Low serum uric acid levels and levodopa-induced dyskinesia in Parkinson's disease

Abstract

Background Levodopa is the most used and effective medication for motor symptoms of Parkinson disease (PD), its long-term use is associated with the appearance of levodopa-induced dyskinesia (LID). Uric acid (UA) is believed to play an important neuroprotective role in PD. Objective To investigate if serum UA levels are related with the presence of LIDs in PD patients. Also, we investigated the associations among UA levels and clinical features of PD. Methods We enrolled 81 PD patients (dyskinesia = 48; no dyskinesia = 33) in the present study. A blood sample was collected to evaluate serum UA levels, clinical evaluation included the following instruments: Montreal Cognitive Assessment (MoCA), Beck Depression Inventory II (BDI-II), MDS-Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Hoehn and Yahr (HY), and the sub-item 4.1 of MDS-UPDRS IV (score ≥ 1). Additional relevant clinical information was obtained by a clinical questionnaire. Results Serum UA levels were lower in the dyskinesia group when compared with the no dyskinesia group. The same result was found in the UA levels of both men and women. The multivariate analysis showed lower uric acid levels were significantly associated with having dyskinesia (odds ratio [OR] = 0.424; 95% confidence interval [CI]: 0.221–0.746; p = 0.005). Additional analysis verified that serum UA levels are inversely correlated with depressive symptoms, disease duration, MDS-UPDRS IV and time spent with dyskinesia. A positive correlation was found with age at onset of PD symptoms. Conclusions The present study provides a possible role of serum UA levels in LID present in PD patients.

Serum uric acid and Parkinson's disease: A systematic review and meta‐analysis

“…Moreover, a low circulating level of UA may have an association with the severity of PD's clinical presentations as one study revealed that low UA may correlate with dyskinesia severity, especially in women 29 . Moreover, some risk factors of PD such as underlying genetic mutations may be associated with UA metabolism and may affect its serum level in one study, the underlying LRRK2 mutation may associate with a lower level of UA than idiopathic PD 30 …”

Prediction of Parkinson’s Disease Using Machine Learning Methods

“…For example, CSF biomarkers including alpha-synuclein (α-Syn), amyloid β1-42 (Aβ 42 ), total tau (t-tau), and phosphorylated tau (p-tau) are associated with cognitive decline and can serve as independent predictors of cognitive impairment in PD [13]. Low levels of uric acid are significantly correlated with motor impairments [14]. Genetic factors have also played a significant role in PD, although less than 1% of cases are caused by a single gene mutation [2].…”