title: Association of serum carotenoid, retinol, and tocopherol concentrations with the progression of Parkinson's Disease.
abstract: OBJECTIVE
  A pivotal role of oxidative stress has been emphasized in the pathogenesis as well as in the disease progression of Parkinson's disease (PD). We aimed at investigating serum levels of antioxidant vitamins and elucidating whether they could be associated with the pathogenesis and progression of PD.
  
  
  METHODS
  Serum levels of retinol, α- and γ-tocopherols, α- and β-carotenes, lutein, lycopene, zeaxanthin and β-cryptoxanthin were measured and compared between 104 patients with idiopathic PD and 52 healthy controls matched for age and gender. In order to examine the relationship between antioxidant vitamins and the disease progression, multiple group comparisons were performed among the early PD (Hoehn and Yahr stage I and II, N = 47), advanced PD (stage III and IV, N = 57) and control groups. Separate correlation analyses were performed between the measured antioxidant vitamins and clinical variables, such as Hoehn and Yahr stage and Unified Parkinson's Disease Rating Scale (UPDRS) motor score.
  
  
  RESULTS
  Compared to controls, PD patients had lower levels of α- and β-carotenes and lycopene. α-carotene, β-carotene and lycopene levels were significantly reduced in advanced PD patients relative to early PD patients and were negatively correlated with Hoehn and Yahr stage and UPDRS motor score in PD patients. No significant differences were found in serum levels of retinol, α- and γ-tocopherols, and other carotenoids between PD patients and controls. No significant correlations were found between these vitamin levels and clinical variables in PD patients.
  
  
  CONCLUSIONS
  We found that serum levels of some carotenoids, α-carotene, β-carotene and lycopene, were lower in PD patients, and that these carotenoids inversely correlated with clinical variables representing disease progression. Our findings suggest that decreases in serum α-carotene, β-carotene and lycopene may be associated with the pathogenesis as well as progression of PD.
authors.affiliation: Department of Neurology, Korea University Guro Hospital, Korea University College of Medicine, 148 Guro-dong Road, Guro-gu, Seoul 08308, Korea.
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Food and Nutrition, College of Natural Sciences, Myongji University, Yongin, Gyeonggi 17058, Korea.
authors.forename: Jinah
authors.initials: J
authors.lastname: Hwang
authors.affiliation: Department of Food and Nutrition, Soongeui Women's College, Seoul 04628, Korea.
authors.forename: Eugene
authors.initials: E
authors.lastname: Shim
authors.affiliation: Division of General Studies, Kangnam University, Yongin, Gyeonggi 16979, Korea.
authors.forename: Eun-Jung
authors.initials: EJ
authors.lastname: Chung
authors.affiliation: Division of Diet Research, Institute of Food & Culture, Pulmuone, Seoul 13722, Korea.
authors.forename: Sung Hee
authors.initials: SH
authors.lastname: Jang
authors.affiliation: Department of Neurology, Korea University Guro Hospital, Korea University College of Medicine, 148 Guro-dong Road, Guro-gu, Seoul 08308, Korea.
authors.forename: Seong-Beom
authors.initials: SB
authors.lastname: Koh
keywords: Parkinson disease; carotenoids; disease progression; oxidative stress