Predicting urinary creatinine excretion and its usefulness to identify incomplete 24h urine collections

Studies using 24 h urine collections need to incorporate ways to validate the completeness of the urine samples. Models to predict urinary creatinine excretion (UCE) have been developed for this purpose; however, information on their usefulness to identify incomplete urine collections is limited. We aimed to develop a model for predicting UCE and to assess the performance of a creatinine index using para-aminobenzoic acid (PABA) as a reference. Data were taken from the European Food Consumption Validation study comprising two non-consecutive 24 h urine collections from 600 subjects in five European countries. Data from one collection were used to build a multiple linear regression model to predict UCE, and data from the other collection were used for performance testing of a creatinine index-based strategy to identify incomplete collections. Multiple linear regression (n 458) of UCE showed a significant positive association for body weight (ß = 0·07), the interaction term sex × weight (ß = 0·09, reference women) and protein intake (ß = 0·02). A significant negative association was found for age (ß = - 0·09) and sex (ß = - 3·14, reference women). An index of observed-to-predicted creatinine resulted in a sensitivity to identify incomplete collections of 0·06 (95 % CI 0·01, 0·20) and 0·11 (95 % CI 0·03, 0·22) in men and women, respectively. Specificity was 0·97 (95 % CI 0·97, 0·98) in men and 0·98 (95 % CI 0·98, 0·99) in women. The present study shows that UCE can be predicted from weight, age and sex. However, the results revealed that a creatinine index based on these predictions is not sufficiently sensitive to exclude incomplete 24 h urine collections

Fitness-for-purpose of dietary survey duration: A case-study with the assessment of exposure to ochratoxin A

International audienceThe duration of food consumption survey may have a marked effect on estimates of usual nutrient intakes in individuals and groups. This arises from a high degree of within-person variability in food intakes, primarily on a day-to-day basis. Both the level of observation-populations versus individuals-and the desirable level of precision decide upon the 'fitness-for-purpose' of dietary survey duration. Though similar from a methodological standpoint, the question was rarely addressed in the case of non-nutrients. Our work aims at estimating the number of days of food records needed for the assessment of usual intakes of food chemicals as a function of research purpose. Focusing on the French population exposure to food mycotoxin ochratoxin A, we implement a range of well-established methods borrowed from the field of nutrient intakes assessment. Our results on OTA show that: (a) at the population level, as low as three days give satisfactory distributional estimates; yet, the implementation of variance reduction methods is of particular relevance when higher percentiles of exposure are at stake; (b) the estimation of individual usual intakes based on food records is behind practical possibilities, which calls for alternative options such as biomarkers of exposure. (c) 2005 Elsevier Ltd. All rights reserved

Assessment of infant exposure to food chemicals: the French Total Diet Study design

<div><p>As part of the previous French Total Diet Studies (TDS) focusing on exposure to food chemicals in the population aged 3 years and older, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) launched a specific TDS on infants to complete its overall chemical food safety programme for the general population. More than 500 chemical substances were analysed in food products consumed by children under 3 years old, including nutrients, several endocrine disruptors resulting from human activities (polychlorinated biphenyls, dioxins and furans, brominated flame retardants, perfluoroalkyl acids, pesticide residues, etc.) or migrating from food contact materials such as bisphenol A or phthalates, but also natural substances such as mycotoxins, phytoestrogens and steroids. To obtain a representative and general view of infant food consumption, food items were selected based on results of a national consumption survey conducted specifically on this population. Moreover, a specific study on food was conducted on 429 households to determine which home-cooking practices are employed to prepare food consumed by infants. Overall, the targeted chemical substances were analysed in more than 450 food samples, representing the purchase and home-cooking practices of over 5500 food products. Foods included common foods such as vegetables, fruit or cakes as well as specific infant foods such as infant formula or jarred baby food. The sampling plan covered over 80% of the total diet. Specificities in infant food consumption and habits were therefore considered to define this first infant TDS. This study, conducted on a large scale and focusing on a particularly sensitive population, will provide accurate information on the dietary exposure of children under 3 years to food chemicals, especially endocrine disruptors, and will be particularly useful for risk assessment analysis under the remit of ANSES’ expert committees.</p></div

Epitaxial lift-off of InGaAs solar cells from InP substrate using a strained AlAs/InAlAs superlattice as a novel sacrificial layer

International audienceIn this work we present a new epitaxial lift-off (ELO) approach based on the use of a strained AlAs/InAlAs superlattice (SL) as sacrificial layer for InP related materials. Such an ELO process enables the fabrication and transfer of a thin active III-V heterostructure via its separation from its III-V parent substrate using selective chemical etching. The strategy is of particular interest for large area devices such as solar cells. The process studied here also allows the substrate reuse for a low-cost approach based on III-V-based device fabrication. In order to realize the ELO process on InP substrates, the main difficulty is the lack of lattice-matched materials offering the high chemical etching selectivity needed over both the substrate and the lattice-matched alloys of the active heterostructure. The present study therefore contributes effective strategy for overcoming the latter constraints. The AlAs/InAlAs SL was thus explored as a potential candidate as sacrificial layer for the InP lattice matched materials. The growth conditions of such SLs were investigated to produce low defect SLs compatible with the properties of an optimal sacrificial layer. The under-etching behavior of such SLs in a hydrofluoric acid-based solution was also studied in detail. The results show that advantageous under-etching rates, high enough for a full wafer detachment, combined with a low defect density, can be obtained with novel sacrificial layers based on such thin AlAs/InAlAs SL. Finally, the fabrication of solar cells via an active heterostructure grown over an optimized SL on a monolithic substrate and via a thin reported active heterostructure was performed. The solar cells perform well and demonstrate the suitability of such SLs as a sacrificial layer for InP related materials

Food balance sheet and household budget survey dietary data and mortality patterns in Europe

Worldwide dietary data for nutrition monitoring and surveillance are commonly derived from food balance sheets (FBS) and household budget surveys (HBS). We have compared food supply from FBS and food availability data from HBS among eighteen European countries and have estimated the extent to which they correlate, focusing on food groups which are comparably captured by FBS and HBS and for which there is epidemiological evidence that they can have a noticeable impact on population mortality. Spearman&apos;s correlation coefficient was +0.78 (P&amp;lt;10-3) for vegetables (including legumes),+0.76 (P&amp;lt;10 -3) for fruits, +0.69 (P&amp;lt;10-3) for fish and seafood and +0.93 (P&amp;lt;10-3) for olive oil. With respect to meat and meat products, the coefficient was lower at +0.39 (P=0.08). Moreover, we have examined whether the supply (FBS) or the availability (HBS) of food groups known or presumed to have beneficial effect on the occurrence of CHD and total cancer can predict overall, coronary and cancer mortality in ecological analyses. After controlling for purchasing power parity-adjusted gross domestic product and tobacco smoking we found that for vegetables, fruits, fish and seafood, as well as for olive oil, both the FBS and the HBS estimates were inversely associated with all three indicators of mortality, although the number of countries with complete information on all study variables hindered formal statistical documentation (P&amp;gt;005 in some instances). FBS and HBS have their own strengths and weaknesses, but they may complement each other in dietary assessments at the population level

Valeurs sanitaires de références du chlordécone: Avis de l'Anses. Rapport d'expertise collective

L’ANSES a été saisie le 10 juillet 2018 par la Direction générale de l’alimentation (DGAL), la Direction générale de la santé (DGS) et la Direction générale de la concurrence, de la consommation et de la répression des fraudes (DGCCRF) pour la réalisation de l’expertise suivante : saisine de l’ANSES relative aux valeurs sanitaires de références pour le chlordécone.Dans le cadre du plan Chlordécone 3 (2014-2020), l’ANSES et Santé Publique France (SPF) ont été mobilisées pour réévaluer les risques et les niveaux d’exposition de la population antillaise afin d’adapter les mesures de gestion.L’ANSES a publié un avis en décembre 2017 relatif à l’actualisation des données d’exposition par voie alimentaire afin d’évaluer les risques des populations antillaises et émettre des recommandations de consommation dans le cadre du projet KANNARI « Santé, nutrition et exposition au chlordécone aux Antilles » (ANSES 2017).Pour formuler cet avis, l'ANSES avait mené une analyse des études scientifiques parues depuis 2007 et jusqu'en 2014 (9 études épidémiologiques et 13 études toxicologiques chez l’animal citées en annexe 2 de l'avis du 6 décembre 2017) : elle avait conclu que les étudestoxicologiques publiées depuis l'établissement des valeurs toxicologiques de référence (VTR) en 2003 ne remettaient pas en cause celles-ci.Il est rappelé que 2 valeurs toxicologiques de référence (VTR) externes ont été définies en 2003 (AFSSA 2003): une VTR chronique de 0,5 µg/kg de poids corporel/j ; une VTR aiguë de 10 µg/kg pc/j.Par ailleurs, dans le cadre de la publication du volet imprégnation de l'étude KANNARI par SPF et aussi compte-tenu du contexte de fortes inquiétudes de la population antillaise au regard des données d’exposition interne il est apparu nécessaire aux ministères de tutelle depouvoir disposer d’une VTR interne afin d'interpréter ces données. Dans le cadre de la préparation de la restitution des travaux de SPF et de l'ANSES aux agences régionales de santé, aux préfectures et à leurs services, le 13 juin 2018, ainsi qu'au comité de pilotage du plan Chlordécone du 20 juin 2018, les deux agences (ANSES et SPF) ont proposé que soit conduite une expertise pluridisciplinaire afin de définir une VTR interne et, à cette occasion, de réexaminer les VTR (externes), permettant à la fois d'assurer la cohérence des valeurs sanitaires de référence utilisées pour interpréter les deux volets de l'étude KANNARI, de les fonder sur une revue de littérature couvrant des périodes identiques, et de prendre en compte les données scientifiques les plus récentes comme le recours à un modèle pharmacocinétique à base physiologique (PBPK). Á cet égard, la saisine avait rappelé « l'importance du projet PK-chlor Antilles sur cette question qui permettra de développer un modèle prédictif PBPK afin d'estimer des doses d'exposition externes à partir de doses internes (sang) ». Ce modèle avait vocation à être mobilisé pour estimer une VTR à partir de données d’exposition interne existantes chez l’Homme. Il est demandé à l’ANSES de mener une expertise afin de définir une VTR interne et, à cette occasion de réexaminer les VTR externes, notamment en complétant les analyses antérieures par la prise en compte des nouvelles études épidémiologiques concernant l'exposition interne globale des populations. L’expertise doit porter sur l’ensemble des études épidémiologiques et toxicologiques postérieures à celles considérées dans l’élaboration des VTR publiées en 2003. L’ANSES devra aussi se rapprocher de l'Inserm chargé de la coordination du projet PKchlor Antilles. Ce travail sera mené en lien étroit avec SPF, notamment pour la définition d'une VTR interne pour le chlordécone.Si les VTR devaient être modifiées, il serait demandé à l’ANSES de reconsidérer ses précédentes recommandations toujours dans l’optique de poursuivre l'objectif de réduction de l'exposition de la population antillaise au chlordécone, en particulier pour les populations les plus vulnérables.Concernant la VTR aiguë, elle n’a pas été modifiée par l’ATSDR dans sa plus récente évaluation du chlordécone (ATSDR 2019, 2020). Le GT note que, selon les informations à disposition, le chlordécone n’est plus fabriqué, ni autorisé en tant que produits phytopharmaceutiques depuis de nombreuses années (1993) ; en conséquence, l’exposition aiguë chez l’Homme est très peu probable aujourd’hui et ne sera pas développée dans ce rapport.Le présent avis porte sur la mise à jour de la VTR chronique externe et sur l’établissement d’une VTR chronique interne. Les conclusions à tirer en matière d’adaptation des recommandations, seront transmises ultérieurement aux tutelles au travers d’un autre avis

A conceptual framework for the collection of food products in a Total Diet Study

A total diet study (TDS) provides representative and realistic data for assessing the dietary intake of chemicals, such as contaminants and residues, and nutrients, at a population level. Reproducing the diet through collection of customarily consumed foods and their preparation as habitually eaten is crucial to ensure representativeness, i.e., all relevant foods are included and all potential dietary sources of the substances investigated are captured. Having this in mind, a conceptual framework for building a relevant food-shopping list was developed as a research task in the European Union's 7th Framework Program project, 'Total Diet Study Exposure' (TDS-Exposure), aimed at standardising methods for food sampling, analyses, exposure assessment calculations and modelling, priority foods, and selection of chemical contaminants. A stepwise approach following the knowledge translation (KT) model for concept analysis is proposed to set up a general protocol for the collection of food products in a TDS in terms of steps (characterisation of the food list, development of the food-shopping list, food products collection) and pillars (background documentation, procedures, and tools). A simple model for structuring the information in a way to support the implementation of the process, by presenting relevant datasets, forms to store inherent information, and folders to record the results is also proposed. Reproducibility of the process and possibility to exploit the gathered information are two main features of such a system for future applications.EC’s Program (FP7/2012-2016) under grant agreement 289108info:eu-repo/semantics/publishedVersio