title: Disease burden and risk profile in referred patients with moderate chronic kidney disease: composition of the German Chronic Kidney Disease (GCKD) cohort.
abstract: BACKGROUND
  A main challenge for targeting chronic kidney disease (CKD) is the heterogeneity of its causes, co-morbidities and outcomes. Patients under nephrological care represent an important reference population, but knowledge about their characteristics is limited.
  
  
  METHODS
  We enrolled 5217 carefully phenotyped patients with moderate CKD [estimated glomerular filtration rate (eGFR) 30-60 mL/min per 1.73 m(2) or overt proteinuria at higher eGFR] under routine care of nephrologists into the German Chronic Kidney Disease (GCKD) study, thereby establishing the currently worldwide largest CKD cohort.
  
  
  RESULTS
  The cohort has 60% men, a mean age (±SD) of 60 ± 12 years, a mean eGFR of 47 ± 17 mL/min per 1.73 m(2) and a median (IQR) urinary albumin/creatinine ratio of 51 (9-392) mg/g. Assessment of causes of CKD revealed a high degree of uncertainty, with the leading cause unknown in 20% and frequent suspicion of multifactorial pathogenesis. Thirty-five per cent of patients had diabetes, but only 15% were considered to have diabetic nephropathy. Cardiovascular disease prevalence was high (32%, excluding hypertension); prevalent risk factors included smoking (59% current or former smokers) and obesity (43% with BMI >30). Despite widespread use of anti-hypertensive medication, only 52% of the cohort had an office blood pressure <140/90 mmHg. Family histories for cardiovascular events (39%) and renal disease (28%) suggest familial aggregation.
  
  
  CONCLUSIONS
  Patients with moderate CKD under specialist care have a high disease burden. Improved diagnostic accuracy, rigorous management of risk factors and unravelling of the genetic predisposition may represent strategies for improving prognosis.
authors.affiliation: Department of Nephrology and Hypertension, Friedrich-Alexander University Erlangen-Nürnberg, FAU, Erlangen, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Titze
authors.affiliation: Department of Medical Informatics, Biometry and Epidemiology, University of Erlangen-Nürnberg, Erlangen, Germany Department of Medical Biometry, Informatics, and Epidemiology, (IMBIE), University of Bonn, Bonn, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Schmid
authors.affiliation: Division of Nephrology, University of Freiburg, Freiburg, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Köttgen
authors.affiliation: Department of Internal Medicine III, University Hospital Jena, Jena, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Busch
authors.affiliation: Department of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Floege
authors.affiliation: Division of Nephrology, Department of Medicine, University Hospital of Würzburg, Würzburg, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Wanner
authors.affiliation: Division of Genetic Epidemiology, Department of Medical Genetics, Molecular and Clinical Pharmacology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Florian
authors.initials: F
authors.lastname: Kronenberg
authors.affiliation: Department of Nephrology and Hypertension, Friedrich-Alexander University Erlangen-Nürnberg, FAU, Erlangen, Germany.
authors.forename: Kai-Uwe
authors.initials: KU
authors.lastname: Eckardt
mesh_terms: D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000209:etiology / Q000503:physiopathology*; D015331:Cohort Studies; D015897:Comorbidity; D003928:Diabetic Nephropathies / Q000175:diagnosis* / Q000209:etiology; D005260:Female; D005858:Germany; D005919:Glomerular Filtration Rate; D006801:Humans; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011507:Proteinuria / Q000175:diagnosis* / Q000209:etiology; D012017:Referral and Consultation; D051436:Renal Insufficiency, Chronic / Q000150:complications / Q000503:physiopathology*; D012307:Risk Factors
keywords: cardiovascular disease; chronic kidney disease; epidemiology; nephrology referral