A three-generation study on the association of tobacco smoking with asthma

Publisher's version (útgefin grein)
Background Mothers’ smoking during pregnancy increases asthma risk in their offspring. There is some evidence that grandmothers’ smoking may have a similar effect, and biological plausibility that fathers’ smoking during adolescence may influence offspring’s health through transmittable epigenetic changes in sperm precursor cells. We evaluated the three-generation associations of tobacco smoking with asthma. Methods Between 2010 and 2013, at the European Community Respiratory Health Survey III clinical interview, 2233 mothers and 1964 fathers from 26 centres reported whether their offspring (aged ≤51 years) had ever had asthma and whether it had coexisted with nasal allergies or not. Mothers and fathers also provided information on their parents’ (grandparents) and their own asthma, education and smoking history. Multilevel mediation models within a multicentre three-generation framework were fitted separately within the maternal (4666 offspring) and paternal (4192 offspring) lines. Results Fathers’ smoking before they were 15 [relative risk ratio (RRR) = 1.43, 95% confidence interval (CI): 1.01–2.01] and mothers’ smoking during pregnancy (RRR = 1.27, 95% CI: 1.01–1.59) were associated with asthma without nasal allergies in their offspring. Grandmothers’ smoking during pregnancy was associated with asthma in their daughters [odds ratio (OR) = 1.55, 95% CI: 1.17–2.06] and with asthma with nasal allergies in their grandchildren within the maternal line (RRR = 1.25, 95% CI: 1.02–1.55). Conclusions Fathers’ smoking during early adolescence and grandmothers’ and mothers’ smoking during pregnancy may independently increase asthma risk in offspring. Thus, risk factors for asthma should be sought in both parents and before conception.
The present analyses are part of the Ageing Lungs in European Cohorts (ALEC) Study [www.alecstudy.org], which has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 633212. The coordination of the European Community Respiratory Health Survey (ECRHS) was supported by the European Commission (phases 1 and 2) and the Medical Research Council (phase 3). Local funding agencies for the ECRHS are reported in the Supplementary Appendix, available as Supplementary data at IJE online. Conflict of interest: J.W.H. reports grants from the European Union’s Horizon 2020 programme (633212), the Medical Research Council UK (MC_PC_15078) and the National Institutes of Health USA (R01 AI091905, R01 AI121226) during the conduct of the study. R.J. reports grants from the Estonian Research Council (personal grant No. 562) during the conduct of the study, grants/grants pending from the Estonian Research Council (personal research grant No. 562), personal fees for consulting and lecturing from GlaxoSmithKline, Boehringer and Novartis and travel/accommodation/meeting expenses paid by GlaxoSmithKline and Boehringer, outside the submitted work. C.R. reports personal fees for consulting and lecturing from ALK, Astra Zeneca, GSK, Boheringer and Novartis, outside the submitted work. A.G.C. reports grants from Chiesi Farmaceutici and GlaxoSmithKline Italy, during the conduct of the study. P.D. reports personal fees for consulting and lecturing from ALK and Stallergenes Greer and personal fees for consulting from Circassia, Chiesi Farmaceutici, ThermofisherScientific and Menarini, outside the submitted work. D.J. reports grants from the Medical Research Council and the European Union’s Horizon 2020 programme, during the conduct of the study. All other authors declare no competing interests.