Adding Continuous Glucose Monitoring When Starting a GLP-1 Drug Nearly Doubles Blood Sugar Improvement | Research

The takeaway

Starting a GLP-1 drug with FreeStyle Libre continuous glucose monitoring produced a 2.43% HbA1c reduction versus 1.73% with GLP-1 alone — a 0.70% greater improvement in real-world T2D patients.

0.70% greater HbA1c reduction
Adding FreeStyle Libre when starting a GLP-1 drug produced this clinically meaningful additional benefit at 6 months compared to GLP-1 therapy alone

What the researchers found

Initiating GLP-1 RA therapy with FreeStyle Libre produced 0.70% greater HbA1c reduction at 6 months compared to GLP-1 RA alone in matched cohorts (-2.43% vs. -1.73%, p<0.001) among adults with T2D and baseline HbA1c ≥8%.

Why it matters

This suggests that combining drug therapy with glucose monitoring technology produces better outcomes than either alone. For the millions starting GLP-1 drugs, adding a CGM could substantially amplify their benefits — potentially reducing diabetes complications and healthcare costs.

The numbers in context

Significant additional HbA1c reduction in the GLP-1+FSL group versus GLP-1-only group, measured from real-world electronic health records.

How the study worked

Real-world retrospective cohort using Optum's Market Clarity linked EHR-claims database (2018-2022). Adults with T2D and HbA1c ≥8% starting first GLP-1 RA. GLP-1+FSL group (n=478) acquired FSL within ±30 days of first GLP-1. 1:5 matched to GLP-1-only controls (n=2,390) on insulin therapy, age, sex, baseline HbA1c, and GLP-1 type. HbA1c change at 6 months.

Who was studied

Adults with type 2 diabetes initiating GLP-1 therapy

What this study cannot tell us

Retrospective observational design — patients who adopt both GLP-1 and CGM may be more health-motivated than those choosing only one. Selection bias cannot be fully eliminated by matching. The study captures only 6-month outcomes. The mechanism of benefit (behavioral change from CGM data) is assumed but not measured. Only FreeStyle Libre was studied — other CGM systems may differ.

How to read the evidence

Moderate evidence from a large real-world cohort study with propensity matching. The sample size is robust but the observational design cannot eliminate all confounding, particularly motivation bias.

When this study was published

Published in 2024, reflecting the current convergence of GLP-1 drug therapy and continuous glucose monitoring technology.

The bigger picture

The diabetes technology landscape is converging — GLP-1 drugs and CGM are two of the most impactful innovations in type 2 diabetes management. This study suggests they're even more powerful together. As CGM becomes cheaper and more accessible, pairing it with GLP-1 therapy could become standard practice for newly diagnosed or poorly controlled T2D patients.

Questions still open

Is the benefit sustained beyond 6 months, or does CGM engagement wane over time?
Which specific behavioral changes (diet, exercise, medication timing) does CGM visibility drive in GLP-1 users?
Would a randomized trial confirm the additive benefit, controlling for the motivation bias?

Common questions

Why would wearing a glucose monitor make a GLP-1 drug work better?

The GLP-1 drug does its job regardless of whether you wear a monitor. But the monitor changes YOUR behavior. When you can see your glucose rising after certain foods or dropping during exercise in real-time, you naturally make adjustments — eating fewer high-sugar foods, timing meals better, staying more active. These behavioral changes amplify the drug's effects. It's the difference between flying blind and having a dashboard.

Should everyone starting a GLP-1 drug also get a continuous glucose monitor?

This study suggests the combination is more effective, especially for people with poorly controlled diabetes (HbA1c ≥8%). However, insurance coverage for CGM in T2D varies, and some people may not benefit as much if they're already well-controlled or don't engage with the glucose data. Discuss with your endocrinologist whether the additional cost and effort of CGM is worthwhile for your specific situation.

Read the original research

Initiating GLP-1 Therapy in Combination with FreeStyle Libre Provides Greater Benefit Compared with GLP-1 Therapy Alone.

Diabetes technology & therapeutics, 26(10), 754-762

View on PubMed ↗Publisher’s paper ↗

Citation

Wright, Eugene E; Roberts, Gregory J; Chuang, Joyce S; Nabutovsky, Yelena; Virdi, Naunihal; Miller, Eden. (2024). Initiating GLP-1 Therapy in Combination with FreeStyle Libre Provides Greater Benefit Compared with GLP-1 Therapy Alone.. Diabetes technology & therapeutics, 26(10), 754-762. https://doi.org/10.1089/dia.2024.0015