Prenatal exposure to environmental heavy metals and newborn telomere length: A systematic review and meta-analysis.

Exposure to environmental heavy metals is associated with telomere length (TL) alteration. Available information regarding the effect of prenatal exposure to environmental pollutants on newborn TL is controversial. The aim of this study is to systematically review and conduct a meta-analysis of the existing epidemiological studies on the associations between prenatal metal exposure and newborn TL. A comprehensive literature search was performed using the online databases of PubMed, Web of Science, and ScienceDirect from their inception to December 1, 2023. Thirteen eligible studies were included from the overall initial identification of 3559 records. The effect size was expressed as standardized beta coefficients with 95% confidence intervals (CIs) by the restricted maximum-likelihood approach with a weighted random-effects model. Prenatal exposure to environmental heavy metals was associated with a shorter newborn TL (standardized beta = -0.04; 95% CI: -0.08, 0.00; p = 0.05). Subgroup analysis showed that prenatal exposure to cadmium was significantly, negatively associated with TL in newborns (standardized beta = -0.05; 95% CI: -0.10, -0.01; p = 0.021). Heavy metal exposure during the third trimester was significantly associated with a shorter TL in newborns (standardized beta = -0.05; 95% CI: -0.11, -0.01; p = 0.045). No significant association was found between the newborn's sex and exposure sample type. This study provides evidence for the negative effect of prenatal exposure to heavy metals on newborn TL. In particular, cadmium exposure and exposure during the third trimester of pregnancy are critical factors associated with heavy metal-induced TL shortening.

Factors associated with syndemic anemia and stunting among children in Myanmar: A cross-sectional study from a positive deviance approach.

BACKGROUND: Anemia and stunting in children are detrimental to the prospects of a normal, healthy upbringing. Having similar risk factors and serious consequences, the syndemic aspect of these two ailments is mostly underrated, and positive deviant (PD) factors that ensure non-anemic status in stunted children have not been studied to date. METHODS: This study aimed to identify PD factors that have potential to prevent syndemic anemia among stunted children aged 6-59 months in Myanmar. This was a cross-sectional secondary analysis of the Myanmar Demographic and Health Survey (DHS) data conducted in 2016, applying the PD concept, where children who were stunted without anemia were considered as PDs. RESULTS: Among 1248 stunted children, those who had the syndemic condition were compared with their PD peers in terms of maternal characteristics as well as socioeconomic and health-related factors. Multivariable logistic regression analyses were used to identify the determinants of syndemic state. The results showed that three out of every five stunted children were anemic. The syndemic risk was decreased among children of maternal age groups 20-34 years and 35-44 years: [aOR] = 0.19, 95% CI = 0.05-0.69; p = 0.012, and aOR = 0.19, 95% CI = 0.05-0.75; p = 0.018, respectively. Moderately stunted children (aOR = 0.53, 95% CI = 0.34-0.81; p = 0.004) and children who were not currently breastfed (aOR = 1.56, 95% CI = 1.01-2.41; p = 0.044) were less likely to develop the syndemic condition. CONCLUSION: Maternal age, stunting severity, breastfeeding duration, and maternal anemic status are strong predictors in determining hemoglobin concentrations among stunted children. This study suggests that nutritional interventions targeting PD factors could represent syndemic action in improving child health.

Telomeres susceptibility to environmental arsenic exposure: Shortening or lengthening?

Maintaining telomere length plays a crucial role in regulating cellular life span. Telomere lengthening or shortening is one of the important biomarkers which could predict the preceding or present diseases. Meanwhile, the impact of environmental arsenic exposure on telomere length has increasingly concerned. Although previous studies demonstrated the effects of arsenic on telomere length, the findings were unclear on whether telomere shortens or lengthens by arsenic exposure. Thus, this manuscript summarized and discussed the telomere length alteration following arsenic exposure and the possible does-response effect of arsenic on telomere length. The present review suggested that different age groups may respond differently to arsenic exposure, and the dose-response effect of arsenic could be a critical factor in its effect on telomere length. Moreover, speciation analysis of arsenic could be more informative in identifying the effect of arsenic on telomere length.