title: Macular pigment optical density is related to blood glutathione levels in healthy individuals.
abstract: OBJECTIVE
  To assess the relationship between macular pigment optical density (MPOD) and blood markers for antioxidant defense in otherwise healthy volunteers.
  
  
  METHODS
  Forty-seven healthy volunteers were subjected to blood analysis to detect the level of circulating glutathione in its reduced (GSH) and oxidized (GSSG) forms. The level of MPOD was measured using heterochromatic flicker photometry. Systemic blood pressure (BP) parameters, heart rate (HR), body mass index (BMI), and plasma levels of total, HDL, and LDL cholesterol and triglycerides (TGs) were also determined.
  
  
  RESULTS
  A simple correlation model revealed that the level of MPOD correlated significantly and positively with both GSH (P < 0.001) and t-GSH (P < 0.001) levels but not with those of GSSG (P > 0.05). Age, sex, systemic BP parameters, HR, BMI, and plasma levels of cholesterol and TGs did not have any influence on either MPOD or glutathione levels (all P > 0.05). In addition, a forward stepwise multiple regression analysis showed MPOD to have a significantly and independent correlation with GSH levels (β = 0.63; P < 0.001).
  
  
  CONCLUSIONS
  In otherwise healthy older individuals, there is a positive correlation between local and systemic antioxidant defense mechanisms.
authors.affiliation: Ophthalmic Research Group, School of Life and Health Sciences, Aston University, Birmingham, United Kingdom.
authors.forename: Lu
authors.initials: L
authors.lastname: Qin
authors.forename: Hannah
authors.initials: H
authors.lastname: Bartlett
authors.forename: Helen R
authors.initials: HR
authors.lastname: Griffiths
authors.forename: Frank
authors.initials: F
authors.lastname: Eperjesi
authors.forename: Richard A
authors.initials: RA
authors.lastname: Armstrong
authors.forename: Doina
authors.initials: D
authors.lastname: Gherghel
mesh_terms: D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000378:metabolism*; D015415:Biomarkers / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003720:Densitometry / Q000379:methods; D005260:Female; D005978:Glutathione / Q000097:blood*; D019803:Glutathione Disulfide / Q000097:blood; D006801:Humans; D014975:Lutein / Q000378:metabolism*; D008266:Macula Lutea / Q000166:cytology / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology; D010783:Photometry / Q000379:methods; D014280:Triglycerides / Q000097:blood; D024341:Xanthophylls / Q000378:metabolism*; D055815:Young Adult; D065146:Zeaxanthins
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D014280:Triglycerides; D024341:Xanthophylls; D065146:Zeaxanthins; D005978:Glutathione; D019803:Glutathione Disulfide; D014975:Lutein