title: A longitudinal assessment of the natural rate of decline in renal function with age.
abstract: BACKGROUND
  Cross-sectional studies have long suggested that renal function declines with age. Longitudinal studies regarding this issue are limited.
  
  
  METHODS
  We retrospectively analyzed a database of subjects attending a screening center in Israel between the years 2000-2012. Only subjects with normal estimated glomerular filtration rate (eGFR) were included. eGFR was assessed consequently at 5 or more yearly visits. The rate of decline in GFR with age was assessed in healthy subjects and in subjects with comorbidities.
  
  
  RESULTS
  The cohort included 2693 healthy subjects and 230 subjects with different comorbidities. Mean (±standard error) annual rate of decline in eGFR in healthy subjects was 0.97 ± 0.02 ml/min/year/1.73 m(2). This decline increased significantly from 0.82 ± 0.22 in age-group 20-30 years to 0.84 ± 0.08, 1.07 ± 0.08 and 1.15 ± 0.12 ml/min/year/1.73 m(2) in age groups 31-40, 41-50 and 50 years and older respectively (p < 0.001). No correlation was found between the annual decline in eGFR and body mass index. In subjects with hypertension, diabetes mellitus, impaired fasting glucose or combined comorbidity the decline in eGFR was 1.12 ± 0.12, 0.77 ± 0.16, 0.85 ± 0.17, and 1.18 ± 0.26 ml/min/year/1.73 m(2) respectively.
  
  
  CONCLUSIONS
  This large longitudinal study provides new data on the decrease in eGFR with age. Accurate prediction of the natural rate of GFR decline might be used to distinguish between normally aging kidneys and those with chronic disease. This approach could avoid unnecessary diagnostic procedures in the former and facilitate appropriate treatment in the latter.
authors.affiliation: Department of Medicine F-Recanati, Rabin Medical Center (Beilinson Campus), 49100, Petah Tikva, Israel. dreytancohen@gmail.com.|Clinical Pharmacology Unit, Rabin Medical Center (Beilinson Campus), Petah Tikva, Israel. dreytancohen@gmail.com.|Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel. dreytancohen@gmail.com.
authors.forename: Eytan
authors.initials: E
authors.lastname: Cohen
authors.affiliation: Faculty of Industrial Engineering and Management, Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Yuval
authors.initials: Y
authors.lastname: Nardi
authors.affiliation: Nephrology Institute and Dialysis Unit, Schneider's Children Medical Center of Israel Petah Tikva, Petah Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel.
authors.forename: Irit
authors.initials: I
authors.lastname: Krause
authors.affiliation: Department of Medicine F-Recanati, Rabin Medical Center (Beilinson Campus), 49100, Petah Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel.
authors.forename: Elad
authors.initials: E
authors.lastname: Goldberg
authors.affiliation: Nephrology Unit, Rabin Medical Center (Beilinson Campus), Petah Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel.
authors.forename: Gai
authors.initials: G
authors.lastname: Milo
authors.affiliation: Recanati Center for Preventive Medicine, Rabin Medical Center (Beilinson Campus), Petah Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel.
authors.forename: Moshe
authors.initials: M
authors.lastname: Garty
authors.affiliation: Department of Medicine F-Recanati, Rabin Medical Center (Beilinson Campus), 49100, Petah Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel.
authors.forename: Ilan
authors.initials: I
authors.lastname: Krause
mesh_terms: D000328:Adult; D000367:Age Factors; D000375:Aging; D015897:Comorbidity; D016208:Databases, Factual; D003920:Diabetes Mellitus / Q000453:epidemiology; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D007557:Israel / Q000453:epidemiology; D007668:Kidney / Q000503:physiopathology*; D007674:Kidney Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors
keywords: Estimated GFR; Longitudinal study; Renal function decline