title: Determinants and functional significance of renal parenchymal volume in adults.
abstract: OBJECTIVE
  The significance of renal parenchymal volume and the factors that influence it are poorly understood.
  
  
  METHODS
  Renal parenchymal volume (RPV) was measured on contrast-enhanced CT scans after exclusion of sinus fat and vessels in 224 healthy subjects evaluated as kidney donors and in a separate cohort of 22 severely obese individuals before and after 6 months of weight loss. GFR was measured by iohexol clearance in 76 of the transplant donors. RPV was correlated with age, GFR, and various anthropometric parameters.
  
  
  RESULTS
  In potential transplant donors, RPV correlated with body surface area (BSA; r = 0.68) and was 7% larger in men but did not vary with age or race. Gender and body size were independent determinants of RPV. RPV correlated well with GFR (r = 0.62) and accounted for almost all of the variability in a model of GFR that included age, race, gender, and body surface area. GFR correlated more strongly with RPV than with creatinine-based equations. The same relationship between RPV and BSA was observed in obesity, and RPV decreased with weight loss.
  
  
  CONCLUSIONS
  In healthy adults younger than 65 years, renal parenchymal volume is governed by body size and gender but not age or race and is strongly correlated with GFR. This indicates that renal parenchymal volume varies to meet metabolic demand and is closely linked to renal function.
authors.affiliation: Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
authors.forename: Samuel
authors.initials: S
authors.lastname: Johnson
authors.forename: Rahul
authors.initials: R
authors.lastname: Rishi
authors.forename: Andreea
authors.initials: A
authors.lastname: Andone
authors.forename: Wassim
authors.initials: W
authors.lastname: Khawandi
authors.forename: Jafar
authors.initials: J
authors.lastname: Al-Said
authors.forename: Nana
authors.initials: N
authors.lastname: Gletsu-Miller
authors.forename: Edward
authors.initials: E
authors.lastname: Lin
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Baumgarten
authors.forename: W Charles
authors.initials: WC
authors.lastname: O'Neill
mesh_terms: D000328:Adult; D049628:Body Size; D001830:Body Surface Area; D003404:Creatinine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011859:Radiography
chemical_list: D003404:Creatinine