[Bone mineral density of the lumbar spine and proximal femur of normal females in Buenos Aires].

The bone mineral density (BMD) of the lumbar spine and proximal femur was determined in 170 and 131 respectively normal females from 20 to 79 years of age. The BMD was determined by dual photon absorptiometry with a Lunar DP3 equipment. The results per decade of age are shown on table 2. The percentage fall between the 3rd and 8th decades of age at different skeletal sites is summarized on table 3. Meanwhile the bone loss at the lumbar spine and mid-radius from a previous study was approximately 3% before the menopause, the BMD of proximal femur diminished approximately 14% over the neck and 19% at the Ward's triangle during the same period. From age 50 to 80 the average bone loss was similar at the spine and femoral neck (approximately 15%) but it was more severe at the Ward's triangle (approximately 24%). The results obtained in the Buenos Aires females were compared to the values observed in studies performed in United States and Australia using the same equipment. No differences were found among the three populations using the Bonferroni's analysis for multiple comparisons. The BMD appears to be similar in different caucasian populations when the same type of equipment is used, but the values cannot be compared with the results obtained with other equipment. A sustained diminution of the proximal femur BMD was observed from age 20 to 80, whereas over the spine a distinct difference before and after the menopause was found.