Insulin-like growth factor 1



Insulin-like growth factor 1 (IGF-1), also called somatomedin C, is a protein that in humans is encoded by the IGF1 gene.

IGF-1 has also been referred to as a “sulfation factor” and its effects were termed “nonsuppressible insulin-like activity” (NSILA) in the 1970s.

IGF-1 is a hormone similar in molecular structure to insulin. It plays an important role in childhood growth and continues to have anabolic effects in adults. A synthetic analog of IGF-1, mecasermin, is used for the treatment of growth failure.

IGF-1 consists of 70 amino acids in a single chain with three intramolecular disulfide bridges. IGF-1 has a molecular weight of 7,649 daltons.

Results show that intraneural injection of IGF-1 in an 18 mm cryopreserved isograft improve Axon regeneration and functional recovery 1).

GH-secreting pituitary neuroendocrine tumor is related to high levels of growth hormone (GH) and insulin-like growth factor-I (IGF-1).

Insulin-like Growth Factors (IGFs) have been shown to increase the rate of peripheral nervous system axon regeneration. IGF-1 and IGF-II mRNA levels are significantly increased distal to the site of crush injury in rat sciatic nerves.

At the site of nerve repair, locally delivered IGF-I can significantly increase the rate of axon regeneration within a nerve graft and help expedite functional recovery of a paralyzed muscle.

As the only GH receptor antagonist (GHRA) available, pegvisomant has shown its effectiveness in the control of insulin like growth factor IGF-1 2).


Co-secretion of growth hormone (GH) and prolactin (PRL) from a single pituitary neuroendocrine tumor is common. In fact, up to 25% of patients with acromegaly may have PRL co-secretion. The prevalence of acromegaly among patients with a newly diagnosed prolactinoma is unknown. Given the possibility of mixed GH and PRL co-secretion, the current recommendation is to obtain an insulin-like growth factor-1 (IGF-1) in patients with prolactinoma at the initial diagnosis. Long-term follow-up of IGF-1 is not routinely done 3).

1)
González Porto SA, Domenech N, Blanco FJ, Centeno Cortés A, Rivadulla Fernández C, Álvarez Jorge Á, Sánchez Ibáñez J, Rendal Vázquez E. Intraneural IFG-1 in Cryopreserved Nerve Isografts Increase Neural Regeneration and Functional Recovery in the Rat Sciatic Nerve. Neurosurgery. 2018 Jul 27. doi: 10.1093/neuros/nyy339. [Epub ahead of print] PubMed PMID: 30060164.
2)
Neggers SJ, van Aken MO, de Herder WW, et al. Quality of life in acromegalic patients during long-term somatostatin analog treatment with and without pegvisomant. J Clin Endocrinol Metab. 2008;93(10):3853–3859.
3)
Manuylova E, Calvi LM, Hastings C, Vates GE, Johnson MD, Cave WT Jr, Shafiq I. Late presentation of acromegaly in medically controlled prolactinoma patients. Endocrinol Diabetes Metab Case Rep. 2016;2016. pii: 16-0069. PubMed PMID: 27855229.