Introduction Shift work causes misalignment between internal circadian time and the external light/dark cycle and is associated with metabolic disorders and cancer. Approximately 20% of the working population in industrialised countries work permanent or rotating night shifts, exposing this large population to the risk of circadian misalignment-driven disease. Analysis of the impact of shift work on chronic inflammatory diseases is lacking. We investigated the association between shift work and asthma.
Methods We describe the cross-sectional relationship between shift work and prevalent asthma in >280000 UK Biobank participants, making adjustments for major confounding factors (smoking history, ethnicity, socioeconomic status, physical activity, body mass index). We also investigated chronotype.
Results Compared with day workers, ‘permanent’ night shift workers had a higher likelihood of moderate-severe asthma (OR 1.36 (95% CI 1.03 to 1.8)) and all asthma (OR 1.23 (95% CI 1.03 to 1.46)). Individuals doing any type of shift work had higher adjusted odds of wheeze/whistling in the chest. Shift workers who never or rarely worked on nights and people working permanent nights had a higher adjusted likelihood of having reduced lung function (FEV1 <80% predicted). We found an increase in the risk of moderate-severe asthma in morning chronotypes working irregular shifts, including nights (OR 1.55 (95% CI 1.06 to 2.27)).
Conclusions The public health implications of these findings are far-reaching due to the high prevalence and co-occurrence of both asthma and shift work. Future longitudinal follow-up studies are needed to determine if modifying shift work schedules to take into account chronotype might present a public health measure to reduce the risk of developing inflammatory diseases such as asthma.
- asthma epidemiology
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Correction notice This article has been corrected since it was published Online First. Some author names were misspelt and missing middle initials.
Contributors HJD, RM, DR and MR conceived the study and planned and conducted it. RM, HJD, JT, MR and DR acquired the data. RM, HJD, JT, MR, DR, HD and RS performed the data analysis. HJD, RM, DR, ASL, JB, RS, CV, FS, SS, SK, DL, HD and MR interpreted the data and wrote the manuscript.
Funding RM is funded by a Wellcome Trust Grant (107849/Z/15/Z) and a Medical Research Council grant MR/P023576/1). CV was supported in part by the National Institutes of Health grant R01 DK105072. HD is supported by NIDDK R01DK107859. RS is supported by NIDDK R01DK102696 and R01DK107859 and MGH Research Scholar Fund. FS was supported in part by National Institutes of Health grants R01 DK102696 and R01 DK105072. SS was supported by National Institutes of Health grants R01-HL-125893, R01-HL-142064 and R01-HL-140577 and by the Oregon Institute of Occupational Health Sciences via funds from the State of Oregon (ORS 656.630). SK is supported by a NIHR Oxford Senior Fellowship and the NIHR Oxford Biomedical Research Centre. DL works in a unit that is supported by the University of Bristol ((MC_UU_00011/6); she is a National Institute of Health Research Senior Investigator (NF-0616-10102). ASL is a Wellcome Investigator Wellcome Trust (107849/Z/15/Z). JB is funded by a Medical Research Council Grant (MR/L006499/1). DR is a Wellcome Investigator Wellcome Trust (107849/Z/15/Z) and holds a Medical Research Council Programme grant (MR/P023576/1). HJD is supported by the NIHR Manchester Biomedical Research Centre.
Competing interests FS has received lecture fees from Bayer HealthCare (2016), Sentara HealthCare (2017), Philips (2017), Vanda Pharmaceuticals (2017) and Pfizer Pharmaceuticals (2018). DL has received research support from Medtronic Ltd and Roche Diagnostics for research unrelated to that presented here. MR has received speaker fees and research support from Novo Nordisk and Roche Diabetes Care for research unrelated to that presented here.
Patient consent for publication Not required.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement All data relevant to the study are included in the article or uploaded as supplementary information. All data is available on request from the first or corresponding author and the codes used to analyse the data.
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