title: Change of glomerular filtration rate in healthy adults with aging.
abstract: OBJECTIVE
  In order to determine the relationship between glomerular filtration rate (GFR) and age, the associated factors, and the accurate method of GFR in healthy adults, we conducted a cross-sectional study in community-dwelling adults in Beijing.
  
  
  METHODS
  Renal function of 201 clinically healthy subjects was determined using technetium-99 m-labelled diethylene triamine pentacetic acid ((99m)Tc-DTPA). Estimated GFR was calculated with the Cockcroft-Gault (CG) equation, abbreviated Modification of Diet in Renal Disease (MDRD) equation, and plasma clearance of creatinine (Ccr). Serum cystatin C, biomarkers of inflammatory and endothelial cells were analyzed as well. Protein intake, carotid artery intima-media thickness and plaque formation were assayed as well.
  
  
  RESULTS
  Glomerular filtration rate was negatively associated with age and the correlation coefficient for (99m)Tc-GFR, CG-GFR, MDRD-GFR, Ccr were -0.643, -0.736, -0.55 and -0.619, respectively (P < 0.001), while the correlation coefficient between cystatin C and age was 0.681 (P < 0.001). Estimated GFR were associated with measured GFR, and the correlation coefficient for Ccr, CG-GFR and MDRD-GFR were 0.813, 0.582 and 0.418, respectively (P < 0.001). The area under the receiver-operator curve of Ccr was larger, CG was smaller while MDRD was the smallest, and the difference was significant (P < 0.001). So a predicted equation was presented by cystatin C and C-reactive protein for the elderly.
  
  
  CONCLUSIONS
  In the clinically healthy adults, GFR declined with age. MDRD and CG equation are not suitable to estimate GFR in healthy adults. The predicted equation established by cystatin C and C-reactive protein may be more accurate.
authors.affiliation: Institute of Nephrology of PLA, General Hospital of PLA, Beijing, China.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Sun
authors.forename: Yunshuang
authors.initials: Y
authors.lastname: Chen
authors.forename: Xiangmei
authors.initials: X
authors.lastname: Chen
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Wang
authors.forename: Chunsheng
authors.initials: C
authors.lastname: Xi
authors.forename: Shupeng
authors.initials: S
authors.lastname: Lin
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D050197:Atherosclerosis / Q000503:physiopathology; D002097:C-Reactive Protein / Q000032:analysis; D055316:Cystatin C / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D016284:Technetium Tc 99m Pentetate
chemical_list: D055316:Cystatin C; D002097:C-Reactive Protein; D016284:Technetium Tc 99m Pentetate