Differential impact of smoking on mortality and kidney transplantation among adult Men and Women undergoing dialysis

Abstract

BackgroundThe extent to which smoking contributes to adverse outcomes among men and women of all ages undergoing dialysis is uncertain. The objective of this study was to determine the differential impact of smoking on risks of mortality and kidney transplantation by age and by sex at dialysis initiation.MethodsWe conducted a population-based cohort of incident U.S dialysis patients (n = 1, 220, 000) from 1995–2010. Age- and sex-specific mortality and kidney transplantation rates were determined for patients with and without a history of cardiovascular disease. Multivariable Cox regression evaluated relative hazard ratios (HR) for death and kidney transplantation at 2 years stratified by atherosclerotic condition, smoking status and age. Analyses were adjusted for demographic characteristics, non-cardiovascular conditions, laboratory variables, socioeconomic and lifestyle factors.ResultsThe average age was 62.8 (±15) years old, 54 % were male, and the majority was white. During 2-year follow-up, 40.5 % died and 5.7 % were transplanted. Age- and sex-specific mortality rates were significantly higher while transplantation rates were significantly lower for smokers with atherosclerotic conditions than non-smokers (P < 0.01). The adjusted mortality hazards were significantly higher for smokers with pre-existing coronary disease (HR 1.15, 95 % CI (1.11–1.18), stroke (HR 1.21, 1.16–1.27) and peripheral vascular disease (HR = 1.21, 1.17–1.25) compared to non-smokers without these conditions (HR 1.00, referent group). The magnitude of effect was greatest for younger patients than older patients. Contrastingly, the adjusted risks of kidney transplantation were significantly lower for smokers with coronary disease: (HR 0.60, 0.52–0.69), stroke; (HR 0.47, 0.37–0.60), and peripheral arterial disease (HR 0.55, 0.46–0.66) respectively compared to non-smokers without these conditions.ConclusionsWe provide compelling evidence that smoking is associated with adverse clinical outcomes and reduced lifespans among dialysis patients of all ages and sexes. The adverse impact is greatest for younger men and women.Electronic supplementary materialThe online version of this article (doi:10.1186/s12882-016-0311-x) contains supplementary material, which is available to authorized users.

Analysis of Smoking in Chronic Kidney Dialytic Patients and Cardiovascular Events

“…It is interesting to note that other authors have already alluded to age, CKD and tobacco, and there are reports in the literature that the impact of smoking-related mortality is greater among younger dialytic chronic kidney than older ones [25]. According to what was stated by Stack et al [25], in addition to the high prevalence, complications arising from atherosclerosis have a massive effect on increased mortality of patients with dialytic chronic kidney disease. Therefore, the control of cardiovascular risk factors is extremely important, especially in these patients.…”

“…Because it is characterized as a modifiable risk factor and evidence suggests that smoking is responsible for increased mortality, number of cardiovascular events, post-transplant graft rejection rate, and acceleration of atherosclerosis in chronic renal patients. [25] The poor approach to this issue, especially of passive exposure to tobacco, is remarkable, as this contact appears to be common: among the 46 patients who reported cardiovascular events, only 11 (24%) never came into contact with this substance, while that in the group that was already actively and / or passively exposed, the prevalence of these events was 76%, identifying a positive association between tobacco and the occurrence of such events (prevalence ratio 3.1), besides to reiterate it. CAD was the most prevalent cardiovascular complication in the sample (24.6%) followed by stroke (12.7%).…”