Ahmed Abdelraouf Salem1, Kira Trares2, Matthias Kohl3, Eugène Jansen4, Hermann Brenner5, Ben Schöttker6. 1. Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany; Department of Medical and Life Science, Furtwangen University, Germany. 2. Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany; Network Aging Research, Heidelberg University, Germany. 3. Department of Medical and Life Science, Furtwangen University, Germany. 4. Centre for Health Protection, National Institute of Public Health and the Environment, Bilthoven, the Netherlands. 5. Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany; Network Aging Research, Heidelberg University, Germany; Division of Preventive Oncology, German Cancer Research Center (DKFZ) and National Center for Tumor Diseases (NCT), Heidelberg, Germany; German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany. 6. Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany; Network Aging Research, Heidelberg University, Germany. Electronic address: b.schoettker@dkfz.de.
Abstract
INTRODUCTION: Cross-sectional studies have consistently shown an association between current smoking and oxidative stress biomarkers. However, no longitudinal studies have been performed so far. METHODS: The oxidative stress biomarkers "total thiol groups of serum proteins" (TTP), and "derivatives of reactive oxygen metabolites" (D-ROM) were measured in serum samples of 3835 participants of a population-based, German cohort study of older adults (age: 60-84 years) with repeated measurements for 2834 participants three years later. Multivariable linear regression models were applied and β-coefficients with 95% confidence intervals were obtained. RESULTS: In both cross-sectional and longitudinal analysis, current smoking was statistically significantly associated with increased D-ROM levels, and a dose-response relationship between the amount of daily tobacco consumption and the D-ROM concentrations was observed that plateaued at ≥15 g of tobacco consumption per day. Former smoking was also associated with D-ROM levels. Only former smokers who quitted smoking more than 10 years ago had no increased D-ROM levels compared to never smokers. There was neither a cross-sectional nor longitudinal association between any of the smoking variables and TTP levels. CONCLUSION: This large population-based cohort of older German adults suggests that smoking has long-term effects on the oxidative stress burden. The further increasing D-ROM levels of current smokers at an older age and the observation that it may take more than 10 years until the redox balance is restored are solid arguments for quitting smoking as soon as possible at any age.
INTRODUCTION: Cross-sectional studies have consistently shown an association between current smoking and oxidative stress biomarkers. However, no longitudinal studies have been performed so far. METHODS: The oxidative stress biomarkers "total thiol groups of serum proteins" (TTP), and "derivatives of reactive oxygen metabolites" (D-ROM) were measured in serum samples of 3835 participants of a population-based, German cohort study of older adults (age: 60-84 years) with repeated measurements for 2834 participants three years later. Multivariable linear regression models were applied and β-coefficients with 95% confidence intervals were obtained. RESULTS: In both cross-sectional and longitudinal analysis, current smoking was statistically significantly associated with increased D-ROM levels, and a dose-response relationship between the amount of daily tobacco consumption and the D-ROM concentrations was observed that plateaued at ≥15 g of tobacco consumption per day. Former smoking was also associated with D-ROM levels. Only former smokers who quitted smoking more than 10 years ago had no increased D-ROM levels compared to never smokers. There was neither a cross-sectional nor longitudinal association between any of the smoking variables and TTP levels. CONCLUSION: This large population-based cohort of older German adults suggests that smoking has long-term effects on the oxidative stress burden. The further increasing D-ROM levels of current smokers at an older age and the observation that it may take more than 10 years until the redox balance is restored are solid arguments for quitting smoking as soon as possible at any age.