Trabecular bone score and bone quantitative ultrasound in Spanish postmenopausal women. The Camargo Cohort Study

Objective: To evaluate trabecular bone score (TBS) in Spanish postmenopausal women from our area. To analyze its relationship with bone mineral density (BMD), bone quantitative ultrasound (QUS) and serum concentrations of 25-hydroxyvitamin D (25(OH)D), intact parathyroid hormone (PTH) and bone turnover markers. Study design: A total of 1450 postmenopausal women aged 44-94 (62 +/- 10) participated in this cross-sectional study nested in a population-based cohort. BMD and TBS were assessed by DXA. QUS measurements were performed using a Sahara Clinical Sonometer. Serum 25(OH)D, PTH, P1NP, beta-CTX were determined by electrochemiluminescence. Results: Mean TBS of postmenopausal women in our region was 1.341 +/- 0.111. Nearly 50 % of them had normal values. Only 11 % had scores compatible with a clearly degraded microarchitecture. TBS decreased with age, correlated negatively with BMI and was lower in current smokers than in non-smokers. An association was observed between TBS and QUS, although the association was weak and lower than that found between TBS and BMD or QUS and BMD. No association was found between TBS and 25(OH)D, PTH or bone turnover markers. Conclusions: Half of postmenopausal women in our region have TBS values that indicate a preserved microarchitecture. Only about 10 % have scores compatible with a clearly degraded microarchitecture. A weak association was observed between TBS and QUS, suggesting that the two techniques capture different aspects of bone microarchitecture. The absence of association with 25(OH)D, PTH, and bone turnover markers may be due to the fact that TBS assesses a specific (mostly trabecular) part of the skeleton, whilst the three serum factors are related to the whole skeleton.