To the Editor
We welcome the comments on our article by Dr Palvisko and colleagues and thank them for drawing our attention to the large autopsy series published in 19881 where the presence of emphysema was predictive of reduced mortality from kidney disease. At first glance, this study may appear to contradict our finding that emphysema is associated with an increased prevalence of mild kidney insufficiency.2
However, we believe that this paradox might have a rather uncomplicated explanation. The key difference is that mortality from kidney disease is very different from suffering from mild kidney disease. Epidemiologic studies demonstrate that patients with mild kidney disease do not usually die of end-stage renal disease but, rather, of cardiovascular causes.3 Therefore, patients with emphysema may have a disproportionately high prevalence of early stage kidney disease but may die preferentially of cardiovascular instead of advanced kidney disease.
What is not contradictory is that in considering the results of each study, one must conclude that further research is required into the development of renal comorbidities in patients with COPD. Both studies suggest that renal disease may be an important contributor to the disproportionate burden of cardiovascular disease and cardiovascular death in patients with COPD.
Footnotes
Financial/nonfinancial disclosures: The authors have reported to CHEST the following conflicts of interest: Dr Palevsky has been a consultant for sanofi-aventis US LLC; Cytopherx, Inc; and Complexa, Inc, and is a member of Spectral Diagnostics' EUPHRATES study. Drs Chandra and Sciurba have reported that no potential conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article.
Reproduction of this article is prohibited without written permission from the American College of Chest Physicians. See online for more details.
References
- 1.Pratt PC, Roggli VL, Tesoriero VJ. Lower incidence of death from chronic renal disease in patients with nonlethal emphysema: a statistical study. Mod Pathol. 1988;1(1):57–63. [PubMed] [Google Scholar]
- 2.Chandra D, Stamm JA, Palevsky PM. The relationship between pulmonary emphysema and kidney function in smokers. Chest. 2012;142(3):655–662. doi: 10.1378/chest.11-1456. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Sarnak MJ. Cardiovascular complications in chronic kidney disease. Am J Kidney Dis. 2003;41(suppl 5):11–17. doi: 10.1016/s0272-6386(03)00372-x. [DOI] [PubMed] [Google Scholar]