Trabecular Bone Score (TBS) Predicts Vertebral Fractures in Japanese Women Over 10 Years Independently of Bone Density and Prevalent Vertebral Deformity: The Japanese Population-Based Osteoporosis (JPOS) Cohort Study

Abstract

Bone strength is predominantly determined by bone density, but bone microarchitecture also plays an important role. We examined whether trabecular bone score (TBS) predicts the risk of vertebral fractures in a Japanese female cohort. Of 1950 randomly selected women aged 15 to 79 years, we analyzed data from 665 women aged 50 years and older, who completed the baseline study and at least one follow-up survey over 10 years, and who had no conditions affecting bone metabolism. Each survey included spinal imaging by dual-energy X-ray absorptiometry (DXA) for vertebral fracture assessment and spine areal bone mineral density (aBMD) measurement. TBS was obtained from spine DXA scans archived in the baseline study. Incident vertebral fracture was determined when vertebral height was reduced by 20% or more and satisfied McCloskey-Kanis criteria or Genant's grade 2 fracture at follow-up. Among eligible women (mean age 64.1 AE 8.1 years), 92 suffered incident vertebral fractures (16.7/10 3 person-years). These women were older with lower aBMD and TBS values relative to those without fractures. The unadjusted odds ratio of vertebral fractures for one standard deviation decrease in TBS was 1.98 (95% confidence interval [CI] 1.56, 2.51) and remained significant (1.64, 95% CI 1.25, 2.15) after adjusting for aBMD. The area under the receiver operating characteristic curve of TBS and aBMD combined was 0.700 for vertebral fracture prediction and was not significantly greater than that of aBMD alone (0.673). However, reclassification improvement measures indicated that TBS and aBMD combined significantly improved risk prediction accuracy compared with aBMD alone. Further inclusion of age and prevalent vertebral deformity in the model improved vertebral fracture prediction, and TBS remained significant in the model. Thus, lower TBS was associated with higher risk of vertebral fracture over 10 years independently of aBMD and clinical risk factors including prevalent vertebral deformity. TBS could effectively improve fracture risk assessment in clinical settings.

Oxygen-sensing PHDs regulate bone homeostasis through the modulation of osteoprotegerin

“…We did not detect changes in cortical bone, a large determinant of bone strength and nonvertebral fracture risk. However, trabecular bone is important for the prevention of osteoporosis, particularly for the impediment of vertebral fractures, which result in pain, functional disability, and decreased quality of life (Gerdhem 2013;Iki et al 2014). Therefore, the resulting increases in trabecular bone volume afforded by PHD2 and PHD3 inactivation may have important clinical implications.…”

Quantitative imaging methods in osteoporosis

“…TBS is less expensive and more easily accessible than CT or MRI for wide-spread clinical implementation or as an outcome in large research studies. The very first TBS reports showed applications for the prediction of fracture risk in osteoporosis (39)(40)(41), have added value in those individuals with bone density outside of the osteoporosis range (42) and monitoring of treatment effects (43,44), and similarly, TBS may find an application in other conditions such as primary hyperparathyroidism (45), hypercortisolism (46), rheumatoid arthritis (47), and diabetes-related bone disease (48). A major advantage is that it can be derived from DXA scans using dedicated post-processing software.…”

Trabecular bone score: perspectives of an imaging technology coming of age

“…A number of cross-sectional (24)(25)(26)(27)(28)(29) and prospective (15,16,30,31) studies have shown an association between LS TBS and vertebral, hip, and other types of osteoporotic fractures in postmenopausal women. A recent published cross-sectional study has also demonstrated that TBS is associated with fractures in men (32).…”

“…Data from prospective studies are summarized in table 3 (15,16,30,31). The Manitoba study was the largest one to examine the ability of LS TBS to predict fracture risk (16).…”