Cigarette smoking and adverse health outcomes in patients treated with maintenance dialysis

Background The association of smoking with new-onset cardiovascular disease, chronic lung disease, malignancy and mortality in dialysis is well-known. The smoking prevalence and its association with clinical outcome was assessed. Methods Multicentre cohort study using 'ANZDATA' Registry, 57 838 adults who commenced dialysis (>3 months) between 1990 and 2016 were included. Patients' demographics, initial dialysis modality, presence of comorbidities and smoking history are predictors. The primary outcome was all-cause mortality. Secondary outcomes were smoking prevalence, cause-specific mortality, non-skin cancers, cardiovascular and chronic lung diseases. Results Of the 57 838 patients, 56 512 (mean age of 58.9 +/- 15.1 years, 40.1% female, 43% diabetic), had data on smoking history with 13.6% current, 40.7% former and 45.6% never smokers. Former and current smokers had 10% (HR 1.10; 95% CI: 1.08, 1.13) and 22%(HR 1.22; 95% CI: 1.18, 1.26) higher risk of all-cause mortality. They were 13% (HR 1.13; 95% CI: 1.09, 1.18) and 23% (HR 1.23; 95% CI: 1.17, 1.29) for CVD mortality. Smoking was associated with higher mortality from respiratory failure (HR 1.59; 95% CI: 1.13, 2.23, p = .073 and HR 1.33; 95% CI: 1.01, 1.74, p = .042) for current and former smokers. Current and former smokers had higher risk for non-skin cancer (HR 1.30; 95% CI: 1.19, 1.42 and HR 1.24; 95% CI: 1.17, 1.32). Smoking was associated with a higher rate of death from cancer (HR 1.26; 95% CI 1.19-1.33) and chronic lung disease (HR 1.48; 95% CI 1.15-1.92). Former and current smokers had a higher adjusted risk for de novo vascular disease (PVD, CVD), CAD (adjusted RR 1.1; 95% Cl: 1.09-1.12). Conclusions In dialysis patients, smoking was associated with higher rates of all-cause mortality, cardiovascular mortality, respiratory failure, chronic lung disease and malignancy along with higher risks of non-skin cancers, de novo vascular disease and chronic lung disease.