FRI0083 GLUCOCORTICOID USE IS ASSOCIATED WITH DETERIORATION OF MUSCLE QUALITY AND FUNCTION: FROM THE CHIKARA STUDY

Abstract

Background:We previously reported that glucocorticoid (GC) use was an independent risk factor for developing sarcopenia in patients with rheumatoid arthritis (RA)1. On the other hand, sarcopenia was not associated with deterioration of muscle function (dynapenia)2.Objectives:Factors associated with deterioration of muscle quality and function were prospectively investigated.Methods:Muscle quality and function were examined by measuring power, speed, and balance in standing-up motion using an exercise functional analysis device (BM-220, Tanita, Japan) at baseline and at 2-year follow-up in the prospective, observational CHIKARA study. Associations between changes in these parameters (Δ muscle quality, Δ muscle function) and body composition, disease activity, treatment, physical function, and history of falls and fractures were investigated by univariate and multivariate analyses.Results:Eighty-one RA patients completed the survey. Their average age was 66 years, disease duration was 5.3 years, the simplified disease activity index (SDAI) was 5.3, and the modified Health Assessment Questionnaire (mHAQ) was 0.25 at baseline. Of the patients, 12.3% used GCs at an average dose of 3.08 mg/day over 2 years. The average GC dose was negatively correlated with changes in muscle quality (r=-0.25, p=0.03), power (r=-0.23, p=0.04), and speed (r=-0.24, p=0.03). The SDAI at baseline was negatively correlated with power (r=-0.23, p=0.04) and speed (r=-0.22, p=0.05) (Table 1). No factor was associated with the mHAQ and a history of falls. No independent factor was identified on multiple regression analysis.Table 1.Associations between changes in muscle quality and function and body composition, disease activity, treatment, physical function, and history of falls and fracturesΔ muscle qualityΔ muscle functionpowerspeedbalancerprprprpage, years-0.210.063-0.110.337-0.230.0410.180.105GC dose, mg/day-0.250.025-0.230.041-0.240.032-0.020.883CRP, mg/dl0.010.9100.030.7810.030.7990.200.067MMP-3, ng/ml-0.250.022-0.130.249-0.170.1340.020.847DAS28ESR-0.090.441-0.050.665-0.090.4350.010.961SDAI-0.140.216-0.230.041-0.220.0480.010.917mHAQ-0.130.248-0.040.728-0.060.578-0.060.585SMI, kg/m20.030.764<0.010.9980.030.7610.240.034BMR, kcal/day0.050.2780.010.960.110.3220.180.111fall0.070.5310.120.2860.020.871-0.020.852fracture<0.010.973<0.010.989-0.050.677-0.190.097Δ, changes from baseline; GC, glucocorticoid; CRP, C-reactive protein; MMP-3, matrix metalloproteinase 3; DAS, Disease Activity Score; ESR, erythrocyte sedimentation rate; SDAI, simplified disease activity index; mHAQ, modified Health Assessment Questionnaire; SMI, skeletal muscle index; BMR, basal metabolic rate.Conclusion:GC use was associated with deterioration in muscle quality and function, as well as sarcopenia development. GC use adversely affected muscle mass, quality, and function. In addition, since high disease activity led to low exercise function, disease activity control is important to prevent deterioration of exercise function.