Whole-hand and regional bone mineral density involvement in rheumatoid arthritis

Abstract

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by symmetric polyarthritis that can lead to joint deformity and disability and osteoporosis. We aimed to evaluate the whole-hands and regional BMD in RA patients compare to controls. In addition, we evaluated the BMD of the dominant versus non-dominant hands in healthy subjects. We included adult female and male RA patients and control subjects matched by age, sex and BMI. BMD (g/cm2) was measured DXA in lumbar spine (LS), whole-hands and three regions of interest: carpus, metacarpal bones and phalanges. Results: 44 control subjects (49.5±11.8 y) and 60 with RA (52.7±12.7 y) were included. Significant lower BMD in RA patients was found in LS (-8.7%), dominant whole-hand (-9.5%), carpus, metacarpal bones, and phalanges, and non-dominant whole-hand (-8.7%), metacarpal bones, and phalanges compared to controls. A significant positive correlation was found between LS and whole-hand BMD (dominant r=0.63, non-dominant r=0.67). Finally, the whole-hand, metacarpal bones and carpus BMD were significantly higher in the dominant hand compared to non-dominant hand without differences in the ROI phalanges. In conclusion hand BMD was significantly lower in RA patients compared to control subjects and there was a significant correlation with LS BMD. We demonstrated that BMD measurements of the whole-hand, and different ROI (carpus, metacarpal bones and phalanges) by DXA would be an easily reproducible technique to evaluate bone loss. In addition, the whole-hand, metacarpal bones and carpus BMD were significantly higher in the dominant hand compared to non-dominant hand without differences in the phalanges.