Combining SGLT2 inhibitor with GLP-1 drug improves beta-cell function more than either alone in 90-patient RCT | Research

The takeaway

In 90 T2DM patients, dapagliflozin + exenatide combination provided superior beta-cell function improvement versus either monotherapy, assessed by 180-minute oral glucose tolerance testing of insulin secretion and sensitivity.

Combination improves beta-cell function
SGLT2i + GLP-1RA combination therapy improved actual insulin-producing cell function more than either drug alone—not just glucose levels

What the researchers found

Dapagliflozin + exenatide: superior β-cell function improvement vs monotherapy. 90-minute OGTT assessment. 90 T2DM patients. Hypothesis confirmed: combination > individual agents for BCF. Insulin sensitivity also improved.

Why it matters

Understanding that combination therapy improves the actual function of insulin-producing cells—not just their surroundings—provides a mechanistic rationale for dual prescribing.

How the study worked

RCT. 90 T2DM patients. 3 arms: dapagliflozin, exenatide, combination. 180-min OGTT. Beta-cell function and insulin sensitivity assessment.

What this study cannot tell us

Specific BCF metrics and effect sizes not in abstract preview. Relatively small (90 patients). OGTT is a research tool, not routine clinical practice.

How to read the evidence

Small RCT with gold-standard BCF assessment (OGTT). Good mechanistic evidence.

When this study was published

Published in 2025.

The bigger picture

This provides the cellular mechanism for why SGLT2i + GLP-1RA combination works better: the drugs don't just lower glucose—they actually help beta-cells work better together.

Questions still open

Which BCF metric improved most with combination?
Is the BCF improvement durable after drug discontinuation?
Would tirzepatide + SGLT2i show even greater BCF improvement?

Common questions

Why combine two diabetes drugs?

This study shows the combination actually improves how well insulin-producing cells function—something neither drug achieves as effectively alone. It's not just about lowering blood sugar from two directions, but about the drugs working together to help your pancreas perform better.

What is beta-cell function?

Beta-cells are the insulin-producing cells in the pancreas. In type 2 diabetes, they become progressively dysfunctional. This study measured beta-cell function using a 3-hour glucose tolerance test and found that combining an SGLT2 inhibitor with a GLP-1 drug improved it more than either drug alone.

Read the original research

Changes in β-Cell Function and Insulin Sensitivity During Treatment With Dapagliflozin Alone or in Combination With Exenatide in Type 2 Diabetes.

Diabetes care, 48(9), 1545-1552

View on PubMed ↗Publisher’s paper ↗

Citation

Triplitt, Curtis; Cersosimo, Eugenio; Alatrach, Mariam; Adams, John; Hansis-Diarte, Andrea; Baskoy, Gozde; Gastaldelli, Amalia; Chavez-Velazquez, Alberto; DeFronzo, Ralph A. (2025). Changes in β-Cell Function and Insulin Sensitivity During Treatment With Dapagliflozin Alone or in Combination With Exenatide in Type 2 Diabetes.. Diabetes care, 48(9), 1545-1552. https://doi.org/10.2337/dc25-0490