Association of Smoking with Cardiovascular and Infection-Related Morbidity and Mortality in Chronic Hemodialysis

Abstract

Smoking is common in the hemodialysis population and is associated with increased all-cause mortality and development of cardiovascular disease. Cause-specific outcomes have not yet been examined in detail. This study investigated the association of baseline smoking status with all-cause, cardiovascular, and infection-related morbidity and mortality in patients undergoing long-term hemodialysis. Post hoc analysis of the HEMO Study in patients with available comorbidity, clinical, and nutritional data. Cox proportional hazards regression models were fit to estimate the association of smoking status with mortality. Poisson and negative binomial regression models were fit to estimate the association of smoking status with hospitalization rate. Complete data were available for 1842 individuals (44% male, 63% black, 45% diabetic). Mean age was 58 ± 14 years. At baseline, 17% were current smokers and 32% were former smokers. After case-mix adjustment, compared with never smoking, current smoking was associated with greater infection-related mortality (hazard ratio [HR], 2.04; 95% confidence interval [CI], 1.32-3.10) and all-cause mortality (HR, 1.44; 95% CI, 1.16-1.79) and greater cardiovascular (incidence rate ratio [IRR], 1.49; 95% CI, 1.22-1.82), infection-related (IRR, 1.35; 95% CI, 1.11-1.64) and all-cause (IRR, 1.43; 95% CI, 1.24-1.65) hospitalization rates. The population attributable fraction (i.e., fraction of observed deaths that may have been avoided) was 5.3% for current smokers versus never-smokers and 2.1% for current versus former smokers. Active smoking is prevalent in the chronic hemodialysis population and is associated with greater all-cause, cardiovascular, and infection-related morbidity and mortality.