Cardiovascular disease risk factors among American Indians. The Strong Heart Study

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.

Arsenic Exposure and Epigenetic Aging: The Association with Cardiovascular Disease and All-Cause Mortality in the Strong Heart Study

BACKGROUND

Inorganic arsenic (As) may increase the risk of cardiovascular disease (CVD) and all-cause mortality through accelerated aging, which can be estimated using epigenetic-based measures.

OBJECTIVES

We evaluated three DNA methylation-based aging measures (PhenoAge, GrimAge, DunedinPACE) (epigenetic aging measures) as potential mediators of the previously reported association of As exposure with CVD incidence, CVD mortality, and all-cause mortality in the Strong Heart Study (SHS), an epidemiological cohort of American Indian adults.

METHODS

Blood DNA methylation and urinary As levels were measured in 2,323 SHS participants (41.5% men, mean age of 55 years old). PhenoAge and GrimAge values were calculated using a residual-based method. We tested the association of urinary As with epigenetic aging measures using linear regression, the association of epigenetic aging measures with the three health outcomes using additive hazards models, and the mediation of As-related CVD incidence, CVD mortality, and all-cause mortality by epigenetic aging measures using the product of coefficients method.

RESULTS

SHS participants with higher vs. lower urinary As levels had similar PhenoAge age, older GrimAge age, and faster DunedinPACE. An interquartile range increase in urinary As was associated with higher of PhenoAge age acceleration [mean difference  ( 95 %  confidence interval ) = 0.48 (0.17, 0.80) years], GrimAge age acceleration [0.80 (0.60, 1.00) years], and DunedinPACE [0.011 (0.005, 0.018)], after adjusting for age, sex, center location, genetic components, smoking status, and body mass index. Of the 347 incident CVD events per 100,000 person-years associated with a doubling in As exposure, 21.3% (9.1, 57.1) and 22.6% (9.5, 56.9), were attributable to differences in GrimAge and DunedinPACE, respectively.

DISCUSSION

Arsenic exposure was associated with older GrimAge and faster DunedinPACE measures of biological age. Furthermore, accelerated biological aging measured from DNA methylation accounted for a relevant fraction of As-associated risk for CVD, CVD mortality, and all-cause mortality in the SHS, supporting the role of As in accelerated aging. Research of the biological underpinnings can contribute to a better understanding of the role of aging in arsenic-related disease. https://doi.org/10.1289/EHP11981.

Nutritional Avocado Intervention Improves Physical Activity Measures in Hispanic/Latino Families: A Cluster RCT

Introduction

Nutrition and physical activity are key components for the prevention of cardiovascular disease. There remains a paucity of trial data on the effect of specific nutritional interventions on physical activity and sedentary time. One question is how a common nutrient-dense food such as avocado may impact physical activity and sedentary time in Hispanic/Latino families, a group that reports the lowest levels of physical activity.

Design

This is a 6-month clustered RCT.

Setting/participants

Seventy-two families (235 individuals) who identified as Hispanic/Latino were enrolled through the San Ysidro Health Center (San Diego, CA) between April 2017 and June 2018.

Intervention

After a 2-week run-in period, 35 families were randomized to the intervention arm (14 avocados/family/week), and 37 families were assigned to the control arm (3 avocados/family/week).

Main outcome measures

Linear mixed-effects models were used to assess changes in physical activity (MET minutes per week) between the groups during the 6-month trial. Secondary outcomes included sedentary time (minutes/week), BMI, and systolic and diastolic blood pressures.

Results

An adherence goal of >80% was achieved for both arms. Total mean physical activity increased by 2,197 MET minutes per week more in the intervention group (p<0.01) than in the control group, driven by between-group differences in moderate (p<0.01) versus vigorous (p=0.06) physical activity. After accounting for longitudinal repeated measures per participant and nested family effects, total adult physical activity remained significantly higher in the intervention than in the control group (+1,163 MET minutes per week on average per participant), with a significant intervention interaction term (p<0.01). There were no significant changes in sedentary time, BMI, or blood pressure.

Conclusions

Higher allocation of avocados was associated with significantly higher physical activity and no adverse changes in BMI or blood pressure, suggesting that this nutritional intervention may have beneficial pleiotropic effects.Trial registration: This study is registered at www.clinicaltrials.gov as NCT02903433.

Cardiometabolic risk among rural Native American adults in a large multilevel multicomponent intervention trial

This cross-sectional analysis of the baseline evaluation sample of the Obesity Prevention and Evaluation of InterVention Effectiveness in Native Americans 2 (OPREVENT2) study included 601 Native American adults ages 18-75 living in rural reservation communities in the Midwest and Southwest United States. Participants completed a self-report questionnaire for individual and family history of hypertension, heart disease, diabetes and obestiy. Body mass index (BMI), percent body fat, and blood pressure were measured by trained research staff. About 60% of respondents had a BMI >30 kg/m2. Approximately 80% had a waist-to-hip ratio and percent body fat classified as high risk, and nearly 64% had a high-risk blood pressure measurement. Although a large proportion of participants reported a family history of chronic disease and had measurements that indicated elevated risk, relatively few had a self-reported diagnosis of any chronic disease. Future studies should examine potential connections between healthcare access and discordance in self-reported versus measured disease risks and diagnoses.

Plasma lipidomic profile of depressive symptoms: a longitudinal study in a large sample of community-dwelling American Indians in the strong heart study

Dyslipidemia has been associated with depression, but individual lipid species associated with depression remain largely unknown. The temporal relationship between lipid metabolism and the development of depression also remains to be determined. We studied 3721 fasting plasma samples from 1978 American Indians attending two exams (2001-2003, 2006-2009, mean ~5.5 years apart) in the Strong Heart Family Study. Plasma lipids were repeatedly measured by untargeted liquid chromatography-mass spectrometry (LC-MS). Depressive symptoms were assessed using the 20-item Center for Epidemiologic Studies for Depression (CES-D). Participants at risk for depression were defined as total CES-D score ≥16. Generalized estimating equation (GEE) was used to examine the associations of lipid species with incident or prevalent depression, adjusting for covariates. The associations between changes in lipids and changes in depressive symptoms were additionally adjusted for baseline lipids. We found that lower levels of sphingomyelins and glycerophospholipids and higher level of lysophospholipids were significantly associated with incident and/or prevalent depression. Changes in sphingomyelins, glycerophospholipids, acylcarnitines, fatty acids and triacylglycerols were associated with changes in depressive symptoms and other psychosomatic traits. We also identified differential lipid networks associated with risk of depression. The observed alterations in lipid metabolism may affect depression through increasing the activities of acid sphingomyelinase and phospholipase A2, disturbing neurotransmitters and membrane signaling, enhancing inflammation, oxidative stress, and lipid peroxidation, and/or affecting energy storage in lipid droplets or membrane formation. These findings illuminate the mechanisms through which dyslipidemia may contribute to depression and provide initial evidence for targeting lipid metabolism in developing preventive and therapeutic interventions for depression.

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.

American Indians and atrial fibrillation

The American Indian population is known to experience high rates of cardiovascular disease and have a heightened vulnerability to severe outcomes driven by an overall poor health status and lower access to quality health care. Our group has previously published an analysis demonstrating that American Indians have the highest risk of atrial fibrillation (AF), as well as of AF-related stroke, when compared with other races and ethnicities. Despite this, AF in this population has not been extensively studied and additional publications are scarce. Our review article provides an up-to-date summary of the relevant literature addressing the relationship between race, ethnicity, and AF by focusing on American Indians.

Epigenetic Biomarkers of Lead Exposure and Cardiovascular Disease: Prospective Evidence in the Strong Heart Study

Background Lead is a cardiotoxic metal with a variety of adverse health effects. In the absence of data on bone lead exposure, epigenetic biomarkers can serve as indicators of cumulative lead exposure and body burden. Herein, we leveraged novel epigenetic biomarkers of lead exposure to investigate their association with cardiovascular disease (CVD) incidence and mortality. Methods and Results Blood DNA methylation was measured using the Illumina MethylationEPIC BeadChip among 2231 participants of the Strong Heart Study (SHS) at baseline (1989-1991). Epigenetic biomarkers of lead levels in blood, patella, and tibia were estimated using previously identified cytosine-guanine dinucleotide (CpG) sites. CVD incidence and mortality data were available through 2017. Median concentrations of lead epigenetic biomarkers were 13.8 μg/g, 21.3 μg/g, and 2.9 μg/dL in tibia, patella, and blood, respectively. In adjusted models, the hazard ratio (HR) (95% CI) of CVD mortality per doubling increase in lead epigenetic biomarkers were 1.42 (1.07-1.87) for tibia lead, 1.22 (0.93-1.60) for patella lead, and 1.57 (1.16-2.11) for blood lead. The corresponding HRs for incident CVD were 0.99 (0.83-1.19), 1.07 (0.89-1.29), and 1.06 (0.87-1.30). The association between the tibia lead epigenetic biomarker and CVD mortality was modified by sex (interaction P value: 0.014), with men at increased risk (HR, 1.42 [95% CI, 1.17-1.72]) compared with women (HR, 1.04 [95% CI, 0.89-1.22]). Conclusions Tibia and blood epigenetic biomarkers were associated with increased risk of CVD mortality, potentially reflecting the cardiovascular impact of cumulative and recent lead exposures. These findings support that epigenetic biomarkers of lead exposure may capture some of the disease risk associated with lead exposure.

Are Cardiometabolic Markers of Allostatic Load Associated With Pronociceptive Processes in Native Americans?: A Structural Equation Modeling Analysis From the Oklahoma Study of Native American Pain Risk

Native Americans (NAs) experience higher rates of chronic pain than the general U.S. population, but the risk factors for this pain disparity are unknown. NAs also experience high rates of stressors and cardiovascular and metabolic health disparities (eg, diabetes, cardiovascular disease) consistent with allostatic load (stress-related wear-and-tear on homeostatic systems). Given that allostatic load is associated with chronic pain, then allostatic load may contribute to their pain disparity. Data from 302 healthy, pain-free men and women (153 NAs, 149 non-Hispanic Whites [NHW]) were analyzed using structural equation modeling to determine whether cardiometabolic allostatic load (body mass index, blood pressure, heart rate variability) mediated the relationship between NA ethnicity and experimental measures of pronociceptive processes: temporal summation of pain (TS-pain) and the nociceptive flexion reflex (TS-NFR), conditioned pain modulation of pain (CPM-pain) and NFR (CPM-NFR), and pain tolerance. Results indicated that NAs experienced greater cardiometabolic allostatic load that was related to enhanced TS-NFR and impaired CPM-NFR. Cardiometabolic allostatic load was unrelated to measures of pain perception (CPM-pain, TS-pain, pain sensitivity). This suggests cardiometabolic allostatic load may promote spinal sensitization in healthy NAs, that is not concomitant with pain sensitization, perhaps representing a unique pain risk phenotype in NAs. PERSPECTIVE: Healthy, pain-free Native Americans experienced greater cardiometabolic allostatic load that was associated with a pronociceptive pain phenotype indicative of latent spinal sensitization (ie, spinal sensitization not associated with hyperalgesia). This latent spinal sensitization could represent a pain risk phenotype for this population.

Cancer mortality in a population-based cohort of American Indians - The strong heart study

BACKGROUND

Cancer mortality among American Indian (AI) people varies widely, but factors associated with cancer mortality are infrequently assessed.

METHODS

Cancer deaths were identified from death certificate data for 3516 participants of the Strong Heart Study, a population-based cohort study of AI adults ages 45-74 years in Arizona, Oklahoma, and North and South Dakota. Cancer mortality was calculated by age, sex and region. Cox proportional hazards model was used to assess independent associations between baseline factors in 1989 and cancer death by 2010.

RESULTS

After a median follow-up of 15.3 years, the cancer death rate per 1000 person-years was 6.33 (95 % CI 5.67-7.04). Cancer mortality was highest among men in North/South Dakota (8.18; 95 % CI 6.46-10.23) and lowest among women in Arizona (4.57; 95 % CI 2.87-6.92). Factors independently associated with increased cancer mortality included age, current or former smoking, waist circumference, albuminuria, urinary cadmium, and prior cancer history. Factors associated with decreased cancer mortality included Oklahoma compared to Dakota residence, higher body mass index and total cholesterol. Sex was not associated with cancer mortality. Lung cancer was the leading cause of cancer mortality overall (1.56/1000 person-years), but no lung cancer deaths occurred among Arizona participants. Mortality from unspecified cancer was relatively high (0.48/100 person-years; 95 % CI 0.32-0.71).

CONCLUSIONS

Regional variation in AI cancer mortality persisted despite adjustment for individual risk factors. Mortality from unspecified cancer was high. Better understanding of regional differences in cancer mortality, and better classification of cancer deaths, will help healthcare programs address cancer in AI communities.

Incident Strokes Among American Indian Individuals With Atrial Fibrillation

BACKGROUND

American Indian individuals experience a relatively high risk for cardiovascular disease and have exhibited a higher risk of stroke compared with other racial and ethnic minorities. Although this population has the highest incidence of atrial fibrillation (AF) compared with other groups, the relationship between AF and nonhemorrhagic stroke among American Indian individuals compared with other groups has not been thoroughly studied.

METHODS and RESULTS

We used the Healthcare Cost and Utilization Project to evaluate risk of nonhemorrhagic stroke among American Indian individuals, with comparisons to White, Black, Hispanic, and Asian individuals, among all adult California residents receiving care in an emergency department, inpatient hospital unit, or ambulatory surgery setting from 2005 to 2011. Of 16 951 579 patients followed for a median 4.1 years, 105 822 (0.6%) were American Indian. After adjusting for age, sex, income level, insurance payer, hypertension, diabetes mellitus, coronary artery disease, congestive heart failure, cardiac surgery, valvular heart disease, chronic kidney disease, smoking, obstructive sleep apnea, pulmonary disease, and alcohol use, American Indian individuals with AF exhibited the highest risk of nonhemorrhagic stroke when compared with either non‐American Indian individuals with AF (hazard ratio, 1.38; 95% CI, 1.23–1.55; P<0.0001) or to each race and ethnicity with AF. American Indian individuals also experienced the highest overall risk for stroke, with no evidence that AF disproportionately heightened that risk in interaction analyses.

CONCLUSIONS

American Indian individuals experienced the highest risk of nonhemorrhagic stroke, whether in the presence or absence of AF. Our findings likely suggest an opportunity to further study, if not immediately address, guideline‐adherent anticoagulation prescribing patterns among American Indian individuals with AF.

American Indian Alcohol Use from a Sex-Specific Wellness Approach: Exploring Its Associated Physical, Behavioral, and Mental Risk and Protective Factors

PURPOSE

The top causes of death for American Indians (AIs), including heart and liver disease, are associated with alcohol use. Using the culturally based Framework of Historical Oppression, Resilience, and Transcendence (FHORT), the purpose of this article was to examine AI alcohol use from a sex-specific wellness approach, exploring its associated physical, behavioral, and mental risk and protective factors.

METHOD

Data were drawn from a cross-sectional survey with 479 AI adults in South Dakota. We employed a series of multiple hierarchical regression analyses to assess the associations of demographic (sex, age, marital status, income, and educational attainment), physical (Body Mass Index and cardiovascular risk), behavioral (smoking and health self-efficacy) and mental (depressive symptoms) factors with alcohol use.

RESULTS

Results indicated that surveyed males tended to drink three times that of females, and depressive symptoms were associated with higher levels of alcohol use.

DISCUSSION

This study highlights the need to examine AI alcohol use with sex in mind.

Associations of Binge Drinking With Vascular Brain Injury and Atrophy in Older American Indians: The Strong Heart Study

Objectives: American Indians (AIs) generally consume less alcohol than the US general population; however, the prevalence of alcohol use disorder is higher. This is the first large cohort study to examine binge drinking as a risk factor for vascular brain injury (VBI). Methods: We used linear and Poisson regression to examine the association of self-reported binge drinking with VBI, measured via magnetic resonance imaging (MRI), in 817 older AIs who participated in the Strong Heart and Cerebrovascular Disease and Its Consequences in American Indians studies. Results: Any binge drinking at multiple time-points was associated with increased sulcal (β = 0.360, 95% CI [0.079, 0.641]) and ventricle dilatation (β = 0.512, 95% CI [0.174, 0.850]) compared to no binge drinking. Discussion: These observed associations are consistent with previous findings. Identifying how binge drinking may contribute to VBI in older AIs may suggest modifiable health behaviors for neurological risk reduction and disease prevention.

Systemic Disease and Ocular Comorbidity Analysis of Geographically Isolated Federally Recognized American Indian Tribes of the Intermountain West

BACKGROUND

The American Indian Navajo and Goshute peoples are underserved patient populations residing in the Four Corners area of the United States and Ibupah, Utah, respectively.

METHODS

We conducted a cross-sectional study of epidemiological factors and lipid biomarkers that may be associated with type II diabetes, hypertension and retinal manifestations in tribal and non-tribal members in the study areas (n = 146 participants). We performed multivariate analyses to determine which, if any, risk factors were unique at the tribal level. Fundus photos and epidemiological data through standardized questionnaires were collected. Blood samples were collected to analyze lipid biomarkers. Univariate analyses were conducted and statistically significant factors at p < 0.10 were entered into a multivariate regression.

RESULTS

Of 51 participants for whom phenotyping was available, from the Four Corners region, 31 had type II diabetes (DM), 26 had hypertension and 6 had diabetic retinopathy (DR). Of the 64 participants from Ibupah with phenotyping available, 20 had diabetes, 19 had hypertension and 6 had DR. Navajo participants were less likely to have any type of retinopathy as compared to Goshute participants (odds ratio (OR) = 0.059; 95% confidence interval (CI) = 0.016-0.223; p < 0.001). Associations were found between diabetes and hypertension in both populations. Older age was associated with hypertension in the Four Corners, and the Navajo that reside there on the reservation, but not within the Goshute and Ibupah populations. Combining both the Ibupah, Utah and Four Corners study populations, being American Indian (p = 0.022), residing in the Four Corners (p = 0.027) and having hypertension (p < 0.001) increased the risk of DM. DM (p < 0.001) and age (p = 0.002) were significantly associated with hypertension in both populations examined. When retinopathy was evaluated for both populations combined, hypertension (p = 0.037) and living in Ibupah (p < 0.001) were associated with greater risk of retinopathy. When combining both American Indian populations from the Four Corners and Ibupah, those with hypertension were more likely to have DM (p < 0.001). No lipid biomarkers were found to be significantly associated with any disease state.

CONCLUSIONS

We found different comorbid factors with retinal disease outcome between the two tribes that reside within the Intermountain West. This is indicated by the association of tribe and with the type of retinopathy outcome when we combined the populations of American Indians. Overall, the Navajo peoples and the Four Corners had a higher prevalence of chronic disease that included diabetes and hypertension than the Goshutes and Ibupah. To the best of our knowledge, this is the first study to conduct an analysis for disease outcomes exclusively including the Navajo and Goshute tribe of the Intermountain West.

Whole blood viscosity in microvascular angina and coronary artery disease: Significance and utility

INTRODUCTION AND OBJECTIVES

Whole blood viscosity (WBV) is the intrinsic resistance of blood flow in vessels, and when elevated induces endothelial shear stress and endothelial inflammation and can accelerate the atherosclerotic process. This study aims to compare WBV levels in patients with microvascular angina (MVA), patients with coronary artery disease (CAD), and normal controls, and to identify the relationship between WBV and high-sensitivity C-reactive protein as a marker of inflammation in MVA and CAD.

METHODS

A total of 573 patients were studied. The MVA group consisted of 189 subjects, the CAD group consisted of 203 subjects, and the control group consisted of 181 age- and gender-matched individuals. WBV was calculated from hematocrit and plasma protein concentration at a low shear rate (0.5 s^-1) and high shear rate (208 s^-1) by a validated equation.

RESULTS

Patients with CAD and MVA had significantly higher WBV at both low and high shear rates compared to the control group. Correlation analysis revealed a significant relationship between high-sensitivity C-reactive protein and WBV at low (r=0.556; p<0.001) and high shear rates (r=0.562) in the CAD group and at low (r=0.475) and high shear rates (r=0.493) in the MVA group.

CONCLUSIONS

Overall, this study demonstrated a significant and independent association between blood viscosity and the existence of endothelial inflammation and the atherosclerotic process.

Assessing peripheral fibers, pain sensitivity, central sensitization, and descending inhibition in Native Americans: main findings from the Oklahoma Study of Native American Pain Risk

Native Americans (NAs) have a higher prevalence of chronic pain than other U.S. racial/ethnic groups, but there have been few attempts to understand the mechanisms of this pain disparity. This study used a comprehensive battery of laboratory tasks to assess peripheral fiber function (cool/warm detection thresholds), pain sensitivity (eg, thresholds/tolerances), central sensitization (eg, temporal summation), and pain inhibition (conditioned pain modulation) in healthy, pain-free adults (N = 155 NAs, N = 150 non-Hispanic Whites [NHWs]). Multiple pain stimulus modalities were used (eg, cold, heat, pressure, ischemic, and electric), and subjective (eg, pain ratings and pain tolerance) and physiological (eg, nociceptive flexion reflex) outcomes were measured. There were no group differences on any measure, except that NAs had lower cold-pressor pain thresholds and tolerances, indicating greater pain sensitivity than NHWs. These findings suggest that there are no group differences between healthy NAs and NHWs on peripheral fiber function, central sensitization, or central pain inhibition, but NAs may have greater sensitivity to cold pain. Future studies are needed to examine potential within-group factors that might contribute to NA pain risk.

Food Diversity and Indigenous Food Systems to Combat Diet-Linked Chronic Diseases

Improving food and nutritional diversity based on the diversity of traditional plant-based foods is an important dietary strategy to address the challenges of rapidly emerging diet- and lifestyle-linked noncommunicable chronic diseases (NCDs) of indigenous communities worldwide. Restoration of native ecosystems, revival of traditional food crop cultivation, and revival of traditional knowledge of food preparation, processing, and preservation are important steps to build dietary support strategies against an NCD epidemic of contemporary indigenous communities. Recent studies have indicated that many traditional plant-based foods of Native Americans provide a rich source of human health-relevant bioactive compounds with diverse health benefits. Based on this rationale of health benefits of traditional plant-based foods, the objective of this review is to present a state-of-the-art comprehensive framework for ecologically and culturally relevant sustainable strategies to restore and integrate the traditional plant food diversity of Native Americans to address the NCD challenges of indigenous and wider nonindigenous communities worldwide.

Mental Health of the Participants of the Third Age University Program: A Cross-Sectional Study

INTRODUCTION

Population aging is a progressive demographic phenomenon observed in all countries worldwide. The progressive global process of population aging poses many threats, especially in the context of the mental health of the elderly. Third Age Universities are an essential preventive measure shown to improve the quality of life and psychological wellbeing of the elderly.

OBJECTIVES

The aim of this study was to analyze the mental status of older persons attending Third Age Universities in Poland, with particular emphasis on sociodemographic sources of variance in psychological indices.

METHODS

The study included a group of the Third Age University program participants from Poland. A total of 247 persons were enrolled, among them 215 women and 32 men. The study was carried out as a diagnostic survey, using the following validated psychometric scales: The Mood Disorder Questionnaire (MDQ), Geriatric Depression Scale (GDS), General Health Questionnaire-28 (GHQ-28), The Athens Insomnia Scale (AIS), Courtauld Emotional Control Scale (CECS), State-Trait Anxiety Inventory (STAI) and SMAST-G-Short Michigan Alcoholism Screening Test-Geriatric Version.

RESULTS

The vast majority of the respondents did not screen positively for possible bipolar disorder. However, more than 90% of the participants presented with the symptoms of mild depression, and more than one-third had manifestations of non-psychotic mental morbidity. Nearly half of the respondents had complaints associated with insomnia, and in more than one-fourth, SMAST-G score raised suspicion of problem alcohol drinking. Retired participants were shown to present with significantly higher levels of anger control than the occupationally active respondents. Respondents with poor economic status had significantly higher levels of symptoms for non-psychotic mental disorders. Men significantly more often than women showed symptoms raising suspicion of alcohol-related problems.

DISCUSSION

In conclusion, the study group was characterized primarily by the mild depressive and anxiety symptoms. The mental health of the Polish participants of the Third Age University program was significantly modulated by their socio-occupational and marital status, and financial condition. The study showed that persons with likely problem alcohol drinking differed from other respondents in terms of the occurrence of possible bipolar disorder, depression, and non-psychotic symptoms of mental disorders, state and trait anxiety levels and anger control. There is a need for further research in the field of mental health status in the Third Age Universities seniors to determine the prevalence of these phenomena on a national scale.

Abnormal Dispersion of Ventricular Repolarization as a Risk Factor in Patients with Human Immunodeficiency Virus: Tp-e Interval, Tp-e/QTc Ratio

OBJECTIVE

In recent years, there has been worldwide recognition of the problems associated with Human Immunodeficiency Virus (HIV) infection and Acquired Immune Deficiency Syndrome (AIDS). The prevalence of cardiovascular disease in the HIV-infected population is increasing. Repolarization abnormalities, the significant contributor to life-threatening arrhythmias and mortality, are the most frequent electrocardiographic changes in this population. This study aimed to evaluate the changes in Tp-e interval, Tp-e/QT and Tp-e/corrected QT (QTc) ratios, and traditional electrocardiographic features of electrical dispersion in adults infected with HIV.

SUBJECTS AND METHODS

A total of 235 participants were selected in the current study. The HIV group consisted of 85 subjects (median age 36 years [25-48], and the control group included 150 individuals (median age 39 years [27-51]). Tp-e interval, Tp-e/QT and Tp-e/QTc ratios were measured by the 12-lead electrocardiogram.

RESULTS

Tp-e interval, cTp-e interval, and Tp-e/QT and Tp-e/QTc ratios were significantly higher in HIV patients compared to the control group (p = 0.006, p = 0.004, p = 0.003, and p = 0.002, respectively). In correlation analysis, there was inverse correlation between the mean cTp-e interval and CD4 count and Tp-e/QTc ratios and CD4 count (r = - 0.407, p < 0.001, r = - 0.416, p < 0.001, respectively). Besides, there was correlation between the mean cTp-e interval and high-sensitivity C-reactive protein (hsCRP) and Tp-e/QTc ratios and hsCRP (r = 0.403, p = 0.001, r = 0.406, p = 0.001, respectively).

CONCLUSION

Our study revealed that the cTp-e interval, Tp-e/QT and cTp-e/QT ratios were prolonged and correlated to the severity of the disease in HIV-infected patients. Our findings may shed light on the cTp-e interval and Tp-e/QTc ratio and lead to further studies showing a relationship with ventricular arrhythmias and mortality in HIV-infected individuals.

Follow-up Study Methods for a Longitudinal Cohort of Alaska Native and American Indian People Living within Urban South Central Alaska: The EARTH Study

Longitudinal data are needed to investigate chronic disease causation and improve prevention efforts for Alaska Native and American Indian (ANAI) people. This paper describes the methods used to conduct follow-up data collection of a longitudinal cohort that enrolled ANAI adults between 2004 and 2006 in south central Alaska. The follow-up study re-examined ANAI participants in a large, urban centre in south central Alaska between 2015 and 2017. Computerized surveys were used to collect self-reported health, lifestyle, physical activity, and diet data. Clinical measurements included blood pressure, fasting blood glucose and lipid panel, urine albumin/creatinine, height, weight, and waist and hip circumference. Participants were provided individual results at the conclusion of their visit. A total of 1320 south central Alaska study participants completed the baseline visit. Study staff attempted to contact all living cohort members for inclusion in the follow-up study. More than 11,000 attempted contacts were made. Of the 637 available for participation, 388 completed the follow-up visit. The proportion of women increased from baseline to follow-up examinations (67 vs. 72%, p < 0.01). Self-reported health status of being married or living as married (46% vs. 39%, p < 0.01), and those reporting being employed or self-employed (55% vs. 47%, p < 0.01) were higher at follow-up when compared to baseline. Almost all participants at follow-up (97%) agreed to long-term storage of biological specimens for future study. Despite demographic differences between the follow-up and baseline cohorts, longitudinal data collected will provide novel insight on chronic disease development and prevention for ANAI people as well as other populations.

Lifestyle Risk Factors and Findings on Brain Magnetic Resonance Imaging of Older Adult American Indians: The Strong Heart Study

BACKGROUND

Clinical stroke is prevalent in American Indians, but the lifestyle risk factors for vascular brain injury have not been well-studied in this population. The purpose of this study was to correlate brain magnetic resonance imaging (MRI) findings with obesity, alcohol use, and smoking behaviors in elderly American Indians from the Strong Heart Study.

METHODS

Cranial MRI scans (n = 789) were analyzed for dichotomous measures of infarcts, hemorrhages, white matter hyperintensities (WMH), and cerebral atrophy and continuous measures of total brain, WMH, and hippocampal volume. Poisson regression was used to estimate prevalence ratios, and linear regression was used to estimate measures of association for continuous outcomes. Models were adjusted for the risk factors of interest as well as age, sex, study site, income, education, hypertension, diabetes, and low-density lipoprotein cholesterol.

RESULTS

Smoking was associated with increased hippocampal atrophy (p = 0.002) and increased prevalence of sulcal widening (p < 0.001). Relative to nonsmokers, smokers with more than 25 pack-years of smoking had a 27% (95% CI 7-47%) increased prevalence of high-grade sulci, p = 0.005. Body mass index was inversely associated with prevalence of nonlacunar infarcts and sulcal widening (all p = 0.004). Alcohol use was not significantly associated with any of the measured MRI findings.

CONCLUSIONS

This study found similar associations between smoking and vascular brain injury among American Indians, as seen in other populations. In particular, these findings support the role of smoking as a key correlate for cerebral atrophy.

Proximate determinants of tuberculosis in Indigenous peoples worldwide: a systematic review

BACKGROUND

Indigenous peoples worldwide carry a disproportionate tuberculosis burden. There is an increasing awareness of the effect of social determinants and proximate determinants such as alcohol use, overcrowding, type 1 and type 2 diabetes, substance misuse, HIV, food insecurity and malnutrition, and smoking on the burden of tuberculosis. We aimed to understand the potential contribution of such determinants to tuberculosis in Indigenous peoples and to document steps taken to address them.

METHODS

We did a systematic review using seven databases (MEDLINE, Embase, CINAHL, Global Health, BIOSIS Previews, Web of Science, and the Cochrane Library). We identified English language articles published from Jan 1, 1980, to Dec 20, 2017, reporting the prevalence of proximate determinants of tuberculosis and preventive programmes targeting these determinants in Indigenous communities worldwide. We included any randomised controlled trials, controlled studies, cohort studies, cross-sectional studies, case reports, and qualitative research. Exclusion criteria were articles in languages other than English, full text not available, population was not Indigenous, focused exclusively on children or older people, and studies that focused on pharmacological interventions.

FINDINGS

Of 34 255 articles identified, 475 were eligible for inclusion. Most studies confirmed a higher prevalence of proximate determinants in Indigenous communities than in the general population. Diabetes was more frequent in Indigenous communities within high-income countries versus in low-income countries. The prevalence of alcohol use was generally similar to that among non-Indigenous groups, although patterns of drinking often differed. Smoking prevalence and smokeless tobacco consumption were commonly higher in Indigenous groups than in non-Indigenous groups. Food insecurity was highly prevalent in most Indigenous communities evaluated. Substance use was more frequent in Indigenous inhabitants of high-income countries than of low-income countries, with wide variation across Indigenous communities. The literature pertaining to HIV, crowding, and housing conditions among Indigenous peoples was too scant to draw firm conclusions. Preventive programmes that are culturally appropriate targeting these determinants appear feasible, although their effectiveness is largely unproven.

INTERPRETATION

Indigenous peoples were generally reported to have a higher prevalence of several proximate determinants of tuberculosis than non-Indigenous peoples, with wide variation across Indigenous communities. These findings emphasise the need for community-led, culturally appropriate strategies to address smoking, food insecurity, and diabetes in Indigenous populations as important public health goals in their own right, and also to reduce the burden of tuberculosis.

FUNDING

Canadian Institutes of Health Research.

Vascular Risk Factors and Findings on Brain MRI of Elderly Adult American Indians: The Strong Heart Study

BACKGROUND

Clinical stroke is prevalent in American Indians, but the risk factors for cerebrovascular pathology have not been well-studied in this population. The purpose of this study was to correlate abnormalities on brain magnetic resonance imaging (MRI) with clinical risk factors in a cohort of elderly American Indians.

METHODS

Brain MRI scans from 789 participants of the Strong Heart Study were analyzed for infarcts, hemorrhage, white matter disease, and measures of cerebral atrophy including ventricular and sulcal grade and total brain volume. Clinical risk factors included measures of hypertension, diabetes, and high levels of low-density lipoprotein (LDL) cholesterol. Regression models adjusted for potential confounders were used to estimate associations between risk factors and brain MRI outcomes.

RESULTS

-Hypertension was associated with the presence of infarcts (p = 0.001), ventricle enlargement (p = 0.01), and increased white matter hyperintensity volume (p = 0.01). Diabetes was associated with increased prevalence of cerebral atrophy (p < 0.001), ventricular enlargement (p = 0.001), and sulcal widening (p = 0.001). High LDL was not significantly associated with any of the measured cranial imaging outcomes.

CONCLUSIONS

This study found risk factors for cerebrovascular disease in American Indians similar to those seen in other populations and provides additional evidence for the important roles of hypertension and diabetes in promoting cerebral infarcts and brain atrophy, respectively.

Urinary tungsten and incident cardiovascular disease in the Strong Heart Study: An interaction with urinary molybdenum

BACKGROUND

Tungsten (W) interferes with molybdenum (Mo) binding sites and has been associated with prevalent cardiovascular disease (CVD). We evaluated if (1) W exposure is prospectively associated with incident CVD and (2) the association between urinary W levels and incident CVD is modified by urinary Mo levels.

METHODS

We estimated multi-adjusted hazard ratios (HRs) for incident CVD outcomes by increasing W levels for 2726 American Indian participants in the Strong Heart Study with urinary metal levels measured at baseline (1989-1991) and CVD events ascertained through 2008.

RESULTS

Increasing levels of baseline urinary W were not associated with incident CVD. Fully-adjusted HRs (95% CIs) of incident CVD comparing a change in the IQR of W levels for those in the lowest and highest tertile of urinary Mo were 1.05 (0.90, 1.22) and 0.80 (0.70, 0.92), respectively (p-interaction = 0.02); for CVD mortality, the corresponding HRs were 1.05 (0.82, 1.33) and 0.73 (0.58, 0.93), respectively (p-interaction = 0.03).

CONCLUSIONS

The association between W and CVD incidence and mortality was positive although non-significant at lower urinary Mo levels and significant and inverse at higher urinary Mo levels. Although prior cross-sectional epidemiologic studies in the general US population found positive associations between urinary tungsten and prevalent cardiovascular disease, our prospective analysis in the Strong Heart Study indicates this association may be modified by molybdenum exposure.

Patient-provider relationship and perceived provider weight bias among American Indians and Alaska Natives

Objective

The objective of this study was to examine patient-provider relationships among American Indians and Alaska Native (AI/AN) patients by examining associations between patient activation, perceived provider weight bias and working alliance. Patient activation is generally defined as having the knowledge, skills and confidence to manage one's health.

Methods

Among a sample of 87 AI/AN adults presenting for general medical care at an urban clinic in the north-west region of the USA, ordinary least squares regression analysis was completed to examine associations.

Results

Better working alliance scores were associated with increased patient activation, while perceived provider weight bias was associated with reduced patient activation. In addition, those with class II obesity had decreased patient activation.

Conclusion

These findings point to the importance of a positive patient-provider relationship in AI/ANs. Optimal patient engagement and subsequent health outcomes warrant additional consideration of patients' perceptions of provider weight bias within the context of health promotion and interventions.

Serum lipids and mortality in an American Indian population: A longitudinal study

BACKGROUND

In Caucasians, lower triglycerides (TG), total or LDL cholesterol and high HDL cholesterol are generally associated with lower mortality. However, low cholesterol is associated with higher mortality in some Asian populations. This study examines the relationship between serum lipids and mortality in American Indians.

METHODS

2125 American Indians aged ≥40years were examined biennially between 1993 and 2007. Vital status was determined through 2011. Mortality rates, adjusted for age, sex and diabetes, were calculated using Poisson regression.

RESULTS

The median baseline age was 46years and 61% were women. Over a median follow-up of 10.1years, 522 deaths occurred. Relationships between baseline lipids, except for HDL cholesterol, and all-cause mortality were negative and linear in persons without diabetes and U-shaped in persons with diabetes. For HDL cholesterol, the relationship was U-shaped in the total cohort. Cardiovascular mortality was positively associated with total, LDL and non-HDL cholesterol whereas lower lipid concentrations were adversely associated with mortality from liver disease or external causes, except for HDL cholesterol, where associations were positive.

CONCLUSION

The common belief that low cholesterol and TG are beneficial for health is not universally observed; evidence suggests increased mortality at both ends of the cholesterol and TG distributions.

Chronic arsenic exposure and risk of carotid artery disease: The Strong Heart Study

BACKGROUND

Inorganic arsenic exposure from naturally contaminated groundwater is related to vascular disease. No prospective studies have evaluated the association between arsenic and carotid atherosclerosis at low-moderate levels. We examined the association of long-term, low-moderate inorganic arsenic exposure with carotid arterial disease.

METHODS

American Indians, 45-74 years old, in Arizona, Oklahoma, and North and South Dakota had arsenic concentrations (sum of inorganic and methylated species, μg/g urine creatinine) measured from baseline urine samples (1989-1991). Carotid artery ultrasound was performed in 1998-1999. Vascular disease was assessed by the carotid intima media thickness (CIMT), the presence of atherosclerotic plaque in the carotid, and by the number of segments containing plaque (plaque score).

RESULTS

2402 participants (mean age 55.3 years, 63.1% female, mean body mass index 31.0kg/m², diabetes 45.7%, hypertension 34.2%) had a median (interquintile range) urine arsenic concentration of 9.2 (5.00, 17.06) µg/g creatinine. The mean CIMT was 0.75mm. 64.7% had carotid artery plaque (3% with >50% stenosis). In fully adjusted models comparing participants in the 80th vs. 20th percentile in arsenic concentrations, the mean difference in CIMT was 0.01 (95% confidence interval (95%CI): 0.00, 0.02) mm, the relative risk of plaque presence was 1.04 (95%CI: 0.99, 1.09), and the geometric mean ratio of plaque score was 1.05 (95%CI: 1.01, 1.09).

CONCLUSIONS

Urine arsenic was positively associated with CIMT and increased plaque score later in life although the association was small. The relationship between urinary arsenic and the presence of plaque was not statistically significant when adjusted for other risk factors. Arsenic exposure may play a role in increasing the severity of carotid vascular disease.

Cadmium body burden and increased blood pressure in middle-aged American Indians: the Strong Heart Study

Cadmium (Cd) is an environmental pollutant that has been associated with cardiovascular disease in populations, but the relationship of Cd with hypertension has been inconsistent. We studied the association between urinary Cd concentrations, a measure of total body burden, and blood pressure in American Indians, a US population with above national average Cd burden. Urinary Cd was measured using inductively coupled plasma mass spectrometry, and adjusted for urinary creatinine concentration. Among 3714 middle-aged American Indian participants of the Strong Heart Study (mean age 56 years, 41% male, 67% ever-smokers, 23% taking antihypertensive medications), urinary Cd ranged from 0.01 to 78.48 μg g^-1 creatinine (geometric mean=0.94 μg g^-1) and it was correlated with smoking pack-year among ever-smokers (r²=0.16, P<0.0001). Participants who were smokers were on average light-smokers (mean 10.8 pack-years), and urinary Cd was similarly elevated in light- and never-smokers (geometric means of 0.88 μg g^-1 creatinine for both categories). Log-transformed urinary Cd was significantly associated with higher systolic blood pressure in models adjusted for age, sex, geographic area, body mass index, smoking (ever vs never, and cumulative pack-years) and kidney function (mean blood pressure difference by lnCd concentration (β)=1.64, P=0.002). These associations were present among light- and never-smokers (β=2.03, P=0.002, n=2627), although not significant among never-smokers (β=1.22, P=0.18, n=1260). Cd was also associated with diastolic blood pressure among light- and never-smokers (β=0.94, P=0.004). These findings suggest that there is a relationship between Cd body burden and increased blood pressure in American Indians, a population with increased cardiovascular disease risk.

Central obesity and coronary risk factors

A cross-sectional study of 130 Bengalee Hindu men (mean age=50.3 years; SD=10.5 years) was undertaken to investigate the relationship of body mass index (BMI), waist circumference (WC) and waist-hip ratio (WHR) with total cholesterol (TC), high density (HDL-C), low density (LDL-C) and very low-density (VLDL-C) lipoprotein cholesterol, fasting plasma glucose (FPG) and triglycerides (FTG). Correlation studies revealed that WHR was significantly correlated (r=0.245, p<0.01) with TC. WC and WHR had significant correlations with VLDL-C, FPG and FTG. All subjects were further divided into two groups based on WHR<0.95 (centrally non-obese, CNO) and WHR>0.95 (centrally obese, CO) following the US Joint National Committee (JNC) guidelines. Students’ t-test revealed that CO subjects (n=83) had a significantly higher mean TC (p<0.05), VLDL (p<0.05), FPG (p<0.01) and FTG (p<0.05) compared with CNO individuals (n=47). Results of analysis of variance (ANOVA) of central obesity status (CNO=no, CO=yes) and BMI (BMI tertiles used as a categorical variable) with these metabolic variables revealed that CO status had a significant effect (p<0.05) on TC, VLDL-C, FPG and FTG. BMI tertiles did not a have significant effect on any of these metabolic variables. There was no significant BMI tertile-central obesity status interaction. It can therefore be concluded that the JNC guidelines of WHR>0.95 to define central obesity can be used, irrespective of BMI, among this population, to identify individuals who have enhanced metabolic risk factors of coronary heart disease (CHD). Furthermore, it can be routinely used for health promotion purposes among Bengalee men.

Smoking-attributable mortality in American Indians: findings from the Strong Heart Study

Cigarette smoking is the leading preventable cause of death worldwide. American Indians have the highest proportion of smoking in the United States. However, few studies have examined the impact of cigarette smoking on disease mortality in this ethnically important but traditionally understudied minority population. Here we estimated the association of cigarette smoking with cardiovascular disease (CVD), cancer and all-cause mortality in American Indians participating in the Strong Heart Study, a large community-based prospective cohort study comprising of 4549 American Indians (aged 45-74 years) followed for about 20 years (1989-2008). Hazard ratio and population attributable risk (PAR) associated with cigarette smoking were estimated by Cox proportional hazard model, adjusting for sex, study site, age, educational level, alcohol consumption, physical activity, BMI, lipids, renal function, hypertension or diabetes status at baseline, and interaction between current smoker and study site. We found that current smoking was significantly associated with cancer mortality (HR 5.0, [1.9-13.4]) in men, (HR 3.9 [1.6-9.7] in women) and all-cause mortality (HR 1.8, [1.2-2.6] in men, HR 1.6, [1.1-2.4] in women). PAR for cancer and all-cause mortality in men were 41.0 and 18.4 %, respectively, whereas the corresponding numbers in women were 24.9 and 10.9 %, respectively. Current smoking also significantly increases the risk of CVD deaths in women (HR 2.2 [1.1, 4.4]), but not men (HR 1.2 [0.6-2.4]). PAR for CVD mortality in women was 14.9 %. In summary, current smoking significantly increases the risk of CVD (in women), cancer and all-cause mortality in American Indians, independent of known risk factors. Culturally specific smoking cessation programs are urgently needed to reduce smoking-related premature deaths.

The Association of Panic Disorder, Posttraumatic Stress Disorder, and Major Depression With Smoking in American Indians

INTRODUCTION

Rates of cigarette smoking are disproportionately high among American Indian populations, although regional differences exist in smoking prevalence. Previous research has noted that anxiety and depression are associated with higher rates of cigarette use. We asked whether lifetime panic disorder, posttraumatic stress disorder, and major depression were related to lifetime cigarette smoking in two geographically distinct American Indian tribes.

METHODS

Data were collected in 1997-1999 from 1506 Northern Plains and 1268 Southwest tribal members; data were analyzed in 2009. Regression analyses examined the association between lifetime anxiety and depressive disorders and odds of lifetime smoking status after controlling for sociodemographic variables and alcohol use disorders. Institutional and tribal approvals were obtained for all study procedures, and all participants provided informed consent.

RESULTS

Odds of smoking were two times higher in Southwest participants with panic disorder and major depression, and 1.7 times higher in those with posttraumatic stress disorder, after controlling for sociodemographic variables. After accounting for alcohol use disorders, only major depression remained significantly associated with smoking. In the Northern Plains, psychiatric disorders were not associated with smoking. Increasing psychiatric comorbidity was significantly linked to increased smoking odds in both tribes, especially in the Southwest.

CONCLUSIONS

This study is the first to examine the association between psychiatric conditions and lifetime smoking in two large, geographically diverse community samples of American Indians. While the direction of the relationship between nicotine use and psychiatric disorders cannot be determined, understanding unique social, environmental, and cultural differences that contribute to the tobacco-psychiatric disorder relationship may help guide tribe-specific commercial tobacco control strategies.

Lung function and heart disease in American Indian adults with high frequency of metabolic abnormalities (from the Strong Heart Study)

The associations of pulmonary function with cardiovascular disease (CVD) independent of diabetes mellitus (DM) and metabolic syndrome have not been examined in a population-based setting. We examined prevalence and incidence CVD in relation to lower pulmonary function in the Strong Heart Study second examination (1993 to 1995) in 352 CVD and 2,873 non-CVD adults free of overt lung disease (mean age 60 years). Lung function was assessed by standard spirometry. Participants with metabolic syndrome or DM with or without CVD had lower pulmonary function than participants without these conditions after adjustment for hypertension, age, gender, abdominal obesity, smoking, physical activity index, and study field center. CVD participants with DM had significantly lower forced vital capacity than participants with CVD alone. Significant associations were observed between reduced pulmonary function, preclinical CVD, and prevalent CVD after adjustment for multiple CVD risk factors. During follow-up (median 13.3 years), pulmonary function did not predict CVD incidence, it predicted CVD mortality. Among 3,225 participants, 412 (298 without baseline CVD) died from CVD by the end of 2008. In models adjusted for multiple CVD risk factors, DM, metabolic syndrome, and baseline CVD, compared with highest quartile of lung function, lower lung function predicted CVD mortality (relative risk up to 1.5, 95% confidence interval 1.1 to 2.0, p<0.05). In conclusion, a population with a high prevalence of DM and metabolic syndrome and lower lung function was independently associated with prevalent clinical and preclinical CVD, and its impairment predicted CVD mortality. Additional research is needed to identify mechanisms linking metabolic abnormalities, low lung function, and CVD.

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.

Smoking abstinence-related expectancies among American Indians, African Americans, and women: potential mechanisms of tobacco-related disparities

Research has documented tobacco-related health disparities by race and gender. Prior research, however, has not examined expectancies about the smoking cessation process (i.e., abstinence-related expectancies) as potential contributors to tobacco-related disparities in special populations. This cross-sectional study compared abstinence-related expectancies between American Indian (n = 87), African American (n = 151), and White (n = 185) smokers, and between women (n = 231) and men (n = 270) smokers. Abstinence-related expectancies also were examined as mediators of race and gender relationships with motivation to quit and abstinence self efficacy. Results indicated that American Indians and African Americans were less likely than Whites to expect withdrawal effects, and more likely to expect that quitting would be unproblematic. African Americans also were less likely than Whites to expect smoking cessation interventions to be effective. Compared with men, women were more likely to expect withdrawal effects and weight gain. These expectancy differences mediated race and gender relationships with motivation to quit and abstinence self-efficacy. Findings emphasize potential mechanisms underlying tobacco-related health disparities among American Indians, African Americans, and women and suggest a number of specific approaches for targeting tobacco dependence interventions to these populations.

Psychological trauma symptoms and Type 2 diabetes prevalence, glucose control, and treatment modality among American Indians in the Strong Heart Family Study

AIMS

The aims of this paper are to examine the relationship between psychological trauma symptoms and Type 2 diabetes prevalence, glucose control, and treatment modality among 3776 American Indians in Phase V of the Strong Heart Family Study.

METHODS

This cross-sectional analysis measured psychological trauma symptoms using the National Anxiety Disorder Screening Day instrument, diabetes by American Diabetes Association criteria, and treatment modality by four categories: no medication, oral medication only, insulin only, or both oral medication and insulin. We used binary logistic regression to evaluate the association between psychological trauma symptoms and diabetes prevalence. We used ordinary least squares regression to evaluate the association between psychological trauma symptoms and glucose control. We used binary logistic regression to model the association of psychological trauma symptoms with treatment modality.

RESULTS

Neither diabetes prevalence (22%-31%; p=0.19) nor control (8.0-8.6; p=0.25) varied significantly by psychological trauma symptoms categories. However, diabetes treatment modality was associated with psychological trauma symptoms categories, as people with greater burden used either no medication, or both oral and insulin medications (odds ratio=3.1, p<0.001).

CONCLUSIONS

The positive relationship between treatment modality and psychological trauma symptoms suggests future research investigate patient and provider treatment decision making.

Cardiovascular Disease Among Alaska Native Peoples

Although Alaska Native peoples were thought to be protected from cardiovascular disease (CVD), data now show that this is not the case, despite traditional lifestyles and high omega-3 fatty acid intake. In this article, the current understanding of CVD and its risk factors among Alaska Native peoples, particularly among the Yupik and Inupiat populations, will be discussed, using data from three major studies funded by the National Institutes of Health: Genetics of Coronary Artery Disease among Alaska Natives (GOCADAN), Center for Native Health Research (CANHR), and Education and Research Towards Health (EARTH). Data from these epidemiologic studies have focused concern on CVD and its risk factors among Alaska Native peoples. This review will summarize the findings of these three principal studies and will suggest future directions for research and clinical practice.

Design of a randomized controlled trial of a web-based intervention to reduce cardiovascular disease risk factors among remote reservation-dwelling American Indian adults with type 2 diabetes

We describe a randomized controlled trial, the Lakota Oyate Wicozani Pi Kte (LOWPK) trial, which was designed to determine whether a Web-based diabetes and nutritional intervention can improve risk factors related to cardiovascular disease (CVD) among a group of remote reservation-dwelling adult American Indian men and women with type 2 diabetes who are at high risk for CVD. Enrollment on a rolling basis of 180 planned participants began during 2009; an average 18-month follow-up was completed by June 2011. The primary outcome variable is change in glycosylated hemoglobin level after an average 18-month follow-up period. Secondary outcome variables include changes in low-density lipoprotein cholesterol, systolic blood pressure, body mass index, and smoking status, as well as an evaluation of intervention cost-effectiveness. If effective, the LOWPK trial may serve as a guide for future chronic disease intervention trials in remote, technologically challenged settings.

Differences in risk factors for coronary heart disease among diabetic and nondiabetic individuals from a population with high rates of diabetes: the Strong Heart Study

CONTEXT

Coronary heart disease (CHD) is the leading cause of death in the United States.

OBJECTIVE

This study compares differences in risk factors for CHD in diabetic vs. nondiabetic Strong Heart Study participants.

DESIGN

This was an observational study.

SETTING

The study was conducted at three centers in Arizona, Oklahoma, and North and South Dakota.

PARTICIPANTS

Data were obtained from 3563 of 4549 American Indians free of cardiovascular disease at baseline.

INTERVENTION(S)

CHD events were ascertained during follow-up.

MAIN OUTCOME MEASURE

CHD events were classified using standardized criteria.

RESULTS

In diabetic and nondiabetic participants, 545 and 216 CHD events, respectively, were ascertained during follow-up (21,194 and 22,990 person-years); age- and sex-adjusted incidence rates of CHD were higher for the diabetic group (27.5 vs. 12.1 per 1,000 person-years). Risk factors for incident CHD common to both groups included older age, male sex, prehypertension or hypertension, and elevated low-density lipoprotein cholesterol. Risk factors specific to the diabetic group were lower high-density lipoprotein cholesterol, current smoking, macroalbuminuria, lower estimated glomerular filtration rate, use of diabetes medication, and longer duration of diabetes. Higher body mass index was a risk factor only for the nondiabetic group. The association of male sex and CHD was greater in those without diabetes than in those with diabetes.

CONCLUSIONS

In addition to higher incidence rates of CHD events in persons with diabetes compared with those without, the two groups differed in CHD risk factors. These differences must be recognized in estimating CHD risk and managing risk factors.

An evaluation of the physical activity and health status of British Columbian Aboriginal populations

Aboriginal people have experienced elevated rates of obesity, diabetes, cardiovascular disease, and other chronic conditions that are disproportionate to the general Canadian population. We sampled British Columbian Aboriginal populations to determine the current health status of this population. A total of 882 Aboriginal adults ≥16 years of age from 25 locations around the province were sampled from 2007–2011. Health measurements evaluated included body mass index, waist circumference, physical activity, smoking behaviours, and resting blood pressure as well as histories of diabetes, cardiovascular disease, and hypertension. Nonfasting measures of blood sugar, total cholesterol, and high-density lipoprotein cholesterol were also recorded. We used logistical regression to quantify variations in diabetes and cardiovascular disease risk factors with age, gender, geographic location, on- and off-reserve and urban–rural areas of residence, smoking, and physical activity behaviour. The prevalence of diabetes, hypertension, and high total cholesterol were found to be greater among males, while females experienced greater rates of abdominal obesity and physical inactivity. Rates of chronic conditions were similar across on- and off-reserve, urban–rural areas, and geographic region residences, though rural, on-reserve, and northern residents experienced greater risk of poor health status. Larger proportions of on-reserve, rural, and interior individuals were found to be more physically inactive. Aboriginal populations still experience substantially poorer health status in comparison with the general population. Initiatives to improve the health of this population are urgently needed addressing all sectors of the Aboriginal population, all geographic regions, and all areas of residence, with special emphasis on rural, on-reserve, and northern populations.

Incremental value of biochemical and echocardiographic measures in prediction of ischemic stroke: the Strong Heart Study

BACKGROUND AND PURPOSE

American Indians have high rates of stroke. Improved risk stratification could enhance prevention, but the ability of biochemical and echocardiographic markers of preclinical disease to improve stroke prediction is not well-defined.

METHODS

We evaluated such markers as predictors of ischemic stroke in a community-based cohort of American Indians without prevalent cardiovascular or renal disease. Laboratory markers included C-reactive protein, fibrinogen, urine albumin-to-creatinine ratio, and glycohemoglobin (HbA1c), whereas echocardiographic parameters comprised left atrial diameter, left ventricular mass, mitral annular calcification, and the ratio of early to late mitral diastolic velocities. Predictive performance was judged by indices of discrimination, reclassification, and calibration.

RESULTS

After adjustment for standard risk factors, only HbA1c, albuminuria, and left atrial diameter were significantly associated with first ischemic stroke. Addition of HbA1c, although not urine albumin-to-creatinine ratio, to a basic clinical model significantly improved the C-statistic (0.714 versus 0.695; P=0.044), whereas left atrial diameter modestly enhanced integrated discrimination improvement (0.90%; P=0.004), but not the C-statistic (0.701; P=0.528). When combined with HbA1c, left atrial diameter further increased integrated discrimination improvement (1.81%; P<0.001) but not the C-statistic (0.716). No marker achieved significant net reclassification improvement.

CONCLUSIONS

In this cohort at high cardiometabolic risk, HbA1c emerged as the foremost predictor of ischemic stroke when added to traditional risk factors, affording substantially improved discrimination, with a more modest contribution for left atrial diameter. These findings bolster the role of HbA1c in cardiovascular risk assessment among persons with glycometabolic disorders and provide impetus for further study of the incremental value of echocardiography in high-risk populations.

The burden of cancer risk in Canada's indigenous population: a comparative study of known risks in a Canadian region

BACKGROUND

Canadian First Nations, the largest of the Aboriginal groups in Canada, have had lower cancer incidence and mortality rates than non-Aboriginal populations in the past. This pattern is changing with increased life expectancy, a growing population, and a poor social environment that influences risk behaviors, metabolic conditions, and disparities in screening uptake. These factors alone do not fully explain differences in cancer risk between populations, as genetic susceptibility and environmental factors also have significant influence. However, genetics and environment are difficult to modify. This study compared modifiable behavioral risk factors and metabolic-associated conditions for men and women, and cancer screening practices of women, between First Nations living on-reserve and a non-First Nations Manitoba rural population (Canada).

METHODS

The study used data from the Canadian Community Health Survey and the Manitoba First Nations Regional Longitudinal Health Survey to examine smoking, binge drinking, metabolic conditions, physical activity, fruit/vegetable consumption, and cancer-screening practices.

RESULTS

First Nations on-reserve had significantly higher rates of smoking (P < 0.001), binge drinking (P < 0.001), obesity (P < 0.001) and diabetes (P < 0.001), and less leisure-time physical activity (P = 0.029), and consumption of fruits and vegetables (P < 0.001). Sex differences were also apparent. In addition, First Nations women reported significantly less uptake of mammography screening (P < 0.001) but similar rates for cervical cancer screening.

CONCLUSIONS

Based on the findings of this retrospective study, the future cancer burden is expected to be high in the First Nations on-reserve population. Interventions, utilizing existing and new health and social authorities, and long-term institutional partnerships, are required to combat cancer risk disparities, while governments address economic disparities.

Sex differences in obesity-related changes in left ventricular morphology: the Strong Heart Study

OBJECTIVES

It is unclear whether there are sex differences in the relations of left ventricular mass to body composition and fat distribution in nonobese or obese hypertensive and nonhypertensive individuals and whether the obesity-related increase in left ventricular mass is similar in men and women.

METHODS

We examined sex differences in the relations between left ventricular mass and both body composition and fat distribution, in the presence or absence of obesity in 1068 men and 1851 women (65%) of the Strong Heart Study cohort, without prevalent cardiovascular disease or severe chronic kidney disease. Fat-free mass (FFM) and adipose mass were estimated by bioelectric impedance analysis and fat distribution by waist-to-hip ratio (WHR).

RESULTS

Adipose mass was significantly higher in women than in men for any weight category (P < 0.0001). After adjusting for age, hypertension, systolic blood pressure (BP) and diabetes, both left ventricular mass/height (LVMi) and left ventricular mass (LVM)/FFM were greater in obese women than obese men (P < 0.0001). Relative wall thickness was also greater in women than in men (P < 0.0001). LVM was independently related to Doppler-stroke volume, FFM and systolic BP in both sexes, with WHR and adipose mass contributing to variance of LVM in women but not in men (both P < 0.03).

CONCLUSION

Obesity influences left ventricular geometry substantially more in women than in men, possibly due to biological factors specifically associated with female adiposity.

Obesity in adults is associated with reduced lung function in metabolic syndrome and diabetes: the Strong Heart Study

OBJECTIVE

The purposes of this study were to investigate whether reduced lung function is associated with metabolic syndrome (MS) and diabetes (DM) in American Indians (AIs) and to determine whether lower pulmonary function presents before the development of DM or MS.

RESEARCH DESIGN AND METHODS

The Strong Heart Study (SHS) is a multicenter, prospective study of cardiovascular disease (CVD) and its risk factors among AI adults. The present analysis used lung function assessment by standard spirometry at the SHS second examination (1993-1995) in 2,396 adults free of overt lung disease or CVD, with or without DM or MS. Among MS-free/DM-free participants, the development of MS/DM at the SHS third examination (1996-1999) was investigated.

RESULTS

Significantly lower pulmonary function was observed for AIs with MS or DM. Impaired pulmonary function was associated with MS and DM after adjustment for age, sex, abdominal obesity, current smoking status, physical activity index, hypertension, and SHS field center. Both forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were negatively associated with insulin resistance or DM severity and with serum markers of inflammation (P < 0.05). FVC and FEV1-to-FVC ratio both predicted DM in unadjusted analyses but not when adjusted for covariates, including waist circumference. In the adjusted model, abdominal obesity predicted both MS and DM.

CONCLUSIONS

Reduced lung function is independently associated with MS and with DM, and impaired lung function presents before the development of MS or DM; these associations may result from the effects of obesity and inflammation.

The metabolic syndrome--from insulin resistance to obesity and diabetes

In today's society with the escalating levels of obesity, diabetes, and cardiovascular disease, the metabolic syndrome is receiving considerable attention and is the subject of much controversy. Greater insight into the mechanism(s) behind the syndrome may improve our understanding of how to prevent and best manage this complex condition.

Tobacco use and cardiovascular disease among American Indians: the strong heart study

Tobacco use among American Indians has a long and complicated history ranging from its utilization in spiritual ceremonies to its importance as an economic factor for survival. Despite this cultural tradition and long history, there are few studies of the health effects of tobacco in this population. The Strong Heart Study is a prospective observational study of cardiovascular disease (CVD) in 13 American Indian tribes in Arizona, Oklahoma, and North and South Dakota with 4,549 participants. Baseline examinations were followed by two examinations at regular intervals and 16 years of morbidity and mortality follow-up. Hazard ratios (HRs) for non-fatal CVD for current smokers vs. non-smokers after adjusting for other risk factors were significant in women (HR = 1.94, 95% CI 1.54 to 2.45) and men (HR = 1.59, 95% CI 1.16 to 2.18). Hazard ratios for fatal CVD for current smokers vs. non-smokers after adjusting for other risk factors were significant in women (HR = 1.64, 95% CI 1.04 to 2.58), but not in men. Individuals who smoked and who were diagnosed with diabetes mellitus, hypertension or renal insufficiency were more likely to quit smoking than those without these conditions. On average, American Indians smoke fewer cigarettes per day than other racial/ethnic groups; nevertheless, the ill effects of habitual tobacco use are evident in this population.