title: Longitudinal Study of the Decline in Renal Function in Healthy Subjects.
abstract: BACKGROUND
  Chronic kidney disease is an important concern in preventive medicine, but the rate of decline in renal function in healthy population is not well defined. The purpose of this study was to determine reference values for the estimated glomerular filtration rate (eGFR) and rate of decline of eGFR in healthy subjects and to evaluate factors associated with this decline using a large cohort in Japan.
  
  
  METHODS
  Retrospective cross-sectional and longitudinal studies were performed with healthy subjects aged ≥18 years old who received a medical checkup. Reference values for eGFR were obtained using a nonparametric method and those for decline of eGFR were calculated by mixed model analysis. Relationships of eGFR decline rate with baseline variables were examined using a linear least-squares method.
  
  
  RESULTS
  In the cross-sectional study, reference values for eGFR were obtained by gender and age in 72,521 healthy subjects. The mean (±SD) eGFR was 83.7±14.7 ml/min/1.73 m2. In the longitudinal study, reference values for eGFR decline rate were obtained by gender, age, and renal stage in 45,586 healthy subjects. In the same renal stage, there was little difference in the rate of decline regardless of age. The decline in eGFR depended on the renal stage and was strongly related to baseline eGFR, with a faster decline with a higher baseline eGFR and a slower decline with a lower baseline eGFR. The mean (±SD) eGFR decline rate was ‒1.07±0.42 ml/min/1.73 m2/year (‒1.29±0.41%/year) in subjects with a mean eGFR of 81.5±11.6 ml/min/1.73 m2.
  
  
  CONCLUSIONS
  The present study clarified for the first time the reference values for the rate of eGFR decline stratified by gender, age, and renal stage in healthy subjects. The rate of eGFR decline depended mainly on baseline eGFR, but not on age, with a slower decline with a lower baseline eGFR.
authors.affiliation: Center for Preventive Medicine, St. Luke's Affiliated Clinic, St. Luke's International University, Tokyo, Japan.
authors.forename: Mika
authors.initials: M
authors.lastname: Baba
authors.affiliation: Ohta Nishinouchi Hospital, Koriyama, Japan.
authors.forename: Takuro
authors.initials: T
authors.lastname: Shimbo
authors.affiliation: Department of Functional Diagnostic Science, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Horio
authors.affiliation: Center for Advanced Medicine and Clinical Research, Nagoya University Hospital, Nagoya, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Ando
authors.affiliation: Department of Nephrology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Yasuda
authors.affiliation: Division of Nephrology, Department of Medicine, St. Luke's Hospital, St. Luke's International University, Tokyo, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Komatsu
authors.affiliation: Center for Preventive Medicine, St. Luke's Affiliated Clinic, St. Luke's International University, Tokyo, Japan.
authors.forename: Katsunori
authors.initials: K
authors.lastname: Masuda
authors.affiliation: Department of Nephrology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Seiichi
authors.initials: S
authors.lastname: Matsuo
authors.affiliation: Department of Nephrology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Shoichi
authors.initials: S
authors.lastname: Maruyama
mesh_terms: D000328:Adult; D000367:Age Factors; D003430:Cross-Sectional Studies; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D064368:Healthy Volunteers; D006801:Humans; D007564:Japan; D007668:Kidney / Q000503:physiopathology*; D007677:Kidney Function Tests / Q000379:methods / Q000592:standards*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012189:Retrospective Studies; D012737:Sex Factors