Comparison of the accumulation of toxic metal biomarkers in Asian subgroups and other races in the United States: NHANES 2015-2016.

Toxic metals such as lead (Pb), cadmium (Cd), mercury (Hg) and arsenic (As) that lead to many visceral organ and nervous system diseases have attracted global attention due to their gradual accumulation in human bodies. The tolerance levels of exposure to toxic metals among race/ethnic groups are different due to the variance of sociodemographic, dietary, and behavioral characteristics. Few studies focused on investigating the biomarker levels of toxic metals in different race/ethnic groups and the potential mechanisms for controlling the accumulation in human bodies. Therefore, we selected eight biomarkers for four toxic metals from the National Health and Nutrition and Examination Survey (NHANES) in the 2-year data cycle of 2015-2016 to reveal the accumulation levels in different races. According to the NHANES rules, we applied probability sampling weights. The geometric mean levels of these biomarkers were calculated in all five race/ethnic groups (Mexican American, white, black, Asian, and other Hispanic) and two Asian subgroups (U.S.-born Asian, and other-born Asian), and compared with each other. The results showed that all the biomarkers in other-born Asians were 1.1-6.7 times in blood and 1.1-3.6 times in urine higher than other race/ethnic groups. Except Hg and As, the lowest biomarker levels were recorded in U.S.-born Asians, only 0.6-0.9 times of lead and 0.3-0.8 times of cadmium than other race/ethnic groups. Furthermore, the major factors of higher Hg and As biomarker levels in Asians were dietary intake of seafood and rice, indicating different accumulation mechanisms among Asians and other race/ethnic groups, especially for U.S.-born Asians. These findings provided new insight into a deeper understanding the accumulation of toxic metals and human health.

Measurement invariance of the Barratt Impulsiveness Scale across black and white adults with cocaine use disorder.

This study tests for measurement invariance of impulsivity assessed by the Barratt Impulsiveness Scale (BIS) across Black and White adults with cocaine use disorder and examines the association of BIS impulsivity with treatment retention and outcomes. Data from four clinical trials were combined providing a total sample of 302 participants with cocaine abuse/dependence (42% Black, 58% White, 44% female, agemean = 40.22, SD = 9.26). We used multi-group confirmatory factor analyses to test for measurement invariance across race and examined bivariate correlations between BIS impulsivity and treatment retention and outcomes by race. Factor analyses indicated a 22-item, two-factor (motor impulsiveness and nonplanning impulsiveness) brief BIS fit the data best (RMSEA = 0.073 [90% CI: 0.065-0.080]; CFI = 0.904; TLI = 0.893; SRMR = 0.073) and was configural, metric, and scalar invariant across race. Higher motor impulsiveness was associated with higher percentage cocaine negative urines in the overall sample (r = -0.15, p = .01), but this association only remained in the Black subsample when examined across race (r = 0.28, p < .001). Higher motor impulsiveness was also associated with increased days abstinent from cocaine in the Black subsample only (r = 0.28, p < .001). Nonplanning impulsiveness was associated with lower percentage of treatment days abstinent from cocaine in the White subsample only (r = -0.16, p = .045). These findings 1) provide evidence for a 21-item, two-factor brief BIS that is invariant across Black and White adults with cocaine use disorder, and 2) suggest that BIS impulsivity may be associated with poorer cocaine treatment outcomes among White but not Black adults.