PMID-11735244 – Ipamorelin Counteracts Glucocorticoid Bone Loss
Andersen NB, Malmlof K, Johansen PB, Andreassen TT, Friis Jorgensen PH, Høyer PE. The growth hormone secretagogue ipamorelin counteracts glucocorticoid-induced decrease in bone formation of adult rats. Growth Horm IGF Res. 2001;11(5):266-272.
Quick Reference
| Property | Value |
|---|---|
| PMID | 11735244 |
| DOI | 10.1054/ghir.2001.0239 |
| Year | 2001 |
| Journal | Growth Hormone & IGF Research |
| Study Type | Animal in vivo |
| Evidence Level | V |
| Sample | Adult rats receiving chronic glucocorticoid treatment (3 months) |
| Peptide(s) Studied | Ipamorelin |
Key Findings
- 3-month study demonstrating ipamorelin's bone-protective properties during glucocorticoid-induced osteopenia
- Ipamorelin co-administered with glucocorticoid increased periosteal bone formation rate by approximately 4-fold compared to glucocorticoid alone
- Muscle strength was also improved in the ipamorelin-treated group
- The bone-protective effect was mediated through GH/IGF-1 axis stimulation counteracting glucocorticoid catabolic effects
- Ipamorelin did not simply prevent bone loss — it actively stimulated new bone formation even in the presence of glucocorticoid suppression
- Body weight and lean mass were better maintained in the ipamorelin group
Study Design
Adult rats received chronic prednisolone (glucocorticoid) treatment for 3 months to model steroid-induced osteopenia. A treatment group received concurrent ipamorelin injections. Bone formation was assessed by dynamic histomorphometry using fluorochrome labeling (calcein). Periosteal and endocortical bone formation rates were quantified. Muscle strength was measured by biomechanical testing. Serum GH and IGF-1 levels were measured to confirm mechanism.
Limitations
- Rat bone remodeling differs from human — rats lack Haversian remodeling in cortical bone
- Single glucocorticoid dose level used — may not reflect the range of clinical steroid exposure
- No assessment of bone microarchitecture (trabecular bone structure)
- 3-month duration, while substantial for rats, may not predict long-term outcomes
- No fracture risk assessment
- Ipamorelin was the only GH secretagogue tested — no comparison with other GHRPs
Clinical Relevance
Glucocorticoid-induced osteoporosis is the most common form of secondary osteoporosis, affecting millions of patients on chronic steroids for autoimmune diseases, COPD, and transplant immunosuppression. The 4-fold increase in bone formation is a striking effect size that, if translatable, could position ipamorelin as an adjunctive therapy for steroid-dependent patients. This study also supports the broader use of ipamorelin in protocols targeting bone health and musculoskeletal recovery, particularly in patients with catabolic states. The concurrent improvement in muscle strength adds further value for frail or sarcopenic populations.
Related
#research #animal-in-vivo #ipamorelin #evidence-level-V