The prevalence of undiagnosed renal failure in a cohort of COPD patients in western Norway

Abstract

Patients with COPD are at risk for other comorbid diseases, like heart failure, coronary heart disease, and depression. However, little is known about COPD phenotypes and prevalence of sub-clinical renal failure. 433 COPD patients and 233 subjects without COPD, from Western Norway, age 40-75, GOLD stage II-IV, were examined in 2006/07 upon entry to the Bergen COPD Cohort Study. Plasma creatinine was measured in 422 of the COPD patients. The Glomerular Flow Rate (GFR) was determined with the Cockcroft Gault formula, and having a GFR < 60 was defined as renal failure. Examined explanatory factors were sex, age, smoking habits, GOLD stage, hypoxemia, exacerbation history, cachexia, use of daily inhaled steroids, Charlson comorbidity score, use of ACE inhibitors and/or ARBs, and the inflammatory plasma markers C-reactive protein (CRP), soluble tumor necrosis factor receptor 1 (sTNF-R1) and neutrophil gelatinase associated lipocalin (NGAL). Associations between explanatory variables and renal failure were examined by a logistic regression analysis. The prevalence of having GFR < 60 was 9.6% in female COPD patients and 5.1% in male COPD patients (p = 0.08). In multivariable analysis, female sex, higher age, cachexia, and the inflammatory markers sTNF-R1 and NGAL were all independently associated with a higher risk for renal failure, whereas use of inhaled steroids, Charlson score, GOLD stage, respiratory failure, and exacerbation frequency were not. Undiagnosed renal failure is a concern particularly in elderly COPD patients and COPD patients with cachexia.

Prevalence of chronic kidney disease in patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis

“…Adjustment in analysis: yes Confounding variables: yes; age, gender, first diagnosis of COPDLoss to follow up: noneOverall incidence of CKD was higher in COPD group than in non-COPD group. The adjusted hazard ratio of case was 1.61 ( P <0.0001) times that of control.Ford, E S.; 2015 [20]Study design: retrospective case-control studyFunding: NoneSetting & period: 5711 American men and women aged 40 to 79 years who participated in the Third National Health and Nutrition Examination Survey (NHANES III) during the term 1988 through 1994 and followed through 2006COPD group: 1390 participantsNon-COPD group: 4321 participantsDiagnosis of COPD: spirometryCKD definition: eGFR calculation using the Chronic Kidney Disease Epidemiology Collaboration equationsBlinding of outcome adjudicator: not reportedSelection bias: noInformation bias: objectiveoutcome evaluation: yes;standardized CKD riskmeasurement: yesConfounding: no Matching: yes. Adjustment in analysis: yes Confounding variables: noLoss to follow up: noneThe rates of incidence or prevalence of CKD was not reported.Comparative data on mean eGFR values in COPD group and Non-COPD group was reported.Adjusted mean levels of eGFR were significantly lower in adults with moderate-severe COPD (87.7 mL/min/1.73 m2) than in adults with normal lung function (89.6 mL/min/1.73 m2) ( p  = 0.015)García-Olmos et al, 2013 [21]Study design: Observational, cross-sectional studyFunding: CDTI/Ministry of Science and InnovationSetting & period: practice population allocated to 129 Family Physicians, conducted in a health area of the MadridPatient group: 3,183 patients, 76% male, mean age of 71.41 ± 11.50 yearsDiagnosis of COPD: from clinical history in EMRCKD definition: not defined, obtained from EMRSelection bias: not validated COPD diagnostic methodInformation bias:Objective outcome evaluation: no;standardized CKD risk measurement: no6.34% of patients have chronic renal failureMarti et al, 2005 [22]Study design: Retrospective cohort studyFunding: In part by grant from Fundacio ‘noma’Catalana de Pneumologia and by Red Respira-ISCIII-RTIC-03/11Setting & period: patients with COPD initiating LTOT >15 h/day during 1992–1999 in a tertiary teaching hospital (Vall d’Hebron Hospital, Barcelona, Spain)Patient group: 128 patients, 98.4% male, mean age ± SD 68.9 ± 9.7 yearsDiagnosis of COPD: PFTsCKD definition: not defined, assessed using Charlson indexSelection bias: yes, COPD patients only on long term O2 therapyInformation bias:Objective outcome evaluation: no;standardized CKD risk measurement: no1.6% of patients are reported to have renal diseaseTerzano et al, 2010 [23]Study design: Prospective longitudinal studyFunding:Setting & period: Consecutive COPD patients admitted to four hospitals in Italy for acute exacerbation from 1999 to 2000, and followed up until December 2007Patient group: 288 patients, 78.8% male, mean age 69.2 years (SD ± 6.4)Diagnosis of COPD: standardizedCKD definition: not defined, assessed using Charlson indexSelection bias: yes, patients admitted for acute exacerbationInformation bias:Objective outcome evaluation: no;standardized CKD risk measurement: no26.3% of patients are reported to have chronic renal failur...…”

“…Three of the 9 studies included in meta-analysis utilized nationally representative samples in their respective countries [22, 24, 25]. Only 2 studies reported data on hospitalized patients [19, 26] while the remaining 4 studies included patients from outpatient settings [17, 20, 21, 23]. Of the 10 studies that were excluded from the meta-analysis, six studies reported data on hospitalized patients [18, 27–30, 34]…”

Anaemia in chronic obstructive pulmonary disease: an insight into its prevalence and pathophysiology

“…The study of Incalzi et al [83] among 356 consecutive elderly (>65 years old) COPD outpatients was the first to indicate that 20.8 % of COPD patients presented with reduced estimated glomerular filtration rate (e-GFR) (<60 ml/min per 1.73 m 2 ) and abnormal serum creatinine levels and 22.2 % with reduced e-GFR without abnormal serum creatinine levels. More recent studies have confirmed the high prevalence of microalbuminuria [84] and renal dysfunction among COPD patients compared with controls [85], although rates were lower in younger COPD cohorts [86].…”

Target renal damage: the microvascular associations of increased aortic stiffness in patients with COPD

“…The proportion of patients with COPD having co-existent renal impairment has been highlighted [15,16]. However, identification of renal disease on serum creatinine or creatinine based estimated glomerular filtration rate (eGFR) alone is likely to underestimate the prevalence; further, the eGFR role in an older population has been questioned.…”