title: Renal "hyperfiltrators" are at elevated risk of death and chronic diseases.
abstract: BACKGROUND
  The definition of glomerular hyperfiltration has not been agreed upon and the pathophysiological mechanisms have not been well explored. Low serum creatinine concentrations may be associated with increased risk of coronary heart disease (CHD) or cardiopulmonary events the impact of which needs further study.
  
  
  METHODS
  Consecutive applicants to a cardiovascular hospital free of moderate/severe chronic kidney disease (age 55.6 ± 8.2 years) were grouped into those without ("healthy", n = 469) and with CHD (320 stable and acute coronary syndrome cases) at baseline and into sex-specific quartiles of CKD-EPI equation-estimated glomerular filtration rate (eGFR). New or recurrent cardiovascular (myocardial infarction, stroke, heart failure [HF]) events, obstructive pulmonary disease (COPD) and death were determined during 3-years' follow-up.
  
  
  RESULTS
  Among 25 deaths and 75 cardiopulmonary events, HF was the leading nonfatal event. Age, serum uric acid and left ventricular ejection fraction proved the best independent inverse covariates of eGFR in the "healthy" sample. The highest eGFR quartile ("hyperfiltrators"), exhibiting significantly lower serum LDL-cholesterol levels, significantly predicted the combined outcome (at a RR of 6) in "healthy" subjects, after adjustment for sex, age, body mass index, smoking status and presence of hypertension. This finding was paralleled by the highest eGFR quartile calculated also by the MDRD equation, replicating this also in the CHD group.
  
  
  CONCLUSIONS
  Renal "hyperfiltrators" represent individuals with autoimmune activation (involving serum creatinine, partly escaping assay), are misclassified into optimal renal function and actually are at significantly higher risk of death, HF or cardiopulmonary events. Low serum creatinine levels may represent a clue to the existence of autoimmune activation.
authors.affiliation: Cardiology, Siyami Ersek Center for Cardiovascular Surgery, Istanbul, Turkey. svtaltay@gmail.com.
authors.forename: Servet
authors.initials: S
authors.lastname: Altay
authors.forename: Altan
authors.initials: A
authors.lastname: Onat
authors.forename: Fatma
authors.initials: F
authors.lastname: Özpamuk-Karadeniz
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Karadeniz
authors.forename: Tuğba
authors.initials: T
authors.lastname: Kemaloğlu-Öz
authors.forename: Günay
authors.initials: G
authors.lastname: Can
mesh_terms: D000328:Adult; D000368:Aged; D015551:Autoimmunity; D001794:Blood Pressure; D015992:Body Mass Index; D002423:Cause of Death; D008078:Cholesterol, LDL / Q000097:blood; D002908:Chronic Disease / Q000453:epidemiology; D003327:Coronary Disease / Q000453:epidemiology / Q000503:physiopathology; D003404:Creatinine / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006333:Heart Failure / Q000453:epidemiology; D006801:Humans; D007249:Inflammation; D007678:Kidney Glomerulus / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009026:Mortality; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology / Q000503:physiopathology; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D014527:Uric Acid / Q000097:blood
chemical_list: D008078:Cholesterol, LDL; D014527:Uric Acid; D003404:Creatinine