Enhanced bone quality assessment through trabecular bone score and bone mineral density in lumbar spine

Bone mineral density (BMD) alone is insufficient to fully capture fracture risk. This study investigated the association between lumbar spine BMD (LS-BMD) and trabecular bone score (TBS) and constructed age- and sex-specific centile reference curves for both measures in a Taiwanese population.

This cross-sectional study included 1,196 participants. LS-BMD was measured at L1-L4 by dual-energy X-ray absorptiometry (DXA), and TBS was derived from the same images using TBS iNsight software (Med-Imaps). Pearson correlation and multiple linear regression were performed to examine BMD-TBS associations and identify predictors of TBS variation. Generalized Additive Models for Location, Scale and Shape (GAMLSS) with cubic spline smoothing was applied separately by sex to generate continuous age-specific centile curves (5th-95th percentiles) for ages 20-90 years.

The cohort comprised 530 (44.3%) participants with normal BMD, 493 (41.2%) with osteopenia, and 173 (14.5%) with osteoporosis. LS-BMD and TBS were positively correlated (r = 0.68). LS-BMD, BMI, and age were significant independent predictors of TBS (adjusted R² = 0.672); menopausal status was not. GAMLSS centile curves revealed that female LS-BMD peaked at ages 30-40 years and declined sharply after age 50, while male upper BMD centiles remained stable despite concurrent TBS decline, a BMD-TBS dissociation undetectable by mean-based analyses.

LS-BMD and TBS provide complementary information on bone quantity and microarchitectural integrity. The sex-specific GAMLSS-derived centile curves constitute the first full-distribution normative reference standards for LS-BMD and TBS in a Taiwanese population, extending beyond conventional T-score classification.