Abstract
Background/Objectives: The objective of this investigation was to assess the prevalence of sarcopenia and identify its related risk factors in patients with rheumatoid arthritis (RA) using data from the nationally representative 2008–2011 Korea National Health and Nutrition Examination Survey (KNHANES). Methods: We analyzed data from the 2008–2011 KNHANES to identify the factors associated with sarcopenia in patients with RA. Sarcopenia was defined as the ratio of appendicular skeletal muscle mass to total body weight (multiplied by 100), with cut-offs of <29.0% for men and <22.9% for women. To identify the specific factors independently associated with sarcopenia, a multivariate logistic regression model was employed, accounting for sample weights and the complex survey design. Results: Among 238 patients with RA included in the analysis, 44 (weighted prevalence: 22.7%) had sarcopenia. The sarcopenia group had a higher proportion of males (55.0% vs. 15.3%, p < 0.001), body mass index (BMI) (26.1 vs. 23.3 kg/m(2), p < 0.001), and waist circumference (86.9 vs. 79.0 cm, p < 0.001) than the non-sarcopenia group. After adjustment for potential confounders, including age, sex, obesity, physical activity, and daily protein intake, male sex (odds ratio [OR]: 4.17; 95% confidence interval [CI]: 1.48–11.77, p = 0.007) and obesity (OR: 3.06; 95% CI: 1.16–8.07, p = 0.024) were independently associated with sarcopenia. In sex-specific analyses, low physical activity was significantly associated with sarcopenia only in male patients (OR: 13.00; 95% CI: 1.90–88.75, p = 0.012). Conclusions: Our findings indicate that being male and having a higher BMI are significant independent indicators of sarcopenia risk within the Korean RA population. This highlights their critical role in the development of sarcopenia among RA patients.