Costly and disabling fractures of the spine, hip, wrist, and other bones can be preceded by years of undetected bone loss. Complications of osteoporosis are the 12th leading cause of death in America and are responsible for more deaths in women than cancers of the breast and cervix combined. Women are at four times greater risk of developing osteoporosis than men, with postmenopausal women particularly vulnerable. Finding accurate, convenient methods of monitoring the bone loss that can lead to osteoporosis is critical in combating this crippling disease.
Bone is an active living tissue made of a protein framework to which various minerals attach.
Throughout life, bone is constantly dissolved in a process called bone resorption and reformed in a dynamic process called bone remodeling. As bone is resorbed by osteoclasts, bone collagen degradation fragments are released into the bloodstream and excreted in the urine. In childhood and adolescence, bone remodeling is associated primarily with bone growth. After age 30 to 35, resorption by osteoclasts progressively outweighs formation of new bone, resulting in an increase in bone loss that can Iead to osteoporosis. In postmenopausal women, this process is accelerated by declining estrogen levels.