Measurement of bone mineral content (BMC) of the lumbar spine, II. Correlation between forearm BMC and lumbar spine BMC

Abstract
A comparison between forearm bone mineral content (BMC) and lumbar BMC was made in post-menopausal women. Women without symptoms, women with clinical spinal osteoporosis, and women with prednisone-treated rheumatoid arthritis were studied. A conventional two-dimensional single-photon osteo-densitometer was used for measurement of forearm BMC. A new two-dimensional dual-photon osteodensitometer was used for measurement of lumbar BMC. Its radioactive source was 153Gadolinium. The mean lumbar BMC was significantly reduced in women with clinical spinal osteoporosis (P <0.001). The mean forearm BMC of those patients was normal. Thus, forearm BMC was a poor indicator of spinal osteopenia. If forearm BMC was used to predict lumbar BMC erroneously high results were obtained in women with clinical spinal osteoporosis, and erroneously low values were obtained in prednisone-treated women with rheumatoid arthritis.