Wysham KD, et al. - In a study population of rheumatoid arthritis (RA) patients, RA characteristics, medication use, and body composition were assessed as contributors to low bone mineral density (BMD) in these patients. A strong association of high anti-cyclic citrullinated peptide (CCP) positivity and appendicular lean mass index (ALMI) with BMD was evident in this patient population. The observed linear relationship of anti-CCP levels with lower BMD supported the presumption that processes specific to RA negatively impact BMD. In contrast, a positive association of ALMI with BMD underscored the significance of this potentially modifiable risk factor. These data highlight the complicated interplay of RA disease-specific and functional factors and their impact on bone mass.