Smoking has no impact on survival and it is not associated with ACE gene I/D polymorphism in hemodialysis patients

INTRODUCTION: The relationship between smoking and mortality in patients on hemodialysis is controversial. Earlier studies showed that the insertion/deletion (I/D) polymorphism of the ACE gene might have an effect on mortality. The aim of this study was to test the impact of smoking on survival and whether this association was influenced by ACE gene I/D polymorphism in patients on maintenance hemodialysis. PARTICIPANTS AND METHODS: In this prospective, multicenter cohort study we analyzed 709 prevalent patients on maintenance hemodialysis. Patients were allocated into groups based on their smoking habit. Outcome data were collected during the 144-month follow-up period. Outcomes of current smokers and lifelong non-smokers were compared. In order to control for interactions between predictor variables, we also identified 160 matched pairs for further sub-analysis. RESULTS: The vast majority of patients (67%) were non-smokers, followed by current smokers (22.2%) and ex-smokers (9.8%). Smoking had no impact on survival in the matched pair analysis (p = 0.99). After adjustment for ACE I/D polymorphism and other co-variates, smoking had no effect on survival. CONCLUSION: Our data suggest that smoking has no impact on survival; neither is it associated with ACE gene I/D polymorphism in hemodialysis patients.