What does pain sensitivity really predict in rheumatoid arthritis patients?

OBJECTIVES

The present study aimed to compare the pressure-pain threshold (PPT) values in patients with rheumatoid arthritis (RA) and age-gender matched controls with chronic nonspecific low back pain and to determine whether PPT values could be beneficial as a disease activity predictor after secondary fibromyalgia had been ruled out.

METHODS

This study contained a cross-sectional observational study of participants with RA and chronic nonspecific low back pain controls without fibromyalgia. Visual analog scale (VAS), fatigue severity scale (FSS), pain catastrophizing scale (PCS), health assessment questionnaire (HAQ), hospital anxiety and depression scale (HADS), and disease activity score (DAS28) were administered. Pressure-pain threshold (PPT) values were measured with a baseline dolorimeter at the thumbnail bed, the dorsal aspect of the wrist, and the trapezius muscle on the dominant side.

RESULTS

There were no differences in PPT scores at all points between RA and control groups. Female participants with RA had statistically lower PPT scores (high pain sensitization) at the wrist (p<0.001) and trapezius (p<0.001), but not at the nail bed (p=0.084). Multiple regression analysis identified only HADS-Depression as a determinant of the PPTs at all points.

CONCLUSION

The present study suggests that lower PPT is associated with depressive symptoms in participants with RA, and pressure algometry should be considered as an additional evaluation to detect pain/depression overlap.