Understanding the impact of malaria on the interpretation of micronutrient biomarkers

Accurate estimates of population micronutrient status are needed to guide policies, programmes, and the choice of interventions to prevent and control micronutrient deficiencies. It is widely accepted that some micronutrient biomarker concentrations should be corrected for inflammation status with the use of inflammation marker concentrations, to improve the specificity with which deficiency is indicated. However, there is evidence to suggest that malaria infection could have an inflammation- independent, additive effect on certain biomarkers, particularly ferritin, which complicates the assessment of iron status in malaria-endemic areas. OŌen, the population groups with greater risk of micronutrient deficiencies also have greater risk of contracting malaria. This research started with a systematic literature review, finding that micronutrient biomarkers are affected by malaria infection, and the intensity of this relationship varied according to the stage of infection. Then, an analysis of cross-sectional data from representative population-based surveys (eight datasets, n=7,886 children) investigated the relationship between malaria, ferritin concentrations, and inflammation. Inflammaton-adjusted ferritin concentrations were 44% (95% CI 39, 52; p<0.001) greater in malaria- infected children, compared to uninfected children. Age and malaria exposure, the two main determinants of malaria immunity, were shown to modify this association. The potential role of malaria immunity in mediating the relationship between malaria and micronutrient biomarkers was explored further through an analysis of the 2015 Malawi micronutrient survey dataset. This analysis demonstrated a clear pattern of association between low level of immunity and greater changes in ferritin concentrations during malaria infection. The results of this research indicate the need to account for malaria in the assessment of iron status in malaria-endemic areas, particularly in populations with low immunity to malaria. The findings have potential applications for research on the epidemiology and aetiology of micronutrient deficiencies, and in population micronutrient surveillance, particularly in malaria endemic areas

Errors in chromosome segregation during oogenesis and early embryogenesis

Errors in chromosome segregation occurring during human oogenesis and early embryogenesis are very common. Meiotic chromosome development during oogenesis is subdivided into three distinct phases. The crucial events, including meiotic chromosome pairing and recombination, take place from around 11 weeks until birth. Oogenesis is then arrested until ovulation, when the first meiotic division takes place, with the second meiotic division not completed until after fertilization. It is generally accepted that most aneuploid fetal conditions, such as trisomy 21 Down syndrome, are due to maternal chromosome segregation errors. The underlying reasons are not yet fully understood. It is also clear that superimposed on the maternal meiotic chromosome segregation errors, there are a large number of mitotic errors taking place post-zygotically during the first few cell divisions in the embryo. In this chapter, we summarise current knowledge of errors in chromosome segregation during oogenesis and early embryogenesis, with special reference to the clinical implications for successful assisted reproduction

Prevention of unhealthy weight in children by promoting physical activity using a socio-ecological approach: what can we learn from intervention studies?

International audienceAIM: Our objectives was to identify the characteristics of interventions likely to successfully prevent overweight in youngsters by promoting physical activity (PA), with special focus on dimensions of the socio-ecological model of behaviour and health, and unresolved issues. METHODS: This was a systematic review of population-based interventions either promoting PA or limiting sedentary behaviour in children with measure of weight status as an endpoint. The efficacy of studies was evaluated according to the levels of PA determinants in the socio-ecological model (individual, interpersonal, institutional environment, community) targeted by the interventions. RESULTS: A total of 54 studies met our inclusion criteria, most of them published within the last 5 years and targeting children aged 6-12 years. Twenty-three interventions targeted individual and/or interpersonal PA determinants only; 26 targeted determinants at three or four levels with at least one environment component at the institutional level; and five were multilevel community-based interventions. Our review indicated that programmes targeting PA determinants at the different levels of the socio-ecological model, including the social and organizational/built environments, had the greatest potential for preventing obesity in youngsters. Targeting various facets of PA, including everyday PA, might represent another key element for program efficacy on weight status. CONCLUSION: Data regarding the efficacy of comprehensive PA interventions that simultaneously address individual attitudes and skills, the social context, and the environment, to prevent overweight in children are encouraging. Further studies are needed to evaluate the maintenance of the effects and whether such strategies apply to young children and older adolescents, and to different cultural contexts

Le statut en vitamines anti-oxydantes module les effets de l’activité physique sur le niveau de leptine et sur les caractéristiques métaboliques liées au poids chez l’adolescent

International audienc

A Practical Guide to Adjust Micronutrient Biomarkers for Inflammation Using the BRINDA Method.

The Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) research group was formed over a decade ago to improve the interpretation of micronutrient biomarkers in settings with inflammation. The BRINDA inflammation adjustment method uses regression correction to adjust for the confounding effects of inflammation on select micronutrient biomarkers and has provided important insights to micronutrient research, policy, and programming. However, users may face challenges when applying the BRINDA inflammation adjustment methods to their own data due to varying guidance on the adjustment approach for different biomarkers and the need to develop statistical programming to conduct these analyses. This may result in lost opportunities to have results of micronutrient data readily available during critical decision-making periods. Our research objectives are to 1) provide an all-in-one summary of the BRINDA method in adjusting multiple micronutrient biomarkers for inflammation, 2) evaluate whether malaria as a binary variable should be included in the BRINDA inflammation adjustment method, and 3) present standardized and user-friendly BRINDA adjustment R package and SAS macro. This paper serves as a practical guidebook for the BRINDA inflammation adjustment approach and aids users to use the BRINDA R package and SAS to streamline their analyses