Association of Dietary Intake and Biomarker Levels of Arsenic, Cadmium, Lead, and Mercury among Asian Populations in the United States: NHANES 2011-2012.

BACKGROUND: We have recently shown that biomarker levels of selected metals are higher in Asians than in other U.S. ethnic groups, with important differences within selected Asian subgroups. Much of this difference may be dietary in origin; however, this is not well established. OBJECTIVE: We evaluated dietary intake of toxic metals as a source of increased biomarker levels of metals among U.S. Asians. METHODS: We estimated daily food consumption and dietary intake of arsenic, cadmium, lead, and mercury by combining 24-hr dietary intake recall data from the 2011-2012 National Health and Nutrition Examination Survey (NHANES) with data from the USDA Food Composition Intake Database and FDA Total Dietary Study. We analyzed associations between dietary metal intake and biomarker levels of the metals using linear regression. Further, estimated food consumption and metal intake levels were compared between Asians and other racial/ethnic groups (white, black, Mexican American, and other Hispanic) and within three Asian subgroups (Chinese, Indian Asian, and other Asians). RESULTS: Significant associations (p < 0.05) were found between biomarker levels and estimated dietary metal intake for total and inorganic arsenic and mercury among Asians. Asians had the highest daily fish and rice consumption across the racial/ethnic groups. Fish was the major contributor to dietary mercury and total arsenic intake, whereas rice was the major contributor to inorganic arsenic dietary intake. Fish consumption across the Asian subgroups varied, with Asian Indians having lower fish consumption than the other Asian subgroups. Rice consumption was similar across the Asian subgroups. CONCLUSIONS: We confirmed that estimated dietary intake of arsenic (total and inorganic) and mercury is significantly associated with their corresponding biomarkers in U.S. Asians, using nationally representative data. In contrast, estimated dietary intake of cadmium and lead were not significantly associated with their corresponding biomarker levels in U.S. Asians. Citation: Awata H, Linder S, Mitchell LE, Delclos GL. 2017. Association of dietary intake and biomarker levels of arsenic, cadmium, lead, and mercury among Asian populations in the United States: NHANES 2011-2012. Environ Health Perspect 125:314-323; http://dx.doi.org/10.1289/EHP28.

Biomarker Levels of Toxic Metals among Asian Populations in the United States: NHANES 2011-2012.

INTRODUCTION: The Centers for Disease Control and Prevention (CDC) recently found that Asians have considerably higher biomarker levels of cadmium, lead, mercury, and arsenic than whites, blacks, Mexican Americans, and other Hispanics in the United States. OBJECTIVE: Our goal was to further evaluate the higher metal biomarker levels among Asians. METHODS: Biomarker data (blood cadmium, blood lead, blood mercury, urinary total arsenic, and urinary dimethylarsinic acic) from individuals ≥ 6 years of age were obtained from the 2011-2012 National Health and Nutrition Examination Survey (NHANES). We compared geometric mean levels of these five metal biomarkers in Asians with those of four other NHANES race/ethnic groups (white, black, Mexican American, and other Hispanic), and across three Asian subgroups (Chinese, Asian Indian, and other Asian). We also evaluated associations between biomarker levels and sociodemographic, physical, dietary, and behavioral covariates across the Asian subgroups. RESULTS: Asians had significantly higher levels of all five metal biomarkers than other race/ethnic groups (p < 0.05), regardless of sociodemographic, physical, dietary, behavioral, or geographic characteristics. We also found variations in biomarker levels across the Asian subgroups. In general, Asian Indians had lower levels than the other two Asian subgroups, except for blood lead. The following characteristics were found to be significant predictors of several biomarker levels: sex, age, education, birthplace, smoking, and fish consumption. CONCLUSIONS: Overall, the Asian group had the highest geometric mean biomarker levels for all of the five metal variables. Furthermore, we provided evidence that significant variations in the biomarker levels are present across the Asian subgroups in the United States. Citation: Awata H, Linder S, Mitchell LE, Delclos GL. 2017. Biomarker levels of toxic metals among Asian populations in the United States: NHANES 2011-2012. Environ Health Perspect 125:306-313; http://dx.doi.org/10.1289/EHP27.

Population pharmacokinetics of aprepitant and dexamethasone in the prevention of chemotherapy-induced nausea and vomiting.

PURPOSE: To develop a population pharmacokinetic model of aprepitant and dexamethasone in Japanese patients with cancer, explore the factors that affect the pharmacokinetics of aprepitant, and evaluate the effect of aprepitant on the clearance of intravenous dexamethasone. METHODS: A total of 897 aprepitant concentration measurements were obtained from 290 cancer patients and 25 healthy volunteers. For dexamethasone, a total of 847 measurements were obtained from 440 patients who were co-administered aprepitant (40, 125 mg, or placebo). Plasma concentration of aprepitant and dexamethasone were determined by liquid chromatography connected with a tandem mass spectrometer and analyzed by a population approach using NONMEM software. RESULTS: The plasma concentration time course of aprepitant was described using a one-compartment model with first-order absorption and lag time. Oral clearance (CL/F) of aprepitant was changed by aprepitant dose at doses of 40 or 125 mg. Body weight was the most influential intrinsic factor to CL/F of aprepitant. Age, ALT, and BUN also had mild effects on the CL/F. Typical population estimates of CL/F, apparent distribution volume (V(d)/F), absorption constant (K(a)) and absorption lag time were 1.54 L/h, 72.1 L, 0.893/h and 0.295 h, respectively. Inter-individual variability in CL/F, V(d)/F and K(a) were 53.9, 21.0, and 141%, respectively; intra-individual variability was 27.7%. The plasma concentration time course of intravenous dexamethasone was also described using a one-compartment model. Clearance of dexamethasone was decreased 24.7 and 47.5% by co-administration of aprepitant 40 and 125 mg. All final model estimates of aprepitant and dexamethasone fell within 10% of the bootstrapped mean. CONCLUSIONS: A pharmacokinetic model for aprepitant has been developed that incorporates body weight, age, ALT, BUN and aprepitant dose to predict the CL/F. The results of population pharmacokinetic analysis of dexamethasone support dose adjustment of dexamethasone in the case of co-administration with aprepitant.