The Effect of Proton Pump Inhibitors on Glycemic Control in Patients with Type 2 Diabetes

Background: Type 2 diabetes patients have decreased pancreatic beta cell mass with a decline in beta cell function. Gastrin has increased beta cell proliferation in vitro and in animal studies. High gastric acid levels inhibit gastrin secretion. Proton pump inhibitors (PPIs) lower gastric acid, subsequently increasing gastrin levels. This may stimulate beta cell proliferation and function, and improve glycemic control. Studies with small numbers of type 2 diabetes patients have shown a slightly lower A1C in those taking PPI versus non-PPI users. Methods: This study was a retrospective multicenter electronic data analysis using data obtained from health care facilities within Veterans Integrated Service Network (VISN) 21. Patients were included if they had established care within VISN 21 and had type 2 diabetes with an A1C > 6.5%, were started on a PPI concurrently with stable doses of metformin or sulfonylurea (SFU) monotherapy, had at least two documented A1C values, and had a medication possession ratio >80% for metformin, SFU, or a PPI. Veterans were excluded if they were using insulin, combination antihyperglycemic therapy, or oral corticosteroids. A control group not using PPI was also identified. Results: There was a statistically significant decrease in A1C within each group. However, there was no statistically significant difference between the PPI and control group in the post-A1C. Conclusion: In patients with type 2 diabetes, A1C improved in both groups, but PPI addition did not affect glycemic control. Future randomized controlled trials are needed to determine the value of PPIs as a treatment option for patients with type 2 diabetes.