Insulinlike growth factors: Potential therapeutic options for osteoporosis

The insulinlike growth factors (IGFs) are important components of the bone remodeling unit. These peptides are present in very large concentrations within the skeletal matrix and play a critical role in differentiated osteoblast function and osteoclast recruitment. IGF-I may also mediate GH's actions in the skeleton. Hence, the IGFs have promise as future anabolic agents for the treatment of osteoporosis. However, the skeletal IGF regulatory system is complex and redundant, making it exceedingly difficult to predict how administration of recombinant growth factors might ultimately affect bone mass. In addition, the lack of long-term controlled clinical trials and the prevalence of significant side effects limit the clinical application of these growth factors. Nonetheless, new and innovative delivery systems for these proteins might make the application of the IGFs a potential therapeutic option for the management of osteoporosis.