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.

Resuts Forty-two women with previously undiagnosed angina (cases) were compared with 877 women with no reported angina (controls). The mean plasma vitamin C was 50.2μmol/l in cases and 58.3 μmol/l in controls. The age-adjusted odds ratio for a 50 μmol/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.

Conslusions 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.