Objective: The aim of this study was to assess the effect of baseline inflammation on Magnetic Resonance Imaging (MRI) on the change in Bone Mineral Density (BMD) over 5 years in patients with early spondyloarthritis (SpA). Methods: From the patients of the DESIR cohort (an early axial SpA cohort), patients with BMD data at both baseline and 5 years, and baseline spine and sacroiliac joints MRI were included. Inflammation was assessed with the SpondyloArthritis Research Consortium of Canada (SPARCC) spine score. Significant BMD loss was defined by a change of >0.03g/cm2. No patients had received TNF blockers before inclusion in the cohort. Univariate and multivariable prognostic analyses were performed. An inverse propensity score weighting method was used to handle confounders. Results: One hundred and eighty-three patients were included (mean age 33.9±8.7 years, 58.5% men). A significant bone loss was reported in 51% (n=92) of patients at either lumbar spine or hip. Fourteen (7%) patients had low BMD (Z-score <-2) at the end of the follow-up vs. 28 (15%) at baseline. In multivariable analysis, age was a protective factor of 5 year-BMD loss at any site (OR=0.96, 95% CI [0.93-0.99]). Baseline MRI inflammation has no significant effect on BMD change at any site (OR=0.84, 95% CI [0.46-1.53]). Conclusion: Half of patients with early SpA have a significant bone loss at either lumbar spine or hip over 5 years. Baseline MRI inflammation is not a determinant of this bone loss.