The results of different observational studies showed anti-diabetic properties for the PPIs with a global glucose-lowering power around 0.6-0.7 % points of HbA1c. Small clinical trials have proved that PPI have significant impact on fasting blood glucose, HbA1C, C-peptides and beta cell mass. In most of the trials there was significant drop in fasting blood glucose after 12 weeks of PPI but post prandial and immediate effects were not explored.