Consequences of chronic kidney disease in chronic obstructive pulmonary disease

BACKGROUND: The combination of chronic obstructive pulmonary disease (COPD) and chronic kidney disease (CKD) is associated with a higher prevalence of comorbidities and increased mortality. The impact of kidney function on patient-centered outcomes in COPD has not been evaluated. METHODS: Patients from the German COPD and Systemic Consequences - Comorbidities Network (COSYCONET) cohort COPD were analysed. CKD was diagnosed if the estimated glomerular filtration rate (eGFR) measurements were < 60 mL/min/1.73m(2) at study inclusion and six month later. The effect of CKD, on comorbidities, symptoms [modified British Medical Research Council dyspnoea scale], physical capacity [six-minute walk test, and timed up and go] and St George's Respiratory Questionnaire were analysed. Restricted cubic spline models were used to evaluate a nonlinear relationship between eGFR with patient-centered outcomes, cox survival analysis was applied to evaluate mortality. RESULTS: 2274 patients were analysed, with CKD diagnosed in 161 (7.1%). Spline models adjusted for age, gender, BMI, FEV1 and cardiovascular comorbidities revealed independent associations between eGFR with modified British Medical Research Council dyspnoea scale, St George's Respiratory Questionnaire, (p < 0.001 and p = 0.011), six-minute walk test (p = 0.015) and timed up and go (p < 0.001). CKD was associated with increased mortality, independently from for other cardiovascular comorbidities (hazard ratio 2.3; p < 0.001). CONCLUSION: These data show that CKD is a relevant comorbidity in COPD patients which impacts on patient-centered outcomes and mortality. TRIAL REGISTRATION: NCT01245933.

• Trudzinski, F. C.
• Alqudrah, M.
• Omlor, A.
• Zewinger, S.
• Fliser, D.
• Speer, T.
• Seiler, F.
• Biertz, F.
• Koch, A.
• Vogelmeier, C.
• Welte, T.
• Watz, H.
• Waschki, B.
• Fahndrich, S.
• Jorres, R.
• Bals, R.
• German, Cosyconet consortium