Ultrasound and X-ray-based bone densitometry in patients with anorexia nervosa

In 20 patients (mean age 23 +/- 5 years) with anorexia nervosa (AN), bone m ass was evaluated by broadband ultrasound attenuation (BUA) of the calcaneu s, peripheral quantitative computed tomography (pQCT) of the distal radius, and dual X-ray absorptiometry (DXA) of the lumbar spine and the hip. Compa red with 20 age- and sex-matched healthy controls, patients with AN showed marked osteopenia at all measuring sites. Values of BUA (33.0 +/- 9dB/MHz v s. 51.0 +/- 5.7 dB/MHz; P < 0.0001) and of BMD of all regions of the hip (e .g., femoral neck: 0.71 +/- 0.13 g/cm(2) versus 0.89 +/- 0.07 g/cm(2); P < 0.001), lumbar spine (0.82 +/- 0.15 g/cm(2) versus 1.24 +/- 0.06 g/cm(2); P < 0.003) and total BMD of the peripheral radius (303.2 +/- 75 g/cm(3) vers us 369.4 +/- 53.2 g/cm(3), P < 0.001) were significantly reduced. Calculati ng a Z-score we found the most prominent differences between AN and control s by BUA of the calcaneus (-3.2 +/- 1.6), followed by DXA at the lumbar spi ne (-2.9 +/- 2.2) and the hip (femoral neck -2.1 +/- 1.7) and by pQCT at th e distal radius (total BMD -1.2 +/- 2.0). There were highly significant cor relations between BUA of the calcaneus and BMD of the femoral neck (r = 0.7 8, P < 0.0001) and lumbar spine (r = 0.75, P < 0.0001) as well as between B MD values of the femoral neck and lumbar spine (r = 0.95; P < 0.0001). In a ddition, there were significant correlations (P < 0.001) between body mass index (BMI) and the three different measuring sites and between the duratio n of the disease and BUA (r = 0.5, P < 0.05). Our data suggest that BUA of the calcaneus is a valuable tool in the management of osteoporosis. Being a fast, radiation-foe investigation method of good acceptance, it may be wel l suited for an assessment of the skeletal status in patients with AN.