In patients with rheumatoid arthritis (RA), poorer muscle performance composite scores are associated with increased disease activity based on the Disease Activity Score for 28 joints (DAS28), according to a cross-sectional analysis published in PLoS One.
A total of 199 consecutive outpatients with RA underwent cross-sectional evaluation. Measurements of grip strength, endurance of upper and lower limbs, and trunk strength were combined as a muscle performance composite score with a standardized method of assessment. DAS28, radiographs of small joints graded with the Larsen score, rheumatoid factor, body mass index (BMI), use of antirheumatic medications, and comorbidities were ascertained. Patient questionnaires were administered that evaluated socioeconomic data, pain level, global disease activity, Beck Depression Inventory, level of physical activity, and the mental and physical components scores of Short-Form-36 (SF-36).
Of the 199 patients evaluated, 36% (n=72) experienced remission, 17% (n=33) experienced low or moderate DAS28 values, and 47% (n=94) experienced high DAS28 values. The participants who were in remission had significantly shorter disease duration (P <.001), as well as significantly better parameters in terms of pain (P <.001), physician’s assessment (P <.001), Larsen scores (P <.001), Beck scores (P = .003), and physical component scores on the SF-36 (P <.001) compared with participants with low/moderate and high DAS28 values. The patients in remission were also more physically active compared with the other patients (P =.037).
Following adjustment for age, gender, disease duration, radiographs, and BMI, decreasing muscle performance composite scores values were significantly associated with increasing DAS28 activity (linearity, P <.001).
The investigators concluded that the muscle performance composite score has a linear association with DAS28 activity, with modifiable risk factors including muscle performance and physical activity. Prospective studies are warranted in order to establish a link between muscle strength and disease activity in patients with RA. Study findings suggest that muscle performance could be performed in clinical practice as part of routine patient care in the RA population.
Uutela TI, Kautiainen HJ, Häkkinen AH. Decreasing muscle performance associated with increasing disease activity in patients with rheumatoid arthritis. PLoS One. 2018;13(4): e0194917.