Grip Strength Asymmetry as a Better Indicator of Residual Hand Symptoms than Absolute Grip Strength After Achieving Treat-To-Target in Rheumatoid Arthritis

Objective This study aimed to identify factors associated with residual hand symptoms in well-controlled rheumatoid arthritis (RA) patients. Methods Data from 464 RA patients with DAS28-ESR < 3.2 and bilateral grip strength measurements were analysed. Grip strength asymmetry was defined as a grip difference rate ≥ 20%, calculated as follows: (Stronger hand grip strength—Weaker hand grip strength)/Stronger hand grip strength × 100. Patients were grouped by the presence (n = 107) or absence (n = 357) of hand symptoms. Multivariable logistic regression was used to identify associated factors. The relationship between grip strength asymmetry and hand symptoms was also examined. Results Patients with hand symptoms were younger (64.3 versus 69.1 years), had higher DAS28-ESR scores (2.42 versus 2.04), and a greater grip difference rate (19.9% versus 14.5%) compared to those without. Multivariable analysis showed that age (OR 0.97), Steinbrocker stage (OR 1.36), and grip difference rate (OR 1.02) were independently associated with hand symptoms. The prevalence of hand symptoms and swelling was higher in the grip strength asymmetry group than in the non-asymmetry group (hand symptoms: 30.8% versus 19.8%; swelling: 11.2% versus 5.3%). Conclusions Grip strength asymmetry may serve as a simple and accessible marker for residual joint symptoms in RA patients achieving T2T.