The Study
GLP-1 and Insulin Recruit Muscle Microvasculature and Dilate Conduit Artery Individually But Not Additively in Healthy Humans
This study is like a carefully controlled experiment where each person gets different treatments in random order. It shows that GLP-1 and insulin each make tiny blood vessels in muscles open up and increase blood flow, but doing both together doesn’t work better than either one alone.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Two hormones, insulin and GLP-1, help open small blood vessels in muscles when your body needs to deliver fuel. This study checks if they work better together.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 554 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1This means both hormones help muscles get nutrients quickly after eating, but they use the same pathway so can’t double the effect.
- 2Each hormone alone increased blood vessel size and flow in muscles by about 30%.
- 3But together, they didn’t do more than either one alone.
- 4They didn’t change how stiff the big arteries are.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of the Endocrine Society
Year
2018
Authors
Alvin W.K. Tan, S. Subaran, Matthew A Sauder, W. Chai, L. Jahn, D. Fowler, J. Patrie, K. Aylor, A. Basu, Zhenqi Liu
Related Content
Claims (6)
Insulin helps your muscles take in more creatine by making blood flow better and boosting a pump-like system in muscle cells, which helps bring in more nutrients.
When healthy adults get a specific dose of a hormone called GLP-1 through an IV, it quickly boosts blood flow in the small vessels of their heart and muscles, helping deliver more nutrients and hormones where they're needed.
When healthy adults get a controlled dose of insulin for two hours, it boosts blood flow and blood volume in their heart and muscle tissues, helping more nutrients move between blood and muscles.
When healthy adults get both GLP-1 and insulin at the same time, it doesn’t boost blood flow to their heart or muscles any more than using just one of the hormones alone.
Giving healthy adults normal levels of certain hormones like GLP-1 and insulin — either alone or together — doesn't change how stiff their main artery is over about two and a half hours.
When healthy adults get infusions of two hormones—GLP-1 or insulin—each one widens a major arm artery and boosts blood flow by about 30%. But when both are given together, they don’t widen the artery any more than just one alone, meaning they don’t add up.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.