L-shaped association of bone mineral density with all-cause mortality in individuals with osteoarthritis.

BACKGROUND

Osteoarthritis (OA) is a common joint disease that poses a significant public health burden, particularly in older adults. Despite research on its impact, the role of bone mineral density (BMD) in OA prognosis remains underexplored. This study investigates the association between BMD, measured using dual-energy X-ray absorptiometry (DXA), and all-cause mortality in individuals with OA using data from the National Health and Nutrition Examination Survey (NHANES).

METHODS

This retrospective cohort study utilized NHANES data from 1999 to 2018, including participants aged 20 years and older (n = 55,081). After excluding individuals with missing BMD or mortality data, 1,573 participants diagnosed with OA were analyzed.

RESULTS

The multivariate-adjusted hazard ratio (HR) for BMD and all-cause mortality was 0.344 (0.153, 0.774), indicating a protective effect of higher BMD. We observed an L-shaped relationship between BMD and mortality: a 1-unit decrease in BMD was associated with a 97.3% increased HR for mortality when BMD was below 1.216 g/cm² (HR 0.027, 95% CI 0.010-0.069). No significant association was found for higher BMD levels (HR 4.490, 95% CI 0.431-46.754). In age-stratified analysis, a significant association was found in both those under and over 50 years old.

CONCLUSIONS

This study reveals an L-shaped association between BMD and all-cause mortality in individuals aged 20 and older with OA, underscoring the importance of maintaining bone health in this population. These findings highlight BMD as a prognostic marker and suggest that monitoring BMD could improve clinical outcomes for OA patients.

CLINICAL TRIAL NUMBER

Not applicable.