Plasma status of retinol, α- and γ-tocopherols, and main carotenoids to first myocardial infarction: case control and follow-up study

OBJECTIVE: Epidemiologic studies have suggested that dietary intake and plasma concentrations of antioxidants have an inverse relation with coronary heart disease. To test whether fat-soluble antioxidants can play a role against the occurrence of myocardial infarction (MI), we measured plasma levels of retinol, tocopherols, and individual carotenoids in MI patients. METHODS: A case-control and follow-up study of patients in the Móstoles area (Madrid, Spain). One hundred six patients (62 after 1 y) and 104 control subjects participated in the study. Blood samples were collected after overnight fast or during the first 24 h of MI onset for biochemical profiles of retinol, α- and γ-tocopherols, and carotenoid by means of a quality-controlled high-performance liquid chromatography. RESULTS: During the acute phase after MI onset, plasma levels of retinol, γ-tocopherol, and xanthophylls (lutein/zeaxanthin and β-cryptoxanthin) decreased, whereas α-tocopherol, α-carotene, β-carotene, and lycopene showed levels similar to those of control subjects. Logistic regression analysis showed low concentrations of γ-tocopherol (and retinol) in plasma as the only statistically significant factor associated with MI, after adjusting for traditional risk factors. However, 1 y later, the MI patients showed a general improvement in plasma lipids and fat-soluble antioxidant status, and none of the analytes was associated with MI. CONCLUSIONS: The decreased plasma status of retinol, γ-tocopherol, and xanthophylls during the acute phase of MI normalized the year after the MI event, suggesting that most subjects had followed an overall healthier lifestyle and dietary pattern. The results also raise concerns on the usefulness of these plasma compounds as specific, relevant, and predictive markers in relation to coronary heart disease.