title: Effects of caffeine on glucose tolerance: a placebo-controlled study.
abstract: OBJECTIVE
  The investigation was performed to study the effects of 200 mg oral caffeine on glucose tolerance.
  
  
  METHODS
  Single-blind Latin square with active treatment (caffeine) and placebo.
  
  
  METHODS
  The University of Padova, Department of Internal Medicine.
  
  
  METHODS
  30 nonsmoking healthy subjects aged 26-32 years who abstained not only from coffee but also from tea, chocolate and cola for 4 weeks and who had given their informed consent.
  
  
  METHODS
  A 75 g oral glucose tolerance test (OGTT) was performed after giving caffeine or placebo (highly decaffeinated coffee).
  
  
  RESULTS
  The glycaemic curve was normal in all subjects and was similar in the two groups until the second hour; in subjects taking caffeine a shift towards the right was detected at the 2nd, 3rd and 4th hours in comparison to those taking the placebo. Blood insulin levels were comparable after caffeine and after placebo along the entire OGTT.
  
  
  CONCLUSIONS
  The data suggest that caffeine intake induces a rise in blood glucose levels that is insulin independent.
authors.affiliation: Department of Clinical and Experimental Medicine, University of Padova, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Pizziol
authors.forename: V
authors.initials: V
authors.lastname: Tikhonoff
authors.forename: C D
authors.initials: CD
authors.lastname: Paleari
authors.forename: E
authors.initials: E
authors.lastname: Russo
authors.forename: A
authors.initials: A
authors.lastname: Mazza
authors.forename: G
authors.initials: G
authors.lastname: Ginocchio
authors.forename: C
authors.initials: C
authors.lastname: Onesto
authors.forename: L
authors.initials: L
authors.lastname: Pavan
authors.forename: E
authors.initials: E
authors.lastname: Casiglia
authors.forename: A C
authors.initials: AC
authors.lastname: Pessina
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D002099:Cacao; D002110:Caffeine / Q000494:pharmacology*; D002253:Carbonated Beverages; D003069:Coffee; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D007700:Kinetics; D008297:Male; D010919:Placebos; D013662:Tea
chemical_list: D001786:Blood Glucose; D003069:Coffee; D007328:Insulin; D010919:Placebos; D013662:Tea; D002110:Caffeine