiratory tract infections.A comprehensive list of grant funding is available on the ALSPAC website (www.bristol.ac.uk/alspac/external/documents/grant-acknowledgements.pdf). BAMSE: BAMSE was funded by the Swedish Research Council, the Swedish Heart Lung Foundation, ALF Region Stockholm and SFO Epidemiology Karolinska Institutet. E. Mélen is supported by a European Research Council grant (TRIBAL, 757919). BiB (Born in Bradford): BiB is only possible because of the enthusiasm and commitment of the children and parents in BiB. We are grateful to all the participants, practitioners and researchers who have made BiB happen. The BiB study presents independent research commissioned by the National Institute for Health Research Collaboration for Applied Health Research and Care (NIHR CLAHRC) and the Programme Grants for Applied Research funding scheme (RP-PG-0407-10044). Core support for BiB is also provided by the Wellcome Trust (WT101597MA). BILD: This study was funded by the Swiss National Science Foundation (320030_163311). CoNER: Funds were obtained from the special programme (Programmi speciali – Art.12 bis, comma 6 D.lgs.229/99 Sanitaria e della Vigilanza sugli Enti) funded by the Italian Ministry of Health. Approval for the study was obtained from the Ethics Committee of the S. Orsola-Malpighi Teaching Hospital in April 2004 (52/2004/U/Tess). COPSAC 2000 and COPSAC 2010: All funding received by COPSAC is listed on www.copsac.com. The Lundbeck Foundation (R16-A1694), Ministry of Health (903516), Danish Council for Strategic Research (0603-00280B) and Capital Region Research Foundation have provided core support to the COPSAC research centre. We express our deepest gratitude to the children and families of the COPSAC 2000 and COPSAC 2010 cohort studies for all their support and commitment. We acknowledge and appreciate the unique efforts of the COPSAC research team. DNBC (Danish National Birth Cohort): The authors would like to thank the participants, the first Principal Investigator of DNBC, Jørn Olsen, the scientific managerial team and DNBC secretariat for being, establishing, developing and consolidating the DNBC. The DNBC was established with a significant grant from the Danish National Research Foundation. Additional support was obtained from the Danish Regional Committees, Pharmacy Foundation, Egmont Foundation, March of Dimes Birth Defects Foundation, Health Foundation and other minor grants. The DNBC Biobank has been supported by the Novo Nordisk Foundation and Lundbeck Foundation. Follow-up of mothers and children has been supported by the Danish Medical Research Council (SSVF 0646, 271-08-0839/06-066023, O602-01042B, 0602-02738B), Lundbeck Foundation (195/04, R100-A9193), Innovation Fund Denmark 0603-00294B (09-067124), Nordea Foundation (02-2013-2014), Aarhus Ideas (AU R9-A959-13-S804), University of Copenhagen Strategic Grant (IFSV 2012) and Danish Council for Independent Research (DFF-4183-00594, DFF-4183-00152). A. Pinot de Moira is funded by a Lundbeck Foundation grant (R264-2017-3099). EDEN: We thank the EDEN mother–child cohort study group (I. Annesi-Maesano, J.Y. Bernard, J. Botton, M.A. Charles, P. Dargent-Molina, B. de Lauzon-Guillain, P. Ducimetière, M. de Agostini, B. Foliguet, A. Forhan, X. Fritel, A. Germa, V. Goua, R. Hankard, B. Heude, M. Kaminski, B. Larroque†, N. Lelong, J. Lepeule, G. Magnin, L. Marchand, C. Nabet, F. Pierre, R. Slama, M.J. Saurel-Cubizolles, M. Schweitzer and O. Thiebaugeorges). We thank all funding sources for the EDEN study (not allocated for the present study but for the cohort): Foundation for Medical Research (FRM), National Agency for Research (ANR), National Institute for Research in Public health (IRESP: TGIR cohorte santé 2008 programme), French Ministry of Health (DGS), French Ministry of Research, INSERM Bone and Joint Diseases National Research (PRO-A) and Human Nutrition National Research Programs, Paris-Sud University, Nestlé, French National Institute for Population Health Surveillance (InVS), French National Institute for Health Education (INPES), the European Union FP7 programmes (FP7/2007-2013, HELIX, ESCAPE, ENRIECO, MeDALL projects), Diabetes National Research Program (in collaboration with the French Association of Diabetic Patients (AFD)), French Agency for Environmental Health Safety (now ANSES), Mutuelle Générale de l'Education Nationale complementary health insurance (MGEN), French national agency for food security, and French speaking association for the study of diabetes and metabolism (ALFEDIAM). The funding source had no involvement in the conception of the present study. FLEHS: This study was conducted within the framework of the Flemish Centre of Expertise on Environment and Health, funded by the Dept of the Environment of the Flemish Government, Flemish Agency of Care and Health, and Flemish Dept of Economy, Science and Innovation. GASPII: The GASPII cohort was funded by the Italian Ministry of Health (2001), the research leading to these results has received funding from the European Community's Seventh Framework Program under grant agreement 261357 (MeDALL). Generation R: This study was funded by Erasmus MC Rotterdam, Erasmus University Rotterdam and the Netherlands Organisation for Health Research and Development. V.W.V. Jaddoe received a grant from the European Research Council (ERC-2014-CoG-648916). L. Duijts received funding from cofunded ERA-Net on Biomarkers for Nutrition and Health (ERA HDHL), Horizon 2020 (696295; 2017), the Netherlands Organisation for Health Research and Development (ZonMw; 529051014; 2017), Science Foundation Ireland (SFI/16/ERA-HDHL/3360), and European Union (ALPHABET project). The project received funding from the European Union's Horizon 2020 research and innovation programme (LIFECYCLE, 733206, 2016; EUCAN-Connect 824989; ATHLETE, 874583). The researchers are independent from the funders. The study sponsors had no role in the study design, data analysis, interpretation of data or writing of this report. Generation XXI: Generation XXI was supported by the European Regional Development Fund (ERDF) through the Operational Programme Competitiveness and Internationalization and national funding from the Foundation for Science and Technology (FCT), Portuguese Ministry of Science, Technology and Higher Education, and by the Unidade de Investigação em Epidemiologia – Instituto de Saúde Pública da Universidade do Porto (EPIUnit) (UIDB/04750/2020), Administração Regional de Saúde Norte (Regional Dept of Ministry of Health) and Fundação Calouste Gulbenkian. A.C. Santos is founded by FCT Investigator contracts IF/01060/2015. GINI: The GINIplus study was mainly supported for the first 3 years by the Federal Ministry for Education, Science, Research and Technology (interventional arm) and Helmholtz Zentrum München (former GSF) (observational arm). The 4- and 6-year follow-up examinations of the GINIplus study were covered from the respective budgets of the five study centres (Helmholtz Zentrum München (former GSF), Research Institute at Marien-Hospital, Wesel, LMU Munich, TU Munich and from 6 years onwards also from IUF – Leibniz Research Institute for Environmental Medicine at the University of Düsseldorf). HUMIS: We thank all mothers for participating in the HUMIS study. HUMIS was funded by a grant from the Norwegian Research Council (226402). The HUMIS study was approved by the Norwegian Data Inspectorate (2002/1398) and by the Regional Ethics Committee for Medical Research in Norway (S-02122), and the specific use in the current study was approved by the Ethics Committee as well (2010/1259/REK sør-øst). INMA: Gipuzkoa: This study was funded by grants from Instituto de Salud Carlos III (FIS-PI09/00090, FIS-PI18/01142 including FEDER funds), CIBERESP, Dept of Health of the Basque Government (2013111089) and annual agreements with the municipalities of the study area (Zumarraga, Urretxu, Legazpi, Azkoitia y Azpeitia and Beasain). Menorca: This study was funded by grants from Instituto de Salud Carlos III (Red INMA G03/176; CB06/02/0041; 97/0588; 00/0021-2, PI061756; PS0901958, PI14/00677 including FEDER funds), CIBERESP, Beca de la IV convocatoria de Ayudas a la Investigación en Enfemerdades Neurodegeneratives de La Caixa, and EC contract QLK4-CT-200-00263. Sabadell: This study was funded by grants from Instituto de Salud Carlos III (Red INMA G03/176; CB06/02/0041; PI041436; PI081151 including FEDER funds), Generalitat de Catalunya-CIRIT 1999SGR 00241 and Fundació La marató de TV3 (090430). ISGlobal is a member of the CERCA Programme, Generalitat de Catalunya. M. Casas holds a Miguel Servet fellowship (CP16/00128) funded by Instituto de Salud Carlos III and cofunded by the European Social Fund “Investing in your future”. Valencia: This study was funded by grants from the European Union (FP7-ENV-2011 cod 282957 and HEALTH.2010.2.4.5-1), Spain: Instituto de Salud Carlos III (Red INMA G03/176, CB06/02/0041; FIS-FEDER: PI03/1615, PI04/1509, PI04/1112, PI04/1931, PI05/1079, PI05/1052, PI06/1213, PI07/0314, PI09/02647, PI11/01007, PI11/02591, PI11/02038, PI13/1944, PI13/2032, PI14/00891, PI14/01687, PI16/1288, PI17/00663; Miguel Servet-FEDER CP11/00178, CP15/00025, CPII16/00051), Generalitat Valenciana: FISABIO (UGP 15-230, UGP-15-244, UGP-15-249), and Alicia Koplowitz Foundation 2017. Isle of Wight: This study was funded by grants from the National Institutes of Health USA (R01HL082925), Asthma UK (364), Isle of Wight NHS Trust and the British Medical Association. KOALA: The collection of data relevant for this study was funded by grants from the Netherlands Organisation for Health Research and Development (ZonMw; 2100.0090) and the Netherlands Asthma Foundation (3.2.03.48, 3.2.07.022). The researchers are independent from the funders. The funders had no role in the study design, data analysis, interpretation of data or writing of this report. We thank the children and parents for their participation in the KOALA study. LRC (Leicestershire Respiratory Cohorts): This study was funded by grants from the Swiss National Science Foundation (SNF: 320030-182628, 320030-162820, 3233-069348, 3200-069349) and Asthma UK 07/048. Lifeways Cross-Generation Cohort Study: This study was funded by the Health Research Board, Ireland, and the Irish Dept of Health and Children's Health Promotion Policy Unit. LISA: The LISA study was mainly supported by grants from the Federal Ministry for Education, Science, Research and Technology and in addition from Helmholtz Zentrum München (former GSF), Helmholtz Centre for Environmental Research – UFZ, Leipzig, Research Institute at Marien-Hospital Bad Honnef for the first 2 years. The 4-, 6-, 10- and 15-year follow-up examinations of the LISA study were covered from the respective budgets of the involved partners (Helmholtz Zentrum München (former GSF), Helmholtz Centre for Environmental Research – UFZ, Leipzig, Research Institute at Marien-Hospital Wesel, Pediatric Practice, Bad Honnef, IUF – Leibniz Research Institute for Environmental Medicine at the University of Düsseldorf) and in addition by a grant from the Federal Ministry for Environment (IUF Düsseldorf, FKZ 20462296). Further, the 15-year follow-up examination of the LISA study was supported by the Commission of the European Communities, the Seventh Framework Program: MeDALL project. This project has received funding from the European Research Council under the European Union’s Horizon 2020 research and innovation programme (949906). LucKi: LucKi is supported by Child and Youth Health Care Zuyderland, Public Health Service South Limburg and Maastricht University. We thank all parents and children for their participation in LucKi. LUKAS: This study was funded by research grants from the Academy of Finland (139021, 287675, 296814, 296817, 308254); Juho Vainio Foundation; EVO/VTR funding; Päivikki and Sakari Sohlberg Foundation; Farmers’ Social Insurance Institution (Mela); Finnish Cultural Foundation; Foundation for Pediatric Research; European Union QLK4-CT-2001-00250; and Finnish Institute for Health and Welfare, Finland. MAS-90: This study was funded by grants from the German Federal Ministry of Education and Research (MBMF; 07015633m 07ALE27, 01EE9405/5, 01EE9406) and the German Research Foundation (DFG; KE1462/2-1). Millennium Cohort Study: This study was funded by the Economic and Social Research Council and a consortium of UK government funders. We are grateful to the participating families and the Centre for Longitudinal Studies (CLS), UCL Institute of Education, for the use of these data and to the UK Data Service for making them available. However, neither CLS nor the UK Data Service bear any responsibility for the analysis or interpretation of these data. This work was supported by the Welcome Trust (187389/B/08/Z). MoBa: The Norwegian Mother, Father and Child Cohort Study is supported by the Norwegian Ministry of Health and Care Services and Ministry of Education and Research. We are grateful to all the participating families in Norway who take part in this ongoing cohort study. This research was supported by the Research Council of Norway through its Centres of Excellence funding scheme (262700). NINFEA: The authors are grateful to all the participants of the NINFEA cohort. The NINFEA study was partially funded by the Compagnia San Paolo Foundation. This research was partially funded by the European Union's Horizon 2020 research and innovation programme (LIFECYCLE, 733206). PELAGIE: We are grateful to the families who participated and continue to participate in the study. The cohort is supported by INSERM and received funding from the French National Research Agency, Fondation de France, French Agency for Food, Environmental and Occupational Health & Safety, National Institute for Public Health Surveillance (InVS), French Ministry of Labour, and French Ministry of Ecology. PIAMA: This study was funded by the Netherlands Organisation of Health Research and Development, Netherlands Organisation for Scientific Research, Netherlands Asthma Fund, Netherlands Ministry of Spatial Planning, Housing and the Environment, and Netherlands Ministry of Health, Welfare and Sport. REPRO_PL: This study was funded by the National Science Center Poland (DEC-2014/15/B/N27/00998). Rhea: This study was funded by the European Union Social Fund and the Hellenic Ministry of Health (“Program of prevention and early diagnosis of obesity and neurodevelopment disorders in preschool age children in the prefecture of Heraklion, Crete, Greece”; MIS 349580, NSRF 2007–2013). Additional funding from the National Institute of Environmental Health Sciences (NIEHS) supported L. Chatzi (R01ES030691, R01ES029944, R01ES030364, R21ES029681, R21ES028903, P30ES007048). STEPS: This study was funded by the University of Turku, Abo Akademi University, Turku University Hospital, Academy of Finland (123571, 140251, 277535) and Foundation for Pediatric Research Finland. SWS: This study was funded by the Medical Research Council, British Heart Foundation, Arthritis Research UK, Food Standards Agency, NIHR Southampton Biomedical Research Centre and the European Union's Seventh Framework Programme (FP7/2007–2013), project EarlyNutrition (289346), and the European Union's Horizon 2020 research and innovation programme (LIFECYCLE, 733206). WHISTLER: The WHISTLER birth cohort was supported with a grant from the Netherlands Organisation for Health Research and Development (2001-1-1322) and by an unrestricted grant from GlaxoSmithKline Netherlands. GlaxoSmithKline had no role in study design, in the collection, analysis and interpretation of data, in the writing of the report, and in the decision to submit the report for publication. WHISTLER-Cardio was supported with an unrestricted strategic grant from the University Medical Center Utrecht (UMCU)

The influence of Epstein-Barr virus and cytomegalovirus on childhood respiratory health: A population-based prospective cohort study

Background: Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infection are common in early childhood. CMV infection favours a T-helper-1 and EBV infection a T-helper-2 cell response, possibly leading to disbalanced T-helper cell response, and subsequent risk of asthma or atopy. Objective: To study the associations of EBV and CMV with lung function, asthma and inhalant allergic sensitization at school age. Methods: This study among 3546 children was embedded in a population-based prospective cohort. At age 6 years, serum IgG levels against EBV and CMV were measured by ELISA. At age 10 years, lung function was measured by spirometry, asthma by questionnaire and inhalant allergic sensitization by skin prick test. Results: Unadjusted models showed that seropositivity for EBV was associated with a higher FEV1 and FEF75 (Z-score difference (95% CI): 0.09 (0.02, 0.16) and 0.09 (0.02, 0.15)), while seropositivity for CMV was not. Specific combinations of viruses showed that seropositivity for EBV was only associated with FEV1 and FEF75 in the presence of seropositivity for CMV (0.12 (0.04, 0.20)) and 0.08 (0.01, 0.15)). Seropositivity for CMV in the absence of seropositivity for EBV was associated with an increased risk of inhalant allergic sensitization (OR (95% CI): 1.31 (1.02, 1.68)). All effect estimates attenuated into non-significant mainly after adjustment for child's ethnicity. Seropositivity for EBV or CMV was not associated with asthma. Conclusions and Clinical Relevance: Associations of EBV and CMV infections in early childhood with school-age lung function and inhalant allergic sensitization are explained by ethnicity, or sociodemographic and lifestyle-related factors