title: Serum homocysteine and physical exercise in patients with Parkinson's disease.
abstract: BACKGROUND
  Hyperhomocysteinemia is a major risk factor for cerebral and peripheral vascular diseases, as well as cortical and hippocampal injury, including an increased risk of dementia and cognitive impairment. Elevated serum homocysteine (Hcy) concentrations are common in patients with Parkinson's disease (PD) who have been treated with levodopa; however, physical exercises can help reduce Hcy concentrations. The aim of the present study was to compare serum Hcy levels in patients with PD who partook in regular physical exercises, sedentary PD patients, and healthy controls.
  
  
  METHODS
  Sixty individuals were enrolled in the present study across three groups: (i) 17 patients who did not partake of any type of exercise; (ii) 24 PD patients who exercised regularly; and (iii) 19 healthy individuals who did not exercise regularly. All participants were evaluated by Hoehn and Yahr scale, the Unified Parkinson's Disease Rating Scale (UPDRS) and Schwab and England scale (measure daily functionality). The serum levels of Hcy were analyzed by blood samples collected of each participant. An analysis of variance and a Tukey's post hoc test were applied to compare and to verify differences between groups. Pearson's correlation and stepwise multiple regression analyses were used to consider the association between several variables.
  
  
  RESULTS
  Mean plasma Hcy concentrations in individuals who exercised regularly were similar to those in the healthy controls and significantly lower than those in the group that did not exercise at all (P= 0.000). In addition, patients who did not exercise were receiving significantly higher doses of levodopa than those patients who exercised regularly (P= 0.001). A positive relationship between levodopa dose and Hcy concentrations (R(2) = 0.27; P= 0.03) was observed in patients who did not exercise, but not in those patients who exercised regularly (R(2) = 0.023; P= 0.15).
  
  
  CONCLUSIONS
  The results of the present study suggest that, even with regular levodopa therapy, Hcy concentrations in PD patients who exercise regularly are significantly lower than in patients who do not exercise and are similar Hcy concentrations in healthy controls.
authors.affiliation: Laboratory of Aging and Physical Activity (LAFE), Biosciences Institute, Department of Physical Education, São Paulo State University, Rio Claro Campus, Brazil. carla_unesp@yahoo.com.br
authors.forename: Carla Manuela Crispim
authors.initials: CM
authors.lastname: Nascimento
authors.forename: Florindo
authors.initials: F
authors.lastname: Stella
authors.forename: Célia Regina
authors.initials: CR
authors.lastname: Garlipp
authors.forename: Ruth Ferreira
authors.initials: RF
authors.lastname: Santos
authors.forename: Sebastião
authors.initials: S
authors.lastname: Gobbi
authors.forename: Lilian Teresa Bucken
authors.initials: LT
authors.lastname: Gobbi
mesh_terms: D000368:Aged; D000978:Antiparkinson Agents / Q000009:adverse effects / Q000627:therapeutic use; D015444:Exercise / Q000502:physiology*; D005260:Female; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood* / Q000139:chemically induced / Q000534:rehabilitation*; D007980:Levodopa / Q000009:adverse effects / Q000627:therapeutic use; D008297:Male; D016555:Matched-Pair Analysis; D008609:Mental Status Schedule; D008875:Middle Aged; D010300:Parkinson Disease / Q000097:blood* / Q000188:drug therapy / Q000534:rehabilitation*
chemical_list: D000978:Antiparkinson Agents; D006710:Homocysteine; D007980:Levodopa