AB0173 MORPHOLOGICAL PARAMETERS ASSESSED BY ULTRASOUND IN QUADRICEPS MUSCLE WERE ASSOCIATED WITH CLINICAL FEATURES, MUSCLE STRENGTH, FUNCTIONAL CAPACITY AND PHYSICAL FUNCTION OF RHEUMATOID ARTHRITIS PATIENTS

Abstract

BackgroundRheumatoid arthritis (RA) patients usually present extra-articular manifestations (1,2), which affect muscle mass and, consequently, physical function (3). Among the various methods to assess muscle mass we tested muscle morphology by ultrasound (MU) to verify the associations of the quadriceps muscle with clinical features, muscle strength, functional capacity and physical function.ObjectivesTo assess the MU of the quadriceps muscle and verify the muscle quality assessed by the pennation angle and its associations with clinical features, muscle strength, functional capacity and physical function in RA patients.MethodsRA women, age ≥18years and who met 2010 American College of Rheumatology (ACR) criteria were included. Morphological parameters in quadriceps muscle consisted of the pennation angle of rectus femoris (RF), vastus intermedius (VI) and vastus lateralis (VL). RA activity was measured by 28-joint disease activity score (DAS28), muscle strength by handgrip and chair stand tests, functional capacity by health assessment questionnaire (HAQ), and physical function by timed-up-and-go (TUG) test and short physical performance battery (SPPB). Pearson’s or Spearman’s correlation coefficients were explored. The significance level was set at p ≤ 0.05 for all analyzes.ResultsEighty-one patients were included (age: 58.64±9.52 years old; DAS28: 3.24±1.34). Smaller pennation angle in rectus femoris (RF) were associated with lower handgrip strength (r= 0.224, p=0.044), chair stand test (r= -0.372, p=0.004), HAQ (r= -0.404, p=0.001), SPPB (r= 0.262, p=0.047), as well as higher disease activity by DAS-28 (r= -0.415, p<0.0001) and age (r= -0.290, p=0.009). Smaller pennation angle in vastus intermedius (VI) were associated with worse chair stand (r= -0.281, p=0.033), HAQ (r= -0.302, p=0.015) and higher disease activity by DAS-28 (r= -0.304, p=0.006). Lastly, smaller pennation angle in vastus lateralis (VL) were associated with worse chair stand (r= -0.290, p=0.027), as well as higher DAS-28 (r= -0.237, p=0.033) and age (r= -0.272, p=0.014).ConclusionThe pennation angles of the quadriceps muscle evaluated by ultrasound (RF, VI and VL muscles) were associated with chair stand test and DAS-28. In addition, the level of disease activity assessed by DAS-28 also appears to be affecting the quadriceps muscle. Finally, MU may be a useful method to evaluate the impact of the disease on skeletal muscle.