Source: Masters Abstracts International, Volume: 50-04, page: 2410.

Adviser: Kathleen McCarty.

Background: Maternal exposure to inorganic arsenic (iAs) increases risk for low birth weight outcomes. Metabolic efficiency has been shown to modify the relationship between iAs exposure and both cancer and cardiovascular diseases. No previous studies have investigated this modification for reproductive outcomes.

Objective: This study investigated whether maternal metabolic efficiency of iAs, measured by primary and secondary methylation indices (PMI and SMI), affected low birth weight outcomes in a population exposed to arsenic at moderate levels through drinking water.

Methods: A case-control study of 19 cases and 19 controls was conducted in Northwestern Romania in 2010. Well water samples were collected to assess exposure for each subject. Water arsenic concentration was determined using atomic absorption spectrometry (AAS) with a vapor generation system. Urine samples were collected from each subject for arsenic metabolite analysis. Urinary arsenic speciation was determined using inductively coupled plasma mass spectrometry (ICP-MS) with hydride generation (HG).

Results: SMI varied significantly between the low and moderately exposed subjects (p=0.0159) but not between the normal and low birth weight subjects (p=1.000). PMI did not vary significantly between any of the groups (p=0.5385). Concentrations of the individual urinary arsenic metabolites AsIII and monomethylarsonic acid (MMA) varied significantly (p=0.0028, p=0.0438) by birth weight within the moderately exposed group and iAs and dimethylarsinic acid (DMA) varied between these groups but not significantly (p=0.0540, p=0.0996).

Conclusion: Maternal methylation efficiency did not affect low birth weight outcomes in the study population. However, a difference in absolute excretion between moderately exposed cases and controls was observed.