Risk factors for sarcopenia in RA include older age, a lower body mass index (BMI), body fat, duration of the disease, bone erosion, joint damage, malnutrition and low protein intake, functional disability, higher protein levels, C reactive (CRP), erythrocyte sedimentation rate (ESR), rheumatoid factor (RF), matrix metalloprotease 3 (MMP3), and glucocorticoid use [83]. The gene discussed is MMP3; the disease is nutritional deficiency disease.