title: Serum uric acid and risk of dementia in Parkinson's disease.
abstract: OBJECTIVE
  Low serum uric acid (UA) levels have been associated with a worse cognitive function later in life and also with a higher risk and faster progression of Parkinson's disease (PD). Here we studied whether serum UA levels and the genetic variants related to its variability are associated with the presence of dementia in a cohort of patients with PD.
  
  
  METHODS
  The study included 343 PD patients, which were examined for the presence of dementia according to the MDS Task Force criteria (level 1). The predominant PD phenotype and UPDRS-III and Hoehn-Yahr scales were recorded. Serum UA levels were determined in each participant. Genotyping of SLC2A9 rs734553, ABCG2 rs2231142, SLC17A1 rs1183201, SLC22A11 rs17300741, SLC22A12 rs505802, GCKR rs780094, PDZK1 rs12129861, LRRC16A + SCGN rs742132, and SLC16A9 rs12356193 was carried out by Taqman analysis. For each subject we calculated a cumulative genetic risk score (GRS), defined as the total number of risk alleles (range 2-15) associated to lower serum UA levels.
  
  
  RESULTS
  72 out of 343 PD patients (21%) presented dementia. Serum UA levels were not different between PD patients with or without dementia. No significant association was detected between any single SNP and the risk of PD-dementia. When we analyzed the combined effect of the eight SNPs using the cumulative GRS no significant association between the number of risk alleles and the risk of PD was observed.
  
  
  CONCLUSIONS
  Our data suggest that serum UA levels have not a significant impact on the risk of dementia in PD.
authors.affiliation: Service of Neurology, Universitary Hospital Marqués de Valdecilla (IFIMAV), University of Cantabria (UC), Santander, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: González-Aramburu
authors.affiliation: Service of Neurology, Universitary Hospital Marqués de Valdecilla (IFIMAV), University of Cantabria (UC), Santander, Spain; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Spain.
authors.forename: Pascual
authors.initials: P
authors.lastname: Sánchez-Juan
authors.affiliation: Service of Neurology, Universitary Hospital Marqués de Valdecilla (IFIMAV), University of Cantabria (UC), Santander, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Sierra
authors.affiliation: Department of Clinical Analysis, Universitary Hospital Marqués de Valdecilla, Santander, Spain.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Fernández-Juan
authors.affiliation: Service of Neurology, Universitary Hospital Marqués de Valdecilla (IFIMAV), University of Cantabria (UC), Santander, Spain.
authors.forename: Coro
authors.initials: C
authors.lastname: Sánchez-Quintana
authors.affiliation: Service of Neurology, Universitary Hospital Marqués de Valdecilla (IFIMAV), University of Cantabria (UC), Santander, Spain; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Spain.
authors.forename: José
authors.initials: J
authors.lastname: Berciano
authors.affiliation: Service of Neurology, Universitary Hospital Marqués de Valdecilla (IFIMAV), University of Cantabria (UC), Santander, Spain; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Spain.
authors.forename: Onofre
authors.initials: O
authors.lastname: Combarros
authors.affiliation: Service of Neurology, Universitary Hospital Marqués de Valdecilla (IFIMAV), University of Cantabria (UC), Santander, Spain; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Spain. Electronic address: jinfante@humv.es.
authors.forename: Jon
authors.initials: J
authors.lastname: Infante
mesh_terms: D000368:Aged; D004252:DNA Mutational Analysis; D003704:Dementia / Q000097:blood* / Q000209:etiology* / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D015201:Meta-Analysis as Topic; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications* / Q000235:genetics; D014527:Uric Acid / Q000097:blood*
chemical_list: D014527:Uric Acid
keywords: Dementia; Genetics; Parkinson's disease; Serum; Uric acid