title: Islet number rather than islet size is a major determinant of β- and α-cell mass in humans.
abstract: OBJECTIVE
  The objective of the study was to clarify the relative contribution of islet number and islet size to β- and α-cell mass in humans.
  
  
  METHODS
  We obtained the pancreas at autopsy from 72 Japanese adults with no history of diabetes or pancreatitis (aged 47 ± 12 years, body mass index 24.1 ± 5.0 kg/m(2)). Pancreatic sections were stained for insulin or glucagon, and fractional β-cell area (%BCA) and α-cell area (%ACA) were measured. Islet number and islet size as well as β-cell turnover were also quantified. Glycosylated hemoglobin measured within 1 year prior to death was obtained in 38 individuals.
  
  
  RESULTS
  There was considerable interindividual variation in islet density and mean islet size, with a significant negative correlation between the two (r = -0.25, P = .03). There were significant positive correlations between islet density and %BCA or %ACA (r = 0.63, P < .001, and r = 0.41, P = .001), whereas mean islet size correlated with neither of them. Islet density as well as %BCA, but not mean islet size, was negatively correlated with glycosylated hemoglobin (r = -0.37, P = .02, and r = -0.36, P = .03).
  
  
  CONCLUSIONS
  The present study suggests that islet number rather than islet size is a major determinant of β- and α-cell mass in humans. Interindividual difference in islet number may contribute to susceptibility to development of glucose intolerance.
authors: Departments of Internal Medicine (K.K., Y.S., S.S., H.I.) and Pathology (T.Y.), Keio University School of Medicine, Tokyo 160-8582, Japan.
authors: Kinsei
authors: K
authors: Kou
authors: Yoshifumi
authors: Y
authors: Saisho
authors: Seiji
authors: S
authors: Sato
authors: Taketo
authors: T
authors: Yamada
authors: Hiroshi
authors: H
authors: Itoh
mesh_terms: D000328:Adult; D000368:Aged; D002452:Cell Count; D005260:Female; D050416:Glucagon-Secreting Cells / Q000166:cytology*; D006801:Humans; D050417:Insulin-Secreting Cells / Q000166:cytology*; D007515:Islets of Langerhans / Q000166:cytology*; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D010179:Pancreas / Q000033:anatomy & histology* / Q000166:cytology