Biomarker-based validity of a food frequency questionnaire estimating intake in Brazilian children and adolescents.

This study evaluated the validity of nutrient and food group intakes estimated by an FFQ against biomarkers. A 71-item semiquantitative FFQ was administered to 210 Brazilian children and adolescents aged 9-13 years. Intakes were correlated with biomarkers in plasma and red blood cells. Correlations between nutrients and their biomarkers were presented for animal protein, myristic acid (C14:0), EPA, DHA, ß-carotene, folate, and vitamins B3, B5 and B6. Food groups and biomarkers were correlated as follows: fish products with EPA and DHA; milk and dairy with C14:0, pyridoxal 5'-phosphate and vitamin B12; total vegetables and dark green and orange vegetables with ß-carotene; 5-methyltetrahydrofolate with green vegetables; and flour products with para-aminobenzoylglutamic acid. This FFQ is a valid tool for ranking Brazilian children and adolescents according to their intake of several nutrients and food groups.

Metabolic Groups Related to Blood Vitamin Levels and Inflammatory Biomarkers in Brazilian Children and Adolescents.

Certain B-vitamins and vitamin A may be involved in inflammatory pathways associated with homocysteine and omega-3 fatty acids. The aims of this study were (i) to determine whether different metabolic profiles of B-vitamins and vitamin A in Brazilian children and adolescents were positively or negatively related to homocysteine and omega-3 fatty acids using k-means clustering analysis, (ii) compare nutrient intakes and metabolites between the different metabolic profiles, (iii) evaluate if the statistically significant metabolites found between the metabolic groups, can predict the variation of leukotriene A4 hydrolase (LTA4H) levels, a biomarker of low-grade inflammation, in the total studied population. This cross-sectional study included 124 children and adolescents, aged 9-13 y old. Dietary intake was assessed by the food frequency questionnaire and 24-hour recall. Biomarkers for vitamins B2, B6, B12, folate and vitamin A were measured in plasma. Omega-3 fatty acids and homocysteine were measured in red blood cells (RBC). Two different metabolic profiles were found. Thirty of these individuals had overall average higher riboflavin, pyridoxal, and vitamin B12 plasma levels (metabolic group 1) compared to 94 individuals (group 2). Group 2 had lower dietary intake of vitamin B2, vitamin A, and vitamin B12 and higher RBC levels of homocysteine. EPA and DHA erythrocyte levels were not different between metabolic groups. Multiple linear regression analyses showed that blood cobalamin, riboflavin, pyridoxal and homocysteine combined, explained 9.0% of LTA4H levels variation in the total studied population. The metabolic group that had low plasma levels of riboflavin, pyridoxal, and cobalamin also had a lower dietary intake of B-vitamin and higher RBC homocysteine. The combined levels of the riboflavin, pyridoxal, cobalamin and homocysteine biomarkers can predict the variation of LTA4H in the total population studied, but it is not clear how this regulation occurs.

Homocysteine, folate, hs-C-reactive protein, tumor necrosis factor alpha and inflammatory proteins: are these biomarkers related to nutritional status and cardiovascular risk in childhood-onset systemic lupus erythematosus?

BACKGROUND: Childhood-onset systemic lupus erythematosus (c-SLE) is a chronic autoimmune disease which increases cardiovascular risk factors (CRF) such as elevated homocysteine, TNF-α, and hs-C reactive protein. METHODS: We evaluated BMI, waist circumference (WC), 24-h recalls, SLEDAI-2 K, SLICC/ACR-DI, serum levels of homocysteine, folate, TNF-α, hs-C reactive protein, lipid profile, proteomic data, and duration of corticosteroid therapy in 19 c-SLE and 38 healthy volunteers. Physiological and anthropometric variables of c-SLE and healthy controls were compared by ANCOVA. k-cluster was used to separate c-SLE into two different groups with the best and the worst metabolic profile according to previous analysis showing some metabolites that were statistically different from controls, such as homocysteine, TNF-α, hs-CRP and folate levels. These two clusters were again compared with the control group regarding nutritional parameters, lipid profile and also proteomic data. RESULTS: Individuals with c-SLE presented higher BMI, WC, homocysteine, triglycerides, TNF-α, hs-CRP and lower folate levels when compared to controls. We found 10 proteins whose relative abundances were statistically different between control group and lupus clusters with the best (LCBMP) and the worst metabolic profile (LCWMP). A significant positive correlation was found between TNF-α and triglycerides and between hs-CRP and duration of corticosteroid therapy. CONCLUSION: Cardiovascular disease (CVD) risk parameters were worse in c-SLE. A less protective CVD proteomic profile was found in LCWMP.

Clinical and Vitamin Response to a Short-Term Multi-Micronutrient Intervention in Brazilian Children and Teens: From Population Data to Interindividual Responses.

SCOPE: Micronutrients are in small amounts in foods, act in concert, and require variable amounts of time to see changes in health and risk for disease. These first principles are incorporated into an intervention study designed to develop new experimental strategies for setting target recommendations for food bioactives for populations and individuals. METHODS AND RESULTS: A 6-week multivitamin/mineral intervention is conducted in 9-13 year olds. Participants (136) are (i) their own control (n-of-1); (ii) monitored for compliance; (iii) measured for 36 circulating vitamin forms, 30 clinical, anthropometric, and food intake parameters at baseline, post intervention, and following a 6-week washout; and (iv) had their ancestry accounted for as modifier of vitamin baseline or response. The same intervention is repeated the following year (135 participants). Most vitamins respond positively and many clinical parameters change in directions consistent with improved metabolic health to the intervention. Baseline levels of any metabolite predict its own response to the intervention. Elastic net penalized regression models are identified, and significantly predict response to intervention on the basis of multiple vitamin/clinical baseline measures. CONCLUSIONS: The study design, computational methods, and results are a step toward developing recommendations for optimizing vitamin levels and health parameters for individuals.