Bone-Marrow Mast Cells in Osteoporosis of Aging

Of 135 women beyond fifty years of age who were evaluated for levels of bone density, those with a normal or only a minimally decreased bone density had the highest number of normal bone-marrow mast-cell counts. In contrast, increased numbers of mast cells occurred in patients with a moderate to marked decrease in bone density. It is possible that bone-marrow mast cells and heparin, which is synthesized by mast cells, play an important part in the pathogenesis of age-related osteoporosis.