title: Estimating individual glomerular volume in the human kidney: clinical perspectives.
abstract: BACKGROUND
  Measurement of individual glomerular volumes (IGV) has allowed the identification of drivers of glomerular hypertrophy in subjects without overt renal pathology. This study aims to highlight the relevance of IGV measurements with possible clinical implications and determine how many profiles must be measured in order to achieve stable size distribution estimates.
  
  
  METHODS
  We re-analysed 2250 IGV estimates obtained using the disector/Cavalieri method in 41 African and 34 Caucasian Americans. Pooled IGV analysis of mean and variance was conducted. Monte-Carlo (Jackknife) simulations determined the effect of the number of sampled glomeruli on mean IGV. Lin's concordance coefficient (R(C)), coefficient of variation (CV) and coefficient of error (CE) measured reliability.
  
  
  RESULTS
  IGV mean and variance increased with overweight and hypertensive status. Superficial glomeruli were significantly smaller than juxtamedullary glomeruli in all subjects (P < 0.01), by race (P < 0.05) and in obese individuals (P < 0.01). Subjects with multiple chronic kidney disease (CKD) comorbidities showed significant increases in IGV mean and variability. Overall, mean IGV was particularly reliable with nine or more sampled glomeruli (R(C) > 0.95, <5% difference in CV and CE). These observations were not affected by a reduced sample size and did not disrupt the inverse linear correlation between mean IGV and estimated total glomerular number.
  
  
  CONCLUSIONS
  Multiple comorbidities for CKD are associated with increased IGV mean and variance within subjects, including overweight, obesity and hypertension. Zonal selection and the number of sampled glomeruli do not represent drawbacks for future longitudinal biopsy-based studies of glomerular size and distribution.
authors: Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia.
authors: Victor G
authors: VG
authors: Puelles
authors: Monika A
authors: MA
authors: Zimanyi
authors: Terence
authors: T
authors: Samuel
authors: Michael D
authors: MD
authors: Hughson
authors: Rebecca N
authors: RN
authors: Douglas-Denton
authors: John F
authors: JF
authors: Bertram
authors: James A
authors: JA
authors: Armitage
mesh_terms: D000328:Adult; D001741:Black or African American; D000704:Analysis of Variance; D001344:Autopsy; D001706:Biopsy; D002908:Chronic Disease; D015331:Cohort Studies; D015897:Comorbidity; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000473:pathology*; D007674:Kidney Diseases / Q000453:epidemiology / Q000473:pathology*; D007678:Kidney Glomerulus / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology / Q000473:pathology*; D009929:Organ Size; D050177:Overweight / Q000453:epidemiology / Q000473:pathology*; D012189:Retrospective Studies; D044465:White People