Capsaicin and glucose absorption and utilization in healthy human subjects.

Although many animal experiments (under different experimental circumstances) have been performed, however, to date there have been no human studies of the role of capsaicin-sensitive afferent nerves in carbohydrate metabolism. The glucose loading test (administration of 75 g orally given glucose) was evaluated in 14 human healthy subjects by the simultaneous measurement of plasma level of glucose, C-peptide and glucagon every 15 min for 4 h without and with (ED50) oral application of capsaicin. The plasma level of glucose increased significantly from 30 to 150 min, and the plasma glucagon level increased from 90 to 180 min after the glucose loading when capsaicin administered. The plasma levels of insulin and C-peptide increased from 90 to 165 min after glucose loading but there were no significant difference between the results obtained without and with capsaicin administration. It is concluded that the capsaicin increases the glucose absorption from the gastrointestinal tract and increases the glucagon release (independently of the hormonal antagonist regulation by insulin released after glucose) loading during glucose loading tests carried out in human healthy subjects.