Fatal Firearm Violence Among American Indians and Alaska Natives

There is a dearth of population-based studies regarding firearm-related deaths and years of potential life lost among American Indians and Alaska Natives (AI/AN). Using the Centers for Disease Control and Prevention's (CDC) We Based Injury Statistics Query and Reporting System (WISQARS) data for the three most recent years (2018-2020), we analyzed the demographic characteristics of AI/ANs who succumbed to firearm violence. AI/ANs averaged almost 500 firearm-related deaths per year. The majority of these deaths were observed among individuals 20-39 years of age (53%), males (84.4%), and in the West (55.3%). A plurality of these firearm-related deaths were suicides (48.9%) followed by homicides (43.5%). During the 3-year study period, the age-adjusted firearm death rate increased almost 5 times the growth of the AI/AN population. Also, a staggering 67,050 years of potential life were lost before the age of 80 years (YPLL80) during this period. Firearm suicides were responsible for the largest proportion of YPLL80s (48.5%). Traditional legal interventions [e.g., child access prevention (CAP) laws and extreme risk protection orders (ERPO)], if expanded to more states could potentially help reduce AI/AN firearm mortality. None of the 10 states with the highest firearm mortality of AI/AN have ERPOs and 8 of the 10 do not have CAP laws. Also, a renewed focus on cultural continuity and indigenous protective factors is essential to ameliorate the level of firearm violence in AI/ANs.

Perception of Barriers to and Factors Associated with HPV Vaccination Among Parents of American Indian Adolescents in the Cherokee Nation

The purpose of this study was to understand the perceptions of HPV vaccination barriers and factors among parents or guardians of American Indian adolescents in the Cherokee Nation. Fifty-four parents of American Indian adolescents in the Cherokee Nation participated in one of eleven focus group discussions from June to August 2019. Discussions were recorded, transcribed, coded, and analyzed for themes. Protection against cancer was the primary parent-reported reason for vaccinating their children against HPV. The lack of information and safety concerns about the HPV vaccine were the main reasons for non-vaccination. To increase HPV vaccine uptake, parents strongly supported offering vaccinations in school. Furthermore, increased healthcare provider-initiated discussion can ease parental concerns about HPV vaccine safety and improve coverage.

Association of Achievement of the American Heart Association's Life's Essential 8 Goals With Incident Cardiovascular Diseases in the SHFS

BACKGROUND

Cardiovascular disease (CVD) is a leading cause of morbidity and mortality in American Indian people. In 2022, the American Heart Association developed the Life's Essential 8 goals to promote cardiovascular health (CVH) for Americans, composed of diet, physical activity, nicotine exposure, sleep, body mass index, blood lipids, blood pressure, and blood glucose. We examined whether achievement of Life's Essential 8 goals was associated with incident CVD among SHFS (Strong Heart Family Study) participants.

METHODS AND RESULTS

A total of 2139 SHFS participants without CVD at baseline were included in analyses. We created a composite CVH score based on achievement of Life's Essential 8 goals, excluding sleep. Scores of 0 to 49 represented low CVH, 50 to 69 represented moderate CVH, and 70 to 100 represented high CVH. Incident CVD was defined as incident myocardial infarction, coronary heart disease, congestive heart failure, or stroke. Cox proportional hazard models were used to examine the relationship of CVH and incident CVD. The incidence rate of CVD at the 20-year follow-up was 7.43 per 1000 person-years. Compared with participants with low CVH, participants with moderate and high CVH had a lower risk of incident CVD; the hazard ratios and 95% CIs for incident CVD for moderate and high CVH were 0.52 (95% CI, 0.40-0.68) and 0.25 (95% CI, 0.14-0.44), respectively, after adjustment for age, sex, education, and study site.

CONCLUSIONS

Better CVH was associated with lower CVD risk which highlights the need for comprehensive public health interventions targeting CVH promotion to reduce CVD risk in American Indian communities.

The Báa nnilah Program: Results of a Chronic-Illness Self-Management Cluster Randomized Trial with the Apsáalooke Nation

Indigenous people in Montana are disproportionately affected by chronic illness (CI), a legacy of settler colonialism. Existing programs addressing CI self-management are not appropriate because they are not consonant with Indigenous cultures in general and the Apsáalooke culture specifically. A research partnership between the Apsáalooke (Crow Nation) non-profit organization Messengers for Health and Montana State University co-developed, implemented, and evaluated a CI self-management program for community members. This article examines qualitative and quantitative program impacts using a pragmatic cluster randomized clinical trial design with intervention and waitlist control arms. The quantitative and qualitative data resulted in different stories on the impact of the Báa nnilah program. Neither of the quantitative hypotheses were supported with one exception. The qualitative data showed substantial positive outcomes across multiple areas. We examine why the data sets led to two very different stories, and provide study strengths and limitations, recommendations, and future directions.

The Contribution of Declines in Blood Lead Levels to Reductions in Blood Pressure Levels: Longitudinal Evidence in the Strong Heart Family Study

BACKGROUND

Chronic lead exposure is associated with both subclinical and clinical cardiovascular disease. We evaluated whether declines in blood lead were associated with changes in systolic and diastolic blood pressure in adult American Indian participants from the SHFS (Strong Heart Family Study).

METHODS AND RESULTS

Lead in whole blood was measured in 285 SHFS participants in 1997 to 1999 and 2006 to 2009. Blood pressure and measures of cardiac geometry and function were obtained in 2001 to 2003 and 2006 to 2009. We used generalized estimating equations to evaluate the association of declines in blood lead with changes in blood pressure; cardiac function and geometry measures were considered secondary. Mean blood lead was 2.04 μg/dL at baseline. After ≈10 years, mean decline in blood lead was 0.67 μg/dL. In fully adjusted models, the mean difference in systolic blood pressure comparing the highest to lowest tertile of decline (>0.91 versus <0.27 μg/dL) in blood lead was -7.08 mm Hg (95% CI, -13.16 to -1.00). A significant nonlinear association between declines in blood lead and declines in systolic blood pressure was detected, with significant linear associations where blood lead decline was 0.1 μg/dL or higher. Declines in blood lead were nonsignificantly associated with declines in diastolic blood pressure and significantly associated with declines in interventricular septum thickness.

CONCLUSIONS

Declines in blood lead levels in American Indian adults, even when small (0.1-1.0 μg/dL), were associated with reductions in systolic blood pressure. These findings suggest the need to further study the cardiovascular impacts of reducing lead exposures and the importance of lead exposure prevention.

Incidence of Stomach, Liver, and Colorectal Cancers by Geography and Social Vulnerability Among American Indian and Alaska Native Populations, 2010-2019

Social determinants of health and associated systems, policies, and practices are important drivers of health disparities. American Indian and Alaska Native (AI/AN) populations in the United States have elevated incidence rates of stomach, liver, and colorectal cancers compared with other racial/ethnic groups. In this study, we examined incidence rates of 3 types of gastrointestinal cancer among non-Hispanic AI/AN (NH-AI/AN) and non-Hispanic White (NHW) populations by geographic region and Social Vulnerability Index (SVI) score. Incident cases diagnosed during 2010-2019 were identified from population-based cancer registries linked with the Indian Health Service patient registration databases. Age-adjusted incidence rates (per 100,000 population) for stomach, liver, and colorectal cancers were compared within NH-AI/AN populations and between the NH-AI/AN and NHW populations by SVI score. Rates were higher among NH-AI/AN populations in moderate- and high-SVI-score counties in Alaska, the Southern Plains, and the East than in low-SVI counties. Incidence rates among NH-AI/AN populations were elevated when compared with NHW populations by SVI category. Results indicated that higher social vulnerability may drive elevated cancer incidence among NH-AI/AN populations. Additionally, disparities between NH-AI/AN and NHW populations persist even when accounting for SVI. Exploring social vulnerability can aid in designing more effective interventions to address root causes of cancer disparities among AI/AN populations.

Tobacco and marijuana use during the COVID-19 pandemic lockdown among American Indians residing in California and Oklahoma

INTRODUCTION

American Indian (AI) people experience a disproportionate tobacco and marijuana burden which may have been exacerbated by the COVID-19 pandemic. Little is known about the tobacco and marijuana habits of American Indian individuals during the COVID-19 pandemic. The objective of this study is to examine tobacco and marijuana use as well as change in use during the COVID-19 pandemic among the American Indian community.

METHODS

This cross-sectional study analyzes survey data from a convenience sample of American Indian individuals residing in California and Oklahoma and included adults with and without cancer that resided in both rural and urban areas (n=1068).

RESULTS

During October 2020 - January 2021, 36.0% of participants reported current use of tobacco products, 9.9% reported current use of marijuana products, and 23.7% reported increased use of tobacco and/or marijuana in the past 30 days, with no difference between those with cancer and those without cancer. Tobacco use was associated with marital status, age, employment status, COVID-19 exposure, COVID-19 beliefs, and alcohol consumption. Marijuana use was associated with COVID-19 beliefs, alcohol consumption, and income level. Increased tobacco and/or marijuana use was associated with baseline use of those products. Nearly a quarter of participants reported increased use of tobacco and/or marijuana products during the COVID-19 pandemic.

CONCLUSIONS

We observed high rates of tobacco use during the COVID-19 pandemic, consistent with other studies. Research is needed to examine whether tobacco and marijuana use will decrease to pre-pandemic levels post-pandemic or if these behaviors will persist post-pandemic. Given these findings, there is a pressing need to increase access to evidence-based tobacco and marijuana treatment services in the AI population post COVID-19 pandemic.

Profiles of historical loss and childhood trauma as predictors of mental and cardiometabolic health in American Indian adults

Cardiometabolic disease and mental health conditions are two major contributors to persistent inequities in health and life expectancy for American Indian adults. The atrocities associated with European colonization are linked to intergenerational psychological and emotional wounding (i.e., historical trauma) and high incidence of childhood trauma. Prior work has examined the independent relationships of childhood trauma and thoughts about historical loss with cardiometabolic and mental health in American Indians. In the current work, we used a data-driven approach to identify profiles of childhood trauma and frequency of thoughts about historical loss, and then examined how these profiles related to cardiometabolic and mental health in a sample of American Indian adults from across the United States (N = 727). We found that a profile characterized by high levels of childhood trauma and high frequency of thoughts about historical losses was associated with the greatest risk for mental health conditions. The profile characterized by the highest levels of childhood trauma and by moderate frequency of thoughts about historical losses was associated with the largest risk of cardiometabolic conditions. The findings represent an important first step towards understanding how childhood trauma and thoughts about historical loss may simultaneously inform enduring inequities in American Indian health.

Preferences for CPSTF-Recommended Intervention Approaches for Increasing Cancer Screening Among Screen-Eligible Adults in Zuni Pueblo, USA

We identified preferences toward Community Preventive Services Task Force (CPSTF)-recommended intervention approaches among screen-eligible Zuni Pueblo members in New Mexico, USA and assessed if there were significant differences in those preferences, with the goal of informing the selection of intervention approaches for use in the Zuni Pueblo. We utilize data from a population-based survey (n = 280) focused on 15 CPSTF-recommended intervention approaches designed to improve screening for cervical, breast, and/or colorectal cancer screening. Model-adjusted results suggest some intervention approaches garnered significantly higher support than others. We offer six, data-driven recommendations for consideration by public health practitioners as they endeavor to improve cancer prevention in the Zuni Pueblo. This study provides a replicable model for other public health practitioners and health services researchers to incorporate community preferences in community-level intervention approach selection.

"Sorry for laughing, but it's scary": humor and silence in discussions of Colorectal Cancer with Urban American Indians

BACKGROUND

Given high rates of cancer mortality in Native communities, we examined how urban American Indian and Alaska Native elders talk about colorectal cancer (CRC) and CRC screening.

METHODS

We conducted seven focus groups with a total of 46 participants in two urban clinics in the Pacific Northwest to assess participant awareness, perceptions, and concerns about CRC and CRC screening. Using speech codes theory, we identified norms that govern when and how to talk about CRC in this population.

RESULTS

Our analyses revealed that male participants often avoided screening because they perceived it as emasculating, whereas women often avoided screening because of embarrassment and past trauma resulting from sexual abuse. Both men and women used humor to mitigate the threatening nature of discussions about CRC and CRC screening.

CONCLUSIONS

We offer our analytic results to assist others in developing culturally appropriate interventions to promote CRC screening among American Indians and Alaska Natives.

Factors Associated with COVID-19 Vaccination Uptake in Great Plains American Indian Communities

With the development of the COVID-19 vaccine in late 2020, the importance of understanding the drivers of vaccine acceptance and vaccine hesitancy is important for the health of American Indian and Alaska Native communities. We conducted a cross-sectional, anonymous survey in October 2021 using established quantitative methods of virtual surveys to reach tribal members living on three reservations in the Great Plains (N = 679). We conducted multivariate analyses using logistic regression to assess the association between independent variables and COVID-19 vaccination status after adjusting for confounding. Respondents were more likely to have received a COVID-19 vaccine if they were older, had a full-time job, had previously received a flu vaccination, reported a higher level of trust in the health care system, had increased access to vaccinations, were able to isolate, or if they held a desire to keep their family safe. This study is one of the first to offer insights into the associations and possible determinants of COVID-19 vaccine uptake among American Indians in the Great Plains and was completed as part of the National Institutes of Health Rapid Acceleration of Diagnostics of Underserved Populations consortium. We identified a set of demographic, socioeconomic, and motivational factors that are associated with COVID-19 vaccination uptake among Great Plains American Indians and Alaska Natives. It is possible that future vaccine uptake may be enhanced through economic development, strengthening health care operations and care quality, and focusing vaccination messaging on family and community impact.

Longitudinal lipidomic signature of carotid atherosclerosis in American Indians: Findings from the Strong Heart Family Study

BACKGROUND AND AIMS

Dyslipidemia is an independent risk factor for atherosclerosis and atherosclerotic cardiovascular disease (ASCVD). To date, a comprehensive assessment of individual lipid species associated with atherosclerosis is lacking in large-scale epidemiological studies, especially in a longitudinal setting. We investigated the association of circulating lipid species and its longitudinal changes with carotid atherosclerosis.

METHODS

Using liquid chromatograph-mass spectrometry, we repeatedly measured 1542 lipid species in 3687 plasma samples from 1918 unique American Indians attending two visits (mean ∼5 years apart) in the Strong Heart Family Study. Carotid atherosclerotic plaques were assessed by ultrasonography at each visit. We identified lipids associated with prevalence or progression of carotid plaques, adjusting age, sex, BMI, smoking, hypertension, diabetes, and eGFR. Then we examined whether longitudinal changes in lipids were associated with changes in cardiovascular risk factors. Multiple testing was controlled at false discovery rate (FDR) < 0.05.

RESULTS

Higher levels of sphingomyelins, ether-phosphatidylcholines, and triacylglycerols were significantly associated with prevalence or progression of carotid plaques (odds ratios ranged from 1.15 to 1.34). Longitudinal changes in multiple lipid species (e.g., acylcarnitines, phosphatidylcholines, triacylglycerols) were associated with changes in cardiometabolic traits (e.g., BMI, blood pressure, fasting glucose, eGFR). Network analysis identified differential lipid networks associated with plaque progression.

CONCLUSIONS

Baseline and longitudinal changes in multiple lipid species were significantly associated with carotid atherosclerosis and its progression in American Indians. Some plaque-related lipid species were also associated with risk for CVD events.

A culturally informed model to enhance breast, cervical, and colorectal cancer screenings: perspectives of American Indian adults and healthcare providers in rural New Mexico

PURPOSE

American Indian/Alaska Native (AI/AN) populations have some of the lowest cancer screening rates compared to other racial/ethnic populations. Using community-based participatory research methods, we sought to characterize knowledge, attitudes, beliefs, and approaches to enhance breast, colorectal, and cervical cancer screening.

METHODS

We conducted 12 focus groups between October 2018 and September 2019 with 96 eligible AI adults and healthcare providers, recruited using non-probability purposive sampling methods from the Zuni Pueblo in rural New Mexico. We used the Multi-level Health Outcomes Framework (MHOF) to conduct a qualitative content analysis identifying mutable systems- and individual- level constructs important for behavior change that we crosslinked with the Community Preventive Services Task Force (CPSTF) recommended evidence-based interventions (EBIs) or approaches.

RESULTS

Salient systems-level factors that limited uptake of cancer screenings included inflexible clinic hours, transportation barriers, no on-demand service and reminder systems, and brief doctor-patient encounters. Individual-level barriers included variable cancer-specific knowledge that translated into fatalistic beliefs, fear, and denial. Interventions to enhance community demand and access for screening should include one-on-one and group education, small media, mailed screening tests, and home visitations by public health nurses. Interventions to enhance provider delivery of screening services should include translation and case management services.

CONCLUSIONS

The MHOF constructs crosslinked with CPSTF recommended EBIs or approaches provided a unique perspective to frame barriers and promoters of screening utilization and insights for intervention development. Findings inform the development of culturally tailored, theoretically informed, multi-component interventions concordant with CPSTF recommended EBIs or approaches aimed at improving cancer screening.

COVID-19 Testing Factors Among Great Plains American Indians

BACKGROUND

COVID-19 created unparalleled challenges for vulnerable communities, especially among American Indians and Alaska Natives. An effective COVID-19 response requires a tribally driven effort to understand the perspectives of Tribal members on testing and to ensure that delivery strategies are grounded in the cultural values, traditions, and experiences of the Tribes.

METHODS

We conducted a cross-sectional, anonymous survey in October 2021 using established methods to reach Tribal members residing in three Reservations in the Great Plains (N = 679). Multivariate analyses were conducted using logistic regression to assess the association between independent variables and COVID-19 testing uptake after adjusting for confounding.

RESULTS

After multivariate adjustment, a respondent's employment status, ability to isolate if diagnosed with COVID-19, and endorsing that COVID-19 testing is only needed if one has symptoms were significantly correlated with having been previously tested for COVID-19. Participants without a full-time job were about half as likely to have been tested for COVID-19 compared to those with full-time jobs. Participants who reported not being able to isolate if they tested positive for COVID-19 and participants who did not think testing was needed if asymptomatic were also half as likely to be tested.

CONCLUSIONS

Ensuring that everyone has the ability to isolate, that people who are not working have easy access to testing, and that everyone understands the value of testing after exposure are key steps to maximizing testing uptake. Efforts will only be successful if there is continued investment in programs that provide free testing access for everyone on Reservations.

Cognitive control as a potential neural mechanism of protective role of spirituality in anxiety disorders among American Indian people: An ERP study

Research suggests that traditional cultural factors are protective against mental health conditions in American Indian (AI) populations. This study aims to determine if cognitive control is a neurocognitive mechanism of the protective role of spirituality in AI people with generalized anxiety disorder (GAD). Participants self-identified as AI (n = 52) and included individuals with GAD (n = 16) and without GAD (n = 36). Electroencephalography was collected during a stop-signal task to probe cognitive control using the P3 event-related potential. Higher levels of spirituality attenuated the processing efficiency disruption among individuals with GAD as indicated by P3 amplitudes closer to that of individuals without GAD.

Alzheimer's disease and its related dementias in US Native Americans: A major public health concern

Alzheimer's disease (AD) and Alzheimer's related dementias (ADRD) are growing public health concerns in aged populations of all ethnic and racial groups. AD and ADRD are caused by multiple factors, such as genetic mutations, modifiable and non-modifiable risk factors, and lifestyle. Studies of postmortem brains have revealed multiple cellular changes implicated in AD and ADRD, including the accumulation of amyloid beta and phosphorylated tau, synaptic damage, inflammatory responses, hormonal imbalance, mitochondrial abnormalities, and neuronal loss. These changes occur in both early-onset familial and late-onset sporadic forms. Two-thirds of women and one-third of men are at life time risk for AD. A small proportion of total AD cases are caused by genetic mutations in amyloid precursor protein, presenilin 1, and presenilin 1 genes, and the APOE4 allele is a risk factor. Tremendous research on AD/ADRD, and other comorbidities such as diabetes, obesity, hypertension, and cancer has been done on almost all ethnic groups, however, very little biomedical research done on US Native Americans. AD/ADRD prevalence is high among all ethnic groups. In addition, US Native Americans have poorer access to healthcare and medical services and are less likely to receive a diagnosis once they begin to exhibit symptoms, which presents difficulties in treating Alzheimer's and other dementias. One in five US Native American people who are 45 years of age or older report having memory issues. Further, the impact of caregivers and other healthcare aspects on US Native Americans is not yet. In the current article, we discuss the history of Native Americans of United States (US) and health disparities, occurrence, and prevalence of AD/ADRD, and shedding light on the culturally sensitive caregiving practices in US Native Americans. This article is the first to discuss biomedical research and healthcare disparities in US Native Americans with a focus on AD and ADRD, we also discuss why US Native Americans are reluctant to participate in biomedical research.

Longitudinal Lipidomic Profile of Hypertension in American Indians: Findings From the Strong Heart Family Study

BACKGROUND

Dyslipidemia is an important risk factor for hypertension and cardiovascular disease. Standard lipid panel cannot reflect the complexity of blood lipidome. The associations of individual lipid species with hypertension remain to be determined in large-scale epidemiological studies, especially in a longitudinal setting.

METHODS

Using liquid chromatography-mass spectrometry, we repeatedly measured 1542 lipid species in 3699 fasting plasma samples at 2 visits (1905 at baseline, 1794 at follow-up, ~5.5 years apart) from 1905 unique American Indians in the Strong Heart Family Study. We first identified baseline lipids associated with prevalent and incident hypertension, followed by replication of top hits in Europeans. We then conducted repeated measurement analysis to examine the associations of changes in lipid species with changes in systolic blood pressure, diastolic blood pressure, and mean arterial pressure. Network analysis was performed to identify lipid networks associated with the risk of hypertension.

RESULTS

Baseline levels of multiple lipid species, for example, glycerophospholipids, cholesterol esters, sphingomyelins, glycerolipids, and fatty acids, were significantly associated with both prevalent and incident hypertension in American Indians. Some lipids were confirmed in Europeans. Longitudinal changes in multiple lipid species, for example, acylcarnitines, phosphatidylcholines, fatty acids, and triacylglycerols, were significantly associated with changes in blood pressure measurements. Network analysis identified distinct lipidomic patterns associated with the risk of hypertension.

CONCLUSIONS

Baseline plasma lipid species and their longitudinal changes are significantly associated with hypertension development in American Indians. Our findings shed light on the role of dyslipidemia in hypertension and may offer potential opportunities for risk stratification and early prediction of hypertension.

Metal mixtures and DNA methylation measures of biological aging in American Indian populations

INTRODUCTION

Native American communities suffer disproportionately from elevated metal exposures and increased risk for cardiovascular diseases and diabetes. DNA methylation is a sensitive biomarker of aging-related processes and novel epigenetic-based "clocks" can be used to estimate accelerated biological aging that may underlie increased risk. Metals alter DNA methylation, yet little is known about their individual and combined impact on epigenetic age acceleration. Our objective was to investigate the associations of metals on several DNA methylation-based aging measures in the Strong Heart Study (SHS) cohort.

METHODS

Blood DNA methylation data from 2,301 SHS participants was used to calculate age acceleration of epigenetic clocks (PhenoAge, GrimAge, DunedinPACE, Hannum, Horvath). Urinary metals [arsenic (As), cadmium (Cd), tungsten (W), zinc (Zn), selenium (Se), molybdenum (Mo)] were creatinine-adjusted and categorized into quartiles. We examined associations of individual metals through linear regression models and used Bayesian Kernel Machine Regression (BKMR) for the impact of the total metal mixture on epigenetic age acceleration.

RESULTS

The mixture of nonessential metals (W, As, Cd) was associated with greater GrimAge acceleration and DunedinPACE, while the essential metal mixture (Se, Zn, Mo) was associated with lower epigenetic age acceleration. Cd was associated with increased epigenetic age acceleration across all clocks and BKMR analysis suggested nonlinear associations between Se and DunedinPACE, GrimAge, and PhenoAge acceleration. No interactions between individual metals were observed. The associations between Cd, Zn, and epigenetic age acceleration were greater in never smokers in comparison to current/former smokers.

CONCLUSION

Nonessential metals were positively associated with greater epigenetic age acceleration, with strongest associations observed between Cd and DunedinPACE and GrimAge acceleration. In contrast, essential metals were associated with lower epigenetic aging. Examining the influence of metal mixtures on epigenetic age acceleration can provide insight into metals and aging-related diseases.

Longitudinal lipidomic signatures of all-cause and CVD mortality in American Indians: findings from the Strong Heart Study

Dyslipidemia is an independent and modifiable risk factor for aging and age-related disorders. Routine lipid panel cannot capture all individual lipid species in blood (i.e., blood lipidome). To date, a comprehensive assessment of the blood lipidome associated with mortality is lacking in large-scale community-dwelling individuals, especially in a longitudinal setting. Using liquid chromatograph-mass spectrometry, we repeatedly measured individual lipid species in 3,821 plasma samples collected at two visits (~ 5.5 years apart) from 1,930 unique American Indians in the Strong Heart Family Study. We first identified baseline lipids associated with risks for all-cause mortality and CVD mortality (mean follow-up period: 17.8 years) in American Indians, followed by replication of top hits in European Caucasians in the Malmö Diet and Cancer-Cardiovascular Cohort (n = 3,943, mean follow-up period: 23.7 years). The model adjusted age, sex, BMI, smoking, hypertension, diabetes, and LDL-c at baseline. We then examined the associations between changes in lipid species and risk of mortality. Multiple testing was controlled by false discovery rate (FDR). We found that baseline levels and longitudinal changes of multiple lipid species, e.g., cholesterol esters, glycerophospholipids, sphingomyelins, and triacylglycerols, were significantly associated with risks of all-cause or CVD mortality. Many lipids identified in American Indians could be replicated in European Caucasians. Network analysis identified differential lipid networks associated with risk of mortality. Our findings provide novel insight into the role of dyslipidemia in disease mortality and offer potential biomarkers for early prediction and risk reduction in American Indians and other ethnic groups.

Respecting tribal voices in the development of a gestational diabetes risk reduction preconception counseling program for American Indian/Alaska Native adolescent females: a qualitative study

BACKGROUND

American Indians and Alaska Natives (AI/AN) are disproportionately affected by adolescent obesity, adolescent pregnancy and gestational diabetes mellitus (GDM). GDM is associated with increased risk for perinatal death, obesity, and subsequent type 2 diabetes (T2D) for the offspring. Moreover, mothers with GDM are also at increased risk for T2D post-partum. Yet few lifestyle interventions exist to reduce GDM risk prior to pregnancy. We describe the process of adapting an existing validated preconception counseling intervention for AI/AN adolescent girls at-risk for GDM and their mothers. Perspectives and recommendations were gathered from a diverse array of stakeholders to assure the new program called Stopping GDM was culturally responsive and developed with tribal voices and perspectives represented.

METHODS

We conducted focus groups and individual interviews with multiple AI/AN stakeholders (n = 55). Focus groups and interviews were digitally recorded, transcribed verbatim, and analyzed using a thematic content approach to construct cross-cutting themes across the focus groups and interviews.

RESULTS

Four key themes emerged reflecting issues important to planning a reproductive health intervention: 1) Limited awareness, knowledge, and health education resources about GDM; 2) The importance of acknowledging traditional AI/AN values and the diversity of traditions and culture among AI/AN tribes; 3) The need to cultivate healthy decision-making skills and empower girls to make safe and healthy choices; and 4) Lack of communication about reproductive health between AI/AN mothers and daughters and between AI/AN women and health care professionals.

CONCLUSION

Findings have been used to inform the cultural tailoring and adaptation of an existing preconception counseling program, originally designed for non-AI/AN adolescent girls with diabetes, for AI/AN adolescents at-risk for GDM in future pregnancies.

Volume atrophy in medial temporal cortex and verbal memory scores in American Indians: Data from the Strong Heart Study

INTRODUCTION

Distinguishing Alzheimer's disease (AD) patient subgroups may optimize positive clinical outcomes. Cortical atrophy is correlated with memory deficits, but these associations are understudied in American Indians.

METHODS

We collected imaging and cognition data in the Strong Heart Study (SHS), a cohort of 11 tribes across three regions. We processed 1.5T MRI using FreeSurfer and iterative principal component analysis. Linear mixed models estimated volumetric associations with diabetes.

RESULTS

Over mean 7 years follow-up (N = 818 age 65-89 years), overall volume loss was 0.5% per year. Significant losses associated with diabetes were especially strong in the right hemisphere. Annualized hippocampal, parahippocampal, entorhinal atrophy were worse for men, older age, diabetes, hypertension, stroke; and associated with both encoding and retrieval memory losses.

DISCUSSION

Our findings suggest that diabetes is an important risk factor in American Indians for cortical atrophy and memory loss. Future research should examine opportunities for primary prevention in this underserved population.

Depression, physical activity, and incident cardiovascular disease among American Indians: The strong heart family study

Background

Little is known about the relationship of depression with incident cardiovascular disease (CVD) among American Indians (AIs), a population with a high burden of depressive symptoms and CVD. In this study, we examined the association of depressive symptoms with CVD risk among AIs and assessed whether an objective marker of ambulatory activity influenced the relationship.

Methods

The study comprised participants from the Strong Heart Family Study, a longitudinal study of CVD risk among AIs free of CVD at baseline (2001-2003) and who participated in a follow-up examination (n = 2209). The Center for Epidemiologic Studies of Depression Scale (CES-D) was used to assess depressive symptoms and depressive affect. Ambulatory activity was measured using Accusplit AE120 pedometers. Incident CVD was defined as new myocardial infarction, coronary heart disease, or stroke (through 2017). Generalized estimating equations were used to examine the association of depressive symptoms with incident CVD.

Results

27.5% of participants reported moderate or severe depressive symptoms at baseline and 262 participants developed CVD during follow-up. Compared to participants who reported no depressive symptoms, the odds ratios for developing CVD among those who reported mild, moderate, or severe symptoms were: 1.19 (95% CI: 0.76, 1.85), 1.61 (95% CI: 1.09, 2.37), and 1.71 (95% CI: 1.01, 2.91), respectively. Adjustment for activity did not alter findings.

Limitations

CES-D is a tool used to identify individuals with depressive symptoms and not a measure of clinical depression.

Conclusion

Higher levels of reported depressive symptoms were positively associated with CVD risk in a large cohort of AIs.

Poor self-reported sleep quality associated with suicide risk in a community sample of American Indian adults

Study Objectives

Although American Indian/Alaska Native (AI/AN) have high suicide rates few studies have systematically investigated sleep quality and its association with suicidal behaviors in AI/AN. This study is a cross-sectional investigation of self-reported sleep quality and suicidal behaviors in an adult AI population.

Methods

A semi-structured interview was used to collect data on suicidal ideation, suicidal plans, and suicidal attempts and the Pittsburgh Sleep Quality Index (PSQI) was collected to assess sleep quality in American Indian adults.

Results

In this sample (n = 477), 91 (19%) of the participants endorsed suicidal ideation (thoughts and plans), and 66 (14%) reported suicidal attempts, including four who subsequently died by suicide. More women reported suicidal thoughts or acts than men. Those endorsing suicidal thoughts slept fewer hours during the night, reported more nocturnal awakenings, and showed poorer subjective sleep quality according to PSQI total scores compared to those with no suicidal thoughts or acts. Participants with suicidal acts (n = 66) reported more bad dreams and higher PSQI total scores compared to those with no suicidal thoughts or acts. When those with any suicidal thoughts or acts (n = 157, 33%) were compared to those without, they were more likely to endorse nocturnal awakenings and bad dreams and demonstrated significantly higher PSQI total scores.

Conclusions

Although additional research is needed to evaluate sleep disturbances as a proximal, causal risk factor for suicidal behaviors in AI, findings highlight need for further study of sleep as a warning sign and intervention tool for suicide prevention among American Indian adults.

Striatal hypoactivation during monetary loss anticipation in individuals with substance use disorders in a heterogenous urban American Indian sample

Research suggests that disproportionate exposure to risk factors places American Indian (AI) peoples at higher risk for substance use disorders (SUD). Although SUD is linked to striatal prioritization of drug rewards over other appetitive stimuli, there are gaps in the literature related to the investigation of aversive valuation processing, and inclusion of AI samples. To address these gaps, this study compared striatal anticipatory gain and loss processing between AI-identified with SUD (SUD+; n = 52) and without SUD (SUD-; n = 35) groups from the Tulsa 1000 study who completed a monetary incentive delay (MID) task during functional magnetic resonance imaging. Results indicated that striatal activations in the nucleus accumbens (NAcc), caudate, and putamen were greatest for anticipating gains (ps < 0.001) but showed no group differences. In contrast to gains, the SUD+ exhibited lower NAcc (p = .01, d =0.53) and putamen (p = .04, d =0.40) activation to anticipating large losses than the comparison group. Within SUD+ , lower striatal responses during loss anticipations were associated with slower MID reaction times (NAcc: r = -0.43; putamen: r = -0.35) during loss trials. This is among the first imaging studies to examine underlying neural mechanisms associated with SUD within AIs. Attenuated loss processing provides initial evidence of a potential mechanism wherein blunted prediction of aversive consequences may be a defining feature of SUD that can inform future prevention and intervention targets.

American Indians travel great distances for obstetrical care: Examining rural and racial disparities

Rural, American Indian/Alaska Native (AI/AN) people, a population at elevated risk for complex pregnancies, have limited access to risk-appropriate obstetric care. Obstetrical bypassing, seeking care at a non-local obstetric unit, is an important feature of perinatal regionalization that can alleviate some challenges faced by this rural population, at the cost of increased travel to give birth. Data from five years (2014-2018) of birth certificates from Montana, along with the 2018 annual survey of the American Hospital Association (AHA) were used in logistic regression models to identify predictors of bypassing, with ordinary least squares regression models used to predict factors associated with the distance (in miles) birthing people drove beyond their local obstetric unit to give birth. Logit analyses focused on hospital-based births to Montana residents delivered during this time period (n = 54,146 births). Distance analyses focused on births to individuals who bypassed their local obstetric unit to deliver (n = 5,991 births). Individual-level predictors included maternal sociodemographic characteristics, location, perinatal health characteristics, and health care utilization. Facility-related measures included level of obstetric care of the closest and delivery hospitals, and distance to the closest hospital-based obstetric unit. Findings suggest that birthing people living in rural areas and on American Indian reservations were more likely to bypass to give birth, with bypassing likelihood depending on health risk, insurance, and rurality. AI/AN and reservation-dwelling birthing people traveled significantly farther when bypassing. Findings highlight that distance traveled was even farther for AI/AN people facing pregnancy health risks (23.8 miles farther than White people with pregnancy risks) or when delivering at facilities offering complex care (14-44 miles farther than White people). While bypassing may connect rural birthing people to more risk-appropriate care, rural and racial inequities in access persist, with rural, reservation-dwelling AI/AN birthing people experiencing greater likelihood of bypassing and traveling greater distances when bypassing.

Evidence of secular trends during the COVID-19 pandemic in a stepped wedge cluster randomized trial examining sexual and reproductive health outcomes among Indigenous youth

BACKGROUND

Nen ŨnkUmbi/EdaHiYedo ("We Are Here Now," or NE) is an intervention to prevent STIs, HIV, HCV, and teen pregnancy among Assiniboine and Sioux youth of the Fort Peck Reservation in the state of Montana in the USA. A cluster-randomized stepped-wedge design (SWD) trial is used to evaluate NE, where clusters are schools. The purpose of this study is to evaluate whether there is evidence of a secular trend associated with the COVID-19 pandemic.

METHODS

The original study design is a cluster-randomized stepped-wedge design (SWD), in which five schools that youth from Fort Peck attend are the clusters to be randomized into the intervention one at a time, with all schools eventually being randomized to the intervention across three steps. N/E is a 5-year study involving 456 15- to 18-year-old youth. For this study, we use a mixed quantitative and qualitative methods approach to understand how the COVID-19 pandemic may have been associated with the study's primary outcome variables. Data were drawn from the first cluster exposed to the intervention and one control cluster that did not yet receive the intervention during the period in which COVID-19 mitigation efforts were being implemented. A pre-post COVID questionnaire was added to core measures administered, and semistructured qualitative interviews were conducted with youths regarding their perceptions of how the pandemic altered their sexual behaviors.

RESULTS

One hundred eighteen youth responded to the questionnaire and 31 youth participated in semistructured qualitative interviews. Youth reporting having sex with less people due to COVID-19 reported more sex acts (incident rate ratio (IRR)=3.6, 95% CI 1.6-8.1) in comparison to those who did not report having sex with less people, and youth who reported having sex with the same amount of people due to COVID-19 reported less sex acts (IRR=0.31, 95% CI 0.14-0.7) in comparison to those who did not report having sex with the same amount of people. Youth reporting having sex less times due to COVID-19 experienced a greater number of sex acts in comparison to those who did not report having sex less times (IRR=2.7, 1.2-6.4). Results suggest that more sexually active individuals reported perceiving having sex with less people and less frequent engagement in sex during the pandemic. It is possible that the COVID-19 pandemic period was associated with a truncation in the distribution of sexual activity that would bias an estimate of the intervention's effect.

CONCLUSION

Findings suggest evidence of a secular trend. This trend must be accounted for at trial end, and sensitivity analyses are recommended. Documenting and reporting on these findings encourages transparent reporting during the implementation of a SWD trial during a global pandemic, and informs endline analyses.

TRIAL REGISTRATION

This trial is registered with the Clinical trials registry of the US National Library of Medicine at the National Institutes of Health (NIH). It was registered on October 1, 2018. The study presented in this manuscript is funded by NIH National Institute on Minority Health and Health Disparities (NIMHD), Award # R01MD012761-01, Elizabeth Rink (Principal Investigator). The study's ClinicalTrials.gov number is NCT03694418.

Indigenous peoples and the COVID-19 pandemic: a systematic scoping review

Past influenza pandemics including the Spanish flu and H1N1 have disproportionately affected Indigenous Peoples. We conducted a systematic scoping review to provide an overview of the state of understanding of the experience of Indigenous peoples during the first 18 months of the COVID-19 pandemic, in doing so we capture the state of knowledge available to governments and decision makers for addressing the needs of Indigenous peoples in these early months of the pandemic. We addressed three questions: (a) How is COVID-19 impacting the health and livelihoods of Indigenous peoples, (b) What system level challenges are Indigenous peoples experiencing, (c) How are Indigenous peoples responding? We searched Web of Science, Scopus, and PubMed databases and UN organization websites for publications about Indigenous peoples and COVID-19. Results were analyzed using descriptive statistics and content analysis. A total of 153 publications were included: 140 peer-reviewed articles and 13 from UN organizations. Editorial/commentaries were the most (43%) frequent type of publication. Analysis identified Indigenous peoples from 19 different countries, although 56% of publications were centered upon those in Brazil, United States, and Canada. The majority (90%) of articles focused upon the general adult population, few (<2%) used a gender lens. A small number of articles documented COVID-19 testing (0.04%), incidence (18%), or mortality (16%). Five themes of system level challenges affecting exposure and livelihoods evolved: ecological, poverty, communication, education and health care services. Responses were formal and informal strategies from governments, Indigenous organizations and communities. A lack of ethnically disaggregated health data and a gender lens are constraining our knowledge, which is clustered around a limited number of Indigenous peoples in mostly high-income countries. Many Indigenous peoples have autonomously implemented their own coping strategies while government responses have been largely reactive and inadequate. To 'build back better' we must address these knowledge gaps.

Diagnostic criteria and etiopathogenesis of type 2 diabetes and its complications: Lessons from the Pima Indians

The Phoenix Epidemiology and Clinical Research Branch of the National Institute of Diabetes and Digestive and Kidney Diseases has conducted prospective studies of diabetes and its complications in the Pima Indians living in Arizona, USA for over 50 years. In this review we highlight areas in which these studies provided vital insights into the criteria used to diagnose type 2 diabetes, the pathophysiologic changes that accompany the development of type 2 diabetes, and the course and determinants of diabetes complications-focusing specifically on diabetic kidney disease. We include data from our longitudinal population-based study of diabetes and its complications, studies on the role of insulin resistance and insulin secretion in the pathophysiology of type 2 diabetes, and in-depth studies of diabetic kidney disease that include measures of glomerular function and research kidney biopsies. We also focus on the emerging health threat posed by youth-onset type 2 diabetes, which was first seen in the Pima Indians in the 1960s and is becoming an increasing issue worldwide.

Maternal DNA methylation signatures of arsenic exposure is associated with adult offspring insulin resistance in the Strong Heart Study

Exposure to low to moderate arsenic (As) levels has been associated with type 2 diabetes (T2D) and other chronic diseases in American Indian communities. Prenatal exposure to As may also increase the risk for T2D in adulthood, and maternal As has been associated with adult offspring metabolic health measurements. We hypothesized that T2D-related outcomes in adult offspring born to women exposed to low to moderate As can be evaluated utilizing a maternally-derived molecular biosignature of As exposure. Herein, we evaluated the association of maternal DNA methylation with incident T2D and insulin resistance (Homeostatic model assessment of insulin resistance [HOMA2-IR]) in adult offspring. For DNA methylation, we used 20 differentially methylated cytosine-guanine dinucleotides (CpG) previously associated with the sum of inorganic and methylated As species (ΣAs) in urine in the Strong Heart Study (SHS). Of these 20 CpGs, we found six CpGs nominally associated (p < 0.05) with HOMA2-IR in a fully adjusted model that included clinically relevant covariates and offspring adiposity measurements; a similar model that adjusted instead for maternal adiposity measurements found three CpGs nominally associated with HOMA2-IR, two of which overlapped the offspring adiposity model. After adjusting for multiple comparisons, cg03036214 remained associated with HOMA2-IR (q < 0.10) in the offspring adiposity model. The odds ratio of incident T2D increased with an increase in maternal DNA methylation at one HOMA2-IR associated CpG in the model adjusting for offspring adiposity, cg12116137, whereas adjusting for maternal adiposity had a minimal effect on the association. Our data suggests offspring adiposity, rather than maternal adiposity, potentially influences the effects of maternal DNAm signatures on offspring metabolic health parameters. Here, we have presented evidence supporting a role for epigenetic biosignatures of maternal As exposure as a potential biomarker for evaluating risk of T2D-related outcomes in offspring later in life.

Historical loss: Implications for physical activity levels in American Indian adults

PURPOSE

To investigate the relationship between daily thoughts about historical loss and daily levels of moderate to vigorous physical activity (MVPA) in American Indian (AI) adults residing on the Blackfeet reservation in Browning, Montana.

METHODS

The study was designed and conducted using a community-based participatory research framework and ecological momentary assessment. Over a period of 1 week, 100 AI adults (mean age = 42.18, SD = 14.92) reported how often they thought about historical loss at the end of each day. During this week-long period, all participants wore a wrist-accelerometer to passively and objectively measure levels of physical activity.

FINDINGS

We found that Blackfeet AI adults who reported thinking about historical loss more frequently over the course of the week had lower average levels of MVPA over the course of the week compared to Blackfeet AI adults who reported thinking about historical loss less frequently (B = -10.22, 95% CI = -13.83, -6.60). We also found that on days when Blackfeet AI adults thought more about historical loss compared to their weekly average, they had fewer minutes of MVPA compared to their weekly average of minutes of MVPA (B = -0.87, 95% CI = -1.48, -0.27).

CONCLUSIONS

Our data indicate that thoughts about historical loss are linked to lower levels of MVPA. Given high incidence of chronic health conditions linked to physical inactivity in AIs, more work is needed to identify the mechanisms through which thoughts about historical loss may inhibit physical activity in this population.

Neural processes of inhibitory control in American Indian peoples are associated with reduced mental health problems

American Indians (AI) experience disproportionately high prevalence of suicide and substance use disorders (SUD). However, accounting for risk burden (e.g. historical trauma and discrimination), the likelihood of mental health disorders or SUD is similar or decreased compared with the broader population. Such findings have spurred psychological research examining the protective factors, but no studies have investigated its potential neural mechanisms. Inhibitory control is one of the potential neurobehavioral construct with demonstrated protective effects, but has not been examined in neuroimaging studies with AI populations specifically. We examined the incidence of suicidal thoughts and behaviors (STB) and SUD among AI (n = 76) and propensity matched (sex, age, income, IQ proxy and trauma exposure) non-Hispanic White (NHW) participants (n = 76). Among the AI sample, functional magnetic resonance imaging (fMRI) data recorded during the stop-signal task (SST) was examined in relation to STB and SUDs. AIs relative to NHW subjects displayed lower incidence of STB. AIs with no reported STBs showed greater activity in executive control regions during the SST compared with AI who endorsed STB. AI without SUD demonstrated lower activity relative to those individual reporting SUD. Results are consistent with a growing body of literature demonstrating the high level of risk burden driving disparate prevalence of mental health concerns in AI. Furthermore, differential activation during inhibitory control processing in AI individuals without STB may represent a neural mechanism of protective effects against mental health problems in AI. Future research is needed to elucidate sociocultural factors contributing protection against mental health outcomes in AIs and further delineate neural mechanisms with respect to specific concerns (e.g. SUD vs STB).

Origins of antimining resistance in the life of a grassroots American Indian leader: Prospects for Indigenizing psychobiography

American Indian communities have long been subject to environmental degradation, but successful "grassroots" struggles to end such exploitation are exceedingly rare. How is it that Joseph William Azure-my father and an unsung hero of social change-came to "notice" in 1985 that "our entire [reservation] mountain range was at risk" from destructive gold mining and, in response, to form "a small grassroots traditional society" that created "a lot of local and national publicity for our cause to save" these mountains? To address this question, I adopted and adapted the approaches and methods of psychobiography to trace shifts in his sense of self in response to midlife socialization into Indigenous traditional spirituality. In developing this brief account of his development as a social change agent, I propose that psychobiography may require "Indigenization" if it is to better represent American Indian lives. Specifically, some Indigenous life stories will perhaps require tellings that center on collective endeavors rather than individual ones, reconstruction of life experiences based on comparably limited (material) archives, deeper preservation of the conventions of orality, and curation by close kin rather than by "distanced" analysts.

Implementation fidelity of the Promoting First Relationships intervention program in a Native community

Promoting First Relationship (PFR) is an evidence-based intervention designed to promote positive, supportive relationships between primary caregivers and their young children. Implementing and testing the efficacy of PFR in a remote Native community is especially challenging and requires methods and tools for ensuring implementation fidelity. Tribal members of a Native community were successfully trained and certified to deliver PFR by university-based personnel. During PFR delivery, they achieved very high scores on adherence to intervention content (M = 0.99, SD = 0.02), and their quality of delivery uniformly exceeded established criteria. High attrition occurred before PFR was delivered. However, participants who remained in the study completed all 10 sessions of PFR content. Participants' satisfaction with the program was very high (M = 3.90 [of 4 points], SD = 0.19). High implementation fidelity was attained in the face of many inherent challenges. The suite of methods and tools used for training, monitoring, and evaluating implementation fidelity in this study provides an example that may be useful in the evaluation of evidence-based programs more generally.

Promoting First Relationships(®) for Primary Caregivers and Toddlers in a Native Community: a Randomized Controlled Trial

This study tested the effectiveness of Promoting First Relationships^® (PFR), a preventive intervention program aimed at fostering positive caregiver-child relationships in Native families living on a rural reservation. Participants were 162 primary caregivers (96% Native; 93% female) and their Native toddlers (10-31 months old; 50% female). Families were randomized to a PFR group (n = 81) or Resource and Referral (RR) control group (n = 81), after baseline data collection (Time 1) to assess the quality of caregiver-child interaction, caregiver knowledge about children's social-emotional needs, caregiver depressive symptoms, and child externalizing behavior. After delivery of the PFR intervention or the RR service, follow-up assessments were repeated immediately post-intervention (Time 2) and 3 months later (Time 3). After controlling for baseline assessments, multivariate analyses of covariance revealed that caregivers in the PFR group had significantly higher scores on knowledge about children's social-emotional needs at Time 2 (p < .01, η² = .06) and Time 3 (p < .05, η² = .04) and less severe depressive symptoms at Times 2 and 3 (both p < .05, η² = .04). At Time 3, the quality of caregiver-child interaction was better in the PFR group (p < .01, η² = .06), an effect that was moderated by severity of depressive symptoms (p = .05, η² = .06), with PFR having the greatest impact at low levels of initial symptoms (p = .02). Results support the positive impact of PFR in a Native community and suggest conditions under which the intervention may be most effective.

Recruiting Indigenous Patients Into Clinical Trials: A Circle of Trust

The Circle of Trust is a new conceptual model that can help investigators and the American Indian/Alaska Natives (AI/AN) community work together to promote inclusion of AI/AN populations in clinical trials to improve health outcomes. Racial/ethnic minority groups remain underrepresented in clinical trials and this creates the need and opportunity for novel approaches. Indigenous populations are particularly underrepresented in clinical trials. Studies show that AI/AN have the lowest representation of race/ethnic groups in the United States. American Indian/Alaska Natives suffer from significant health disparities with higher rates of morbidity and mortality and lower rates for preventative measures and access to health services. A variety of barriers to recruitment of minority patients exist at several levels including the system/institutional, interpersonal, and the individual. The authors, experts in AI/AN health and recruitment of minorities into research, collaborated to modify the currently existing and published "trust triangle" model that focuses on minority recruitment to include participants, researcher, and trusted entity. We advocate for expanding the trust triangle into a circle of trust inclusive of community. The "circle of trust" is a new conceptual model that can help investigators and the AI/AN community work together to promote inclusion of AI/AN populations in clinical trials to improve health outcomes.

Intraindividual Cognitive Variability and Magnetic Resonance Imaging in Aging American Indians: Data from the Strong Heart Study

BACKGROUND

American Indians have high prevalence of risk factors for Alzheimer's disease and related dementias (ADRD) compared to the general population, yet dementia onset and frequency in this population are understudied. Intraindividual cognitive variability (IICV), a measure of variability in neuropsychological test performance within a person at a single timepoint, may be a novel, noninvasive biomarker of neurodegeneration and early dementia.

OBJECTIVE

To characterize the cross-sectional associations between IICV and hippocampal, total brain volume, and white matter disease measured by magnetic resonance imaging (MRI) among older American Indians.

METHODS

IICV measures for memory, executive function, and processing speed, and multidomain cognition were calculated for 746 American Indians (aged 64-95) who underwent MRI. Regression models were used to examine the associations of IICV score with hippocampal volume, total brain volume, and graded white matter disease, adjusting for age, sex, education, body mass index, intracranial volume, diabetes, stroke, hypertension, hypercholesterolemia, alcohol use, and smoking.

RESULTS

Higher memory IICV measure was associated with lower hippocampal volume (Beta = -0.076; 95% CI -0.499, -0.023; p = 0.031). After adjustment for Bonferroni or IICV mean scores in the same tests, the associations were no longer significant. No IICV measures were associated with white matter disease or total brain volume.

CONCLUSION

These findings suggest that the IICV measures used in this research cannot be robustly associated with cross-sectional neuroimaging features; nonetheless, the results encourage future studies investigating the associations between IICV and other brain regions, as well as its utility in the prediction of neurodegeneration and dementia in American Indians.

HPV vaccination coverage and factors among American Indians in Cherokee Nation

PURPOSE

We estimated human papillomavirus (HPV) vaccine initiation coverage among American Indian adolescents and identified factors associated with HPV vaccination among parents of these adolescents.

METHODS

We developed, tested, and disseminated a survey to a random sample of 2,000 parents of American Indian adolescents aged 9-17 years who had accessed Cherokee Nation Health Services from January 2019 to August 2020. We used log-binomial regression to estimate the unadjusted and adjusted weighted prevalence proportion ratios (PPR) and 95% confidence intervals (CI) for adolescent HPV vaccine initiation.

RESULTS

HPV vaccine initiation coverage (≥ 1 dose) was 70.7% among adolescents aged 13-17 years. The prevalence of HPV vaccine initiation was higher among American Indian adolescents whose parents were aware of the HPV vaccine (adjusted weighted PPR 3.41; 95% CI 2.80, 4.15) and whose parents received a recommendation from their provider (adjusted weighted PPR 2.70; 95% CI 2.56, 2.84). The most common reasons reported by parents to vaccinate their children were to protect them against HPV-associated cancers (25.7%) and receiving a recommendation from a healthcare provider (25.0%). Parents cited vaccine safety concerns as the main reason for not getting their children vaccinated (33.2%).

CONCLUSIONS

HPV vaccine initiation coverage among American Indian adolescents in Cherokee Nation was consistent with the national survey estimates. However, allaying parental concerns about vaccine safety and encouraging providers to recommend the HPV vaccine could improve coverage.

Epigenetics of type 2 diabetes and diabetes-related outcomes in the Strong Heart Study

BACKGROUND

The prevalence of type 2 diabetes has dramatically increased in the past years. Increasing evidence supports that blood DNA methylation, the best studied epigenetic mark, is related to diabetes risk. Few prospective studies, however, are available. We studied the association of blood DNA methylation with diabetes in the Strong Heart Study. We used limma, Iterative Sure Independence Screening and Cox regression to study the association of blood DNA methylation with fasting glucose, HOMA-IR and incident type 2 diabetes among 1312 American Indians from the Strong Heart Study. DNA methylation was measured using Illumina's MethylationEPIC beadchip. We also assessed the biological relevance of our findings using bioinformatics analyses.

RESULTS

Among the 358 differentially methylated positions (DMPs) that were cross-sectionally associated either with fasting glucose or HOMA-IR, 49 were prospectively associated with incident type 2 diabetes, although no DMPs remained significant after multiple comparisons correction. Multiple of the top DMPs were annotated to genes with relevant functions for diabetes including SREBF1, associated with obesity, type 2 diabetes and insulin sensitivity; ABCG1, involved in cholesterol and phospholipids transport; and HDAC1, of the HDAC family. (HDAC inhibitors have been proposed as an emerging treatment for diabetes and its complications.) CONCLUSIONS: Our results suggest that differences in peripheral blood DNA methylation are related to cross-sectional markers of glucose metabolism and insulin activity. While some of these DMPs were modestly associated with prospective incident type 2 diabetes, they did not survive multiple testing. Common DMPs with diabetes epigenome-wide association studies from other populations suggest a partially common epigenomic signature of glucose and insulin activity.

Blood cadmium, lead, manganese, mercury, and selenium levels in American Indian populations: The Strong Heart Study

BACKGROUND

Many American Indian (AI) communities are in areas affected by environmental contamination, such as toxic metals. However, studies assessing exposures in AI communities are limited. We measured blood metals in AI communities to assess historical exposure and identify participant characteristics associated with these levels in the Strong Heart Study (SHS) cohort.

METHOD

Archived blood specimens collected from participants (n = 2014, all participants were 50 years of age and older) in Arizona, Oklahoma, and North and South Dakota during SHS Phase-III (1998-1999) were analyzed for cadmium, lead, manganese, mercury, and selenium using inductively coupled plasma triple quadrupole mass spectrometry. We conducted descriptive analyses for the entire cohort and stratified by selected subgroups, including selected demographics, health behaviors, income, waist circumference, and body mass index. Bivariate associations were conducted to examine associations between blood metal levels and selected socio-demographic and behavioral covariates. Finally, multivariate regression models were used to assess the best model fit that predicted blood metal levels.

FINDINGS

All elements were detected in 100% of study participants, with the exception of mercury (detected in 73% of participants). The SHS population had higher levels of blood cadmium and manganese than the general U.S. population 50 years and older. The median blood mercury in the SHS cohort was at about 30% of the U.S. reference population, potentially due to low fish consumption. Participants in North Dakota and South Dakota had the highest blood cadmium, lead, manganese, and selenium, and the lowest total mercury levels, even after adjusting for covariates. In addition, each of the blood metals was associated with selected demographic, behavioral, income, and/or weight-related factors in multivariate models. These findings will help guide the tribes to develop education, outreach, and strategies to reduce harmful exposures and increase beneficial nutrient intake in these AI communities.

Prevalence of Diabetic Eye Diseases in American Indians and Alaska Natives (AI/AN) as Identified by the Indian Health Service's National Teleophthalmology Program Using Ultrawide Field Imaging (UWFI)

PURPOSE

Estimates of diabetic eye disease in American Indian and Alaska Natives (AI/AN) vary over time, region, and methods. This article reports recent prevalence of diabetic retinopathy (DR) and diabetic macular edema (DME) in AI/AN served by the Indian Health Services' (IHS) teleophthalmology program, as identified using ultrawide field imaging (UWFI).

METHODS

This was a retrospective analysis of 2016-2019 clinical data (n = 53,900). UWF images were acquired by certified imagers using a validated protocol, and graded by licensed, certified optometrists supervised by an ophthalmologist. Graders evaluated the extent/severity of retinal lesions in comparison to standard photographs. DR lesions predominantly in any peripheral field were considered "predominantly peripheral lesions" (PPL). The analyses calculated prevalence of any DR, any DME, DR and DME severity, sight-threatening disease, and PPL.

RESULTS

Patients averaged 56 years of age with a 68 mmol/mol A1c and 55% had had diabetes for 5+ years. Prevalence of any DR, any DME, and sight-threatening disease was 28.6%, 3.0%, and 3.0%. In patients with mild nonproliferative DR, PPL was seen in 25.3%. PPL suggested a more severe level of DR in 8.7% of patients. DR increased with age. DME decreased with age. Males and patients in the Nashville IHS area had more diabetic eye disease.

CONCLUSION

AI/AN have a high burden of diabetes and its complications. The IHS is resource-constrained, making accurate disease estimates necessary for resource allocation and budget justifications to Congress. These data update the estimates of diabetic eye disease in Indian Country and suggest that UWFI identifies early DR.

Assessing Knowledge and Perceptions About Cancer Among American Indians of the Zuni Pueblo, NM

American Indians (AIs) in New Mexico have lower cancer screening rates compared to other populations and are more likely to be diagnosed with cancer at an advanced stage of the disease as reported by Li et al. (Archives of Internal Medicine 163(1):49-56, 2003). AIs also have the lowest 5-year cancer survival rates compared to any ethnic/racial group in the USA as reported by Clegg et al. (Arch Intern Med 162:1985-1993, 2002) and Edwards et al. (Cancer 97:1407-1427, 2005). Numerous barriers such as cultural beliefs, fear, fatalism, mistrust, stigma, and lack of culturally appropriate interventions could contribute to low cancer screening rates as reported by Daley et al. (J Health Dispar Res Pract 5(2), 2012); Filippi et al. (J Prim Care Community Health 4(3):160-166, 2013); James et al. (Prev Chronic Dis 10:E170, 2013); and Schumacher et al. (Cancer Causes Control 19(7):725-737, 2008). Trained Community Health Representatives (CHRs) from the Zuni Pueblo and native Zuni undergraduate students led six 1-h focus group sessions using a structured focus group guide with probes. The focus groups were conducted among 51 participants from different age groups (20-29 years, n = 19; 30-49 years, n = 17; and 50 years and older, n = 15) stratified by sex. Focus groups were conducted in both English and Shiwi (Zuni) languages. Sessions were audio recorded, and team members took notes. CHRs transcribed the notes and audio recordings, and created a codebook for qualitative data analysis. In the focus groups, participants provided Zuni-specific cultural context, opinion, and experience regarding (1) general knowledge about cancer, (2) cancer risk, (3) cancer risk reduction, (4) personal experiences with cancer, and (5) culturally competent delivery of cancer information and resources. Understanding the perceptions of cancer within the Zuni Pueblo is an essential component in the development of interventional/preventative measures and improvement of current care. Ultimately, this information will provide a basis for the next steps in culturally sensitive cancer care for the Zuni Pueblo.

High Level of Selenium Exposure in the Strong Heart Study: A Cause for Incident Cardiovascular Disease?

Increasing evidence suggests that high selenium (Se) exposure is associated with adverse health effects. However, limited evidence exists on the association of Se exposure with cardiovascular disease (CVD), especially in communities affected by high naturally occurring Se in environmental media. We evaluated the prospective association between urinary Se levels and CVD incidence and mortality for 2727 American Indian adults who participated in the Strong Heart Study, with urinary Se levels measured at baseline (1989-1991) and CVD outcomes ascertained through 2017. The median (interquartile range) of urinary Se was 49.0 (36.7-67.4) μg/g creatinine. The multivariable adjusted hazard ratios (95% confidence interval) of incident CVD, coronary heart disease, and stroke comparing the 75th versus 25th percentile of urinary Se distributions were 1.11 (1.01-1.22), 1.05 (0.94-1.17), and 1.08 (0.88-1.33), respectively. In flexible dose-response models, increased risk for CVD incidence was only observed when the urinary Se level exceeded 60 μg/g creatinine. For CVD mortality, a nonstatistically significant U-shaped relationship was found across urinary Se levels. There was no evidence of effect modification by other urinary metal/metalloid levels. Our observation leads to the hypothesis that elevated Se exposure is a risk factor for CVD, especially in Se-replete populations. Antioxid. Redox Signal. 37, 990-997.

Lipidomic profiling in the Strong Heart Study identified American Indians at risk of chronic kidney disease

Dyslipidemia associates with and usually precedes the onset of chronic kidney disease (CKD), but a comprehensive assessment of molecular lipid species associated with risk of CKD is lacking. Here, we sought to identify fasting plasma lipids associated with risk of CKD among American Indians in the Strong Heart Family Study, a large-scale community-dwelling of individuals, followed by replication in Mexican Americans from the San Antonio Family Heart Study and Caucasians from the Australian Diabetes, Obesity and Lifestyle Study. We also performed repeated measurement analysis to examine the temporal relationship between the change in the lipidome and change in kidney function between baseline and follow-up of about five years apart. Network analysis was conducted to identify differential lipid classes associated with risk of CKD. In the discovery cohort, we found that higher baseline level of multiple lipid species, including glycerophospholipids, glycerolipids and sphingolipids, was significantly associated with increased risk of CKD, independent of age, sex, body mass index, diabetes and hypertension. Many lipid species were replicated in at least one external cohort at the individual lipid species and/or the class level. Longitudinal change in the plasma lipidome was significantly associated with change in the estimated glomerular filtration rate after adjusting for covariates, baseline lipids and the baseline rate. Network analysis identified distinct lipidomic signatures differentiating high from low-risk groups. Thus, our results demonstrated that disturbed lipid metabolism precedes the onset of CKD. These findings shed light on the mechanisms linking dyslipidemia to CKD and provide potential novel biomarkers for identifying individuals with early impaired kidney function at preclinical stages.

Lipidomics profiling of biological aging in American Indians: the Strong Heart Family Study

Telomeres shorten with age and shorter leukocyte telomere length (LTL) has been associated with various age-related diseases. Thus, LTL has been considered a biomarker of biological aging. Dyslipidemia is an established risk factor for most age-related metabolic disorders. However, little is known about the relationship between LTL and dyslipidemia. Lipidomics is a new biochemical technique that can simultaneously identify and quantify hundreds to thousands of small molecular lipid species. In a large population comprising 1843 well-characterized American Indians in the Strong Heart Family Study, we examined the lipidomic profile of biological aging assessed by LTL. Briefly, LTL was quantified by qPCR. Fasting plasma lipids were quantified by untargeted liquid chromatography-mass spectrometry. Lipids associated with LTL were identified by elastic net modeling. Of 1542 molecular lipids identified (518 known, 1024 unknown), 174 lipids (36 knowns) were significantly associated with LTL, independent of chronological age, sex, BMI, hypertension, diabetes status, smoking status, bulk HDL-C, and LDL-C. These findings suggest that altered lipid metabolism is associated with biological aging and provide novel insights that may enhance our understanding of the relationship between dyslipidemia, biological aging, and age-related diseases in American Indians.

The Otago Exercise Program compared to falls prevention education in Zuni elders: a randomized controlled trial

BACKGROUND

When a Zuni elder sustains a fall-related injury, the closest tribal skilled nursing facility is 100 miles from the Pueblo and no physical therapy services are available. Thus, fall prevention strategies as a primary intervention to avert injurious falls and preserve aging in place are needed. The objective of the study is to compare the effectiveness of a community health representative (CHR)-delivered, culturally-adapted Otago Exercise Program (OEP) fall prevention program compared to the standard of care education-based fall risk management.

METHODS

"Standing Strong in Tribal Communities: Assessing Elder Falls Disparity" is mixed-methods research with a randomized controlled trial. The CHRs will be trained to deliver the culturally-adapted OEP trial and offer advantages of speaking "Shiwi" (Zuni tribal language) and understanding Zuni traditions, family structures, and elders' preferences for receiving health information. Focus groups will be conducted to assure all materials are culturally appropriate, and adapted. A physical therapist will train CHRs to screen elders for falls risk and to deliver the OEP to the intervention group and education to the control group. Up to 400 Zuni elders will be screened by the CHRs for falls risk and 200 elders will be enrolled into the study (1:1 random allocation by household). The intervention is 6 months with measurements at baseline, 3, 6 and 12 months. The primary outcome is improved strength and balance (timed up and go, sit to stand and 4 stage balance test), secondary outcomes include falls incidence, self-efficacy using Attitudes to Falls-Related Interventions Scale, Medical Outcomes Study Short Form 12 (SF-12v2) and Self-Efficacy for Managing Daily Activities.

DISCUSSION

Fall prevention for Zuni elders was identified as a tribal priority and this trial is built upon longstanding collaborations between the investigative team, Zuni tribal leaders, and multiple tribal health programs. Delivery by the CHRs make this model more acceptable, and thus, more sustainable long term. This study has the potential to change best practice for elder care in tribal and rural areas with limited access to physical therapist-delivered fall prevention interventions and aligns with tribal goals to avert fall-related injury, reduce healthcare disparity, and preserve elder's independence.

TRIAL REGISTRATION

NCT04876729.

Traditions and Connections for Urban Native Americans (TACUNA): Utilizing community-based input to develop an opioid prevention intervention for urban American Indian/Alaska Native emerging adults

INTRODUCTION

Although approximately 70% of American Indian/Alaska Native (AI/AN) people reside in urban areas, very few opioid prevention interventions exist for urban AI/AN emerging adults. The study team conducted this study to develop Traditions and Connections for Urban Native Americans (TACUNA), a new opioid prevention intervention for urban AI/AN emerging adults ages 18-25. TACUNA comprises three 2-hour virtual workshops.

METHODS

We conducted thirteen focus groups in three urban communities in northern, central, and southern California (six with urban AI/AN emerging adults ages 18-25 [n = 32], four with parents [n = 26], and three with providers [n = 33]) to identify relevant intervention domains. We then incorporated the results of a rapid analysis of the focus groups to develop intervention workshops followed by a pilot test (n = 15) to further refine the intervention and assess feasibility.

RESULTS

Four major domains emerged from focus groups: 1) historical trauma/cultural identity, 2) AI/AN traditional practices, 3) social networks, and 4) substance use. We incorporated all feedback relating to each theme to enhance content of the TACUNA intervention. Pilot test participants felt that TACUNA content was interesting, addressed their issues and concerns as urban AI/AN emerging adults, and believed that the program could help them to establish cultural and social connections to live healthier lives.

CONCLUSIONS

Research activities demonstrate how a community-informed and culturally grounded opioid prevention intervention can be developed for urban AI/AN emerging adults. Addressing issues and challenges with culturally and developmentally relevant intervention content can help to build resilience and hopefully decrease opioid use among this underserved population.

Factors Associated with Cancer Screening Among Hopi Men

Cancer screening rates remain low among American Indian men, and cancer screening behaviors and barriers to cancer screening among American Indian men are not well understood. This study evaluated cancer screening behaviors in 102 Hopi men who were 50 years of age or older from the Hopi Survey of Cancer and Chronic Disease. Reported cancer screening frequencies were 15.7%, 45.1%, and 35.3% for fecal occult blood test (FOBT), colonoscopy, and prostate-specific antigen (PSA) test, respectively. Among men who reported having had a FOBT, 81.2% had the test more than 1 year ago. Among men who reported a colonoscopy, 60.8% had colonoscopy within the past 3 years. Similarly, among men who reported having had PSA, 72.3% had PSA within the past 3 years. "No one told me" was the most common answer for not undergoing FOBT (33.7%), colonoscopy (48.2%), and PSA (39.4%). Men who reported having had a PSA or digital rectal exam were three times as likely to also report having a FOBT or colonoscopy (odds ratio [OR] 3.19, 95% confidence interval [CI]: 1.21-8.46). Younger age (< 65) was associated with reduced odds of ever having prostate cancer screening (OR 0.28, 95% CI: 0.10-0.77). Ever having colorectal cancer screening and previous diagnosis of cancer increased odds of ever having prostate cancer screening (OR 3.15, 95% CI: 1.13-8.81 and OR 5.28, 95% CI: 1.15-24.18 respectively). This study illustrates the importance of community cancer education for men to improve cancer screening participation.

The clinical course of antisocial behaviors in men and women of three racial groups

AIMS

To describe the clinical course and symptom profile of DSM-IV Antisocial Personality Disorder (ASPD) and the syndrome of Adult Antisocial Behavior Syndrome (AABS) and determine if they differ based on sex and race.

METHODS

Using questions from a validated semi-structured interview, data were gathered from 2 independent family studies in: 1) American Indians (AI), and 2) European Americans (EA), African Americans (AA) (total n = 7171) who reported antisocial symptoms.

RESULTS

Within these two samples 1148 (16%) individuals met ASPD criteria, 1932 (27%) met adult ASPD but not childhood conduct disorder (CD) (i.e., AABS). The clinical course of the antisocial behaviors studied did not differ based on race or sex; however, individual symptom counts, and age of onsets of those symptoms, were significantly different across the groups. Women reported fewer symptoms and at an older age (less fights, school suspensions/expulsions, arrests or jail time), than men but were more likely to run away from home. Those with ASPD vs. AABS had more symptoms overall including not experiencing remorse. AA and AI participants and those with ASPD, had more symptoms, and were more likely to be suspended/expelled from school and arrested at a younger age than EA.

CONCLUSION

In these select samples, the order and sequence of antisocial behaviors did not differ by race, AASB vs. ASPD, or sex; however individual symptom endorsement did, with men (vs. women), those with ASPD (vs. AABS), AI and AA (vs. EA) reporting more suspensions/expulsions from school and arrests. This suggests further study of the possible role of race and sex in the consequences associated with antisocial syndromes is warranted.

Racial and Health Disparities among Cirrhosis-related Hospitalizations in the USA

BACKGROUND AND AIMS

Alcohol-associated liver disease (ALD) is the most common cause of advanced liver disease worldwide, including in the USA. Alcohol use and cirrhosis mortality is higher in American Indian/Alaska Native (AI/AN) compared to Whites. Data are scanty on ALD as a liver disease etiology in AI/AN compared to other races and ethnicities.

METHODS

The National Inpatient Sample on 199,748 cirrhosis-related hospitalizations, 14,241 (2,893 AI/AN, 2,893 Whites, 2,882 Blacks, 2,879 Hispanics, and 2,694 Asians or other races) matched 1:1 for race/ethnicity on demographics, insurance, and income quartile of the residence zip code analyzed.

RESULTS

After controlling for geographic location and hospital type, odds ratio (OR) and 95% confidence interval (CI) for ALD as cirrhosis etiology was higher among admissions in AI/AN vs. Whites [1.55 (1.37-1.75)], vs. Blacks [1.87 (1.65-2.11)], vs. Hispanic [1.89 (1.68-2.13)] and Asians/other races [2.24 (1.98-2.53)]. OR was also higher for AI/AN vs. all other races for alcohol-associated hepatitis (AH) as one of the discharge diagnoses. The findings were similar in a subgroup of 4,649 admissions with decompensated cirrhosis and in a cohort of 350 admissions with acute-on-chronic liver failure as defined by EASL-CLIF criteria. Alcohol use disorder diagnosis was present in 38% of admissions in AI/AN vs. 24-30% in other races, p<0.001. A total of 838 (5.9%) admissions were associated with in-hospital mortality. OR (95% CI) for in-hospital mortality in AI/AN individuals was 34% reduced vs. Blacks [0.66 (0.51-0.84)], but no difference was observed on comparison with other races.

CONCLUSIONS

ALD, including AH, is the most common etiology among cirrhosis-related hospitalizations in the USA among AI/AN individuals. In-hospital mortality was observed in about 6% of admissions, which was higher for Blacks and similar in other races compared to admissions for AI/AN. Public health policies should be implemented to reduce the burden of advanced ALD among AI/AN individuals.

An epigenome-wide study of DNA methylation profiles and lung function among American Indians in the Strong Heart Study

BACKGROUND

Epigenetic modifications, including DNA methylation (DNAm), are often related to environmental exposures, and are increasingly recognized as key processes in the pathogenesis of chronic lung disease. American Indian communities have a high burden of lung disease compared to the national average. The objective of this study was to investigate the association of DNAm and lung function in the Strong Heart Study (SHS). We conducted a cross-sectional study of American Indian adults, 45-74 years of age who participated in the SHS. DNAm was measured using the Illumina Infinium Human MethylationEPIC platform at baseline (1989-1991). Lung function was measured via spirometry, including forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC), at visit 2 (1993-1995). Airflow limitation was defined as FEV1 < 70% predicted and FEV1/FVC < 0.7, restriction was defined as FEV1/FVC > 0.7 and FVC < 80% predicted, and normal spirometry was defined as FEV1/FVC > 0.7, FEV1 > 70% predicted, FVC > 80% predicted. We used elastic-net models to select relevant CpGs for lung function and spirometry-defined lung disease. We also conducted bioinformatic analyses to evaluate the biological plausibility of the findings.

RESULTS

Among 1677 participants, 21.2% had spirometry-defined airflow limitation and 13.6% had spirometry-defined restrictive pattern lung function. Elastic-net models selected 1118 Differentially Methylated Positions (DMPs) as predictors of airflow limitation and 1385 for restrictive pattern lung function. A total of 12 DMPs overlapped between airflow limitation and restrictive pattern. EGFR, MAPK1 and PRPF8 genes were the most connected nodes in the protein-protein interaction network. Many of the DMPs targeted genes with biological roles related to lung function such as protein kinases.

CONCLUSION

We found multiple differentially methylated CpG sites associated with chronic lung disease. These signals could contribute to better understand molecular mechanisms involved in lung disease, as assessed systemically, as well as to identify patterns that could be useful for diagnostic purposes. Further experimental and longitudinal studies are needed to assess whether DNA methylation has a causal role in lung disease.