Maternal APOE ε2 as a possible risk factor for elevated prenatal Pb levels

Area of Science:

• Environmental Health
• Human Genetics
• Toxicology

Background:

• Lead (Pb) is a pervasive global contaminant with significant adverse health effects, particularly during human development.
• Prenatal lead exposure can originate from maternal diet and bone stores, posing risks to the fetus.
• Apolipoprotein E gene (APOE) variants are known to affect bone metabolism and hormone levels, potentially influencing lead kinetics.

Purpose of the Study:

• To investigate the combined effects of maternal APOE genotype, fetal sex, and parity on maternal and cord blood lead levels.
• To identify specific APOE alleles that modify prenatal lead exposure.
• To understand how nulliparity influences the relationship between maternal APOE genotype and lead levels.

Main Methods:

• Linear regression models were used to analyze data from 817 pregnant women and 772 newborns.
• Maternal and cord blood lead (mB-Pb, CB-Pb) concentrations were measured, alongside maternal APOE genotypes (ε2, ε3, ε4 alleles).
• Associations were examined, comparing ε2 and ε4 allele carriers to the ε3/ε3 genotype, with adjustments for zinc and selenium levels.

Main Results:

• Geometric means for mB-Pb and CB-Pb were 11.1 ng/g and 9.31 ng/g, respectively.
• In pregnancies with female fetuses, the maternal APOE ε2 allele correlated with higher mB-Pb and CB-Pb, while the ε4 allele correlated with lower levels.
• Nulliparity amplified these observed associations between maternal APOE genotype and lead levels.

Conclusions:

• Maternal APOE genotype, fetal sex, and parity are significant factors modulating prenatal lead kinetics.
• The maternal APOE ε2 allele may represent a genetic risk factor for increased fetal lead exposure.
• These findings underscore the complex interplay of genetic and environmental factors in prenatal lead exposure.