title: Effects of chronic caffeine administration on blood glucose levels and on glucose tolerance in healthy and diabetic rats.
abstract: OBJECTIVE
  To analyse the effect of chronic caffeine use on risk reduction and prognosis of diabetes mellitus.
  
  
  METHODS
  In this 60-day study, five groups of 11 healthy male Wistar rats were selected to receive one of four doses (37.5, 56.2, 75.0 or 93.0 mg/kg per day) of caffeine orally  or no caffeine (control). The effect of caffeine on glycaemia and glucose tolerance was evaluated. After 15 days, each group was treated with 60 mg/kg of streptozotocine to induce diabetes mellitus, and glycaemia and glucose tolerance were assessed for a further 45 days.
  
  
  RESULTS
  In nondiabetic  rats, caffeine had no effect on blood glucose. Compared with controls, the fasting blood glucose levels declined significantly in two caffeine-treated groups (93.0 mg/kg per day and 56.2 mg/kg per day) during the first 15 days following diabetes induction. Glucose tolerance was significantly  improved 120 min after glucose loading in all caffeine-treated groups. The mean ± SE half-maximal effective concentration of caffeine was 35.79 ± 2.44 mg/dl.
  
  
  CONCLUSIONS
  Blood glucose levels decreased, and glucose tolerance improved, in diabetic rats administered increasing  doses of caffeine.
authors: Dr Enrico Stefani Experimental Unit, University Centre for Biomedical Research, University of Colima, Colima, Mexico.
authors: Z
authors: Z
authors: Urzúa
authors: X
authors: X
authors: Trujillo
authors: M
authors: M
authors: Huerta
authors: B
authors: B
authors: Trujillo-Hernández
authors: M
authors: M
authors: Ríos-Silva
authors: C
authors: C
authors: Onetti
authors: M
authors: M
authors: Ortiz-Mesina
authors: E
authors: E
authors: Sánchez-Pastor
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis*; D002110:Caffeine / Q000008:administration & dosage* / Q000494:pharmacology; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000378:metabolism*; D005951:Glucose Tolerance Test; D038321:Glycemic Index / Q000187:drug effects*; D008297:Male; D011379:Prognosis; D051381:Rats; D017208:Rats, Wistar; D012306:Risk; D013311:Streptozocin
chemical_list: D001786:Blood Glucose; D002110:Caffeine; D013311:Streptozocin