Changes in serum uric acid, glutathione, and amyloid-β1-42 levels in Parkinson's disease patients and their association with disease progression and cognitive decline.

OBJECTIVE

This study aims to evaluate the diagnostic significance of serum uric acid (UA), glutathione (GSH), and amyloid-β1-42 (Aβ1-42) levels in relation to disease progression and cognitive impairment in patients with Parkinson's disease (PD).

METHODS

A total of 209 PD patients with disease duration ranging from 4.0 to 6.8 years were enrolled. Based on the Hoehn-Yahr staging system, patients were classified into Early ( = 67), Medium-term ( = 70), and Advanced ( = 72) stages. Cognitive function was assessed using the Mini-Mental State Examination (MMSE), dividing the cohort into CD (cognitive dysfunction,  = 94) and NO-CD (no cognitive dysfunction,  = 115) groups. Serum UA, GSH, and Aβ1-42 levels were analyzed for correlations with clinical data. Independent risk factors and diagnostic value were determined through multivariable logistic regression models and receiver operating characteristic curve analysis.

RESULTS

Serum UA and GSH levels progressively declined with advancing disease stage, while Aβ1-42 increased. Compared to the NO-CD group, the CD group showed lower serum UA and GSH levels, and higher Aβ1-42 levels. Serum UA and GSH were inversely correlated with disease duration, levodopa equivalent daily dose, and Unified Parkinson's Disease Rating Scale scores, while Aβ1-42 showed positive correlations. UA ( = 0.006), GSH ( < 0.001), and Aβ1-42 ( = 0.040) were independent predictors of disease stage. Similarly, UA ( = 0.003), GSH ( < 0.001), and Aβ1-42 ( < 0.001) were independent predictors of cognitive dysfunction. The combined assessment of these markers demonstrated a higher area under the curve (AUC) than individual markers for disease and cognitive decline identification.

CONCLUSIONS

Serum UA, GSH, and Aβ1-42 are independent predictors of disease progression and cognitive decline in PD patients. Their combined use offers enhanced diagnostic accuracy for disease staging and cognitive impairment in PD.