OP0133 THE DECREASE OF MUSCLE MASS BY THE BEHAVIORAL RESTRICTION OF COVID-19 PANDEMIC IN PATIENTS WITH RHEUMATOID ARTHRITIS

Abstract

BackgroundWe previously reported the prevalence of sarcopenia and body compositions at patients with rheumatoid arthritis (RA)1. The behavioral restriction of COVID-19 pandemic influenced for the lifestyle of people included patients with RA.ObjectivesThe change of exercise and daily life activity of patients with RA were investigated and body composition and muscle function were compared pre- and post-behavioral restriction.MethodsWe used the date from prospective observational study (CHIKARA study: UMIN000023744). 70 from 100 patients with RA were followed-up and evaluated the change of exercise and daily life activity by visual analog scale. They were measured the muscle mass, fat mass, basal metabolic rate by body composition analyzer and grip strength as muscle function. The relationship between the change of exercise and daily life activity and body composition was investigated by univariate analysis.ResultsMean age was 69.7 years (women n=57, men n=13). The rate of decrease of exercise by <25%, 26~50%, and 51%< were 70%, 21%, and 9%, respectively (mean:20% decrease). Whereas, the rate of decrease of daily life activities by <25%, 26~50%, and 51%< were 37%, 27%, and 36%, respectively (mean:44% decrease). Muscle mass at post-behavioral restriction decrease significantly compared that at pre-behavioral restriction activities (34.0kg vs 34.7kg, P<0.001). Fat mass at post-behavioral restriction increase significantly compared that at pre-behavioral restriction (16.2kg vs 15.5kg, P=0.014). Grip strength at post-behavioral restriction decrease significantly compared that at pre-behavioral restriction (16.2kg vs 17.2kg, P=0.026). The change of exercise was significantly positively correlated with the change of muscle mass and basal metabolic rate (R=0.273, P=0.021 and R=0.256, P=0.033, relatively) at Table 1. Whereas, the change of daily living activities was not significantly correlated with the change of muscle mass and muscle function.Table 1.Univariate analysis of the changes in daily living activities or exercise and those in body composition or muscle functionChange of daily living activitiesChange of exerciseR valueP valueR valueP valueΔ Weight (kg)-0.1230.311-0.1310.279Δ BMI (kg/m2)-0.1080.397-0.1130.345Δ Muscle mass (kg)0.1400.3110.2730.021Δ Fat mass (kg)-0.0610.614-0.0750.539Δ Fat percentage (%)-0.0030.982-0.0180.884Δ Basal metabolic rate (kcal)0.2010.0950.2560.033Δ Grip strength (kg)0.1170.3360.0370.762Δ Walk speed (m/s)0.1690.1610.1390.250Δ, change from pre- to post-behavioral restriction; BMI, body mass indexAnalyzed by Spearman’s rank correlation coefficientConclusionMuscle mass and grip strength decrease and fat mass increase in patients with RA by the behavioral restriction of COVID-19 pandemic. Muscle mass and basal metabolic rate decrease in patients without exercise habits. Maintenance of muscle mass might be important during the COVID-19 pandemic.