Plasma levels of antioxidant vitamins and cholesterol in a large population sample in Central-Northern Italy

Background: In a population-based multicenter case-control study of diet, l ife-style, and gastric cancer a large series of adults, aged 30-75 years (m ean 58.9 years), were randomly sampled from the general population in 3 are as of Central-Northern Italy. Aim of the study: To evaluate the relationship between plasma levels of ant ioxidant vitamins and cholesterol, and sociodemographic characteristics, li fe-style factors, and dietary intake of selected nutrients in a sample of t he Italian population. Methods: A fasting blood sample was available for 945 subjects (553 men, 39 2 women). The plasma concentrations of ascorbic acid, carotene, retinol, al pha-tocopherol, and cholesterol were determined by a centralized laboratory . All participants answered to a detailed questionnaire collecting informat ion on sociodemographic and anthropometric characteristics, smoking, alcoho l drinking, and dietary habits. Covariance analysis models, with post hoc D unnett tests, including terms for age, sex, study center, and period of blo od drawing, were used for selected multiple-way comparisons of mean values of plasma nutrients. Results: Mean plasma values of retinol were higher among men while women ha d higher levels of plasma carotene, ascorbic acid, alpha-tocopherol, and ch olesterol. Plasma carotene levels showed an inverse association with body m ass index, alcohol consumption, and smoking and a positive association with social class. Carotene concentrations were higher in plasma samples obtain ed in spring/summer, while ascorbic acid levels were higher in autumn/winte r. Partial correlation coefficients between plasma vitamin levels showed a strong correlation between carotene and ascorbic acid (0.69 in men; 0.74 in women), between carotene and alpha-tocopherol (0.44; 0.37), and between al pha-tocopherol and ascorbic acid (0.45; 0.41). Plasma alpha-tocopherol and retinol correlated with plasma cholesterol. On the other hand, plasma carot ene and ascorbic acid were correlated with their estimated dietary intakes, while the intakes of other nutrients, as expected, correlated rather poorl y with the respective plasma concentrations. Conclusions: Socio-economic factors, life-style, and specific nutrient inta ke, in addition to gender, are related to nutrient plasma levels in Italian adults and may provide specific suggestions for the prevention of chronic diseases.