Chronic obstructive pulmonary disease (COPD) in patients starting dialysis increases their mortality risk and decreases their likelihood of receiving a kidney transplant, especially in current smokers, according to researchers.
Austin G. Stack, MD, of the University of Limerick Graduate Entry Medical School in Ireland, and colleagues analyzed data on 769,984 U.S. dialysis patients who commenced dialysis between May 1995 and December 2004. Of these, 7.5% had COPD.
After adjusting for potential confounders, patients with COPD had a 20% increased risk of death compared with those who did not have COPD, the researchers reported in the American Journal of Nephrology (2012;36:287-295). The risk was increased by 28% for patients who had COPD and also smoked.
In addition, in adjusted analyses, nonsmokers with COPD had a 46% decreased likelihood of receiving a kidney transplant compared with subjects who did not have COPD. Smokers with COPD had a 53% decreased likelihood of transplantation.
The detrimental impact of COPD was similar for men and women and varied inversely with age, the study showed.
Emerging evidence suggests that chronic kidney disease is an important co-morbidity in patients with COPD, said Dr. Stack, senior author of the study, but few studies have addressed the impact of COPD on clinical outcomes among patients with advanced kidney failure. To their knowledge, he said, this is the first large-scale study to examine specifically the conjoint impact of COPD and continued smoking in a cohort with end-stage kidney disease.
“Our findings illustrate not only the detrimental effect of COPD on survival and kidney transplantation, which are major clinical outcomes, but also the deleterious effect of continued smoking in this high-risk and vulnerable population,” Dr. Stack told Renal & Urology News. “It also suggests the need for greater recognition of COPD in patients commencing dialysis and the need for cooperation between primary care physicians, pulmonologists, and nephrologists in the care of these high-risk patients.”