Elevated blood lead levels are associated with reduced risk of malaria in Beninese infants

Introduction Elevated blood lead levels (BLL) and malaria carry an important burden of disease in West Africa. Both diseases might cause anemia and they might entail long-term consequences for the development and the health status of the child. Albeit the significant impact of malaria on lead levels described in Nigeria, no evaluation of the effect of elevated BLL on malaria risk has been investigated so far. Materials and Methods Between 2010 and 2012, blood lead levels of 203 Beninese infants from Allada, a semi-rural area 50km North from Cotonou, were assessed at 12 months of age. To assess lead levels, blood samples were analyzed by mass spectrometry. In parallel, clinical, microbiological and hematological data were collected. More precisely, hemoglobin, serum ferritin, CRP, vitamin B12, folate levels, and Plasmodium falciparum parasitemia were assessed and stool samples were also analyzed. Results At 12 months, the mean BLL of infants was 7.41 μg/dL (CI: 65.2; 83), and 128 infants (63%) had elevated blood lead levels, defined by the CDC as BLL>5 μg/dL. Lead poisoning, defined as BLL>10 μg/dL, was found in 39 infants (19%). Twenty-five infants (12.5%) had a positive blood smear at 12 months and 144 infants were anemic (71%, hemoglobin<110 g/L). Elevated blood lead levels were significantly associated with reduced risk of a positive blood smear (AOR = 0.38, P-value = 0.048) and P. falciparum parasite density (beta-estimate = -1.42, P-value = 0.03) in logistic and negative binomial regression multivariate models, respectively, adjusted on clinical and environmental indicators. Conclusion Our study shows for the first time that BLL are negatively associated with malarial risk considering other risk factors. Malaria is one of the main causes of morbidity and mortality in infants under 5 years worldwide, and lead poisoning is the 6th most important contributor to the global burden of diseases measured in disability adjusted life years (DALYs) according to the Institute of Health Metrics. In conclusion, due to the high prevalence of elevated BLL, health interventions should look forward to minimize the exposure to lead to better protect the population in West Africa

Psychometric validation of the revised family affluence scale: a latent variable approach

The aim was to develop and test a brief revised version of the family affluence scale. A total of 7120 students from Denmark, Greenland, Italy, Norway, Poland, Romania, Scotland and Slovakia reported on a list of 16 potential indicators of affluence. Responses were subject to item screening and test of dimensionality. Bifactor analysis revealed a strong general factor of affluence in all countries, but with additional specific factors in all countries. The specific factors mainly reflected overlapping item content. Item screening was conducted to eliminate items with low discrimination and local dependence, reducing the number of items from sixteen to six: Number of computers, number of cars, own bedroom, holidays abroad, dishwasher, and bathroom. The six-item version was estimated with Samejima’s graded response model, and tested for differential item functioning by country. Three of the six items were invariant across countries, thus anchoring the scale to a common metric across countries. The six-item scale correlated with parental reported income groups in six out of eight countries. Findings support a revision to six items in the family affluence scale

Educational expectations and adolescent health behaviour: an evolutionary approach

This research was funded by NHS Health Scotland.Objectives. Previous research finds adolescents expecting to attend university are more likely to demonstrate health-promoting behaviour than those not expecting university attendance. This suggests public health improvements may be achievable by encouraging adolescents to adopt academic goals. We investigate confounders of this putative relationship, focusing on those identified by evolutionary theory. Methods. Multi-level logistic regression was used to analyse the 2010 Scottish Health Behaviour in School-aged Children survey (n = 1834). Results. Adolescents anticipating university attendance exhibited higher levels of engagement in health-protective behaviours (fruit and vegetable consumption, exercise and tooth brushing) and were more likely to avoid health-damaging behaviours (crisps, soft drink and alcohol consumption, tobacco and cannabis use, fighting and intercourse). These relationships persisted when controlling indicators of life history trajectory (pubertal timing, socioeconomic status and father absence). Pupil level: gender, age, perceived academic achievement and peer/family communication and school level: university expectations, affluence, leavers’ destinations, exam performance and school climate were also adjusted. Conclusions. Encouraging adolescents to consider an academic future may achieve public health benefits, despite social factors that might otherwise precipitate poor health via an accelerated life history trajectory.PostprintPeer reviewe