Association Between Dynapenia/Sarcopenia, Extrapyramidal Symptoms, Negative Symptoms, Body Composition, and Nutritional Status in Patients with Chronic Schizophrenia

<b>Background/Objectives:</b> This study aimed to determine the association between chronic schizophrenia, extrapyramidal symptoms (EPSs), body composition, nutritional status, and dynapenia/sarcopenia. <b>Methods:</b> Data from 68 chronic patients with schizophrenia were analyzed using Spearman's rho correlation coefficients, Kruskal-Wallis test, Mann-Whitney U test, and Cramér's V statistics. <b>Results:</b> Among the participants, 32.4% had no loss of muscle mass or function, 39.7% had dynapenia, and 27.9% had sarcopenia. This study identified five key findings: (1) Bilateral grip strength, skeletal muscle index, and walking speed are interrelated, with higher negative symptom scores linked to slower movement and rigidity, particularly in the sarcopenia group, indicating that negative symptoms may contribute to muscle weakness and progression to sarcopenia. (2) Increasing age is associated with a decrease in chlorpromazine equivalent dose and an increase in the severity of EPSs. (3) Blood urea nitrogen (BUN)/creatinine ratio and all sarcopenia risk indicators were significantly negatively correlated. (4) Dynapenia and sarcopenia groups exhibited significant differences in muscle mass and nutritional status compared to the non-penia group, including reduced muscle mass, lower basal metabolic rate, and lower visceral fat levels. (5) There was an association between the Barthel Index (BI) score for activities of daily living (ADL) and dynapenia/sarcopenia. Particularly with regard to ADL, it seems necessary to pay attention to muscle weakness in partially independent patients who score 60 points or more. <b>Conclusions:</b> BUN/creatinine ratio, BI, EPSs, body mass index, grip strength, total protein, and albumin were useful indicators for detecting the risk of dynapenia/sarcopenia in routine psychiatric care.