Opposing Metabolic Effects of Growth Hormone and IGF-I: Review and Clinical Implications.
Level 5 - mechanism / opinion, no new human data
Narrative review synthesizing mechanistic and clinical literature without primary data or systematic review methodology
PubMed 40718994 · doi:10.1210/endrev/bnaf022
What was done
This is a narrative review evaluating the divergent metabolic actions of growth hormone (GH) and insulin-like growth factor I (IGF-I). The authors reviewed evidence contrasting with the classical Somatomedin Hypothesis and proposed biochemical and cellular mechanisms that may explain these opposing effects.
What was found
The abstract reports no quantitative data or numerical findings. It identifies specific metabolic pathways where GH and IGF-I exert opposing activities, including serum lipoprotein(a) levels, sex hormone-binding globulin concentrations, insulin secretion, and adiponectin/leptin dynamics.
Why it matters
Recognizing that GH and IGF-I can produce opposite metabolic outcomes challenges the traditional model that IGF-I acts solely as a downstream mediator of GH, informing clinical understanding of endocrine and metabolic disorders.
Limits
As a narrative review, the paper lacks systematic search methodology, formal quality appraisal of cited studies, and quantitative pooling. The abstract provides no primary data, sample sizes, or specific effect estimates.
Cited by
- supports Growth hormone acts as a signal telling the liver to produce IGF-1.