title: [Was it necessary to modify the classification of chronic kidney disease stages designed by NKF KDOQI? - "Nefrotest" study results].
abstract: BACKGROUND
  The introduction of the classification of chronic kidney disease (CKD) by NKF KDOQI guidelines in 2002, including the staging and risk assessment of this disease, was a landmark event. The division of CKD into stages 1-5 turned out to be very useful and sensitive tool in the hands of both scientists and clinical practitioners; it established common nomenclature pertaining to CKD all over the world. This stratification profoundly changed the approach to CKD, transforming it from a somewhat neglected clinical problem to the phenomenon named "the epidemic of CKD". However, after a short period if clinical experience a heated debate was initiated in the literature, indicating the shortcomings of the adopted classification. The most questionable areas included methodological issues as well as dissimilar prognoses for patients depending on the cause of kidney dysfunction, the presence of proteinuria and comorbidities.
  
  
  OBJECTIVE
  The aim of this study was to evaluate the prevalence of CKD and the risk factors based on NKF KDOQI classification of 2002 in the population of Ostróda administrative district.
  
  
  METHODS
  In total 437 individuals (F 277, M 160) aged 52.7±18.0 were examined. The study was conducted in Ostróda among randomly selected inhabitants of Ostróda adminstrative district. Serum creatinine was determined by a modified Jaffe method and eGFR was calculated (MDRD formula) for each individual. The correlations between serum creatinine and eGFR, gender and age were studied. Additionally, 326 of the examined participants were interviewed to establish CKD risk factors: kidney disease in the family, being overweight and/or obese, arterial hypertension, diabetes, smoking, heart attack, stroke.
  
  
  RESULTS
  58.6% of the examined individuals demonstrated abnormal eGFR values (<90 ml/min/l.73 m2), whereas serum creatinine above the laboratory norm was found in 1.3% of patients. Significant CKD risk factors included an increased prevalence of obesity (78.3%), arterial hypertension (38.6%), and smoking (26.8%); 23.9% reported kidney disease in the family.
  
  
  CONCLUSIONS
  Based on our study, it can be concluded that CKD prevalence evaluated according to the classification of 2002 seems to be overestimated, and the main factor contributing to a false CKD diagnosis is a physiological decline in eGFR values with aging. The modification of CKD classification carried out by NKF in 2012 requires further observation and evaluation of its usefulness in daily clinical practice.
authors.forename: Beata
authors.initials: B
authors.lastname: Januszko-Giergielewicz
authors.forename: Monika
authors.initials: M
authors.lastname: Kubiak
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Bednarski
authors.forename: Jakub
authors.initials: J
authors.lastname: Piotrkowski
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Giergielewiczi
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Smyk
authors.forename: Jerzy
authors.initials: J
authors.lastname: Romaszko
authors.forename: Leszek
authors.initials: L
authors.lastname: Gromadziński
mesh_terms: D000328:Adult; D000368:Aged; D015984:Causality; D015897:Comorbidity; D003951:Diagnostic Errors; D005189:False Positive Reactions; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology; D011044:Poland; D017410:Practice Guidelines as Topic; D015995:Prevalence; D011507:Proteinuria / Q000453:epidemiology; D051436:Renal Insufficiency, Chronic / Q000145:classification* / Q000175:diagnosis / Q000453:epidemiology*; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D009626:Terminology as Topic