title: Changing Clinical Characteristics according to Insulin Resistance and Insulin Secretion in Newly Diagnosed Type 2 Diabetic Patients in Korea.
abstract: BACKGROUND
  The role of increased insulin resistance in the pathogenesis of type 2 diabetes has been emphasized in Asian populations. Thus, we evaluated the proportion of insulin resistance and the insulin secretory capacity in patients with early phase type 2 diabetes in Korea.
  
  
  METHODS
  We performed a cross-sectional analysis of 1,314 drug-naive patients with newly diagnosed diabetes from primary care clinics nationwide. The homeostasis model assessment of insulin resistance (HOMA-IR) was used as an index to measure insulin resistance, which was defined as a HOMA-IR ≥2.5. Insulin secretory defects were classified based on fasting plasma C-peptide levels: severe (<1.1 ng/mL), moderate (1.1 to 1.7 ng/mL) and mild to non-insulin secretory defect (≥1.7 ng/mL).
  
  
  RESULTS
  The mean body mass index (BMI) was 25.2 kg/m(2); 77% of patients had BMIs >23.0 kg/m(2). Up to 50% of patients had central obesity based on their waist circumference (≥90 cm in men and 85 cm in women), and 70.6% had metabolic syndrome. Overall, 59.5% of subjects had insulin resistance, and 20.2% demonstrated a moderate to severe insulin secretory defect. Among those with insulin resistance, a high proportion of subjects (79.0%) had a mild or no insulin secretory defect. Only 2.6% of the men and 1.9% of the women had both insulin resistance and a moderate to severe insulin secretory defect.
  
  
  CONCLUSIONS
  In this study, patients with early phase type 2 diabetes demonstrated increased insulin resistance, but preserved insulin secretion, with a high prevalence of obesity and metabolic syndrome.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Bucheon, Korea.
authors.forename: Jang Won
authors.initials: JW
authors.lastname: Son
authors.affiliation: Department of Endocrinology and Metabolism, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Cheol-Young
authors.initials: CY
authors.lastname: Park
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Bucheon, Korea.
authors.forename: Sungrae
authors.initials: S
authors.lastname: Kim
authors.affiliation: GlaxoSmithKline, Seoul, Korea.
authors.forename: Han-Kyu
authors.initials: HK
authors.lastname: Lee
authors.affiliation: GlaxoSmithKline, Seoul, Korea.
authors.forename: Yil-Seob
authors.initials: YS
authors.lastname: Lee
keywords: Diabetes mellitus, type 2; Insulin resistance; Obesity