The Association Between Short-Term Bone Loss and Future Osteoporotic Vertebral Fractures

To investigate the relationship between longitudinal change in Hounsfield Units (HU) value and future osteoporotic vertebral fracture (OVF).

This longitudinal case-control study involved 52 cases with future OVF and 104 age- and sex-matched controls. Each participant underwent two chest computed tomography (CT) scans. The baseline regional (anterior, middle, posterior, superior, inferior) and integral HU value from T4, T7, T10, and L1 vertebrae were measured. The coefficient of variation (CV) indicated heterogeneity in HU. Bone loss was quantified by the annual rate of HU value loss. Conditional logistic regression was employed to evaluate the independent risk factors (baseline CT characteristics and annual HU value loss) for each vertebra in predicting future OVF.

The baseline regional and integral HU value of T4, T7, T10 and L1 significantly decreased in OVF patients compared to the controls (p ≤ 0.001), with the integral HU value negatively related to future OVF. A decreased superior/inferior HU rate for T7 vertebra (OR=0.397, p=0.003) and an increase in CV for L1 vertebra (OR=1.110, p=0.034) were independently correlated with future OVF. With a follow-up interval of 22.40 ± 12.28 months for the OVF group and 35.15 ± 12.42 months for the control group, a higher annual rate of HU value loss (per 1% increased) was independently positively connected to the risk of future OVF (OR = 1.074, 1.088, and 1.099, for T4, T7, and T10 vertebrae, respectively, all p≤ 0.006).

Reduced baseline vertebral HU value and increased annual HU value loss calculated by chest CT may be crucial for predicting OVF, providing valuable guidance for future short-term (approximately 1-3 years) OVF risk evaluation.