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.

Safety and immunogenicity of a variant-adapted SARS-CoV-2 recombinant protein vaccine with AS03 adjuvant as a booster in adults primed with authorized vaccines: a phase 3, parallel-group study

Background

In a parallel-group, international, phase 3 study (ClinicalTrials.govNCT04762680), we evaluated prototype (D614) and Beta (B.1.351) variant recombinant spike protein booster vaccines with AS03-adjuvant (CoV2 preS dTM-AS03).

Methods

Adults, previously primed with mRNA (BNT162b2, mRNA-1273), adenovirus-vectored (Ad26.CoV2.S, ChAdOx1nCoV-19) or protein (CoV2 preS dTM-AS03 [monovalent D614; MV(D614)]) vaccines were enrolled between 29 July 2021 and 22 February 2022. Participants were stratified by age (18-55 and ≥ 56 years) and received one of the following CoV2 preS dTM-AS03 booster formulations: MV(D614) (n = 1285), MV(B.1.351) (n = 707) or bivalent D614 + B.1.351 (BiV; n = 625). Unvaccinated adults who tested negative on a SARS-CoV-2 rapid diagnostic test (control group, n = 479) received two primary doses, 21 days apart, of MV(D614). Anti-D614G and anti-B.1.351 antibodies were evaluated using validated pseudovirus (lentivirus) neutralization (PsVN) assay 14 days post-booster (day [D]15) in 18-55-year-old BNT162b2-primed participants and compared with those pre-booster (D1) and on D36 in 18-55-year-old controls (primary immunogenicity endpoints). PsVN titers to Omicron BA.1, BA.2 and BA.4/5 subvariants were also evaluated. Safety was evaluated over a 12-month follow-up period. Planned interim analyses are presented up to 14 days post-last vaccination for immunogenicity and over a median duration of 5 months for safety.

Findings

All three boosters elicited robust anti-D614G or -B.1.351 PsVN responses for mRNA, adenovirus-vectored and protein vaccine-primed groups. Among BNT162b2-primed adults (18-55 years), geometric means of the individual post-booster versus pre-booster titer ratio (95% confidence interval [CI]) were: for MV (D614), 23.37 (18.58-29.38) (anti-D614G); for MV(B.1.351), 35.41 (26.71-46.95) (anti-B.1.351); and for BiV, 14.39 (11.39-18.28) (anti-D614G) and 34.18 (25.84-45.22 (anti-B.1.351). GMT ratios (98.3% CI) versus post-primary vaccination GMTs in controls, were: for MV(D614) booster, 2.16 (1.69; 2.75) [anti-D614G]; for MV(B.1.351), 1.96 (1.54; 2.50) [anti-B.1.351]; and for BiV, 2.34 (1.84; 2.96) [anti-D614G] and 1.39 (1.09; 1.77) [anti-B.1.351]. All booster formulations elicited cross-neutralizing antibodies against Omicron BA.2 (across priming vaccine subgroups), Omicron BA.1 (BNT162b2-primed participants) and Omicron BA.4/5 (BNT162b2-primed participants and MV D614-primed participants). Similar patterns in antibody responses were observed for participants aged ≥56 years. Reactogenicity tended to be transient and mild-to-moderate severity in all booster groups. No safety concerns were identified.

Interpretation

CoV2 preS dTM-AS03 boosters demonstrated acceptable safety and elicited robust neutralizing antibodies against multiple variants, regardless of priming vaccine.

Funding

Sanofi and Biomedical Advanced Research and Development Authority (BARDA).

A Framework for Promoting Diversity, Equity, and Inclusion in Genetics and Genomics Research

IMPORTANCE

Research into the genetic and genomic ("genomics") foundations of disease is central to our understanding of disease prevention, early detection, diagnostic accuracy, and therapeutic intervention. Inequitable participation in genomics research by historically excluded populations limits the ability to translate genomic knowledge to achieve health equity and ensure that findings are generalizable to diverse populations.

OBSERVATIONS

We propose a novel framework for promoting diversity, equity, and inclusion in genomics research. Building on principles of community-based participatory research and collective impact frameworks, the framework can guide our understanding of the social, cultural, health system, policy, community, and individual contexts in which engagement and genomics research are being done. Our framework highlights the involvement of a multistakeholder team, including the participants and communities to be engaged, to ensure robust methods for recruitment, retention, return of genomic results, quality of engagement, follow-up, and monitoring of participants.

CONCLUSIONS AND RELEVANCE

The proposed engagement framework will guide investigators in optimizing equitable representation in research and enhancing the rigor of genomics investigation.

Efficacy and Safety of NVX-CoV2373 in Adults in the United States and Mexico

BACKGROUND

NVX-CoV2373 is an adjuvanted, recombinant spike protein nanoparticle vaccine that was shown to have clinical efficacy for the prevention of coronavirus disease 2019 (Covid-19) in phase 2b-3 trials in the United Kingdom and South Africa, but its efficacy had not yet been tested in North America.

METHODS

We conducted a phase 3, randomized, observer-blinded, placebo-controlled trial in the United States and Mexico during the first half of 2021 to evaluate the efficacy and safety of NVX-CoV2373 in adults (≥18 years of age) who had not had severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Participants were randomly assigned in a 2:1 ratio to receive two doses of NVX-CoV2373 or placebo 21 days apart. The primary objective was to determine vaccine efficacy against reverse-transcriptase-polymerase-chain-reaction-confirmed Covid-19 occurring at least 7 days after the second dose. Vaccine efficacy against moderate-to-severe disease and against different variants was also assessed.

RESULTS

Of the 29,949 participants who underwent randomization between December 27, 2020, and February 18, 2021, a total of 29,582 (median age, 47 years; 12.6% ≥65 years of age) received at least one dose: 19,714 received vaccine and 9868 placebo. Over a period of 3 months, 77 cases of Covid-19 were noted - 14 among vaccine recipients and 63 among placebo recipients (vaccine efficacy, 90.4%; 95% confidence interval [CI], 82.9 to 94.6; P<0.001). Ten moderate and 4 severe cases occurred, all in placebo recipients, yielding vaccine efficacy against moderate-to-severe disease of 100% (95% CI, 87.0 to 100). Most sequenced viral genomes (48 of 61, 79%) were variants of concern or interest - largely B.1.1.7 (alpha) (31 of the 35 genomes for variants of concern, 89%). Vaccine efficacy against any variant of concern or interest was 92.6% (95% CI, 83.6 to 96.7). Reactogenicity was mostly mild to moderate and transient but was more frequent among NVX-CoV2373 recipients than among placebo recipients and was more frequent after the second dose than after the first dose.

CONCLUSIONS

NVX-CoV2373 was safe and effective for the prevention of Covid-19. Most breakthrough cases were caused by contemporary variant strains. (Funded by Novavax and others; PREVENT-19 ClinicalTrials.gov number, NCT04611802.).

Efficacy and Safety of NVX-CoV2373 in Adults in the United States and Mexico

BACKGROUND

NVX-CoV2373 is an adjuvanted, recombinant spike protein nanoparticle vaccine that was shown to have clinical efficacy for the prevention of coronavirus disease 2019 (Covid-19) in phase 2b-3 trials in the United Kingdom and South Africa, but its efficacy had not yet been tested in North America.

METHODS

We conducted a phase 3, randomized, observer-blinded, placebo-controlled trial in the United States and Mexico during the first half of 2021 to evaluate the efficacy and safety of NVX-CoV2373 in adults (≥18 years of age) who had not had severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Participants were randomly assigned in a 2:1 ratio to receive two doses of NVX-CoV2373 or placebo 21 days apart. The primary objective was to determine vaccine efficacy against reverse-transcriptase-polymerase-chain-reaction-confirmed Covid-19 occurring at least 7 days after the second dose. Vaccine efficacy against moderate-to-severe disease and against different variants was also assessed.

RESULTS

Of the 29,949 participants who underwent randomization between December 27, 2020, and February 18, 2021, a total of 29,582 (median age, 47 years; 12.6% ≥65 years of age) received at least one dose: 19,714 received vaccine and 9868 placebo. Over a period of 3 months, 77 cases of Covid-19 were noted - 14 among vaccine recipients and 63 among placebo recipients (vaccine efficacy, 90.4%; 95% confidence interval [CI], 82.9 to 94.6; P<0.001). Ten moderate and 4 severe cases occurred, all in placebo recipients, yielding vaccine efficacy against moderate-to-severe disease of 100% (95% CI, 87.0 to 100). Most sequenced viral genomes (48 of 61, 79%) were variants of concern or interest - largely B.1.1.7 (alpha) (31 of the 35 genomes for variants of concern, 89%). Vaccine efficacy against any variant of concern or interest was 92.6% (95% CI, 83.6 to 96.7). Reactogenicity was mostly mild to moderate and transient but was more frequent among NVX-CoV2373 recipients than among placebo recipients and was more frequent after the second dose than after the first dose.

CONCLUSIONS

NVX-CoV2373 was safe and effective for the prevention of Covid-19. Most breakthrough cases were caused by contemporary variant strains. (Funded by Novavax and others; PREVENT-19 ClinicalTrials.gov number, NCT04611802.).

Generalized neural field theory of cortical plasticity illustrated by an application to the linear phase of ocular dominance column formation in primary visual cortex

Physiologically based neural field theory (NFT) is extended to encompass cortical plasticity dynamics. An illustrative application is provided which treats the evolution of the connectivity of left- and right-eye visual stimuli to neuronal populations in the primary visual cortex (V1), and the initial, linear phase of formation of approximately one-dimensional (1D) ocular dominance columns (ODCs) that sets their transverse spatial scale. This links V1 activity, structure, and physiology within a single theory that already accounts for a range of other brain activity and connectivity phenomena, thereby enabling ODC formation and many other phenomena to be interrelated and cortical parameters to be constrained across multiple domains. The results accord with experimental ODC widths for realistic cortical parameters and are based directly on a unified description of the neuronal populations involved, their connection strengths, and the neuronal activity they support. Other key results include simple analytic approximations for ODC widths and the parameters of maximum growth rate, constraints on cortical excitatory and inhibitory gains, elucidation of the roles of specific poles of the V1 response function, and the fact that ODCs are not formed when input stimuli are fully correlated between eyes. This work provides a basis for further generalization of NFT to model other plasticity phenomena, thereby linking them to the range multiscale phenomena accounted for by NFT.

Genetics of Smoking Behaviors in American Indians

BACKGROUND

The smoking behavior of American Indians (AI) differs from that of non-Hispanic whites (NHW). Typically light smokers, cessation interventions in AIs are generally less effective. To develop more effective cessation programs for AIs, clinicians, researchers, and public health workers need a better understanding of the genetic factors involved in their smoking behavior. Our aim was to assess whether SNPs associated with smoking behavior in NHWs are also associated with smoking in AIs.

METHODS

We collected questionnaire data on smoking behaviors and analyzed blood and saliva samples from two Tribal populations with dramatically different cultures and smoking prevalence, one in the Northern Plains (n = 323) and the other in the Southwest (n = 176). A total of 384 SNPs were genotyped using an Illumina custom GoldenGate platform. Samples were also assessed for cotinine and 3-hydroxycotinine as markers of nicotine intake and nicotine metabolite ratio.

RESULTS

Among 499 participants, we identified, in the Northern Plains sample only, a variant of the gamma-aminobutyric acid receptor subunit alpha-2 (GABRA2) (rs2119767) on chromosome 4p that was associated with many of the intake biomarkers of smoking we examined, suggesting a role for this gene in modifying smoking behavior in this population. We also identified three SNPs, in the Southwest sample only, as significant correlates of only cigarettes per day: rs4274224, rs4245147 (both dopamine receptor D2 gene), and rs1386493 (tryptophan hydroxylase 2 gene).

CONCLUSIONS

The contribution of many genes known to underlie smoking behaviors in NHWs may differ in AIs.

IMPACT

Once validated, these variants could be useful in developing more effective cessation strategies.

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.

Type 2 diabetes and later cognitive function in older American Indians: The Strong Heart Study

OBJECTIVES

Insulin resistance is a substantial health issue for American Indians, with type 2 diabetes overrepresented in this population as compared with non-Hispanic whites. Insulin resistance and its related conditions in turn increase risk for dementia and cognitive impairment. The aim of the current study was to determine whether type 2 diabetes and insulin resistance at midlife was associated with later-life cognitive testing in a large sample of older American Indians, aged 65 and older.

METHODS

American Indian participants who underwent both fasting blood draw as part of the Strong Heart Study and had subsequent cognitive testing as part of the later adjunct Cerebrovascular Disease and its Consequences in American Indians study were included (n = 790). Regression models examined type 2 diabetes and impaired fasting glucose and subsequent cognitive test performance as part of a longitudinal study design. The relationship between a continuous measure of insulin resistance and later cognitive test performance was assessed using generalized estimating equations.

RESULTS

Controlling for demographic and clinical factors, verbal fluency and processing speed/working memory were significantly negatively associated with having type 2 diabetes and with insulin resistance, but not with impaired fasting glucose.

CONCLUSION

In this sample of American Indians, type 2 diabetes at midlife was associated with subsequent lower performance on measures of executive function. These results may have important implications for future implementation of diagnostic and intervention services in this population.

Impacts of alcohol availability on Tribal lands where alcohol is prohibited: A community-partnered qualitative investigation

On a Northern Plains reservation where alcohol was prohibited, we investigated community members' views on the impacts of alcohol availability. Our methods combined elements of Tribal community participatory research with qualitative inquiry to elicit these perspectives. We used rapid appraisal techniques to conduct confidential interviews with 31 key leaders representing 7 relevant major community systems, and representing a variety of perspectives. Topics included respondents' understandings of the current systems of alcohol availability and use on the reservation, the impacts of these systems on reservation residents, and possible ways to measure these impacts. Respondents reported impacts on individuals, families, and the tribe overall. Alcohol-related problems shaped and were shaped by a constellation of social-ecological conditions: kinship, housing, employment, public/social service capacity, and the supply of alcohol in nearby off-reservation areas, as well as inter-governmental relationships and the spiritual life of reservation residents. A variety of social-structural determinants magnified alcohol impacts, so that the problem drinking of a small number of individuals could have broad effects on their families and the entire community. Our participatory qualitative methods enabled us to directly include the voices as well as the personal experiences and expertise of community members in this presentation. These methods may be broadly applied within policy analysis to identify ways to reduce harms related to alcohol and other drugs for Indigenous communities.

Relationships Between Smoking Behaviors and Cotinine Levels Among Two American Indian Populations With Distinct Smoking Patterns

Introduction

Smoking prevalence, cigarettes per day (CPD), and lung cancer incidence differ between Northern Plains (NP) and Southwest (SW) American Indian populations. We used cotinine as a biomarker of tobacco smoke exposure to biochemically characterize NP and SW smokers and nonsmokers and to investigate factors associated with variation in tobacco exposure.

Methods

American Indians (N = 636) were recruited from two different tribal populations (NP and SW) as part of a study conducted as part of the Collaborative to Improve Native Cancer Outcomes P50 project. For each participant, a questionnaire assessed smoking status, CPD, second-hand smoke exposure, and traditional ceremonial tobacco use; plasma and/or salivary cotinine was measured.

Results

Cotinine levels were (mean ± 95% confidence interval [CI]) 81.6 ± 14.1 and 21.3 ± 7.3 ng/ml among NP smokers and non-mokers, respectively, and 44.8 ± 14.4 and 9.8 ± 5.8 ng/ml among SW smokers and nonsmokers, respectively. Cotinine levels correlated with CPD in both populations (p < .0001). Cotinine ≥15 ng/ml was measured in 73.4% of NP smokers and 47.8% of SW smokers and in 19.0% of NP nonsmokers and 10.9% of SW nonsmokers. Ceremonial traditional tobacco use was associated with higher cotinine among NP smokers only (p = 0.004). Second-hand smoke exposure was associated with higher cotinine among NP non-smokers (P < 0.02). More secondhand smoke exposure was associated with smoking more CPD in both populations (p = 0.03-0.29). Linear regression modeling mirrored these findings.

Conclusions

High prevalence of smoking in the Northern Plains and high cotinine levels among nonsmokers in both regions highlights the tribal populations' risk for tobacco-related disease.

Implications

There is a high prevalence of smoking in Northern Plains American Indians. Among Northern Plains and Southwest nonsmokers, relatively high cotinine levels, representative of high tobacco exposure, suggest considerable exposure to second-hand smoke. It is critical to highlight the extent of second-hand smoke exposure among the Northern Plains and Southwest American Indians and to enhance efforts to initiate smoke-free policies in tribal communities, which are not subject to state-level polices.

Spatial Epidemiology of Alcohol- and Drug-Related Health Problems Among Northern Plains American Indians: Nebraska and South Dakota, 2007 to 2012

BACKGROUND

Despite high abstinence rates, American Indians experience elevated rates of many alcohol and other drug problems. American Indians also predominantly reside in poor and rural areas, which may explain some observed health disparities. We investigated whether geographic areas including reservations or large American Indian populations exhibited greater incidence of alcohol- and drug-related hospitalizations.

METHODS

We obtained inpatient hospitalization records for 2 Northern Plain states (Nebraska and South Dakota) for the years 2007 to 2012. We constructed zip code counts for 10 categories of hospitalization with diagnoses or injury causation commonly associated with alcohol or drug use. We related these to community sociodemographic characteristics using Bayesian Poisson space-time regression models and examined associations with and without controls for whether each zip code was located within an American Indian reservation.

RESULTS

Controlling for other demographic and economic characteristics, zip codes with greater percentage of American Indians exhibited greater incidence for all 10 substance abuse-related health outcomes (9 of 10 well supported); zip code areas within American Indian reservations had greater incidence of self-inflicted injury and drug dependence and abuse, and reduced incidence of alcohol cirrhosis and prescription opioid poisoning. However, the analyses generally demonstrated no well-supported differences in incidence associated with local residence percentages of American Indian versus African American.

CONCLUSIONS

In our analyses, ethnicity or heredity alone did not account for alcohol- and drug-related hospitalizations among Native populations. Aspects of social, economic, and political dimensions of Native lives must be considered in the etiology of alcohol- and drug-related problems for rural-dwelling indigenous peoples.

Using Genetic Technologies To Reduce, Rather Than Widen, Health Disparities

Evidence shows that both biological and nonbiological factors contribute to health disparities. Genetics, in particular, plays a part in how common diseases manifest themselves. Today, unprecedented advances in genetically based diagnoses and treatments provide opportunities for personalized medicine. However, disadvantaged groups may lack access to these advances, and treatments based on research on non-Hispanic whites might not be generalizable to members of minority groups. Unless genetic technologies become universally accessible, existing disparities could be widened. Addressing this issue will require integrated strategies, including expanding genetic research, improving genetic literacy, and enhancing access to genetic technologies among minority populations in a way that avoids harms such as stigmatization.

Evaluating Strategies For Reducing Health Disparities By Addressing The Social Determinants Of Health

The opportunities for healthy choices in homes, neighborhoods, schools, and workplaces can have decisive impacts on health. We review scientific evidence from promising interventions focused on the social determinants of health and discuss how such interventions can improve population health and reduce health disparities. We found sufficient evidence of successful outcomes to support disparity-reducing policy interventions targeted at education and early childhood; urban planning and community development; housing; income enhancements and supplements; and employment. Cost-effectiveness evaluations show that these interventions lead to long-term societal savings, but the interventions require more routine attention to cost considerations. We discuss challenges to implementation, including the need for long-term financing to scale up effective interventions for implementation at the local, state, and national levels.

Relationship of Medication Use to Health-Related Quality of Life Among a Group of Older American Indians

This cross-sectional study examines the relationship of polypharmacy to health-related quality of life (HRQoL) among a group of older American Indians. An in-home interview and survey were administered to 63 community-dwelling American Indians aged 50 or older who were taking four or more prescription medications regularly. With the component summary scores from the Medical Outcomes Study Short Form-36 instrument analyzed as dependent variables, only the Physical Component Summary (PCS) score (r = .30, p = .02), and not the Mental (r = .06, p = .67), was associated with degree of polypharmacy. This association with PCS score remained significant even after controlling for age, sex, and chronic disease score (adjusted β = -.91, p = .045). This study is the first to describe the relationship between polypharmacy and HRQoL among a group of American Indians, and the results support the need for larger and more comprehensive studies of medication use in this special population.

Evaluating disparities in inpatient surgical cancer care among American Indian/Alaska Native patients

BACKGROUND

American Indian/Alaska Native (AI/AN) patients with cancer have the lowest survival rates of all racial and ethnic groups, possibly because they are less likely to receive "best practice" surgical care than patients of other races.

METHODS

Prospective cohort study comparing adherence with generic and cancer-specific guidelines on processes of surgical care between AI/AN and non-Hispanic white (NHW) patients in Washington State (2010 to 2014) was conducted.

RESULTS

A total of 156 AI/AN and 6,030 NHW patients underwent operations for 10 different cancers, and had similar mean adherence to generic surgical guidelines (91.5% vs 91.9%, P = .57). AI/AN patients with breast cancer less frequently received preoperative diagnostic core needle biopsy (81% vs 94%, P = .004). AI/AN patients also less frequently received care adherent to prostate cancer-specific guidelines (74% vs 92%, P = .001).

CONCLUSION

Although AI/ANs undergoing cancer operations in Washington receive similar overall best practice surgical cancer care to NHW patients, there remain important, modifiable disparities that may contribute to their lower survival.

Evaluating Strategies For Reducing Health Disparities By Addressing The Social Determinants Of Health

The opportunities for healthy choices in homes, neighborhoods, schools, and workplaces can have decisive impacts on health. We review scientific evidence from promising interventions focused on the social determinants of health and discuss how such interventions can improve population health and reduce health disparities. We found sufficient evidence of successful outcomes to support disparity-reducing policy interventions targeted at education and early childhood; urban planning and community development; housing; income enhancements and supplements; and employment. Cost-effectiveness evaluations show that these interventions lead to long-term societal savings, but the interventions require more routine attention to cost considerations. We discuss challenges to implementation, including the need for long-term financing to scale up effective interventions for implementation at the local, state, and national levels.

Strengthening breast and cervical cancer control through partnerships: American Indian and Alaska Native Women and the National Breast and Cervical Cancer Early Detection Program

The National Breast and Cervical Cancer Early Detection Program (NBCCEDP) has played a critical role in providing cancer screening services to American Indian and Alaska Native (AI/ANs) women and strengthening tribal screening capacity. Since 1991, the NBCCEDP has funded states, tribal nations, and tribal organizations to develop and implement organized screening programs. The ultimate goal is to deliver breast and cervical cancer screening to women who do not have health insurance and cannot afford to pay for these services. The delivery of clinical services is supported through complementary program efforts such as professional development, public education and outreach, and patient navigation. This article seeks to describe the growth of NBCCEDP's tribal commitment and the unique history and aspects of serving the AI/AN population. The article describes: 1) how this program has demonstrated success in improving screening of AI/AN women; 2) innovative partnerships with the Indian Health Service, state programs, and other organizations that have improved tribal public health infrastructure; and 3) the evolution of Centers for Disease Control and Prevention work with tribal communities.

Determination of effective brain connectivity from functional connectivity with application to resting state connectivities

Neural field theory insights are used to derive effective brain connectivity matrices from the functional connectivity matrix defined by activity covariances. The symmetric case is exactly solved for a resting state system driven by white noise, in which strengths of connections, often termed effective connectivities, are inferred from functional data; these include strengths of connections that are underestimated or not detected by anatomical imaging. Proximity to criticality is calculated and found to be consistent with estimates obtainable from other methods. Links between anatomical, effective, and functional connectivity and resting state activity are quantified, with applicability to other complex networks. Proof-of-principle results are illustrated using published experimental data on anatomical connectivity and resting state functional connectivity. In particular, it is shown that functional connection matrices can be used to uncover the existence and strength of connections that are missed from anatomical connection matrices, including interhemispheric connections that are difficult to track with techniques such as diffusion spectrum imaging.

Prostate cancer deaths and incident cases among American Indian/Alaska Native men, 1999-2009

OBJECTIVES

We linked databases to improve identification of American Indians/Alaska Natives (AI/ANs) in determining prostate cancer death and incidence rates.

METHODS

We linked prostate cancer mortality and incidence data with Indian Health Service (IHS) patient records; analyses focused on residents of IHS Contract Health Service Delivery Area (CHSDA) counties. We calculated age-adjusted incidence and death rates for AI/AN and White men for 1999 to 2009; men of Hispanic origin were excluded.

RESULTS

Prostate cancer death rates were higher for AI/AN men than for White men. Death rates declined for White men (-3.0% per year) but not for AI/AN men. AI/AN men had lower prostate cancer incidence rates than White men. Incidence rates declined among Whites (-2.2% per year) and AI/ANs (-1.9% per year).

CONCLUSIONS

AI/AN men had higher prostate cancer death rates and lower prostate cancer incidence rates than White men. Disparities in accessing health care could contribute to mortality differences, and incidence differences could be related to lower prostate-specific antigen testing rates among AI/AN men.

Trends and disparities in heart disease mortality among American Indians/Alaska Natives, 1990-2009

OBJECTIVES

We evaluated heart disease death rates among American Indians and Alaska Natives (AI/ANs) and Whites after improving identification of AI/AN populations.

METHODS

Indian Health Service (IHS) registration data were linked to the National Death Index for 1990 to 2009 to identify deaths among AI/AN persons aged 35 years and older with heart disease listed as the underlying cause of death (UCOD) or 1 of multiple causes of death (MCOD). We restricted analyses to IHS Contract Health Service Delivery Areas and to non-Hispanic populations.

RESULTS

Heart disease death rates were higher among AI/AN persons than Whites from 1999 to 2009 (1.21 times for UCOD, 1.30 times for MCOD). Disparities were highest in younger age groups and in the Northern Plains, but lowest in the East and Southwest. In AI/AN persons, MCOD rates were 84% higher than UCOD rates. From 1990 to 2009, UCOD rates declined among Whites, but only declined significantly among AI/AN persons after 2003.

CONCLUSIONS

Analysis with improved race identification indicated that AI/AN populations experienced higher heart disease death rates than Whites. Better prevention and more effective care of heart disease is needed for AI/AN populations.

Historical trends and regional differences in all-cause and amenable mortality among American Indians and Alaska Natives since 1950

American Indian and Alaska Native (AI/AN) death rates declined over most of the 20th century, even before the Public Health Service became responsible for health care in 1956. Since then, rates have declined further, although they have stagnated since the 1980s. These overall patterns obscure substantial regional differences. Most significant, rates in the Northern and Southern Plains have declined far less since 1949 to 1953 than those in the East, Southwest, or Pacific Coast. Data for Alaska are not available for the earlier period, so its trajectory of mortality cannot be ascertained. Socioeconomic measures do not adequately explain the differences and rates of change, but migration, changes in self-identification as an AI/AN person, interracial marriage, and variations in health care effectiveness all appear to be implicated.

Religio-Spiritual Participation in Two American Indian Populations

Following a previous investigation of religio-spiritual beliefs in American Indians, this article examined prevalence and correlates of religio-spiritual participation in two tribes in the Southwest and Northern Plains (N = 3,084). Analysis suggested a "religious profile" characterized by strong participation across three traditions: aboriginal, Christian, and Native American Church. However, sociodemographic variables that have reliably predicted participation in the general American population, notably gender and age, frequently failed to achieve significance in multivariate analyses for each tradition. Religio-spiritual participation was strongly and significantly related to belief salience for all traditions. Findings suggest that correlates of religious participation may be unique among American Indians, consistent with their distinctive religious profile. Results promise to inform researchers' efforts to understand and theorize about religio-spiritual behavior. They also provide tribal communities with practical information that might assist them in harnessing social networks to confront collective challenges through community-based participatory research collaborations.

Association of American Indian cultural identity with physical activity

OBJECTIVE

Cultural factors are associated with health behaviors among American Indians. Accordingly, the objective of our study was to investigate whether cultural identity, defined as the primary language spoken at home, is associated with: 1) higher total physical activity levels, and 2) levels of leisure-time physical activity recommended for health benefits in a diverse sample of American Indians.

DESIGN

Cross-sectional analysis of 5,207 American Indian adults 18 to 82 years. Participants resided on the Oglala Sioux (n=2,025) and Cheyenne River Sioux (n=1,528) reservations in South Dakota, and the Gila River Indian Community (n=1,654) in Arizona.

RESULTS

Bicultural participants in South Dakota, but not Arizona, reported significantly higher total physical activity compared to the English-only group (P<.05). About 35% of English only speakers, 39% of American Indian/Alaska Native only speakers, and 39% of participants speaking both languages met the 150 minutes/week activity threshold. Odds of being sufficiently active were higher among bicultural respondents in both regions when compared to respondents endorsing only English, controlling for sociodemographic and health-related covariates (P<.05).

CONCLUSION

Bicultural respondents among tribal members in South Dakota had significantly higher total physical activity, and higher levels of sufficient leisure-time activity in both South Dakota and Arizona, compared to those who spoke either language exclusively. Interventions that encourage American Indians to develop their bicultural efficacy and to draw on resources for healthy living that may be available in all the cultures with which they identify are recommended.

Influence of caregiving on health-related quality of life among American Indians

Caregiving can have a profound effect on the health of the caregiver, yet research on caregiving among American Indians is limited. The purpose of this study was to examine the influence of caregiving on the health-related quality of life (HRQoL) of American Indians enrolled in the Education And Research Towards Health (EARTH) study. Participants in the EARTH study represented three different tribes in the Northern Plains and Southwestern regions of the United States who completed self-administered, computer-assisted questionnaires between 2003 and 2006. Participants were classified as caregivers if at least one adult relied on them for personal care or as non-caregivers (n = 3,736). Caregivers were further classified according to type; those caring for an adult with unspecified needs (CAU, n = 482) and those caring for an adult with mental or physical difficulties (CAD, n = 295). HRQoL was measured using the mental and physical health component scores of the Medical Outcomes Study 12-item Short-Form Health Survey. Regional differences emerged with regard to caregiver type. Across both regions, non-caregivers reported significantly better mental and physical health than CAD, and the health of participants classified as CAU did not differ from that of non-caregivers. The health of American Indian caregivers depends on the kind of care provided, but detailed measures of caregiving are necessary to understand how caregiving influences health. This has implications for the design of effective interventions in tribal communities.

Community-responsive interventions to reduce cardiovascular risk in American Indians

American Indian and Alaska Native (AI/AN) populations bear a heavy burden of cardiovascular disease (CVD), and they have the highest rates of risk factors for CVD, such as cigarette smoking, obesity, and diabetes, of any U.S. population group. Yet, few randomized controlled trials have been launched to test potential preventive interventions in Indian Country. Five randomized controlled trials were initiated recently in AI/AN communities to test the effectiveness of interventions targeting adults and/or children to promote healthy behaviors that are known to impact biological CVD risk factors. This article provides a context for and an overview of these five trials. The high burden of CVD among AI/AN populations will worsen unless behaviors and lifestyles affecting CVD risk can be modified. These five trials, if successful, represent a starting point in addressing these significant health disparities.

A gene-family analysis of 61 genetic variants in the nicotinic acetylcholine receptor genes for insulin resistance and type 2 diabetes in American Indians

Cigarette smoking is a risk factor for type 2 diabetes. Genetic variants in the nicotinic acetylcholine receptor (nAChR) genes have been associated with smoking phenotypes and are likely to influence diabetes. Although each single variant may have only a minor effect, the joint contribution of multiple single nucleotide polymorphisms (SNPs) to the occurrence of disease may be larger. In this study, we conducted a gene-family analysis to investigate the joint impact of 61 tag SNPs in 7 nAChRs genes on insulin resistance and type 2 diabetes in 3,665 American Indians recruited by the Strong Heart Family Study. Results show that although multiple SNPs showed marginal individual association with insulin resistance and type 2 diabetes, only a few can pass adjustment for multiple testing. However, a gene-family analysis considering the joint impact of all 61 SNPs reveals significant association of the nAChR gene family with both insulin resistance and type 2 diabetes (both P < 0.0001), suggesting that genetic variants in the nAChR genes jointly contribute to insulin resistance and type 2 diabetes among American Indians. The effects of these genetic variants on insulin resistance and diabetes are independent of cigarette smoking per se.

Physical activity and cervical cancer testing among American Indian women

PURPOSE

Studies have shown that women who engage in high levels of physical activity have higher rates of cancer screening, including Papanicalaou (Pap) tests. Because American Indian (AI) women are at high risk for cervical cancer morbidity and mortality, we examined Pap screening prevalence and assessed whether physical activity was associated with screening adherence among AI women from 2 culturally distinct regions in the Northern Plains and the Southwest.

METHODS

A total of 1,979 AI women at least 18 years of age participating in a cross-sectional cohort study reported whether they received a Pap test within the previous 3 years. Physical activity level was expressed as total metabolic equivalent (MET) scores and grouped into quartiles. We used binary logistic regression to model the association of Pap testing and MET quartile, adjusting for demographic and health factors.

FINDINGS

Overall, 60% of women received a Pap test within the previous 3 years. After controlling for covariates, increased physical activity was associated with higher odds of Pap screening (OR = 1.1 per increase in MET quartile; 95% CI = 1.1, 1.2).

CONCLUSIONS

This is the first study to examine physical activity patterns and receipt of cancer screening in AIs. While recent Pap testing was more common among physically active AI women, prevalence was still quite low in all subgroups. Efforts are needed to increase awareness of the importance of cervical cancer screening among AI women.

Geometric effects on complex network structure in the cortex

It is shown that homogeneous, short-range, two-dimensional (2D) cortical connectivity, without modularity, hierarchy, or other specialized structure, reproduces key observed properties of cortical networks, including low path length, high clustering and modularity index, and apparent hierarchical block-diagonal structure in connection matrices. Geometry strongly influences connection matrices, implying that simple interpretations of connectivity measures as reflecting specialized structure can be misleading: Such apparent structure is seen in strictly uniform, locally connected architectures in 2D. Geometry is thus a proxy for function, modularity, and hierarchy and must be accounted for when structural inferences are made.

Cost-effectiveness of lower targets for blood pressure and low-density lipoprotein cholesterol in diabetes: the Stop Atherosclerosis in Native Diabetics Study (SANDS)

BACKGROUND

The Stop Atherosclerosis in Native Diabetics Study (SANDS) reported cardiovascular benefit of aggressive versus standard treatment targets for both low-density lipoprotein cholesterol (LDL-C) and blood pressure (BP) in diabetic individuals.

OBJECTIVE

In this analysis, we examined within trial cost-effectiveness of aggressive targets of LDL-C ≤70 mg/dL and systolic BP ≤115 mmHg versus standard targets of LDL-C ≤100 mg/dL and systolic BP ≤130 mmHg.

DESIGN

Randomized, open label blinded-to-endpoint 3-year trial.

DATA SOURCES

SANDS clinical trial database, Quality of Wellbeing survey, Centers for Medicare and Medicaid Services, Wholesale Drug Prices.

TARGET POPULATION

American Indians ≥ age 40 years with type 2 diabetes and no previous cardiovascular events.

TIME HORIZON

April 2003 to July 2007.

PERSPECTIVE

Health payer.

INTERVENTIONS

Participants were randomized to aggressive versus standard groups with treatment algorithms defined for both.

OUTCOME MEASURES

Incremental cost-effectiveness.

RESULTS OF BASE-CASE ANALYSIS

Compared with the standard group, the aggressive group had slightly lower costs of medical services (-$116) but a 54% greater cost for BP medication ($1,242) and a 116% greater cost for lipid-lowering medication ($2,863), resulting in an increased cost of $3,988 over 3 years. Those in the aggressively treated group gained 0.0480 quality-adjusted life-years (QALY) over the standard group. When a 3% discount rate for costs and outcomes was used, the resulting cost per QALY was $82,589.

RESULTS OF SENSITIVITY ANALYSIS

The use of a 25%, 50%, and 75% reduction in drug costs resulted in a cost per QALY of $61,329, $40,070, and $18,810, respectively.

LIMITATIONS

This study was limited by use of a single ethnic group and by its 3-year duration.

CONCLUSIONS

Within this 3-year study, treatment to lower BP and LDL-C below standard targets was not cost-effective because of the cost of the additional medications required to meet the lower targets. With the anticipated availability of generic versions of the BP and lipid-lowering drugs used in SANDS, the cost-effectiveness of this intervention should improve. Published by Elsevier Inc on behalf of the National Lipid Association.

The prevalence of metabolic syndrome and associated risk factors in Northern Plains and Southwest American Indians

OBJECTIVE

To estimate the prevalence of metabolic syndrome by age, sex, and diabetes status in Northern Plains and Southwest American Indians.

RESEARCH DESIGN AND METHODS

Data for this analysis came from the Education and Research Toward Health (EARTH) study, a 5-year cross-sectional study of Southwest and Northern Plains American Indian adults. The National Cholesterol Education Program's Adult Treatment Panel III (NCEP/ATP III) guidelines were used to identify adults with metabolic syndrome.

RESULTS

The age-adjusted prevalence of the metabolic syndrome was 49.8% among 4,457 participants aged 18-88 years. Age-adjusted prevalence was 42.4% for participants without diabetes and 86.6% for participants with diabetes. In participants aged <40 years, the overall prevalence of metabolic syndrome was 53.1%; 44.9% after excluding individuals with diabetes.

CONCLUSIONS

This study confirms a high prevalence of the metabolic syndrome among Northern Plains and Southwest American Indians of all ages.

Culture and colorectal cancer screening on three American Indian reservations

BACKGROUND

Colorectal cancer (CRC) rates among many American Indian populations are high. Screening by fecal occult blood test (FOBT) and endoscopy is effective for reducing CRC mortality, but little research has examined the extent of such screening in reservation populations. Further, nothing is known of how American Indians' cultural characteristics may be related to screening receipt.

PARTICIPANTS AND SETTING

We examined data from participants recruited from 2 Northern Plains and 1 Southwest reservation for the Education and Research Toward Health (EARTH) study. All participants aged > or = 51 years were eligible for inclusion.

DESIGN

After calculating screening rates, we examined bivariate relationships between screening and participant characteristics, including measures of cultural characteristics including ethnic identity and use of traditional healing practices. We applied multivariate regression to relate these cultural variables to odds of lifetime screening by FOBT or endoscopy.

RESULTS

Of 751 American Indians sampled, 35% reported lifetime CRC screening by at least one modality. Multivariate analyses did not reveal significant relationships or trends relating FOBT to respondents' cultural characteristics. By contrast, odds of endoscopy were significantly lower among persons who spoke a tribal language at home (OR .6, 95% C.I. .4-.9), and trend analysis revealed an inverse relationship between endoscopy and number of identity measures endorsed (Ptrend<.1).

CONCLUSIONS

The sampled population exhibits disparities in CRC compared to the general population, and cultural characteristics are related to odds of endoscopy. Findings warrant culturally tailored CRC screening initiatives for American Indians.

Adult caregiving among American Indians: the role of cultural factors

PURPOSE

With a sample of American Indian adults, we estimated the prevalence of adult caregiving, assessed the demographic and cultural profile of caregivers, and examined the association between cultural factors and being a caregiver. This is the first such study conducted with American Indians.

DESIGN AND METHODS

Data came from a cross-sectional study of 5,207 American Indian adults residing on 2 closely related Lakota Sioux reservations in the Northern Plains and one American Indian community in the Southwest. Cultural factors included measures of cultural identity and traditional healing practices.

RESULTS

Seventeen percent of our sample reported being caregivers. In both the Northern Plains and Southwest, caregiving was positively correlated with younger age, being a woman, larger household size, attending and participating in Native events, and endorsement of traditional healing practices. In both regions, attendance and participation in Native events and engagement in traditional healing practices were associated with increased odds of caregiving after adjusting for covariates. Only in the Northern Plains did we find that speaking some Native language at home was associated with increased odds of being a caregiver. Examination of interaction terms indicated some sex differences in the association between cultural factors and caregiving in the Northern Plains but not in the Southwest.

IMPLICATIONS

Our findings indicate that greater cultural identity and engagement in traditional healing practices are related to caregiving in American Indian populations. Caregiving research, intervention efforts, and caregiving programs and services in Native communities should pay special attention to the dynamics of culture and caregiving.

Safety and feasibility of achieving lower systolic blood pressure goals in persons with type 2 diabetes: the SANDS trial

The Stop Atherosclerosis in Native Diabetics Study (SANDS) was a randomized open-label clinical trial in type 2 diabetics designed to examine the effects of intensive reduction of blood pressure, aggressive vs standard goals (< or =115/75 mm Hg vs < or =130/80 mm Hg), and low-density lipoprotein (LDL) cholesterol on the composite outcome of change in carotid intimal-medial thickness and cardiovascular events. The study demonstrated that in conjunction with a lower LDL cholesterol target of 70 mg/dL, aggressive systolic blood pressure-lowering resulted in a reduction in carotid intimal-medial thickness and left ventricular mass without measurable differences in cardiovascular events. The blood pressure treatment algorithm included renin-angiotensin system blockade, with other agents added if necessary. The authors conclude that both standard and more aggressive systolic blood pressure reduction can be achieved with excellent safety and good tolerability in patients with type 2 diabetes mellitus.

Validation of a dietary history questionnaire for American Indian and Alaska Native people

OBJECTIVE

We assessed reliability and relative validity of a self-administered computer-assisted dietary history questionnaire (DHQ) for use in a prospective study of diet, lifestyle, and chronic disease in American Indians in the Dakotas and Southwestern US and Alaska Native people.

DESIGN

Reliability was assessed by one-month test-retest of the dietary history questionnaire. Validity was assessed by comparison of the weighted average of up to 12 monthly 24-hour recalls collected prospectively and a dietary history questionnaire completed in the 13th month.

PARTICIPANTS

Participants were recruited at the baseline visit of the Education and Research Toward Health Study in Alaska, the Northern Plains and the Dakotas.

RESULTS

Reliability (Pearson correlation) of the DHQ ranged from r = 0.43 for vitamin A density to r = 0.90 for energy intake. The association of nutrient and food estimates assessed by 24-hour recalls and the DHQ completed at the end of the year reflected no bias towards recent intake. Macronutrients expressed as density (nutrients per 1000 calories) did appear to be valid (r = 0.50-0.71) as did several micronutrients (range r = .22 to 0.59), fiber (r = 0.51), and servings of red meat (r = 0.67). However, the DHQ overestimated intake and gross amounts of nutrients were not strongly associated with the weighted average of the 24-hour recalls.

CONCLUSIONS

The DHQ developed for estimation of dietary intake in American Indians and Native people in Alaska is reliable. Estimates of nutrient density appeared to have acceptable relative validity for use in epidemiologic studies.

Epidemiology of physical activity in American Indians in the Education and Research Towards Health cohort

BACKGROUND

The health benefits of an active lifestyle are well established. However, Americans in general and American Indians specifically are not sufficiently active to achieve these health benefits.

PURPOSE

This study presents the descriptive epidemiology of physical activity in a community-based sample of American-Indian adults.

METHODS

Data came from Education and Research Towards Health (EARTH), a cross-sectional study conducted between December 2003 and April 2006 of 5207 American-Indian adults in South Dakota and Arizona. Physical activity was assessed using a culturally tailored, computer-assisted instrument. Both type and intensity of activities were measured; minutes per week averaged over the past year was the primary outcome. Individuals were categorized as being sufficiently active, not sufficiently active, or inactive using a cut point of more or less than 150 minutes/week. Information on age, gender, and BMI was also collected.

RESULTS

More than one third of participants were not sufficiently active (<150 minutes/week) and 18% reported no leisure-time activity. Sufficient activity was less often reported by women than men (41% vs 56%) and by participants from the Southwest than those from the Northern Plains (44% vs 50%). Of all activity categories, the most time was spent on household activities among all participants. There were clear trends in physical (in)activity across BMI strata; time spent in sedentary activities increased while leisure-time activity decreased with BMI.

CONCLUSIONS

American-Indian adults in this cohort exhibited levels of physical (in)activity similar to those of other racial/ethnic groups in the U.S., suggesting a need for specific interventions to increase activity levels across the population.

Patterns of cigarette smoking initiation in two culturally distinct American Indian tribes

OBJECTIVES

To better understand patterns of initiation among American Indians we examined age-related patterns of smoking initiation during adolescence and young adulthood in 2 American Indian tribes.

METHODS

We used log-rank comparison and a Cox proportional hazard regression model to analyze data from a population-based study of Southwest and Northern Plains American Indians aged 18 to 95 years who initiated smoking by age 18 years or younger.

RESULTS

The cumulative incidence of smoking initiation was much higher among the Northern Plains Indians (47%) than among the Southwest Indians (28%; P < .01). In the Southwest, men were more likely than women to initiate smoking at a younger age (P < .01); there was no such difference in the Northern Plains sample. Northern Plains men and women in more recent birth cohorts initiated smoking at an earlier age than did those born in older birth cohorts. Southwest men and women differed in the pattern of smoking initiation across birth cohorts as evidenced by the significant test for interaction (P = .01).

CONCLUSION

Our findings underscore the need to implement tobacco prevention and control measures within American Indian communities.

Dynamical reconnection and stability constraints on cortical network architecture

Stability under dynamical changes to network connectivity is invoked alongside previous criteria to constrain brain network architecture. A new hierarchical network is introduced that satisfies all these constraints, unlike more commonly studied regular, random, and small-world networks. It is shown that hierarchical networks can simultaneously have high clustering, short path lengths, and low wiring costs, while being robustly stable under large scale reconnection of substructures.

Primary liver cancer incidence among American Indians and Alaska Natives, US, 1999-2004

BACKGROUND

American Indians and Alaska Natives (AI/AN) experience higher morbidity and mortality from primary liver cancer than other United States (US) populations, but racial misclassification in medical records results in underestimates of disease burden.

METHODS

To reduce misclassification, National Program of Cancer Registries and Surveillance, Epidemiology, and End Results data were linked with Indian Health Service (IHS) enrollment records to compare primary liver cancer incidence and stage at diagnosis between AI/AN and non-Hispanic whites (NHW) living within the regionalized IHS Contract Health Service Delivery Area counties. Incidence rates are expressed per 100,000 persons and age-adjusted by 19 age groups to the 2000 US standard population.

RESULTS

Overall, AI/AN have a higher proportion of hepatocellular carcinoma compared with NHW, 77.8% versus 66.7%. Liver cancer incidence rates among AI/AN males and females were higher than those among NHW males and females for all regions except for the East. Among males, rates ranged from 7.3 (95% confidence interval [CI], 3.8-12.6) in the East to 17.2 (95% CI, 10.4-26.3) in Alaska. Among females, rates ranged from 3.8 (95% CI, 1.4-8.2) in the East to 6.9 (95% CI, 3.6-11.6) in Alaska. The AI/AN rates for all regions were consistently higher than the NHW rates at every age. An increasing trend among AI/AN was suggested but did not achieve statistical significance.

CONCLUSIONS

Reducing racial misclassification revealed higher disparities in primary liver cancer incidence between NHW and AI/AN populations than previously reported. Further description of the reasons for regional differences in this disparity is needed, as are programs to reduce risk factors and to diagnose primary liver cancer at earlier, more treatable stages.

Prostate cancer incidence among American Indian and Alaska Native men, US, 1999-2004

BACKGROUND

American Indian and Alaska Native (AI/AN) men experience lower incidence of prostate cancer than other race/ethnic populations in the US, but racial misclassification of AI/AN men threatens the validity of these estimates. To the authors' knowledge, little is known concerning prostate-specific antigen (PSA) testing in AI/AN men.

METHODS

The authors linked cancer registry data with Indian Health Service enrollment records to improve race classification. Analyses comparing cancer incidence rates and stage at diagnosis for AI/AN and non-Hispanic white (NHW) men for 6 geographic regions focused on counties known to have less race misclassification. The authors also used Behavioral Risk Factors Surveillance System data to characterize PSA testing in AI/AN men.

RESULTS

Prostate cancer incidence rates were generally lower in AI/AN than in NHW men for all regions combined (rate ratio of 0.68). However, regional variation was noted among AI/AN men, with incidence rates (per 100,000 population) ranging from 65.7 in the Southwest to 174.5 on the Northern Plains. The rate of distant stage disease was somewhat higher among AI/AN (7.8) than NHW (6.2) men. Nationally, AI/AN men were less likely than NHW men to have undergone recent PSA testing (48.4% vs 58.0%), with prominent regional variation in screening rates noted.

CONCLUSIONS

Prostate cancer incidence rates and the proportion of men with recent PSA testing were lower for AI/AN men than for NHW men. However, incident rates and rate of distant stage varied by region more for AI/AN than for NHW. Further research is needed among AI/AN men to evaluate strategies for better understanding the causes of the regional variation in prostate cancer incidence.

Gastric cancer among American Indians and Alaska Natives in the United States, 1999-2004

BACKGROUND

Gastric cancer incidence rates for American Indians and Alaska Natives (AI/ANs) historically have exceeded those for non-Hispanic whites (NHWs). Previous reports may have underestimated the true burden of gastric cancer in AI/AN populations because of misclassification of AI/AN race in cancer registries.

METHODS

Population-based cancer registry data from 1999 through 2004 were used to describe gastric cancer incidence in AI/ANs and NHWs in the US. To address misclassification of race, registry data were linked with Indian Health Service administrative records, and analyses were restricted to residents of Contract Health Service Delivery Areas (CHSDA). Disease patterns were assessed for 6 geographic regions and for all regions combined. Rates were expressed per 100,000 population and were age-adjusted to the 2000 US standard population.

RESULTS

In CHSDA counties, gastric cancer incidence rates for AI/ANs were higher than the rates for NHWs across most regions. For both sexes combined, AI/AN rates ranged from 6.1 in the East region to 24.5 in Alaska; there was relatively little regional variation in NHW rates. Most patients with gastric cancer were diagnosed with late-stage disease, regardless of race, age, or sex. In some regions, cancer rates in the central/distal portions of the stomach were higher among AI/ANs than among NHWs, whereas rates in the proximal stomach were similar between the 2 populations.

CONCLUSIONS

AI/ANs are generally at greater risk for gastric cancer than NHWs. Relatively high rates of cancer in the central/distal portions of the stomach among AI/ANs in some geographic regions may indicate a disproportional burden of Helicobacter pylori-associated disease.

Unique responses of midbrain CART neurons in macaques to ovarian steroids

CART (cocaine and amphetamine regulated transcript) is a neuropeptide involved in the control of several physiological processes, such as response to psychostimulants, food intake, depressive diseases and neuroprotection. It is robustly expressed in the brain, mainly in regions that control emotional and stress responses and it is regulated by estrogen in the hypothalamus. There is a distinct population of CART neurons located in the vicinity of the Edinger-Westphal nucleus of the midbrain that also colocalize urocortin-1. The aims of this study were 1) to determine the distribution of CART immunoreactive neurons in the monkey midbrain, 2) to examine the effects of estrogen (E) and progesterone (P) on midbrain CART mRNA and peptide expression and 3) to determine whether midbrain CART neurons contain steroid receptors. Adult female rhesus monkeys (Macaca mulatta) were spayed and either treated with placebo (OVX), estrogen alone (E), progesterone alone (P) or E+P. Animals were prepared (a) for RNA extraction followed by microarray analysis and quantitative (q) RT-PCR (n=3/group); (b) for immunohistochemical analysis of CART and CART+tryptophan hydroxylase (TPH), CART+estrogen receptors (ER) or CART+progesterone receptors (n=5/group) and (c) for Western blots (n=3/group). Both E- and E+P-administration decreased CART gene expression on the microarray and with qRT-PCR. Stereological analysis of CART immunostaining at five levels of the Edinger-Westphal nucleus indicated little effect of E or E+P administration on the area of CART immunostaining. However, P administration increased CART-immunopositive area in comparison to the OVX control group with Student's t-test, but not with ANOVA. CART 55-102 detection on Western blot was unchanged by hormone administration. ERbeta and PR were detected in CART neurons and CART fibers appeared to innervate TPH-positive serotonin neurons in the dorsal raphe. In summary, E decreased CART mRNA, but this effect did not translate to the protein level. Moreover, P administration alone had a variable effect on CART mRNA, but it caused an increase in CART immunostaining. Together, the data suggest that CART neurons in the midbrain have a unique steroid response, which may be mediated by nuclear receptors, neuroactive steroids or interneurons.

Differential effects of ovarian steroids and raloxifene on serotonin 1A and 2C receptor protein expression in macaques

To further understand the role of ovarian hormones in the function of the serotonin neural system, we investigated the effects of estradiol (E), progesterone (P), and raloxifene on 5HT 1A and 2C receptor protein expression in the dorsal raphe region using Western blot analysis. Adult rhesus macaques (Macaca mulatta) were ovariectomized (Ovx) and implanted with Silastic capsules containing E or P. In the first paradigm, animals that had been Ovx for 6-16 months were treated for 1 month with E (El) or E + P (EP1) and compared to animals that were untreated and Ovx for 5 months (n = 4 per group). In the second paradigm, comparisons were made between animals that were Ovx and untreated for 5 months, or Ovx and immediately implanted with Silastic capsules containing E or E + P for 5 months (E5, EP5), or administered raloxifene in the diet for 5 months (Ral5) (n = 4 per group). The dorsal raphe region was harvested, homogenized and a crude membrane fraction was obtained for examination of receptor proteins. In the first paradigm, 5HT1A receptor protein expression was significantly lower in E1 and EPI treatment groups compared to the Ovx-control group (ANOVA P = 0.01; posthoc P < 0.03), but 5HT2C receptor expression was unaffected by 1 month of E or EP treatment. In the second paradigm, there was no difference in 5HT1A receptor expression between the Ovx-control group and the E5 group, but 5HT1A receptor expression was significantly suppressed in the EP5 group (ANOVA P = 0.04; posthoc P < 0.05). In addition, 5HT2C expression increased in the E5 treatment group relative to the Ovx-control group. Addition of P to the E5 regimen prevented the E5-induced increase in 5HT2C receptor expression and significantly reduced 5HT2C receptor expression to a level below that observed in the Ovx-control group (ANOVA P = 0.001; posthoc P < 0.05). Thus, 5HT1A receptor may lose sensitivity to the suppressive effect of E after 5 months, whereas the 5HT2C receptor increases. However, addition of P in the EP5 regimen maintains the regulatory effects observed with 1 month of treatment. 5HT1A receptor protein levels were higher with raloxifene treatment than in Ovx-control animals (P < 0.01), suggesting that raloxifene may antagonize residual E in Ovx animals.

Effect of lower targets for blood pressure and LDL cholesterol on atherosclerosis in diabetes: the SANDS randomized trial

CONTEXT

Individuals with diabetes are at increased risk for cardiovascular disease (CVD), but more aggressive targets for risk factor control have not been tested.

OBJECTIVE

To compare progression of subclinical atherosclerosis in adults with type 2 diabetes treated to reach aggressive targets of low-density lipoprotein cholesterol (LDL-C) of 70 mg/dL or lower and systolic blood pressure (SBP) of 115 mm Hg or lower vs standard targets of LDL-C of 100 mg/dL or lower and SBP of 130 mm Hg or lower.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, open-label, blinded-to-end point, 3-year trial from April 2003-July 2007 at 4 clinical centers in Oklahoma, Arizona, and South Dakota. Participants were 499 American Indian men and women aged 40 years or older with type 2 diabetes and no prior CVD events.

INTERVENTIONS

Participants were randomized to aggressive (n=252) vs standard (n=247) treatment groups with stepped treatment algorithms defined for both.

MAIN OUTCOME MEASURES

Primary end point was progression of atherosclerosis measured by common carotid artery intimal medial thickness (IMT). Secondary end points were other carotid and cardiac ultrasonographic measures and clinical events.

RESULTS

Mean target LDL-C and SBP levels for both groups were reached and maintained. Mean (95% confidence interval) levels for LDL-C in the last 12 months were 72 (69-75) and 104 (101-106) mg/dL and SBP levels were 117 (115-118) and 129 (128-130) mm Hg in the aggressive vs standard groups, respectively. Compared with baseline, IMT regressed in the aggressive group and progressed in the standard group (-0.012 mm vs 0.038 mm; P < .001); carotid arterial cross-sectional area also regressed (-0.02 mm(2) vs 1.05 mm(2); P < .001); and there was greater decrease in left ventricular mass index (-2.4 g/m(2.7) vs -1.2 g/m(2.7); P = .03) in the aggressive group. Rates of adverse events (38.5% and 26.7%; P = .005) and serious adverse events (n = 4 vs 1; P = .18) related to blood pressure medications were higher in the aggressive group. Clinical CVD events (1.6/100 and 1.5/100 person-years; P = .87) did not differ significantly between groups.

CONCLUSIONS

Reducing LDL-C and SBP to lower targets resulted in regression of carotid IMT and greater decrease in left ventricular mass in individuals with type 2 diabetes. Clinical events were lower than expected and did not differ significantly between groups. Further follow-up is needed to determine whether these improvements will result in lower long-term CVD event rates and costs and favorable risk-benefit outcomes.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00047424.

A prospective cohort of American Indian and Alaska Native people: study design, methods, and implementation

In 2001, the National Cancer Institute funded three centers to test the feasibility of establishing a cohort of American Indian and Alaska Native people. Participating tribal organizations named the study EARTH (Education and Research Towards Health). This paper describes the study methods. A computerized data collection and tracking system was developed using audio computer-assisted survey methodology with touch screens. Data were collected on diet, physical activity, lifestyle and cultural practices, medical and reproductive history, and family history of heart disease, diabetes, and cancer. In addition, a small panel of medical measurements was obtained, including height, weight, waist and hip circumferences, blood pressure, and a lipid panel plus glucose. At the completion of the enrollment visit, data were used to provide immediate health feedback to study participants. During the initial funding period, the authors anticipate enrolling 16,000 American Indian and Alaska Native participants. The age distribution of the study population was similar to that reported in the 2000 US Census for the relevant populations. A component critical to the success of the EARTH Study has been the partnerships with tribal members. The study has focused on involvement of American Indian and Alaska Native communities in development and implementation and on provision of feedback to participants and communities.

The influence of community-based participatory research principles on the likelihood of participation in health research in American Indian communities

OBJECTIVES

Advocates of community-based participatory research (CBPR) have emphasized the need for such efforts to be collaborative, and close partnerships with the communities of interest are strongly recommended in developing study designs. However, to date, no systematic, empiric inquiry has been made into whether CBPR principles might influence an individual's decision to participate in research.

DESIGN, SETTING, AND PARTICIPANTS

Using vignettes that described various types of research, we surveyed 1066 American Indian students from three tribal colleges/universities to ascertain the extent to which respondent age, gender, education, cultural affiliation, tribal status, and prior experience with research may interact with the implementation of critical CBPR principles to increase or decrease the likelihood of participating in health research.

RESULTS

Many factors significantly increased odds of participation and included the study's being conducted by a tribal college/university or national organization, involving the community in study development, an American Indian's leading the study, addressing serious health problems of concern to the community, bringing money into the community, providing new treatments or services, compensation, anonymity, and using the information to answer new questions. Decreased odds of participation were related to possible discrimination against one's family, tribe, or racial group; lack of confidentiality; and possible physical harm.

CONCLUSIONS

Employing CBPR principles such as community involvement in all phases of the research, considering the potential benefits of the research, building on strengths and resources within the community and considering how results will be used is essential to conceptualizing, designing, and implementing successful health research in partnership with American Indians.

Examination of lower targets for low-density lipoprotein cholesterol and blood pressure in diabetes--the Stop Atherosclerosis in Native Diabetics Study (SANDS)

Diabetes incidence is increasing rapidly in the United States. Diabetes increases the risk for cardiovascular disease, the major cause of death in diabetic individuals. The conventional cardiovascular risk factors of hyperlipidemia and hypertension worsen diabetic vascular disease. Treatment targets for low-density lipoprotein cholesterol (LDL-C) and blood pressure in diabetic individuals are being debated. The SANDS is a randomized, open-label, 3-year trial to examine the effects of aggressive LDL-C (goal <70 mg/dL) and blood pressure (BP) (goal <115/75 mm Hg) reduction versus the standard goals of <100 mg/dL for LDL-C and <130/85 mm Hg for BP. Five hundred forty-nine American-Indian men and women >40 years old with type 2 diabetes were randomized to 1 of 2 groups. Lipids and BP are managed using Food and Drug Administration-approved medications in an algorithmic approach. The presence and progression of atherosclerosis are evaluated by carotid ultrasonography; echocardiography assesses cardiac function. The primary end point is the composite outcome of change in carotid artery intimal medial thickness and fatal/nonfatal cardiovascular events. These outcomes are combined by using a ranked analysis for carotid thickness and assigning a "worst rank" for a cardiovascular event. Secondary end points include carotid plaque score, left ventricular geometry and function, serum C-reactive protein, and safety measures. Unique aspects of the study design and analysis plan involve the use of a composite outcome and changes during the trial of LDL-C treatment goals for participants with baseline or incident cardiovascular disease in the conventional group because of changes in the standard of care. Study results will further understanding of the effects of aggressive risk factor reduction on atherosclerosis burden and cardiac function in diabetic individuals in US populations and will help determine optimal LDL-C and BP treatment goals for diabetic patients.