Geometry and bone mass in primary hyperparatiroidism assessed by peripheral quantitative Computed Tomography (rQCT)

PURPOSE: Non-invasive measurement by peripheral quantitative computed tomography (pQCT) of bone geometry, biomechanics, and mineral content in patients (pts) with primary hyperparathyroidism (PHPT). MATERIALS AND METHODS: Total, trabecular and cortical mineral density (totBMD, cortBMD, trab BMD), bone geometrical properties (total area, trabecular area, cortical area, cortical/total area) and cortical thickness as biomechanical parameters, were assessed by pQCT at distal radius in 38 (32 F; 6 M) consecutive patients with PHPT (mean age: 62 yrs; range: 30-77). In a subgroup of 12 patients, bone mineral density (BMD) was also measured by means of dual X-ray absorptiometry (DXA) at the lumbar spine (L2-L4). RESULTS: Serum biochemical characteristics were: iPTH (269+/-214 pg/ml; range: 107-1438, normal: 30-65), Calcium (11.4+/-1.1 mg/dl; range: 10.6-13.5, normal: 8.1-10.4) and Alkaline Phosphatase (398+/- 392 U/L; range:173-1174, normal: 98-279). Compa-red with 87 healthy age-matched subjects, total, trabecular and cortical bone densities were reduced in all patients (TotBMD: 216+/-92 mg/cm(3) vs ctr 342+/-94, -37%, p<0.05; TrabBMD: 93+/-51 mg/cm(3) vs ctr 140+/-54, -34%, p <0.01; CorBMD: 711+/-178 mg/cm(3) vs ctr 802+/-175, -11%, p<0.02), such as cortical thickness (0.143+/-0.02 cm vs ctr 0.157+/-0.03, -9%, p<0.02). Among geometrical parameters, only cortical/total area was significant different in the two groups (0,29 vs 0.31; p<0.04). A strong correlation was found between peripheral trabecular bone density assessed by pQCT and axial bone mineral density measured by DXA at L2-L4 (r=0.80; p