title: Relative contributions of insulin resistance and β-cell dysfunction to the development of Type 2 diabetes in Koreans.
abstract: OBJECTIVE
  Controversies still exist regarding the relative contributions of insulin resistance and β-cell dysfunction to the pathogenesis of Type 2 diabetes in different populations. We examined the associations of baseline insulin resistance and β-cell function indices with the development of Type 2 diabetes in Koreans.
  
  
  METHODS
  We analysed the clinical and laboratory data of 17 878 Korean adults (age 20-79 years) who underwent routine medical examinations with a median interval of 3.5 years (range 2.5-4.7 years). Using the homeostasis model assessment, insulin resistance (HOMA-IR) and β-cell function (HOMA-%B) indices at baseline were assessed.
  
  
  RESULTS
  Those who developed diabetes (n = 732, 4.1%) had significantly higher fasting serum insulin level (53.4 ± 31.2 vs. 41.4 ± 23.4 pmol/l) and HOMA-IR (2.38 ± 1.45 vs. 1.65 ± 1.02) and lower HOMA-%B (74 ± 47 vs. 85 ± 48) at baseline (P < 0.001 for all). Both high HOMA-IR and low HOMA-%B were independently associated with an increased odds ratio of incident Type 2 diabetes. Among the participants who developed diabetes, 29% demonstrated predominant β-cell dysfunction (HOMA-%B < 25th percentile) and 51% had predominant insulin resistance (HOMA-IR > 75th percentile). When we divided the participants according to the median BMI of the whole population (23.7 kg/m²), 49% of participants in the low BMI group demonstrated predominant β-cell dysfunction and 26% had predominant insulin resistance, whilst 21% in the high BMI group demonstrated mainly β-cell dysfunction and 60% had mainly insulin resistance.
  
  
  CONCLUSIONS
  In individuals with low BMI, β-cell dysfunction is the predominant defect, whereas insulin resistance is the predominant pathogenetic factor in individuals with high BMI in the development of Type 2 diabetes in Koreans.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Soonchunhyang University College of Medicine, Bucheon.
authors.forename: C-H
authors.initials: CH
authors.lastname: Kim
authors.forename: H-K
authors.initials: HK
authors.lastname: Kim
authors.forename: E H
authors.initials: EH
authors.lastname: Kim
authors.forename: S J
authors.initials: SJ
authors.lastname: Bae
authors.forename: J-Y
authors.initials: JY
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000453:epidemiology / Q000208:ethnology / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance / Q000208:ethnology; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D050177:Overweight / Q000150:complications* / Q000208:ethnology; D011236:Prediabetic State / Q000150:complications / Q000453:epidemiology / Q000208:ethnology / Q000503:physiopathology*; D015995:Prevalence; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D055815:Young Adult
chemical_list: D007328:Insulin