title: The duration of sulfonylurea treatment is associated with β-cell dysfunction in patients with type 2 diabetes mellitus.
abstract: BACKGROUND
  This study investigated the incidence of β-cell dysfunction and the clinical and biochemical factors affecting that in patients with type 2 diabetes having more than 3 years of follow-up.
  
  
  METHODS
  β-Cell dysfunction was assessed by measuring changes in the fasting serum C-peptide concentrations. Patients were classified into two groups: cases showing a decreased (Group D) or an unchanged or increased (Group I) C-peptide concentration from the baseline.
  
  
  RESULTS
  Of the 504 patients included in this study, 259 (51%) showed decreased C-peptide concentrations, of whom 20% showed a decrease of ≥50%. Most patients, however, had a final C-peptide concentration of ≥1 ng/mL, with only 18 (4%) individuals having a level <0.6 ng/mL. Patients in Group D had a longer duration of diabetes, higher initial hemoglobin A1c concentration, and longer treatment durations with sulfonylurea and insulin compared with Group I. After adjusting for diabetes duration and C-peptide follow-up period, the duration of sulfonylurea treatment was found to be the only factor independently associated with decreases in the C-peptide concentration.
  
  
  CONCLUSIONS
  Although β-cell function deteriorates over time in patients with type 2 diabetes, these cases mainly have fasting serum C-peptide concentrations of ≥1 ng/mL. A longer treatment duration with sulfonylurea is associated with a more rapid decline in the C-peptide concentration.
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Mi-Seon
authors.initials: MS
authors.lastname: Shin
authors.forename: Jee Hee
authors.initials: JH
authors.lastname: Yu
authors.forename: Chang Hee
authors.initials: CH
authors.lastname: Jung
authors.forename: Jenie Yoonoo
authors.initials: JY
authors.lastname: Hwang
authors.forename: Woo Je
authors.initials: WJ
authors.lastname: Lee
authors.forename: Min-Seon
authors.initials: MS
authors.lastname: Kim
authors.forename: Joong-Yeol
authors.initials: JY
authors.lastname: Park
mesh_terms: D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D002096:C-Peptide / Q000097:blood* / Q000187:drug effects; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy* / Q000503:physiopathology; D005215:Fasting / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D050417:Insulin-Secreting Cells / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D056910:Republic of Korea; D013453:Sulfonylurea Compounds / Q000494:pharmacology*
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D007004:Hypoglycemic Agents; D013453:Sulfonylurea Compounds