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Study breakdown

Simplifying Diabetes Treatment: Combining Basal Insulin with GLP-1 Drugs in One Daily Injection

evidence
The takeaway

Fixed-ratio combinations of basal insulin with a GLP-1 receptor agonist (iGlarLixi or IDegLira) can simplify complex insulin regimens while maintaining blood sugar control, reducing weight, and lowering hypoglycemia risk.

1 daily injection

replaces complex multi-injection insulin regimens with equivalent blood sugar control plus weight loss and less hypoglycemia

What the researchers found

Current evidence shows that switching from complex insulin regimens to once-daily fixed-ratio combinations (FRCs) of basal insulin + GLP-1 RA provides equivalent glycemic control with additional benefits: reduced body weight, lower total daily insulin dose, fewer daily injections, and no increase (or a reduction) in hypoglycemia.

Two FRC products are currently available: iGlarLixi (insulin glargine + lixisenatide) and IDegLira (insulin degludec + liraglutide). The review provides a practice-oriented clinical algorithm for simplifying complex insulin regimens using these combinations.

Why it matters

Complex insulin regimens are a major burden for diabetes patients — multiple daily injections, blood sugar monitoring, weight gain, and fear of hypoglycemia reduce quality of life and adherence. Simplifying to a single daily injection that also promotes weight loss addresses several patient complaints at once, potentially improving both outcomes and quality of life.

How the study worked

This is a narrative review examining the current evidence supporting therapy simplification in type 2 diabetes. The authors reviewed clinical trial data for both available fixed-ratio combinations and synthesized the evidence into practical recommendations with a clinical algorithm for implementing the transition from complex insulin to FRC therapy.

What this study cannot tell us

This is a narrative review, not a systematic review or meta-analysis. The clinical algorithm is based on existing evidence but represents expert opinion for practical implementation. Long-term outcomes beyond glycemic control (cardiovascular events, kidney outcomes) specifically for FRC therapy need more data. Cost and insurance coverage of FRCs may limit accessibility.

How to read the evidence

This is a narrative review synthesizing evidence from clinical trials of two approved fixed-ratio combination products. While not a systematic review, it draws on substantial trial data and provides practical clinical guidance.

When this study was published

Published in 2025, this review reflects the current state of evidence and clinical practice for insulin/GLP-1 RA combination therapy in type 2 diabetes.

The bigger picture

This review reflects the broader shift in diabetes management from insulin-centric to incretin-based strategies. As GLP-1 receptor agonists have proven their cardiovascular and renal benefits beyond blood sugar control, combining them with insulin in a single injection represents a practical step toward simpler, more effective, patient-friendly diabetes care.

Questions still open

  • How do iGlarLixi and IDegLira compare head-to-head in clinical outcomes?
  • Will newer GLP-1 RA/insulin combinations with more potent GLP-1 components (like semaglutide) further improve outcomes?
  • What percentage of patients on complex insulin regimens are eligible for and would benefit from simplification to FRCs?

Common questions

Can I switch from multiple insulin injections to a single daily shot?
Yes — fixed-ratio combination drugs like iGlarLixi and IDegLira combine a long-acting insulin with a GLP-1 drug in one pen. Evidence shows they control blood sugar equally well as complex insulin regimens while being simpler, causing less weight gain, and reducing hypoglycemia risk. Talk to your doctor about whether you're a candidate.
What are the advantages of combining insulin with a GLP-1 drug?
GLP-1 drugs help counteract insulin's main downsides: they promote weight loss (instead of insulin-related weight gain), reduce appetite, and lower blood sugar in a way that doesn't cause hypoglycemia. Combining both in one injection gives you the blood sugar control of insulin plus the metabolic benefits of a GLP-1 drug.

Read the original research

Practical limitations of complex insulin therapies in type 2 diabetes: Focus on therapy simplification using fixed-ratio combinations of basal insulin and a glucagon-like peptide-1 receptor agonist.

Diabetes, obesity & metabolism, 27 Suppl 7(Suppl 7), 42-54

Citation

Horváth, Luděk; Novodvorský, Peter; Haluzík, Martin. (2025). Practical limitations of complex insulin therapies in type 2 diabetes: Focus on therapy simplification using fixed-ratio combinations of basal insulin and a glucagon-like peptide-1 receptor agonist.. Diabetes, obesity & metabolism, 27 Suppl 7(Suppl 7), 42-54. https://doi.org/10.1111/dom.16645