Isabel González-Aramburu1, Pascual Sánchez-Juan2, María Sierra1, Eduardo Fernández-Juan3, Coro Sánchez-Quintana1, José Berciano2, Onofre Combarros2, Jon Infante4. 1. Service of Neurology, Universitary Hospital Marqués de Valdecilla (IFIMAV), University of Cantabria (UC), Santander, Spain. 2. 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. 3. Department of Clinical Analysis, Universitary Hospital Marqués de Valdecilla, Santander, Spain. 4. 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.
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.
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 PDpatients, 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 SLC2A9rs734553, ABCG2rs2231142, SLC17A1rs1183201, SLC22A11rs17300741, SLC22A12rs505802, GCKRrs780094, PDZK1rs12129861, LRRC16A + SCGNrs742132, and SLC16A9rs12356193 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 PDpatients (21%) presented dementia. Serum UA levels were not different between PDpatients 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.