Blood lead levels and cumulative blood lead index (CBLI) as predictors of late neurodevelopment in lead poisoned children

Objective: To find the best lead exposure assessment marker for children.

Methods: We recruited 11 children, calculated a cumulative blood lead index (CBLI) for the children, measured their concurrent BLL, assessed their development, and measured their bone lead level.

Results: Nine of 11 children had clinically significant neurodevelopment problems. CBLI and current blood lead level, but not the peak lead level, were significantly or marginally negatively associated with the full-scale IQ score.

Conclusion: Lead exposure at younger age significantly impacts a child’s later neurodevelopment. CBLI may be a better predictor of neurodevelopment than are current or peak blood lead levels.     

Predicting bone turnover following tobacco exposure using bone alkaline phosphatase and N-telopeptide biomarkers and possible variability and effect modification of these markers by race/ethnicity

Abstract

Introduction: This study investigated the systemic response of serum bone alkaline phosphatase (SBAP) and urinary N-telopeptide (UNTX) to tobacco exposure and environmental tobacco smoke (ETS) and the possible effect modification (and variability) of this response by racial/ethnic origin.

Methods: Data (n?=?5411) were obtained from the National Health and Nutrition Examination Survey, with data analysis done on adults aged ≥ 20?years. Outcome variables were SBAP and UNTX. Independent variable was tobacco exposure measured using serum cotinine levels and adjusted for covariates. Generalized linear models were used to explore associations.

Results: A percentage increase in log transformed serum cotinine was associated with a 0.005 percentage increase in log transformed SBAP (CI: 0.002, 0.008) and 0.02 percentage increase in log transformed UNTX (CI: ?0.01, 0.04) with interaction between cotinine and race/ethnicity (p?=?0.01). Stratifying by race/ethnicity, tobacco exposure was associated with significant decreases in UNTX among non-Hispanic Whites – 0.008(?0.014, ?0.002) and Mexican Americans ?0.014 (?0.025, ?0.002) only. Categories of serum cotinine were associated with a monotonic increase in SBAP (p for trend <0.001) and monotonic non-linear decrease in UNTX (p for trend?>?0.05).

Conclusions: Tobacco and environmental tobacco exposure are associated with SBAP and increased bone formation. The response of UNTX to these exposures is modified by race/ethnicity with non-Hispanic Whites and Mexican-Americans less sensitive to the resorptive effects of tobacco exposure on bone.     

Maternal smoking during pregnancy and cord blood DNA methylation: new insight on sex differences and effect modification by maternal folate levels

Maternal smoking during pregnancy may affect newborn DNA methylation (DNAm). However, little is known about how these associations vary by a newborn’s sex and/or maternal nutrition. To fill in this research gap, we investigated epigenome-wide DNAm associations with maternal smoking during pregnancy in African American mother-newborn pairs. DNAm profiling in cord (n = 379) and maternal blood (n = 300) were performed using the Illumina HumanMethylation450 BeadChip array. We identified 12 CpG sites whose DNAm levels in cord blood were associated with maternal smoking, at a false discovery rate <5%. The identified associations in the GFI1 gene were more pronounced in male newborns than in females (P = 0.002 for maternal smoking × sex interaction at cg18146737). We further observed that maternal smoking and folate level may interactively affect cord blood DNAm level at cg05575921 in the AHRR gene (P = 5.0 × 10^?4 for interaction): compared to newborns unexposed to maternal smoking and with a high maternal folate level (>19.2 nmol/L), the DNAm level was about 0.03 lower (P = 3.6 × 10^?4) in exposed newborns with a high maternal folate level, but was 0.08 lower (P = 1.2 × 10^?8) in exposed newborns with a low maternal folate level. Our data suggest that adequate maternal folate levels may partly counteract the impact of maternal smoking on DNAm. These findings may open new avenues of inquiry regarding sex differences in response to environmental insults and novel strategies to mitigate their intergenerational health effects through optimization of maternal nutrition.