Sarcopenia is associated with non-motor symptoms in Han Chinese patients with Parkinson's Disease: a cross-sectional study

Background Sarcopenia is commonly seen in the older adults and increases in incidence with age, also in Parkinson’s disease (PD). Although research has indicated that the development of sarcopenia in patients with PD may be related to both motor symptoms and non-motor symptoms (NMS), the precise relationship between the two conditions remains unclear. Therefore, we aimed to investigate the incidence of sarcopenia in patients with PD and its association with NMS. Methods The study included 123 patients with PD and 38 age- and sex-matched healthy controls (HC). All participants were evaluated for sarcopenia using the 2019 Asian Sarcopenia Diagnostic Criteria, and patients with PD underwent standard assessments of motor symptoms and NMS. Multiple logistic regression and receiver operating characteristic (ROC) curve analyses were used to examine the association between sarcopenia and NMS in patients with PD. Results The incidence of sarcopenia was significantly higher in patients with PD than in HC (26.8% vs. 10.4%, p = 0.046). Multiple logistic regression analysis revealed that poorer sleep quality (odds ratio [OR]: 1.245; 95% confidence interval [CI]: 1.011–1.533; p = 0.040) and fatigue (OR: 1.085, 95% CI: 1.006–1.170, p = 0.034) were independently associated with sarcopenia. ROC analysis indicated that the optimal cut-off value for Pittsburgh Sleep Quality Index (PSQI) scores was 10, with 72.7% sensitivity and 74.4% specificity (area under the curve [AUC] = 0.776, 95% CI: 0.683–0.868, p < 0.001). The optimal cut-off value for Fatigue Severity Scale (FSS) scores was 39, with 87% sensitivity and 50% specificity (AUC = 0.725, 95% CI: 0.629 –0.820, p < 0.001). Joint use of FSS and PSQI scores increased the predictive value for sarcopenia(AUC = 0.804, 95% CI: 0.724–0.885, p < 0.001). Conclusion Patients with PD are more susceptible to sarcopenia than healthy older adults, and fatigue and poorer sleep are positively associated with sarcopenia. Further longitudinal studies are needed to clarify the causal relationships.