The effects of growing up on a farm on adult lung function and allergic phenotypes: an international population-based study

Campbell, B.; Raherison, C.; Lodge, Caroline J.; Lowe, Adrian J.; Gislason, Thorarinn; Heinrich, Joachim; Sunyer Deu, Jordi; Gómez Real, Francisco; Norbäck, Dan; Matheson, Melanie C.; Wjst, Matthias; Dratva, Julia; Marco, Roberto de; Jarvis, Deborah; Schlünssen, Vivi; Janson, Christer; Leynaert, Bénédicte; Svanes, Cecilie; Dharmage, Shyamali C.

doi:http://dx.doi.org/10.1136/thoraxjnl-2015-208154

The effects of growing up on a farm on adult lung function and allergic phenotypes: an international population-based study

Citation

Campbell B, Raherison C, Lodge CJ, Lowe AJ, Gislason T, Heinrich J et al. The effects of growing up on a farm on adult lung function and allergic phenotypes: an international population-based study. Thorax. 2017;72(3):236-44. DOI: 10.1136/thoraxjnl-2015-208154

Abstract

Rationale: Evidence has suggested that exposure to environmental or microbial biodiversity in early life may impact subsequent lung function and allergic disease risk. Objectives: To investigate the influence of childhood living environment and biodiversity indicators on atopy, asthma and lung function in adulthood. Methods and measurements: The European Community Respiratory Health Survey II investigated ∼10 201 participants aged 26–54 years from 14 countries, including participants' place of upbringing (farm, rural environment or inner city) before age 5 years. A ‘biodiversity score’ was created based on childhood exposure to cats, dogs, day care, bedroom sharing and older siblings. Associations with lung function, bronchial hyper-responsiveness (BHR), allergic sensitisation, asthma and rhinitis were analysed. Main results: As compared with a city upbringing, those with early-life farm exposure had less atopic sensitisation (adjusted OR 0.46, 95% CI 0.37 to 0.58), atopic BHR (0.54 (0.35 to 0.83)), atopic asthma (0.47 (0.28 to 0.81)) and atopic rhinitis (0.43 (0.32 to 0.57)), but not non-atopic outcomes. Less pronounced protective effects were observed for rural environment exposures. Women with a farm upbringing had higher FEV1 (adjusted difference 110 mL (64 to 157)), independent of sensitisation and asthma. In an inner city environment, a higher biodiversity score was related to less allergic sensitisation. Conclusions: This is the first study to report beneficial effects of growing up on a farm on adult FEV1. Our study confirmed the beneficial effects of early farm life on sensitisation, asthma and rhinitis, and found a similar association for BHR. In persons with an urban upbringing, a higher biodiversity score predicted less allergic sensitisation, but to a lesser magnitude than a childhood farm environment.