title: Evaluation of beta cell dysfunction by mixed meal tolerance test and oral L-arginine in patients with newly diagnosed type 2 diabetes mellitus.
abstract: OBJECTIVE
  Defective insulin secretion is required for the development of frank diabetes mellitus. We evaluated the secretory response of pancreatic beta cells after the ingestion of mixed meal plus oral L-arginine in newly diagnosed type 2 diabetic patients.
  
  
  METHODS
  Twenty-four newly diagnosed type 2 diabetic patients were enrolled in this study. All patients were ingested a mixed meal of 553 kcal. Serum insulin levels were measured at time 0 just before the mixed meal and at 1, 2, 3, 4 and 5 h after the ingestion of the mixed meal. Twenty-four hours later, all patients ingested mixed meal followed by oral 8 g L-Arginine, and insulin levels were again measured at 0, 1, 2, 3, 4 and 5 h after the ingestion of the meal.
  
  
  RESULTS
  Insulin levels reached to peak values at the 2 (nd) hour, and decreased to baseline levels at the 5 (th) hour measurements both after the ingestion of mixed meal only and after the ingestion of mixed meal plus oral L-Arginine. First and 2 (nd) hour insulin levels were significantly higher after the ingestion of mixed meal plus oral L-Arginine.
  
  
  CONCLUSIONS
  In this study we used for the first time the combination of oral L-arginine with mixed meal test to evaluate the beta cell dysfunction in type 2 diabetic patients. Increments regarding serum insulin levels after the ingestion of mixed meal plus oral L-Arginine suggest that oral L-Arginine could be benefical for the evaluation of beta cell function and secretory defects.
authors.affiliation: Ege University Faculty of Medicine, Department of Endocrinology and Metabolism, Izmir, Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Ozbek
authors.forename: M
authors.initials: M
authors.lastname: Erdogan
authors.forename: M
authors.initials: M
authors.lastname: Karadeniz
authors.forename: S
authors.initials: S
authors.lastname: Cetinkalp
authors.forename: A G
authors.initials: AG
authors.lastname: Ozgen
authors.forename: F
authors.initials: F
authors.lastname: Saygili
authors.forename: C
authors.initials: C
authors.lastname: Yilmaz
authors.forename: M
authors.initials: M
authors.lastname: Tuzun
mesh_terms: D000328:Adult; D001120:Arginine / Q000008:administration & dosage*; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis / Q000378:metabolism* / Q000503:physiopathology; D004435:Eating; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood* / Q000378:metabolism; D000078790:Insulin Secretion; D008297:Male; D008875:Middle Aged; D013997:Time Factors
chemical_list: D007328:Insulin; D001120:Arginine