Serum GDF-15 Levels Correlate With Motor and Nonmotor Symptom Domains and Overall Disease Severity in Patients With Parkinson's Disease.

Objective: Growth differentiation factor 15 (GDF-15) has emerged as a potential biomarker for neurodegenerative diseases. Although elevated serum GDF-15 levels have been reported in Parkinson's disease (PD), their association with clinical features has not been fully characterized.

Methods: We evaluated serum GDF-15 concentrations in 40 patients with PD and analyzed their relationships with clinical measures, including motor severity (MDS-UPDRS), quality of life (PDQ-39), sleep disturbances (PDSS-2), autonomic symptoms (SCOPA-AUT), and cognitive function (MoCA-J).

Results: Higher serum GDF-15 levels were associated with older age and greater symptom burden across multiple domains. Significant relationships were observed with MDS-UPDRS Parts I-III and total scores, PDQ-39 summary index and bodily discomfort index, two different PDSS-2 domains (motor symptoms at night and PD symptoms at night), and SCOPA-AUT total and gastrointestinal dysfunction scores. After adjusting for age, the associations between serum GDF-15 levels and MDS-UPDRS Part II, Part III, and total scores remained significant. No sex-related differences were detected. A trend toward lower MoCA-J scores with increasing GDF-15 levels was observed but did not reach statistical significance.

Conclusion: Serum GDF-15 levels are linked to both motor and nonmotor aspects of PD and may reflect overall disease burden. Further longitudinal studies are needed to determine their value for disease monitoring and prognosis.