A pilot study: the importance of inter-individual differences in inorganic arsenic metabolism for birth weight outcome.

Inorganic arsenic (iAs) exposure is detrimental to birth outcome. We lack information regarding the potential for iAs metabolism to affect fetal growth. Our pilot study evaluated postpartum Romanian women with known birth weight outcome for differences in iAs metabolism. Subjects were chronically exposed to low-to-moderate drinking water iAs. We analyzed well water, arsenic metabolites in urine, and toenail arsenic. Urine iAs and metabolites, toenail iAs, and secondary methylation efficiency increased as an effect of exposure (p<0.001). Urine iAs and metabolites showed a significant interaction effect between exposure and birth weight. Moderately exposed women with low compared to normal birth weight outcome had greater metabolite excretion (p<0.03); 67% with low compared to 10% with normal birth weight outcome presented urine iAs >9 µg/L (p=0.019). Metabolic partitioning of iAs toward excretion may impair fetal growth. Prospective studies on iAs excretion before and during pregnancy may provide a biomarker for poor fetal growth risk.

Blood pressure hyperreactivity: an early cardiovascular risk in normotensive men exposed to low-to-moderate inorganic arsenic in drinking water.

BACKGROUND: Essential hypertension is associated with chronic exposure to high levels of inorganic arsenic in drinking water. However, early signs of risk for developing hypertension remain unclear in people exposed to chronic low-to-moderate inorganic arsenic. OBJECTIVE: We evaluated cardiovascular stress reactivity and recovery in healthy, normotensive, middle-aged men living in an arsenic-endemic region of Romania. METHODS: Unexposed (n = 16) and exposed (n = 19) participants were sampled from communities based on WHO limits for inorganic arsenic in drinking water (<10 µg/l). Water sources and urine samples were collected and analyzed for inorganic arsenic and its metabolites. Functional evaluation of blood pressure included clinical, anticipatory, cold pressor test, and recovery measurements. Blood pressure hyperreactivity was defined as a combined stress-induced change in SBP (> 20 mmHg) and DBP (>15 mmHg). RESULTS: Drinking water inorganic arsenic averaged 40.2 ± 30.4 and 1.0 ± 0.2 µg/l for the exposed and unexposed groups, respectively (P < 0.001). Compared to the unexposed group, the exposed group expressed a greater probability of blood pressure hyperreactivity to both anticipatory stress (47.4 vs. 12.5%; P = 0.035) and cold stress (73.7 vs. 37.5%; P = 0.044). Moreover, the exposed group exhibited attenuated blood pressure recovery from stress and a greater probability of persistent hypertensive responses (47.4 vs. 12.5%; P = 0.035). CONCLUSIONS: Inorganic arsenic exposure increased stress-induced blood pressure hyperreactivity and poor blood pressure recovery, including persistent hypertensive responses in otherwise healthy, clinically normotensive men. Drinking water containing even low-to-moderate inorganic arsenic may act as a sympathetic nervous system trigger for hypertension risk.