title: Oestradiol levels and superoxide dismutase activity in age-related cataract: a case-control study.
abstract: BACKGROUND
  It has been suggested that the higher prevalence of cataract in women is caused by a withdrawal effect of oestrogen at menopause. In vitro studies have demonstrated protection of serum oestradiol (E2) against oxidative stress through upregulation of antioxidant enzymes, including superoxide dismutase (SOD). The purpose of the present study was to investigate E2 levels and SOD erythrocyte activity in patients with age-related cataract.
  
  
  METHODS
  The studied subjects consisted of 103 patients with age-related cataract and 22 controls. Cataracts were classified as nuclear, cortical, or posterior subcapsular. Blood samples were collected and data on smoking, hormonal use, diabetes and age at menarche/menopause was obtained for all individuals. Serum oestradiol analyses were performed with radioimmunoassay (RIA) and SOD activity was measured in erythrocyte lysates.
  
  
  RESULTS
  A negative correlation between age and E2 concentration was seen in a linear regression analysis. No correlation was seen between SOD activity and age or gender and no correlation between E2 levels and SOD activity was found using multiple linear regression. The mean level of E2 for all male subjects was 50.1 ± 16.3 pmol/L, significantly higher compared to 13.8 ± 11.8 pmol/L for postmenopausal women.
  
  
  CONCLUSIONS
  The present study does not support a role for E2-induced effects on SOD in cataract formation. The findings of higher E2 levels in men than in postmenopausal women may suggest that decreased oestrogen at menopause is partially responsible for the gender-related difference in cataract prevalence. However, the latter can only be verified through prospective randomized trials using hormonal replacement therapy.
authors.affiliation: Department of Clinical Neuroscience/Ophthalmology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden. dragana.skiljic@gu.se.|Department of Ophthalmology, Sahlgrenska University Hospital, Mölndal, Sweden. dragana.skiljic@gu.se.
authors.forename: Dragana
authors.initials: D
authors.lastname: Škiljić
authors.affiliation: Department of Mathematical Statistics, Institute of Mathematical Sciences, Chalmers University of Technology, Gothenburg, Sweden.
authors.forename: Staffan
authors.initials: S
authors.lastname: Nilsson
authors.affiliation: Department of Clinical Neuroscience/Ophthalmology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
authors.forename: Anne
authors.initials: A
authors.lastname: Petersen
authors.affiliation: Department of Medical Chemistry and Cell Biology, Institute of Biomedicine, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
authors.forename: Jan-Olof
authors.initials: JO
authors.lastname: Karlsson
authors.affiliation: Department of Clinical Sciences/Ophthalmology, Umeå University, Umeå, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Behndig
authors.affiliation: Department of Ophthalmology, Sahlgrenska University Hospital, Mölndal, Sweden.
authors.forename: Lada
authors.initials: L
authors.lastname: Kalaboukhova
authors.affiliation: Department of Clinical Neuroscience/Ophthalmology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.|Department of Ophthalmology, Sahlgrenska University Hospital, Mölndal, Sweden.
authors.forename: Madeleine
authors.initials: M
authors.lastname: Zetterberg
mesh_terms: D000368:Aged; D000975:Antioxidants / Q000378:metabolism; D016022:Case-Control Studies; D002386:Cataract / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism*; D005260:Female; D016166:Free Radical Scavengers / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology; D011446:Prospective Studies; D012044:Regression Analysis; D013482:Superoxide Dismutase / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D004958:Estradiol; D013482:Superoxide Dismutase
keywords: Age-related cataract; Gender; Oestradiol; Oxidative stress; Superoxide dismutase