Researchers Identify Factors Important for Bones

LOMA LINDA >>Loma Linda University researchers have identified growth hormone/insulin-like growth factors critically important for the regulation of bone formation. The discovery was made through ongoing research conducted to determine the potential of growth hormone/insulin-like growth factor-based, or GH/IGF-based, therapies to treat and prevent osteoporosis and other diseases of low bone mass. The GH/IGF factor axis plays an important role in the regulation of bone remodeling which involves the complex and coordinated interaction of osteoblast lineage cells, which form bone, and osteoclast lineage cells, which resorb bone. It significantly controls both longitudinal bone growth, which is important during childhood, and appositional bone growth, which is important for bone maintenance in adulthood. Deficiencies in this system have been shown to contribute to the development of osteoporosis and other diseases of low bone mass. Richard C. Lindsey and Subburaman Mohan, co-investigators in the study, have found that GH and IGF-I therapies are particularly beneficial for adults with and without osteoporosis. For children with severely impaired longitudinal bone growth who fail to attain normal height in adulthood, treatment with GH or IGF-I is a logical therapy; long-term administration of GH in children with GH-deficient conditions including isolated GH deficiency and multiple pituitary hormone deficiency significantly improved age-adjusted height in a manner consistent with growth approaching the children's genetic height potential. This research was funded by the National Institutes of Health and the US Department of Veterans Affairs. “Age-related loss of bone mass occurs, in part, due to a decrease in components of the GH/IGF system," Mohan said. "Therefore, supplemental anabolic GH and IGF-I therapies for the treatment of age-related bone loss and osteoporosis show great promise, especially as they demonstrate a relatively safe adverse effect profile.” Lindsey continued, "Ultimately, a better understanding of the GH/IGF axis will allow greater pharmacological manipulation of the pathophysiological changes which lead to diseases of low bone mass, helping to treat and, finally, to prevent incapacitating conditions which plague so many worldwide."