Mice lacking acyl-ghrelin had an impaired counterregulatory response to insulin-induced hypoglycemia, showing that ghrelin is permissive for normal blood sugar recovery.
Permissive for blood sugar defenseWithout ghrelin, mice cannot mount a normal counterregulatory response when blood sugar drops dangerously low
What the researchers found
Ghrelin knockout mice showed impaired counterregulatory responses to insulin-induced hypoglycemia, demonstrating that acyl-ghrelin is permissive for normal blood sugar recovery during hypoglycemic episodes.
Why it matters
Hypoglycemia is a major risk for diabetic patients on insulin. Understanding ghrelin's role in blood sugar defense could lead to new strategies to prevent dangerous hypoglycemic episodes.
The numbers in context
10-fold higher GIR in ghrelin-KO; blunted corticosterone and GH; HM01 reduced GIR and increased corticosterone and GH
How the study worked
Used ghrelin knockout mice subjected to insulin-induced hypoglycemia. Measured counterregulatory hormone responses, blood glucose recovery, and compared to wild-type controls.
Who was studied
Ghrelin knockout mice and wild-type littermates; C57BL/6N mice for agonist experiments
What this study cannot tell us
Mouse study — knockout models may not perfectly predict human ghrelin deficiency. Small sample. Complete ghrelin absence is more extreme than natural variation in ghrelin levels.
How to read the evidence
Moderate — well-designed knockout mouse study with clear physiological endpoints, but small sample and species differences apply.
When this study was published
Published in 2020; ghrelin's role in glucose counterregulation continues to be explored.
The bigger picture
This adds ghrelin to the known components of the body's hypoglycemia defense system (glucagon, epinephrine, cortisol, growth hormone), revealing a more complex regulatory network than previously appreciated.
Questions still open
- Do diabetic patients with lower ghrelin levels have worse hypoglycemia awareness?
- Could ghrelin agonists help prevent severe hypoglycemia in insulin-treated diabetics?
- How does ghrelin interact with other counterregulatory hormones during blood sugar defense?
Common questions
Why is hypoglycemia dangerous?
How could ghrelin help prevent low blood sugar?
Read the original research
Acyl-ghrelin Is Permissive for the Normal Counterregulatory Response to Insulin-Induced Hypoglycemia.
Diabetes, 69(2), 228-237
Citation
Shankar, Kripa; Gupta, Deepali; Mani, Bharath K; Findley, Brianna G; Lord, Caleb C; Osborne-Lawrence, Sherri; Metzger, Nathan P; Pietra, Claudio; Liu, Chen; Berglund, Eric D; Zigman, Jeffrey M. (2020). Acyl-ghrelin Is Permissive for the Normal Counterregulatory Response to Insulin-Induced Hypoglycemia.. Diabetes, 69(2), 228-237. https://doi.org/10.2337/db19-0438