Use of food frequency questionnaire to assess relationships between dietary habits and cardiovascular risk factors in NESCAV study: validation with biomarkers

摘要

AbstractBackground:Validation of Food frequency questionnaire (FFQ) is particularly important element, as incorrectinformation may lead to false associations between dietary factors and diseases. The aim of the study was toevaluate the validity of the FFQ used in NESCAV (Nutrition, Environment and Cardiovascular Health) study, bycomparing the estimated intakes of fruits and vegetables and of several micro-nutrients with correspondingnutritional biomarkers.Methods:Relative validity was assessed in a sample of 922 subjects (452 men and 470 women). Comparisonsbetween FFQ-estimates and their corresponding biomarkers were performed through correlation and crossclassification into quintiles by using both crude and energy-adjusted FFQ-estimates. Correlations adjusted forconfounders were also computed. All analyses were performed separately for men and women.Results:Concerning micro-nutrients, significant correlations were found for vitamin B9, D, E, B12β-carotene andiodine in both men and women. Energy-adjustment led to an increase of all correlations cited previously. However,after excluding supplement users, correlations for vitamin D were not significant anymore. Concerning fruits andvegetables, all correlations were significant. Vegetables alone and fruits and vegetables correlated better in men(r around 0.2) than in women (r around 0.1). In men, correlation was also better for vegetables alone and fruits andvegetables than fruits alone.Conclusion:These data demonstrate that this FFQ is a reasonable tool to assess intakes of fruits and vegetablesand of several micro-nutrients. We conclude that our FFQ is suitable to be used in NESCAV study, although proteinand vitamin D estimates should be interpreted with caution