Abstract
Background Clinically suspect arthralgia (CSA) is characterised by arthralgia of small joints and considered a risk stage for development of rheumatoid arthritis (RA). However, it remains unknown if the function of the hands is already affected and what mechanisms underlie impaired hand-function in CSA. Methods We studied various measures of hand function in two CSA populations. CSA patients in the TREAT EARLIER-trial (n=236) were evaluated at baseline for: grip strength on a dynamometer (GS), patient-reported difficulties in the grip domain of the Health Assessment Questionnaire (HAQ) questionnaire and incomplete fist closure at physical examination. Findings were validated in an independent CSA cohort (n=600) where hand function was measured as: GS evaluated by squeezing the examiner's fingers, grip domain of the HAQ questionnaire and fist closure. Contrast-enhanced MRI of the hands measured synovitis, tenosynovitis and bone marrow oedema (summed as subclinical inflammation) in both cohorts. Results GS (on a dynamometer) was reduced in 75% compared with reference values in healthy controls, 60% reported grip difficulties and 13% had incomplete fist closure. Reduced GS was associated with subclinical inflammation (-0.38 kg/point inflammation, 95% CI -0.68 to -0.08). Studying separate MRI features, GS reduction was independently associated with tenosynovitis, decreasing with -2.63 kg (95% CI -2.26 to -0.33)/point tenosynovitis (range observed tenosynovitis scores: 0-20). Similar relations with tenosynovitis were seen for patient-reported grip difficulties (OR 1.12/point, 95% CI 1.07 to 1.42) and incomplete fist closure (OR 1.36/point, 95% CI 1.03 to 1.79). In the validation cohort, 36% had decreased examiner-assessed GS, 51% reported grip difficulties and 14% incomplete fist closure: all were associated with tenosynovitis. Decreased dynamometer-measured GS was most sensitive for detecting tenosynovitis (75%), while incomplete fist closure was most specific (88%-90%). Conclusion Hand function is already often affected before RA development. These limitations are related to subclinical inflammation and tenosynovitis in particular.
| Original language | English |
|---|---|
| Article number | e002885 |
| Journal | RMD Open |
| Volume | 9 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 9 Feb 2023 |
Bibliographical note
Funding Information: This work was supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Starting grant, agreement No 714312), the Dutch Arthritis Society, and by a ZonMW grant (programma translationeel onderzoek).Publisher Copyright: © 2023 Author(s).