Biomarkers of Parkinson's Disease: Screening Vital Signs and Routine Blood Tests

BACKGROUNDThere is a need for reliable, objective, and easily accessible biomarkers for Parkinsons disease. OBJECTIVESThe purpose of this study was to screen biomarkers from vital signs and routine blood tests. METHODSLongitudinal data of up to 7 years of vital signs and routine blood tests from 418 patients with Parkinsons disease (PD) untreated at baseline and 185 individuals without any neurological disease were analyzed using linear mixed models. We nominated the biomarkers whose main associations with the measurements were significant as differentiating biomarkers. Similarly, we nominated the interaction effects between biomarkers and time from baseline as progression biomarkers. We tested for 49 biomarkers, and multiple comparison was corrected with the false-discovery-rate of 0.05. We further evaluated the potential biomarkers with regard to their importance in diagnosis prediction and their association with sub-scores on the Movement Disorder Society-Unified Parkinsons Disease Rating Scale (MDS-UPDRS). We also assessed the relationship of the associations using bioinformatics. RESULTSHeart rate, systolic blood pressure, white blood cell fractions, neutrophil counts, serum albumin, sodium and AST were different between PD and controls. The causality or genetic correlations of these biomarkers to PD were not observed. Chronological changes in height, albumin, hemoglobin, and bicarbonate were different in PD. These biomarkers were associated with MDS-UPDRS sub-scores. ConclusionsIn this study, the potential of some easily accessible biomarkers for diagnosis and disease progression was presented. Further investigation of the mechanisms underlying these associations is important for a deeper understanding of the disease and the better management of patients.