Incident subclinical vertebral fractures and health-related quality of life: JPOS cohort study

Vertebral fractures are the most common osteoporotic fractures, yet approximately two-thirds of radiographically detectable fractures remain clinically unrecognized. The longitudinal impact of such subclinical vertebral fractures on health-related quality of life (HRQOL) is not fully clarified. This study examined whether incident subclinical vertebral fractures were associated with subsequent changes in HRQOL.

This study was nested within the Japanese Population-based Osteoporosis (JPOS) Cohort. Community-dwelling women aged ≥ 50 years without clinical fractures were included. Incident subclinical vertebral fractures, assessed by single-energy X-ray absorptiometry-based vertebral fracture assessment with morphometry, were the primary exposure. HRQOL was evaluated using Japanese SF-36® v2. General linear models estimated associations between incident fractures and follow-up SF-36® subscale scores, adjusting for baseline HRQOL and prespecified covariates. Sensitivity analyses excluding participants with pre-baseline subclinical vertebral fractures or with anti-osteoporosis medication were performed.

Of 344 participants, 53 (15.4%) developed incident subclinical vertebral fractures. Baseline SF-36® standardized subscale scores did not differ between groups. At follow-up, women with incident fractures had significantly lower physical functioning and social functioning scores. After multivariable adjustment, social functioning remained significantly lower in the fracture group (false discovery rate-adjusted p = 0.028). Social functioning declined progressively with increasing fracture number and was significantly lower in lumbar fractures. Sensitivity analyses yielded consistent results with primary analyses.

Incident subclinical vertebral fractures among community-dwelling Japanese women were independently associated with clinically meaningful declines in social functioning, suggesting the importance of early identification to prevent deterioration in HRQOL.