EFFECTS OF CAFFEINE ON GLUCOSE-TOLERANCE - A PLACEBO-CONTROLLED STUDY

Objective: The investigation was performed to study the effects of 200 mg oral caffeine on glucose tolerance. Design: Single-blind Latin squ are with active treatment (caffeine) and placebo. Setting: The Univers ity of Padova, Department of Internal Medicine. Subjects: 30 nonsmokin g 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 t heir informed consent. Interventions: A 75 g oral glucose tolerance te st (OGTT) was performed after giving caffeine or placebo (highly decaf feinated coffee). Results: The glycaemic curve was normal in all subje cts and was similar in the two groups until the second hour; in subjec ts taking caffeine a shift towards the right was detected at the 2nd, 3rd and 4th hours in comparison to those taking the placebo. Blood ins ulin levels were comparable after caffeine and after placebo along the entire OGTT. Conclusions: The data suggest that caffeine intake induc es a rise in blood glucose levels that is insulin independent.