title: Twenty-four-hour profiles of plasma glucose, insulin, C-peptide and free fatty acid in subjects with varying degrees of glucose tolerance following short-term, medium-dose prednisone (20 mg/day) treatment: evidence for differing effects on insulin secretion and action.
abstract: OBJECTIVE
  To determine the time course and prandial effects of short-term, medium-dose prednisone on 24-h metabolic patterns under standardized conditions.
  
  
  BACKGROUND
  Glucocorticoids (GCs) adversely affect glucose homoeostasis but 24-h profiles of glucose, insulin, C-peptide and free fatty acids (FFAs) following short-term, medium-dose prednisone treatment in persons with varying degrees of glucose tolerance are not well defined.
  
  
  METHODS
  An open-label cross-sectional interventional study.
  
  
  METHODS
  Three groups were prospectively studied: persons with type 2 diabetes (T2DM; n = 7), persons 'at risk' for T2DM (AR; n = 8) and persons with normal glucose tolerance (NGT; n = 5).
  
  
  METHODS
  Before and after 3-day treatment with prednisone 20 mg each morning, subjects underwent 24-h frequent blood sampling. Eucaloric mixed meals were provided at 08:00, 12:00 and 18:00 h. Insulin/glucose ratio provided an estimate of β-cell response to meal stimuli.
  
  
  METHODS
  Plasma glucose, insulin, C-peptide, haemoglobin A1c and FFA.
  
  
  RESULTS
  Prednisone induced greater increases in glucose levels from midday (P = 0·001) to midnight (P = 0·02) in the T2DM than the AR and NGT groups. In contrast, insulin (P = 0·03) and C-peptide (P = 0·04) levels decreased postbreakfast in the T2DM group, whereas no changes in the morning but higher C-peptide levels (P = 0·03) from midday to midnight were observed in the AR group. In the T2DM group, insulin/glucose ratio decreased postbreakfast (P = 0·04) and increased postdinner (P = 0·03). Fasting glucose, insulin and C-peptide levels were unchanged in all groups, and FFA levels modestly increased postdinner (P = 0·03) in the NGT group.
  
  
  CONCLUSIONS
  Short-term, medium-dose prednisone treatment induces postprandial hyperglycaemia in T2DM and AR predominantly from midday to midnight because of suppression of insulin secretion followed by decreased insulin action that dissipates overnight. Effective treatment of prednisone-induced hyperglycaemia should target both rapid onset relative insulin deficiency and a less than 24-h total duration of effect.
authors.affiliation: Division of Endocrinology, Diabetes and Clinical Nutrition, Department of Medicine, Oregon Health and Science University, Portland, OR, USA.
authors.forename: Kevin C J
authors.initials: KC
authors.lastname: Yuen
authors.forename: Patricia A
authors.initials: PA
authors.lastname: McDaniel
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Riddle
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000187:drug effects; D002096:C-Peptide / Q000097:blood*; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy*; D005230:Fatty Acids, Nonesterified / Q000097:blood*; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011241:Prednisone / Q000008:administration & dosage / Q000627:therapeutic use*; D011446:Prospective Studies
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D011241:Prednisone