Háskóli ÍslandsUniversity of IcelandJohannessen, AneLønnebotn, MarianneCalciano, LuciaBenediktsdóttir, BryndísBertelsen, Randi JacobsenBråbäck, LennartDharmage, ShyamaliFranklin, Karl A.Gislason, ThorarinnHolm, MathiasJanson, ChristerJarvis, DeborahJõgi, RainKim, Jeong-LimKirkeleit, JorunnLodge, CarolineMalinovschi, AndreiMartinez-Moratalla, JesusNilsen, Roy MiodiniPereira-Vega, AntonioReal, Francisco GómezSchlünssen, ViviAccordini, SimoneSvanes, Cecilie2020-03-162020-03-162020-03Johannessen, A., Lønnebotn, M., Calciano, L., Benediktsdóttir, B., Bertelsen, R. J., Bråbäck, L., . . . Svanes, C. (2020). Being overweight in childhood, puberty, or early adulthood: Changing asthma risk in the next generation? Journal of Allergy and Clinical Immunology, 145(3), 791-799.e794. doi:https://doi.org/10.1016/j.jaci.2019.08.0300091-6749https://hdl.handle.net/20.500.11815/1608Publisher's version (útgefin grein).Background: Overweight status and asthma have increased during the last decades. Being overweight is a known risk factor for asthma, but it is not known whether it might also increase asthma risk in the next generation. Objective: We aimed to examine whether parents being overweight in childhood, adolescence, or adulthood is associated with asthma in their offspring. Methods: We included 6347 adult offspring (age, 18-52 years) investigated in the Respiratory Health in Northern Europe, Spain and Australia (RHINESSA) multigeneration study of 2044 fathers and 2549 mothers (age, 37-66 years) investigated in the European Community Respiratory Health Survey (ECRHS) study. Associations of parental overweight status at age 8 years, puberty, and age 30 years with offspring's childhood overweight status (potential mediator) and offspring's asthma with or without nasal allergies (outcomes) was analyzed by using 2-level logistic regression and 2-level multinomial logistic regression, respectively. Counterfactual-based mediation analysis was performed to establish whether observed associations were direct or indirect effects mediated through the offspring's own overweight status. Results: We found statistically significant associations between both fathers' and mothers' childhood overweight status and offspring's childhood overweight status (odds ratio, 2.23 [95% CI, 1.45-3.42] and 2.45 [95% CI, 1.86-3.22], respectively). We also found a statistically significant effect of fathers' onset of being overweight in puberty on offspring's asthma without nasal allergies (relative risk ratio, 2.31 [95% CI, 1.23-4.33]). This effect was direct and not mediated through the offspring's own overweight status. No effect on offspring's asthma with nasal allergies was found. Conclusion: Our findings suggest that metabolic factors long before conception can increase asthma risk and that male puberty is a time window of particular importance for offspring's health.791-799.e4eninfo:eu-repo/semantics/openAccessAgeing Lungs in European Cohorts studyEpidemiologyMultilevel mediation modelOffspringParental risk factorsAstmiOffitaFaraldsfræðiinfo:eu-repo/semantics/articleJournal of Allergy and Clinical Immunology10.1016/j.jaci.2019.08.030