title: Mortality Outcomes of Patients with Chronic Kidney Disease and Chronic Obstructive Pulmonary Disease.
abstract: BACKGROUND
  Chronic obstructive pulmonary disease (COPD) is associated with higher mortality in the general population. We studied the associations between COPD and death among chronic kidney disease (CKD) patients along with reporting cause-specific death data.
  
  
  METHODS
  We included 56,960 patients with stages 3 and 4 CKD who were followed in a large health care system. Associations between COPD and all-cause mortality and various causes of death (respiratory deaths, cardiovascular deaths, malignancy-related deaths and deaths due to other reasons) were studied using the Cox proportional hazards and competing risk models.
  
  
  RESULTS
  Out of 56,960 CKD patients, 4.7% (n = 2,667) had underlying COPD. Old age, presence of diabetes, hypertension, coronary artery disease, congestive heart failure, and smoking were associated with higher risk for COPD. During a median follow-up of 3.7 years, 15,969 patients died. After covariate adjustment, COPD was associated with a 41% increased risk (95% CI 1.31-1.52) for all-cause mortality, and fourfold increased risk (sub-hazard ratio 4.36, 95% CI 3.54-5.37) for respiratory-related deaths. In a sensitivity analysis that was performed by defining COPD as the use of relevant International Classification of Diseases-9 codes and medications used to treat COPD, similar results were noted.
  
  
  CONCLUSIONS
  COPD is associated with higher risk for death among those with CKD, and an underlying lung disease accounts for significant proportion of deaths. These data highlight the need for further prospective studies to understand the underlying mechanisms and potential interventions to improve outcomes in this population.
authors.affiliation: Selzman Institute for Kidney Health, Section of Nephrology, Department of Medicine, Baylor College of Medicine, Houston, Tex., USA.
authors.forename: Sankar D
authors.initials: SD
authors.lastname: Navaneethan
authors.forename: Jesse D
authors.initials: JD
authors.lastname: Schold
authors.forename: Haiquan
authors.initials: H
authors.lastname: Huang
authors.forename: Georges
authors.initials: G
authors.lastname: Nakhoul
authors.forename: Stacey E
authors.initials: SE
authors.lastname: Jolly
authors.forename: Susana
authors.initials: S
authors.lastname: Arrigain
authors.forename: Raed A
authors.initials: RA
authors.lastname: Dweik
authors.forename: Joseph V
authors.initials: JV
authors.lastname: Nally
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D015897:Comorbidity; D003327:Coronary Disease / Q000453:epidemiology; D003920:Diabetes Mellitus / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000453:epidemiology; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009820:Ohio / Q000453:epidemiology; D016016:Proportional Hazards Models; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000401:mortality*; D051436:Renal Insufficiency, Chronic / Q000401:mortality*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology