BACKGROUND: It is well known that smoking is a major risk factor for lung disease and respiratory symptoms. We examined the association between smoking and the risk of chronic bronchitis in a large twin sample. METHODS: In a population-based questionnaire study of 13,649 twins, aged 50-71 years, from the Danish Twin Registry, we identified 1,146 twin pairs, discordant for a lifetime history smoking. We performed co-twin control analysis to examine the impact of smoking on the risk of chronic bronchitis. RESULTS: The prevalence of chronic bronchitis was 9.7 %. In the total sample, high age, living without a spouse, and smoking remained statistically significant predictors with an up to tenfold increased risk of chronic bronchitis in the heaviest smokers compared with never-smokers, after multivariate adjustment. Among twin pairs discordant for smoking, chronic bronchitis was significantly more common in the smoking twin compared with the nonsmoking co-twin. There was no differential effect of smoking on the risk of chronic bronchitis in monozygotic and dizygotic twins. CONCLUSIONS: The risk of chronic bronchitis increases with age and increasing tobacco consumption. The results indicate a direct relationship between smoking and development of chronic bronchitis, but other environmental factors, such as exposure to household smoking in childhood and living without a spouse, also play a role.
BACKGROUND: It is well known that smoking is a major risk factor for lung disease and respiratory symptoms. We examined the association between smoking and the risk of chronic bronchitis in a large twin sample. METHODS: In a population-based questionnaire study of 13,649 twins, aged 50-71 years, from the Danish Twin Registry, we identified 1,146 twin pairs, discordant for a lifetime history smoking. We performed co-twin control analysis to examine the impact of smoking on the risk of chronic bronchitis. RESULTS: The prevalence of chronic bronchitis was 9.7 %. In the total sample, high age, living without a spouse, and smoking remained statistically significant predictors with an up to tenfold increased risk of chronic bronchitis in the heaviest smokers compared with never-smokers, after multivariate adjustment. Among twin pairs discordant for smoking, chronic bronchitis was significantly more common in the smoking twin compared with the nonsmoking co-twin. There was no differential effect of smoking on the risk of chronic bronchitis in monozygotic and dizygotic twins. CONCLUSIONS: The risk of chronic bronchitis increases with age and increasing tobacco consumption. The results indicate a direct relationship between smoking and development of chronic bronchitis, but other environmental factors, such as exposure to household smoking in childhood and living without a spouse, also play a role.
Authors: G Viegi; P Paoletti; R Prediletto; L Carrozzi; P Fazzi; F Di Pede; G Pistelli; C Giuntini; M D Lebowitz Journal: Eur Respir J Date: 1988-04 Impact factor: 16.671
Authors: Jenny Hallberg; Annica Dominicus; Ulrika K Eriksson; Maria Gerhardsson de Verdier; Nancy L Pedersen; Magnus Dahlbäck; Ulf Nihlén; Tim Higenbottam; Magnus Svartengren Journal: Am J Respir Crit Care Med Date: 2007-11-29 Impact factor: 21.405
Authors: Malin Axelsson; Linda Ekerljung; Jonas Eriksson; Stig Hagstad; Eva Rönmark; Jan Lötvall; Bo Lundbäck Journal: Eur Clin Respir J Date: 2016-07-13