Association between exposure to second-hand smoke and telomere length: cross-sectional study of 1303 non-smokers

Lu, L., Johnman, C., McGlynn, L., Mackay, D. F. , Shiels, P. G. and Pell, J. P. (2017) Association between exposure to second-hand smoke and telomere length: cross-sectional study of 1303 non-smokers. International Journal of Epidemiology, 46(6), pp. 1978-1984. (doi: 10.1093/ije/dyx212) (PMID:29040594)

Abstract

Background: Both active smoking and second-hand smoke (SHS) are important risk factors for many age-related diseases. Active smoking is associated with shortened telomere length. However, whether SHS accelerates telomere attrition with age is uncertain. The aim of this study was to examine the association between SHS exposure and shortening by age of leukocyte telomere length among adult non-smokers. Methods: We undertook a cross-sectional study of the association between self-reported levels of SHS exposure and telomere length shortening per annum on a subgroup of participants from the Scottish Family Health Study. Inclusion was restricted to non-smokers aged ≥ 18 years, who had provided self-reported overall usual SHS exposure (total hours per week) and blood samples for telomere analysis. Linear regression models were used to compare the ratio of telomere repeat copy number to single copy gene number (T/S)by age according to SHS exposure. Results: Of the 1303 eligible participants, 779 (59.8%) reported no SHS exposure, 495 (38.0%) low exposure (1–19 h per week) and 29 (2.2%) high exposure (≥20 h per week). In the univariate linear regression analyses, relative T/S ratio declined with increasing age in all exposure groups. Telomere length decreased more rapidly with increasing age among those with high exposure to SHS [adjusted coefficient −0.019, 95% confidence interval (CI) −0.031- −0.007) when compared with both those with no exposure to SHS (adjusted coefficient −0.006, 95% CI −0.008- −0.004) (high vs no SHS: P = 0.010) and those with low exposure to SHS (adjusted coefficient −0.005, 95% CI −0.007- −0.003) (high vs low SHS: P = 0.005). Conclusions: Our findings suggest that high SHS exposure may accelerate normal biological ageing, and support efforts to protect the public from SHS exposure. Further studies on relevant mechanisms should be conducted.

• Item Type: Articles
• Additional Information: This work was supported by the Paterson Endowment Fund.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: McGlynn, Dr Liane and Mackay, Professor Daniel and Lu, Liya and Johnman, Dr Cathy and Shiels, Professor Paul and Pell, Professor Jill
• Authors: Lu, L., Johnman, C., McGlynn, L., Mackay, D. F., Shiels, P. G., and Pell, J. P.
• College/School: College of Medical Veterinary and Life Sciences; College of Medical Veterinary and Life Sciences > School of Cancer Sciences; College of Medical Veterinary and Life Sciences > School of Health & Wellbeing > Public Health; College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Journal Name: International Journal of Epidemiology
• Publisher: Oxford University Press
• ISSN: 0300-5771
• ISSN (Online): 1464-3685
• Published Online: 11 October 2017
• Copyright Holders: Copyright © 2017 The Authors
• First Published: First published in International Journal of Epidemiology 46(6): 1978-1984
• Publisher Policy: Reproduced in accordance with the publisher copyright policy