TY - JOUR
T1 - Nutritional status has marginal influence on the metabolism of inorganic arsenic in pregnant Bangladeshi women
AU - Li, Li
AU - Ekström, Eva Charlotte
AU - Goessler, Walter
AU - Lönnerdal, Bo
AU - Nermell, Barbro
AU - Yunus, Mohammad
AU - Rahman, Anisur
AU - El Arifeen, Shams
AU - Persson, Lars Åke
AU - Vahter, Marie
PY - 2008/3
Y1 - 2008/3
N2 - Background: The interindividual variation in metabolism of inorganic arsenic (iAs), involving methylation via one-carbon metabolism, has been well documented, but the reasons remain unclear. Objectives: In this population-based study we aimed to elucidate the effect of nutrition on As methylation among women in Matlab, Bangladesh, where people are chronically exposed to iAs via drinking water. Methods: We studied effects of macronutrient status using body mass index (BMI) among 442 women in early pregnancy (gestational week 8), and effects of micronutrient status (plasma folate, vitamin B12, zinc, fertitin, and selenium) among 753 women at gestational week 14. Arsenic metabolites in urine were measured by HPLC combined with hydride generation inductively coupled plasma mass spectrometry. Results: The median concentration of As in urine was 97 μg/L (range, 5-1,216 μg/L, adjusted by specific gravity). The average proportions of iAs, monomethylarsonic acid, and dimethylarsinic acid in urine in gestational week 8 were 15%, 11 %, and 74%, respectively. Thus, the women had efficient As methylation in spite of being poorly nourished (one-third had BMIs < 18.5 kg/m2) and having elevated As exposure, both of which are known to decrease As methylation. The metabolism of iAs was only marginally influenced by micronutrient status, probably because women, especially in pregnancy and with low folate intake, have an efficient betaine-mediated remethylation of homocysteine, which is essential for an efficient As methylation. Conclusions: In spite of the high As exposure and prevalent malnutrition, overall As methylation in women in early pregnancy was remarkably efficient. The As exposure level had the greatest impact on As methylation among the studied factors.
AB - Background: The interindividual variation in metabolism of inorganic arsenic (iAs), involving methylation via one-carbon metabolism, has been well documented, but the reasons remain unclear. Objectives: In this population-based study we aimed to elucidate the effect of nutrition on As methylation among women in Matlab, Bangladesh, where people are chronically exposed to iAs via drinking water. Methods: We studied effects of macronutrient status using body mass index (BMI) among 442 women in early pregnancy (gestational week 8), and effects of micronutrient status (plasma folate, vitamin B12, zinc, fertitin, and selenium) among 753 women at gestational week 14. Arsenic metabolites in urine were measured by HPLC combined with hydride generation inductively coupled plasma mass spectrometry. Results: The median concentration of As in urine was 97 μg/L (range, 5-1,216 μg/L, adjusted by specific gravity). The average proportions of iAs, monomethylarsonic acid, and dimethylarsinic acid in urine in gestational week 8 were 15%, 11 %, and 74%, respectively. Thus, the women had efficient As methylation in spite of being poorly nourished (one-third had BMIs < 18.5 kg/m2) and having elevated As exposure, both of which are known to decrease As methylation. The metabolism of iAs was only marginally influenced by micronutrient status, probably because women, especially in pregnancy and with low folate intake, have an efficient betaine-mediated remethylation of homocysteine, which is essential for an efficient As methylation. Conclusions: In spite of the high As exposure and prevalent malnutrition, overall As methylation in women in early pregnancy was remarkably efficient. The As exposure level had the greatest impact on As methylation among the studied factors.
KW - Arsenic
KW - Metabolite
KW - Methylation
KW - Nutrition
KW - Pregnant women
KW - Urine
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U2 - 10.1289/ehp.10639
DO - 10.1289/ehp.10639
M3 - Article
C2 - 18335097
AN - SCOPUS:40849130997
VL - 116
SP - 315
EP - 321
JO - Environmental Health Perspectives
JF - Environmental Health Perspectives
SN - 0091-6765
IS - 3
ER -