PT  - JOURNAL ARTICLE
AU  - Caroline Lodge
AU  - Adrian Lowe
AU  - Shyamali Dharmage
AU  - David Olsson
AU  - Bertil Forsberg
AU  - Lennart Bråbäck
TI  - LATE-BREAKING ABSTRACT: Does grandmaternal smoking increase the risk of asthma in grandchildren?
AID  - 10.1183/13993003.congress-2015.OA4762
DP  - 2015 Sep 01
TA  - European Respiratory Journal
PG  - OA4762
VI  - 46
IP  - suppl 59
4099  - http://erj.ersjournals.com/content/46/suppl_59/OA4762.short
4100  - http://erj.ersjournals.com/content/46/suppl_59/OA4762.full
SO  - Eur Respir J2015 Sep 01; 46
AB  - Background: There is increasing interest in environmental exposures as heritable risk factors. Animal studies have linked grand-maternal nicotine exposure to lung changes in grand-offspring of unexposed mothers. This has been partially corroborated in limited human studies, although inconsistently.Aim: To investigate the association between grand-maternal smoking during pregnancy and asthma risk in grandchildrenMethods: From 1982-1986, 44,583 grandmothers gave birth to children in Sweden. Subsequently 46,197 of these children (aka mothers) gave birth to 66,271 grandchildren (aka children) (born 1996-2000).Smoking exposure was recorded at 10-12 weeks gestation for both mothers and grandmothers. Also 3 months preconception and third trimester smoking were recorded for mothers. Purchased asthma medication was recorded for children (2005-2013). Current asthma in any year was defined as purchasing inhaled steroids. Maternal smoking, gender, county, social allowance, grand-paternal smoking, grandmothers BMI and grandmothers age, were included as covariates. There was no interaction by maternal smoking.Results: Grandmothers smoking during pregnancy there was associated with an increased asthma risk for grandchildren from 1-6 years (Adjusted odds ratios: 1-2yr, 1.19; 95%CI 1.10,1.27; 2-3yr, 1.22; 1.14,1.31, 3-4yr, 1.11; 1.02,1.21, 4-5yr,1.10; 0.99,1.22, 5-6yr ,1.14; 1.00,1.31).Conclusions: Children aged 1-6 years had a 10- 22% increased risk of asthma if their grandmothers smoked during early pregnancy. These findings support possible epigenetic transmission of risk from environmental exposures in previous generations.