title: Glutathione as a Biomarker in Parkinson's Disease: Associations with Aging and Disease Severity.
abstract: Objectives. Oxidative stress contributes to Parkinson's disease (PD) pathophysiology and progression. The objective was to describe central and peripheral metabolites of redox metabolism and to describe correlations between glutathione (Glu) status, age, and disease severity.Methods. 58 otherwise healthy individuals with PD were examined during a single study visit. Descriptive statistics and scatterplots were used to evaluate normality and distribution of this cross-sectional sample. Blood tests and magnetic resonance spectroscopy (MRS) were used to collect biologic data. Spearman's rank-order correlation coefficients were used to evaluate the strength and direction of the association. The Unified PD Rating Scale (UPDRS) and the Patient-Reported Outcomes in PD (PRO-PD) were used to rate disease severity using regression analysis.Results. Blood measures of Glu decreased with age, although there was no age-related decline in MRS Glu. The lower the blood Glu concentration, the more severe the UPDRS (P= 0.02, 95% CI: -13.96, -1.14) and the PRO-PD (P= 0.01, 95% CI: -0.83, -0.11) scores.Discussion. These data suggest whole blood Glu may have utility as a biomarker in PD. Future studies should evaluate whether it is a modifiable risk factor for PD progression and whether Glu fortification improves PD outcomes.
authors.affiliation: Bastyr University Research Institute, 14500 Juanita Drive NE, Kenmore, WA 98133, USA; UW Graduate Program in Nutritional Sciences, 305 Raitt Hall, P.O. Box 353410, Seattle, WA 98195, USA; Department of Radiology, University of Washington (UW), P.O. Box 357115, 1959 NE, Pacific Seattle, WA 98195, USA.
authors.forename: Laurie K
authors.initials: LK
authors.lastname: Mischley
authors.affiliation: Bastyr University Research Institute, 14500 Juanita Drive NE, Kenmore, WA 98133, USA.
authors.forename: Leanna J
authors.initials: LJ
authors.lastname: Standish
authors.affiliation: Department of Epidemiology, University of Washington (UW), 1959 NE Pacific Street, Health Sciences Building F-262, P.O. Box 357236, Seattle, WA 98195, USA.
authors.forename: Noel S
authors.initials: NS
authors.lastname: Weiss
authors.affiliation: Elson S. Floyd College of Medicine and College of Pharmacy, Washington State University, P.O. Box 1495, Spokane, WA 99210-1495, USA.
authors.forename: Jeannie M
authors.initials: JM
authors.lastname: Padowski
authors.affiliation: Department of Environmental & Occupational Health Sciences, University of Washington, P.O. Box 357234, Seattle, WA 98195, USA.
authors.forename: Terrance J
authors.initials: TJ
authors.lastname: Kavanagh
authors.affiliation: Department of Environmental & Occupational Health Sciences, University of Washington, P.O. Box 357234, Seattle, WA 98195, USA.
authors.forename: Collin C
authors.initials: CC
authors.lastname: White
authors.affiliation: Department of Environmental & Occupational Health Sciences, University of Washington, P.O. Box 357234, Seattle, WA 98195, USA.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Rosenfeld