Comparison of circulating and excreted metals and of autoimmunity between two Great Plains Tribal communities.

Metals contaminants of the environment from mine waste have been implicated as contributing agents in autoimmune disease. The current study compares metals and autoimmunity in two Tribal communities residing in the Black Hills and the Bighorn Mountains geographical regions that are scattered with extant hard rock mines. With documented drinking water contamination in both communities, in vivo levels of more than half of the measured serum and urine metals differed between the two communities and were substantially different from their national median values. Serum autoantibodies associated with systemic autoimmune disease were rare or at low-level, but antibodies to denatured (single-stranded) DNA and thyroid-specific autoantibodies were commonly elevated, especially in women. A three-tier statistical modeling process was carried out to examine individual metals exposure as predictors of autoantibody levels. For the most part only weak positive associations between individual metals and systemic autoantibodies were found, although univariate quantile regression analysis showed positive statistical associations of serum lead and antimony with anti-chromatin and anti-histone autoantibodies. Using age and gender-adjusted multivariable statistical models, metals did not predict anti-thyroglobulin or -thyroid peroxidase significantly and metals were generally negative predictors of the other autoantibodies. Overall these results suggest that elevated levels of environmental metals and metalloids in these communities may result in suppression of autoantibodies associated with systemic autoimmune disease.

Prenatal Metal Exposures and Infants' Developmental Outcomes in a Navajo Population.

Early-life exposure to environmental toxicants can have detrimental effects on children's neurodevelopment. In the current study, we employed a causal modeling framework to examine the direct effect of specific maternal prenatal exposures on infants' neurodevelopment in the context of co-occurring metals. Maternal metal exposure and select micronutrients' concentrations were assessed using samples collected at the time of delivery from mothers living across Navajo Nation with community exposure to metal mixtures originating from abandoned uranium mines. Infants' development across five domains was measured at ages 10 to 13 months using the Ages and Stages Questionnaire Inventory (ASQ:I), an early developmental screener. After adjusting for effects of other confounding metals and demographic variables, prenatal exposure to lead, arsenic, antimony, barium, copper, and molybdenum predicted deficits in at least one of the ASQ:I domain scores. Strontium, tungsten, and thallium were positively associated with several aspects of infants' development. Mothers with lower socioeconomic status (SES) had higher lead, cesium, and thallium exposures compared to mothers from high SES backgrounds. These mothers also had infants with lower scores across various developmental domains. The current study has many strengths including its focus on neurodevelopmental outcomes during infancy, an understudied developmental period, and the use of a novel analytical method to control for the effects of co-occurring metals while examining the effect of each metal on neurodevelopmental outcomes. Yet, future examination of how the effects of prenatal exposure on neurodevelopmental outcomes unfold over time while considering all potential interactions among metals and micronutrients is warranted.

Active smoking, secondhand smoke exposure and serum cotinine levels among Cheyenne River Sioux communities in context of a Tribal Public Health Policy.

INTRODUCTION: American Indians and Alaska Natives face disproportionately high rates of smoking and secondhand smoke (SHS) exposure. The Cheyenne River Sioux Tribe (CRST) is among the few Tribal Nations controlling commercial tobacco exposures in public and work places. We had an opportunity to explore effects of the new commercial tobacco-free policy (implemented in 2015) in an environmental health study (2014-2016) that collected information about commercial tobacco use and SHS prevalence and examined predictor variables of serum cotinine concentrations. METHODS: Self-reported survey data were used in quantile regression statistical modelling to explore changes in cotinine levels, based on smoking status, smokeless tobacco consumption and SHS exposure. RESULTS: From enrolled 225 adults, 51% (N=114) were current smokers. Among 88 non-tobacco users, 35 (40%) reported current SHS exposure. Significant differences in cotinine median concentrations were found among participants with and without current SHS exposure. Extremely high cotinine concentrations (~100 times larger than the median) were detected in some non-tobacco users. After implementing the new smoke-free air Tribal policy, cotinine decreased in participants with intermediate (3-15 ng/mL, non-tobacco users with SHS exposure) and high (>15 ng/mL, mainly tobacco users) cotinine levels showing association with an abatement of opportunities for SHS exposure. Significant predictors of cotinine levels were sampling year, current smoking and tobacco chewing. No gender differences were observed in cotinine. CONCLUSIONS: Our results show decrease in cotinine concentrations in CRST participants since implementation of their 'Smoke-Free Clean Air Act' in 2015.

CHILE: Outcomes of a group randomized controlled trial of an intervention to prevent obesity in preschool Hispanic and American Indian children.

OBJECTIVE: We examined the outcomes of the Child Health Initiative for Lifelong Eating and Exercise (CHILE) study, a group randomized controlled trial to design, implement, and test the efficacy of a trans-community intervention to prevent obesity in children enrolled in Head Start centers in rural American Indian and Hispanic communities in New Mexico. METHODS: CHILE was a 5-year evidence-based intervention that used a socioecological approach to improving dietary intake and increasing physical activity of 1898 children. The intervention included a classroom curriculum, teacher and food service training, family engagement, grocery store participation, and healthcare provider support. Height and weight measurements were obtained four times (fall of 2008, spring and fall of 2009, and spring of 2010), and body mass index (BMI) z-scores in the intervention and comparison groups were compared. RESULTS: At baseline, demographic characteristics in the comparison and intervention groups were similar, and 33% of all the children assessed were obese or overweight. At the end of the intervention, there was no significant difference between the two groups in BMI z-scores. CONCLUSIONS: Obesity prevention research among Hispanic and AI preschool children in rural communities is challenging and complex. Although the CHILE intervention was implemented successfully, changes in overweight and obesity may take longer than 2years to achieve.

Effects of an Obesity Prevention Intervention on Physical Activity Among Preschool Children: The CHILE Study.

Background Limited research addresses interventions to increase physical activity among American Indian and Hispanic preschool-aged children living in rural areas. We examined the impact of a Head Start-based intervention (Child Health Initiative for Lifelong Eating and Exercise [CHILE]) on physical activity at home. Method Sixteen Head Start centers in predominantly Hispanic or American Indian communities were group randomized to the six-component intervention or a comparison group for 2 years. Structured surveys were administered at four assessment times to a convenience sample of caregivers of 655 children in the study. Multilevel modeling was used to assess the effects of the intervention on physical activity. Results The relative change in physical activity in the intervention group compared with the comparison group over the 2-year period was 1.56 (95% confidence interval [1.02, 2.38]; p = .04). Among specific promoted activities (ball playing, dancing, active games, jumping, and walking), dancing increased significantly in the intervention compared with the comparison group (2.9; 95% confidence interval [1.2, 7.1]; p = .02). Conclusions The CHILE intervention was effective at increasing physical activity at home in preschool children in priority populations. Future research should focus on increasing family involvement and strengthening messaging about physical activity in these populations.