# Clinical correlates of physical performance and sarcopenia in Parkinson's disease: a cross-sectional study

## TL;DR

This study finds that physical performance in Parkinson's disease patients is strongly linked to sarcopenia and gait issues, suggesting these factors could help predict functional decline.

## Contribution

The study identifies SARC-F and PIGD as independent predictors of poor physical performance in Parkinson's disease patients.

## Key findings

- Low physical performance was observed in 39% of patients and strongly associated with sarcopenia screening (SARC-F score ≥ 4).
- Higher PIGD scores and SARC-F ≥ 4 correlated with poor physical performance in Parkinson's disease.
- SARC-F and PIGD emerged as independent predictors of poor physical performance in multivariable models.

## Abstract

Parkinson's disease (PD) presents motor and non-motor symptoms that impair function and quality of life. Identifying clinical factors linked to physical performance is key for patient care and management.

To examine associations between sarcopenia-related measures and physical performance in mild-to-moderate PD (Hoehn & Yahr [HY] I–III).

This was a cross-sectional study including patients with idiopathic Parkinson's disease at mild to moderate stages (Hoehn & Yahr I–III), evaluated in the ON medication state. Physical performance was assessed using the Short Physical Performance Battery (SPPB). Sarcopenia was evaluated according to the revised European Working Group on Sarcopenia in Older People (EWGSOP2) consensus, including screening with the SARC-F questionnaire and the Ishii score, assessment of muscle strength by handgrip dynamometry, and evaluation of body composition and appendicular lean mass by whole-body dual-energy X-ray absorptiometry (DXA). Analyses included bivariate comparisons, correlation analyses, and logistic regression models (Enter and Best Subsets).

A total of 127 patients were evaluated (mean age 66 years; 41.7% females). Low physical performance was observed in 39% (n = 50) of patients and was strongly associated with positive screening of sarcopenia (SARC-F score ≥ 4; odds ratio [OR]: 1.67; 95%CI: 1.30–2.15;
p
 < 0.001). Ishii score (
p
 = 0.009), reduced mean handgrip strength (26 ± 10 kgf versus 30 ± 10 kgf;
p
 = 0.02), and postural instability and gait difficulty (PIGD) (
p
 < 0.001) were also significantly associated with low SPPB performance in bivariate analyses. In the multivariable models, SARC-F and PIGD emerged as independent predictors of poor physical performance. The best subset model, combining SARC-F and PIGD, showed good discriminative accuracy (area under the curve [AUC] = 0.82).

Higher PIGD scores and SARC-F ≥ 4 correlated with poor physical performance in PD. Low performance was linked to both SARC-F and Ishii scores, which help identify risk of functional decline. Longitudinal studies are needed to clarify causality and treatment implications.