Graphic Trace Analysis of Ultrasound at the Phalanges May Differentiate Between Subjects with Primary Hyperparathyroidism and with Osteoporosis: A Pilot Study

Abstract

Bone loss characterizes both primary hyperparathyroidism (PHPT) and osteoporosis (OP) but with a different histologic pattern, and this could partially explain the different fracture incidence in these two populations. Quantitative ultrasound (QUS), influenced by bone structural parameters other than bone mineral density (BMD), could evidence these differences, opening new perspectives in the evaluation of patients with metabolic bone diseases. The aim of the present study was to investigate the usefulness of QUS graphic trace parameters, assessed at the phalanx, in discriminating between PHPT bone disease and osteoporosis. We studied 34 patients with PHPT (mean age 59.7 +/- 12.7 years), 35 patients with OP (mean age 60.6 +/- 7.1 years) and 34 healthy subjects as controls (mean age 59.1+/- 9.4 years). In all subjects QUS measurements were performed at the phalanx with a Bone Profiler (IGEA, Italy), obtaining the amplitude-dependent speed of sound (AD-SoS), fast wave amplitude (FWA), signal dynamic (SDy), bone transmission time (BTT) and ultrasound bone profile index (UBPI). Moreover, serum calcium, phosphorus, parathyroid hormone (PTH), bone isoenzyme of alkaline phosphatase (B-ALP) and ionized calcium were measured in all subjects in the morning under fasting conditions. In PHPT patients BTT was correlated with PTH, ionized calcium and B-ALP levels (r = -0.47, -0.57 and -0.44, respectively; p < 0.01), whereas FWA, SDy and UBPI correlated only with B-ALP (r = -0.43, -0.46 and -0.50, respectively; p <0.01). Moreover, FWA, SDY and UBPI were significantly (p<0.01) lower and BTT significantly (p<0.001) higher in OP than in PHPT patients. UBPI, BTT, FWA and the BTT/FWA ratio, but not SDy, were able to discriminate between the two groups (area under the curve =0.66, 0.69, 0.67 and 0.81, respectively). Our findings show that ultrasound signal parameters are differently influenced by bone changes characterizing primary hyperparathyroidism or osteoporosis. This suggests that the QUS signal could be a useful instrument in discriminating and studying some of the bone alterations typical of metabolic bone diseases.

“Trabecular Bone Score” (TBS): An indirect measure of bone micro-architecture in postmenopausal patients with primary hyperparathyroidism

“…Conversely, a high TBS value has been associated with good bone micro-architecture, high connectivity, low trabecular spacing and an augmented number of trabeculae [21][22][23]. These findings are in keeping with the results obtained by utilizing phalangeal ultrasound, which in turn indicates that some parameters, also reflecting bone mineralization but poorly correlated with BMD of the lumbar spine, may be altered in PHPT patients [33,34]. On the other hand, the lack of significant difference of TBS values between PHPT patients with and without non-vertebral fractures, seems to suggest that the technique could be regarded as site-specific tool.…”

Constitutional bone impairment in Noonan syndrome

“…Although several skeletal sites can be explored by QUS methods (e.g., heel, radius, tibia), the phalangeal site is considered optimal as made up of approximately 60% of cortical and 40% trabecular bone, allowing, therefore an appraisal of both skeletal compounds which can be differently affected [Baroncelli, ]. The phalangeal device, we used, assesses the skeletal condition by means of two parameters: AD‐SoS—the speed of the ultrasound wave, mostly reflecting bone density and elasticity [Baroncelli, ; Guglielmi et al, ,b] and BTT—the time of transmission of the ultrasound signal—also closely related to cortical thickness [Barkmann et al, ; Montagnani et al, ; Sakata et al, ]. BTT is more reliable and has a higher accuracy than AD‐SoS in identifying bone damage, presumably because of its exclusive dependency on bone properties [Sakata et al, ; Guglielmi et al, ].…”

Impact of Metabolic Control on Bone Quality in Phenylketonuria and Mild Hyperphenylalaninemia

“…BTT is closely related to cortical width and can discriminate different bone disease patterns independent of bone density (19,35,42).…”