A comparison of radial peripheral quantitative computed tomography, calcaneal ultrasound, and axial dual energy X-ray absorptiometry measurements in women aged 45-55 yr

Perimenopausal bone loss is considered to affect trabecular bone preferenti ally. Peripheral quantitative computed tomography (pQCT) quantifies trabecu lar bone mineral density (BMD) independently at the ultradistal radius. Thi s article examines differences in pQCT BMD between late premenopausal and e arly postmenopausal women, comparing the differences with calcaneal ultraso und and axial dual energy X-ray absorptiometry mea surements. One hundred n ineteen normal perimenopausal women aged 45-55 yr who attended a randomized osteoporosis screening program were stratified by menopausal status into p remenopausal (PRE: n = 79) and postmenopausal (POST: n = 40) groups. All me asurements were lower in the postmenopausal group with the exception of ult rasonic velocity (PRE vs POST: 1397 +/- 53.8 vs 1421 +/- 58.5 m/s, p = 0.03 ). Total (391.8 +/- 52.9 vs 366.3 +/- 68.6 g/cm(3), p = 0.013) and subcorti cal (533.6 +/- 59.4 vs 504.3 +/- 79.8 g/cm(3), p = 0.018), but not trabecul ar (187.5 +/- 38.8 vs 173.2 +/- 46.6 g/cm(3), p = 0.098) or cortical (561 /- 53.4 vs 551.2 +/- 66 g/cm(3) p = 0.174), pQCT BMD measurements were sign ificantly lower in the POST group, as were ultrasonic attenuation (79.4 +/- 16 vs 72.3 +/- 18.0 dB/Mz, p = 0.034), DXA spine (1.032 +/- 16 vs 0.959 +/ - 0.2 g/cm(2), p = 0.003), and all hip (p less than or equal to 0.001) meas urements. Although body mass index (BMI) was positively and menopausal stat us and age negatively correlated with most bone mass measurements, adjustin g for BMI did not alter the relative deficits in postmenopausal compared wi th premenopausal women. This study suggests that early postmenopausal bone loss at the radius preferentially affects subcortical, rather than trabecul ar, bone in the appendicular skeleton, which suggests preferential trabecul ar bone loss in the axial skeleton.