TRABECULAR BONE SCORE (TBS) HAS A POOR DISCRIMINATIVE POWER FOR VERTEBRAL FRACTURES IN 153 ROMANIAN PATIENTS WITH PRIMARY HYPERPARATHYROIDISM.

Background: Trabecular Bone Score (TBS) has been recently proposed as a good tool to investigate secondary osteoporosis.

Objective: The aim of this study was to assess TBS from spine DXA images in patients with primary hyperparathyroidism (PHPT) and look at its correlates.

Methods: 153 patients, mean age 59.1 ± 12.1 yrs, females and males (10%), mean BMI 26.2 ± 4.8 kg/m2, mean serum calcium and PTH of 11.3 ± 1.2 mg/dL and 232 ± 329 pg/mL, respectively; 89% had osteoporosis/osteopenia by LS DXA and 46% had renal involvement. There were 7.6% patients with vertebral fractures, 13.2% patients with nonvertebral fractures. TBS indices were derived from LS-DXA images and cutoff points used were those previously reported.

Results: Mean TBS was in the partially degraded range (1.258 ± 0.115); 32% of patients had degraded microarchitecture (TBS ≤ 1.20), 51% had partially degraded microarchitecture (TBS > 1.20 and < 1.35) and 17% had normal TBS. TBS was significantly correlated with areal BMD both at the LS (r=0.544; p<0.001) and FN (r = 0.315; p < 0.001), and negatively with age (r= - 0.354; p < 0.001) and years since menopause - YSM (r = - 0.257, p = 0.005). Patients with vertebral fractures had mean values of TBS in the degraded range, significantly lower than those without vertebral fractures (1.173 ± 0.076 vs. 1.263 ± 0.115; p = 0.006). The presence of vertebral fracture was independently associated only with YSM (OR = 1.131, 95% CI = 0.032 - 0.214, p = 0.008) but not with TBS.

Conclusions: In a cohort of symptomatic PHPT patients, including postmenopausal, premenopausal and male patients, we have shown that TBS was in the partially degraded range, but it was not independently associated with fractures.