To investigate if in radiographic axial Spondyloarthritis (r-axSpA) low vertebral bone mineral density (BMD) is associated with development of new syndesmophytes at the same vertebral level.
In a post-hoc analysis from the ASSERT trial (infliximab vs placebo), dual-energy X-ray absorptiometry was used to measure baseline BMD (g/cm
We analysed 599 vertebrae in 165 r-axSpA patients (78% male, mean (SD) age 38 (10) years, 67% with at least one syndesmophyte anywhere in the spine). In total, 24 to 74 new syndesmophytes developed in 9 (5%) to 30 (18%) patients and 13 (2%) to 39 (7%) vertebrae, if either a syndesmophyte was seen by both or only one of the readers (ie, specific and sensitive definitions) respectively. In multivariable analyses, no association was found between baseline local vertebral BMD and new syndesmophyte formation after 2 years: adjOR (95% CI): 0.56 (0.01, 44.45) (specific definition) and 0.26 (0.03, 2.63) (sensitive definition).
In patients with active and established r-axSpA, with an observed low incidence of lumbar spine syndesmophyte formation over 2 years, no relationship was found between baseline BMD and new radiographic syndesmophyte formation at the same vertebra.