EFFECT OF PLASMA HOMOCYSTEINE LEVEL AND URINARY MONOMETHYLARSONIC ACID ON THE RISK OF ARSENIC-ASSOCIATED CAROTID ATHEROSCLEROSIS
Resource
TOXICOLOGY AND APPLIED PHARMACOLOGY v.216 n.1 pp.168-175
Journal
TOXICOLOGY AND APPLIED PHARMACOLOGY
Journal Volume
v.216
Journal Issue
n.1
Pages
168-175
Date Issued
2006
Date
2006
Author(s)
WU, MEEI-MAAN
CHIOU, HUNG-YI
HSUEH, YU-MEI
HONG, CHI-TZONG
SU, CHE-LONG
CHANG, SHU-FENG
HUANG, WEN-LING
WANG, YUAN-HUNG
HSIEH, YI-CHEN
CHEN, CHIEN-JEN
Abstract
Arsenic-contaminated well water has been shown to increase the risk of atherosclerosis. Because of involving S- adenosylmethionine, homocysteine may modify the risk by interfering with the biomethylation of ingested arsenic. In this study, we assessed the effect of plasma homocysteine level and urinary monomethylarsonic acid (MMA(V)) on the risk of atherosclerosis associated with arsenic. In total, 163 patients with carotid atherosclerosis and 163 controls were studied. Lifetime cumulative arsenic exposure from well water for study subjects was measured as index of arsenic exposure. Homocysteine level was determined by high- performance liquid chromatography (HPLC). Proportion of MMA( V) (MMA %) was calculated by dividing with total arsenic species in urine, including arsenite, arsenate, MMA(V), and dimethylarsinic acid (MMA(V)). Results of multiple linear regression analysis show a positive correlation of plasma homocysteine levels to the cumulative arsenic exposure after controlling for atherosclerosis status and nutritional factors (P < 0.05). This correlation, however, did not change substantially the effect of arsenic exposure on the risk of atherosclerosis as analyzed in a subsequent logistic regression model. Logistic regression analyses also show that elevated plasma homocysteine levels did not confer an independent risk for developing atherosclerosis in the study population. However, the risk of having atherosclerosis was increased to 5.4-fold (95% CI, 2.0-15.0) for the study subjects with high MMA% ( >= 16.5%) and high homocysteine levels ( >= 12.7 mu mol/l) as compared to those with low MMA % (< 9.9%) and low homocysteine levels (12.7 mu mol/l). Elevated homocysteinemia may exacerbate the formation of atherosclerosis related to arsenic exposure in individuals with high levels of MMA% in urine. (c) 2006 Elsevier Inc. All rights reserved.
Subjects
atherosclerosis
arsenic
homocysteine
biomethylation
risk factors
Type
journal article