title: Residual insulin production and pancreatic ß-cell turnover after 50 years of diabetes: Joslin Medalist Study.
abstract: OBJECTIVE
  To evaluate the extent of pancreatic β-cell function in a large number of insulin-dependent diabetic patients with a disease duration of 50 years or longer (Medalists).
  
  
  METHODS
  Characterization of clinical and biochemical parameters and β-cell function of 411 Medalists with correlation with postmortem morphologic findings of 9 Medalists.
  
  
  RESULTS
  The Medalist cohort, with a mean ± SD disease duration and age of 56.2 ± 5.8 and 67.2 ± 7.5 years, respectively, has a clinical phenotype similar to type 1 diabetes (type 1 diabetes): mean ± SD onset at 11.0 ± 6.4 years, BMI at 26.0 ± 5.1 kg/m(2), insulin dose of 0.46 ± 0.2 u/kg, ∼94% positive for DR3 and/or DR4, and 29.5% positive for either IA2 or glutamic acid decarboxylase (GAD) autoantibodies. Random serum C-peptide levels showed that more than 67.4% of the participants had levels in the minimal (0.03-0.2 nmol/l) or sustained range (≥ 0.2 nmol/l). Parameters associated with higher random C-peptide were lower hemoglobin A1C, older age of onset, higher frequency of HLA DR3 genotype, and responsiveness to a mixed-meal tolerance test (MMTT). Over half of the Medalists with fasting C-peptide > 0.17 nmol/l responded in MMTT by a twofold or greater rise over the course of the test compared to fasting. Postmortem examination of pancreases from nine Medalists showed that all had insulin+ β-cells with some positive for TUNEL staining, indicating apoptosis.
  
  
  CONCLUSIONS
  Demonstration of persistence and function of insulin-producing pancreatic cells suggests the possibility of a steady state of turnover in which stimuli to enhance endogenous β cells could be a viable therapeutic approach in a significant number of patients with type 1 diabetes, even for those with chronic duration.
authors.affiliation: Research Division, Joslin Diabetes Center, Boston, Massachusetts, USA.
authors.forename: Hillary A
authors.initials: HA
authors.lastname: Keenan
authors.forename: Jennifer K
authors.initials: JK
authors.lastname: Sun
authors.forename: Jared
authors.initials: J
authors.lastname: Levine
authors.forename: Alessandro
authors.initials: A
authors.lastname: Doria
authors.forename: Lloyd P
authors.initials: LP
authors.lastname: Aiello
authors.forename: George
authors.initials: G
authors.lastname: Eisenbarth
authors.forename: Susan
authors.initials: S
authors.lastname: Bonner-Weir
authors.forename: George L
authors.initials: GL
authors.lastname: King
mesh_terms: D000368:Aged; D001363:Awards and Prizes; D002096:C-Peptide / Q000097:blood; D015331:Cohort Studies; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy / Q000235:genetics / Q000503:physiopathology*; D005260:Female; D006683:HLA-DQ Antigens / Q000235:genetics; D059866:HLA-DQ beta-Chains; D006684:HLA-DR Antigens / Q000235:genetics; D059811:HLA-DRB1 Chains; D006801:Humans; D007328:Insulin / Q000032:analysis / Q000096:biosynthesis* / Q000627:therapeutic use; D050417:Insulin-Secreting Cells / Q000378:metabolism / Q000473:pathology / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009717:Numismatics; D010641:Phenotype; D013997:Time Factors; D009927:Tissue and Organ Procurement
chemical_list: D002096:C-Peptide; D006683:HLA-DQ Antigens; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D007328:Insulin