SYMMETRY OF BONE-MINERAL DENSITY IN THE HIPS IS NOT AFFECTED BY AGE

To assess the symmetry of bone mineral density (BMD) of the hips, we u sed dual photon absorptiometry (DPA) to asses BMD in 266 normal Chines e women in the bilateral femoral neck, trochanter and Ward's triangle regions. Linear regression analysis of the results showed excellent co rrelation between the hips. The correlation coefficients for the femor al neck, trochanter and Ward's triangle regions were 0.899, 0.892 and 0.935 respectively, and the standard errors of the estimate (S.E.E.) w ere 0.029, 0.027 and 0.022 g cm(-2) respectively. Pooling the BMD data of corresponding regions (n = 532), the correlation coefficient was 0 .813 for femoral neck versus trochanter, 0.889 for femoral neck versus Ward's triangle, and 0.833 for trochanter versus Ward's triangle. Fur ther analysis showed mean correlation coefficients of 0.854 for elderl y subjects (age greater than or equal to 65 years, n = 51) and 0.887 f or younger subjects (age < 65 years, n = 215). In conclusion, assessme nt of left or right hip BMD may be used to represent the BMD of the co ntralateral hip and can reduce both the cost and radiation exposure du ring mass screening for osteoporosis.