title: Vitamin c status and undiagnosed angina.
abstract: BACKGROUND
  Vitamin C has been suggested to be protective for coronary heart disease but the evidence from epidemiological studies is inconclusive and most studies have been conducted in men. We examined the cross-sectional relationship between vitamin C status and previously undiagnosed angina in women.
  
  
  METHODS
  Women aged 45-74 years were recruited from general practices. They completed a health and lifestyle questionnaire and attended for a health check and a blood test. Non-fasting plasma vitamin C was used to define vitamin status and a self-completed Rose angina questionnaire was used to identify cases.
  
  
  RESULTS
  Forty-two women with previously undiagnosed angina (cases) were compared with 877 women with no reported angina (controls). The mean plasma vitamin C was 50.2 mumol/l in cases and 58.3 mumol/l in controls. The age-adjusted odds ratio for a 50 mumol/l increase in plasma vitamin C was 0.34 (95% confidence interval 0.15-0.79). The odds ratio was unaltered after adjustment for body mass index, smoking and established coronary risk factors, and after stratification by smoking, vitamin supplementation and hormone replacement.
  
  
  CONCLUSIONS
  This cross-sectional analysis showed an association in women between lower plasma levels of vitamin C and previously undiagnosed angina. Although we are unable to exclude the possibility that symptomatic prevalent disease modifies plasma vitamin C levels, these data are consistent with a protective effect of vitamin C for coronary heart disease. This relationship requires confirmation in further prospective studies and trials of vitamin C supplementation.
authors.affiliation: Institute of Public Health, University Forvie Site, Cambridge, UK.
authors.forename: A R
authors.initials: AR
authors.lastname: Ness
authors.forename: K T
authors.initials: KT
authors.lastname: Khaw
authors.forename: S
authors.initials: S
authors.lastname: Bingham
authors.forename: N E
authors.initials: NE
authors.lastname: Day
mesh_terms: D000368:Aged; D000787:Angina Pectoris / Q000175:diagnosis* / Q000503:physiopathology; D001205:Ascorbic Acid / Q000032:analysis* / Q000097:blood; D016001:Confidence Intervals; D003327:Coronary Disease / Q000175:diagnosis / Q000503:physiopathology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012016:Reference Values; D012307:Risk Factors; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires
chemical_list: D001205:Ascorbic Acid