Radiofrequency Echographic Multi Spectrometry (REMS) for the evaluation of bone health in systemic lupus...

The aim of this study was to evaluate the agreement between DXA and REMS in a cohort of SLE patients. REMS and DXA showed a fair to moderate agreement on osteoporosis diagnosis, with a similar ability to identify fracture risk. REMS tended to show lower bone mineral density and was more influenced by patients' demographics.

The aim of this study was to assess the diagnostic agreement between Radiofrequency Echographic Multi Spectrometry (REMS) and dual-energy X-ray absorptiometry (DXA) for bone mineral density (BMD) in patients with systemic lupus erythematosus (SLE), particularly those receiving glucocorticoids (GCs).

One hundred-six SLE patients (44 GC-treated) underwent BMD assessment at the lumbar spine (LS), femoral neck (FN), and total hip (TH) using both DXA and REMS. We compared BMD and T-scores between methods and analyzed diagnostic agreement using linear regression, Cohen's kappa and Bland-Altman analysis. Receiver operator characteristic (ROC) curves evaluated the ability of REMS and DXA to discriminate fracture status.

BMD measurements at all sites were significantly lower with REMS when compared with DXA across all skeletal sites (p < 0.001). Agreement in osteoporosis classification was slight to moderate (κ ranging from 0.229 at LS in all patients to 0.549 at FN in GC-treated patients). REMS showed moderate correlation with DXA and demonstrated 45% sensitivity and 88.4% specificity for diagnosing osteoporosis. Both REMS and DXA identified significant BMD differences between patients with and without vertebral fractures across all sites. ROC analysis revealed similar discriminative ability for fracture risk between REMS and DXA. REMS BMD values were more strongly associated with age, sex, and body mass index.

REMS and DXA showed a fair to moderate agreement in osteoporosis diagnosis and in fracture discrimination in SLE patients. While REMS appears a supportive tool in this setting, particularly in GC-treated individuals, further longitudinal studies are warranted to validate its predictive value and clinical utility.