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.
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.
Co-secretion of growth hormone (GH) and prolactin (PRL) from a single pituitary adenoma 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 2).