[Osteodensimetric curves in a female population]

To define female bone osteodensitometric reference curves, for different anatomical sites, in a female population.

A cross-sectional study was performed involving 573 Caucasoid women living in Porto. Bone mineral density was measured using a Hologic® QDR 1500 dual X-ray absorciometry system. Bone mineral density was measured at lumbar spine and proximal left femur and expressed in g/cm(2). Participants were submitted to a bone densitometry by DEXA technique, for the different sites under study. After the results obtained trough densitometry mean BMD was calculated to each age group. Additionally, mean BMD was calculated for young adults (20-39 years old) in order to determine T-scores to draw a reference base. To define reference curves, polynomial regressions of BMD on age were used.

Peak bone mass was found between 20 and 29 years old for lumbar spine and Ward?s triangle, and between 30 and 39 years old for the remaining sites under study. Maximum mean (standard deviation) BMD was 1,011 (0,124) for lumbar spine; 0,819 (0,118) for femur neck; 0,708 (0,084) for the trochanteric region; 1,115 (0,113) for intertrochanteric region; 0,783 (0,168) for Ward?s triangle and 0,951 (0,101) for total femur.

Bone mass peak was achieved in lumbar spine and in Ward?s triangle, between 20 and 29 years old, and between 30 and 39 years for the other studied loci. The sample BMD peak values are lower than the machine reference values.