Serum uric acid levels in patients with Parkinson’s disease: A meta-analysis
March
Serum uric acid levels in patients with Parkinson's disease: A meta-analysis
Min Wen 0 1
Bo Zhou 0
Yun-Hua Chen 0 1
Zhao-Lei Ma 0
Yun Gou 0 1
Chun-Lin Zhang 0
Wen- Feng Yu 0
Ling Jiao 0
0 Editor: Gotthard Kunze, Leibniz-Institut fur Pflanzengenetik und Kulturpflanzenforschung Gatersleben , GERMANY
1 Department of Anatomy, Guizhou Medical University , Guiyang , China , 2 Department of Biology, Guizhou Medical University , Guiyang , China , 3 Department of Neurology, BaiYun Hospital, Guizhou Medical University , Guiyang , China , 4 Key Laboratory of Endemic and Ethnic Diseases , Ministry of Education , P. R. China; Key Laboratory of Medical Molecular Biology, Guizhou Medical University , Guizhou Province, Guiyang , P. R. China , 5 Department of Neurology, Affiliated Hospital, Guizhou Medical University , Guiyang , China
Results
Thirteen studies with a total of 4646 participants (2379 PD patients and 2267 controls) were
included in this meta-analysis. The current results showed that the serum UA levels in PD
patients were significantly lower compared to sex and age-matched healthy controls (SMD:
-0.49, 95% CI: [-0.67, -0.30], Z = 5.20, P < 0.001) and these results showed no geographic
regional (Asia: SMD = −0.65, 95% CI [−0.84, −0.46], Z = 6.75, p <0.001; Non-Asia: SMD =
−0.25, 95% CI [−0.43, −0.07], Z = 2.70, p = 0.007) and sex differences (women: SMD =
−0.53, 95% CI [−0.70, −0.35], z = 5.98, p <0.001; men: SMD = −0.66, 95% CI [−0.87,
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OPEN ACCESS
Data Availability Statement: All relevant data are
within the paper and its Supporting Information
files.
Funding: This study was supported by the Natural
Science Foundation of Guizhou Province of China
(LG [2012]021 and LG[2011]023).
Competing interests: The authors have declared
that no competing interests exist.
Background
Objectives
Methods
−0.44], z = 6.03, p <0.001). Serum UA levels in middle-late stage PD patients with higher
H&Y scales were significantly lower than early stage PD patients with lower H&Y scales
(SMD = 0.63, 95% CI [0.36,0.89], z = 4.64, p <0.001).
Conclusions
Our study showed that the serum UA levels are significantly lower in PD and the level is further decreased as the disease progresses. Thus it might be a potential biomarker to indicate the risk and progression of PD.
1 Introduction
Parkinson's disease (PD) is the second most common neurodegenerative disease that affects
approximately 1±2% of the population over 60 years[
1
]. PD is characterized by an extensive
and progressive loss of dopaminergic neurons in the substantia nigra pars compacta[2]. The
cause and pathogenesis resulting from the loss of selective dopamine neurons in PD remain
elusive. But increasing evidence suggests that an oxidative stress plays an important role in the
degeneration of dopaminergic neurons in PD[
3
]. Consequently, research efforts have been
directed towards understanding the pathological role of oxidative stress in the pathogenesis
and in the hope of developing more effective therapy approaches for the treatment of PD[
4
].
Uric acid (UA), one of the end products of purine metabolism is a natural antioxidant in
blood and brain tissue, which has neuroprotective effects on PD by effectively scavenging
oxygen radicals and reactive nitrogen[5±6]. Numerous large prospective studies have shown that
the high levels of serum or plasma urate reduced the risk of PD [7±8]. Recently, the association
between serum urate levels and PD has gained intensive interests, but results of these studies
have been inconsistent. Some studies have shown a clear trend of lower serum urate levels in
PD and subgroups based on sex [9±17], while others showed no significant variation of lower
serum urate levels in PD [18±23]. Our previous studies showed that the serum UA levels in PD
patients were significantly lower than sex and age-matched healthy controls and the UA
concentrations were decreased with the deterioration of the illness[
24
].
To evaluate the potential relationship between serum urate levels and PD, a meta-analysis
was conducted in this present study by combining all available data together.
2 Materials and methods
2.1 Search strategies
A computerized search of Pubmed, Web of Science, and the Cochrane Library up to Dec 2015
was conducted using the following search strategy: ªParkinson's diseaseº, (ªbloodº, ªplasmaº
or ªserumº), and (ªuric acidº or ªurateº). The search was restricted to English language. The
reference lists of relevant studies were also searched for possible studies meeting criteria. If
there was an initial disagreement on studies to be included, discussion among researchers
established universal agreement. A flowchart of information pertaining to identification,
screening, eligibility, and final studies included was constructed according to ªPreferred
Reporting Items for Systematic Reviews and Meta-analysesº (PRISMA) guidelines [
25
].
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2.2 Inclusion (...truncated)