Research Paper Volume 11, Issue 21 pp 9893—9900
Suppression effect of body weight on the association between cigarette smoking and telomere length: the Bogalusa Heart Study
- 1 Center on Translational Neuroscience, College of Life and Environment Sciences, Minzu University of China, Beijing 100081, China
- 2 Children’s Minnesota Research Institute, Children’s Hospitals and Clinics of Minnesota, Minneapolis, MN 55404, USA
- 3 Department of Epidemiology, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112, USA
- 4 Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health, Beijing 100045, China
- 5 Department of Biostatistics, School of Public Health, Shandong University, Jinan, Shandong 250012, China
Received: August 20, 2019 Accepted: October 29, 2019 Published: November 9, 2019
https://doi.org/10.18632/aging.102439How to Cite
Copyright © 2019 Yun et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
This study aimed to dissect the direct effect of smoking and its indirect effect through body mass index (BMI) on leukocyte telomere length (LTL) and to distinguish the mediation and suppression effects of BMI. The study cohort included 1,037 adults (729 Whites and 308 African Americans; 42.1% males; mean age: 40.3 years) with LTL measurements by Southern blotting. General third variable models were used to distinguish the mediation and suppression effects of BMI on the smoking-LTL association. After adjusting for age, race, sex and alcohol drinking, the total effect of smoking on LTL was significant (standardized regression coefficient, β= -0.061, p=0.034) without BMI included in the model. With additional adjustment for BMI, the indirect effect of smoking on LTL through BMI was estimated at β= 0.011 (p=0.023), and the direct effect of smoking on LTL was strengthened to β= -0.072 (p=0.012). The results were similar when pack-years of smoking was used. The effect parameters did not differ significantly between race and sex groups. These results suggest that BMI has a suppression effect, not a mediation effect, on the smoking-LTL association, which potentially contributes to previous inconsistencies in the effect of smoking on LTL.
Abbreviations
AA: African American; BMI: body mass index; LTL: leukocyte telomere length.