Rationale: Permanent lung function impairment after active tuberculosis infection is relatively common. It remains unclear which spirometric pattern is most prevalent after tuberculosis. Objectives: Our objective was to elucidate the impact of active tuberculosis survival on lung health in the Strong Heart Study (SHS), a population of American Indians historically highly impacted by tuberculosis. As arsenic exposure has also been related to lung function in the SITS, we also assessed the joint effect between arsenic exposure and past active tuberculosis. Methods: The SITS is an ongoing population-based, prospective study of cardiovascular disease and its risk factors in American Indian adults. This study uses tuberculosis data and spirometry data from the Visit 2 examination (1993-1995). Prior active tuberculosis was ascertained by a review of medical records. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and FEV1/FVC were measured by spirometry. An additional analysis was conducted to evaluate the potential association between active tuberculosis and arsenic exposure. Results: A history of active tuberculosis was associated with reduced percent predicted FVC and FEV1, an increased odds of airflow obstruction (odds ratio = 1.45, 95% confidence interval = 1.08-1.95), and spirometric restrictive pattern (odds ratio= 1.73, 95% confidence interval = 1.24-2.40). These associations persisted after adjustment for diabetes and other risk factors, including smoking. We also observed the presence of cough, phlegm, and exertional dyspnea after a history of active tuberculosis. In the additional analysis, increasing urinary arsenic concentrations were associated with decreasing lung function in those with a history of active tuberculosis, but a reduced odds of active tuberculosis was found with elevated arsenic. Conclusions: Our findings support existing knowledge that a history of active tuberculosis is a risk factor for long-term respiratory impairment. Arsenic exposure, although inversely associated with prior active tuberculosis, was associated with a further decrease in lung function among those with a prior active tuberculosis history. The possible interaction between arsenic and tuberculosis, as well as the reduced odds of tuberculosis associated with arsenic exposure, warrants further investigation, as many populations at risk of developing active tuberculosis are also exposed to arsenic-contaminated water.

BACKGROUND AND OBJECTIVE:American Indians have a high prevalence of diabetes and higher incidence of stroke than that of whites and blacks in the U.S. Stroke risk prediction models based on data from American Indians would be of clinical and public health value.METHODS AND RESULTS:A total of 3483 (2043 women) Strong Heart Study participants free of stroke at baseline were followed from 1989 to 2010 for incident stroke. Overall, 297 stroke cases (179 women) were identified. Cox models with stroke-free time and risk factors recorded at baseline were used to develop stroke risk prediction models. Assessment of the developed stroke risk prediction models regarding discrimination and calibration was performed by an analogous C-statistic (C) and a version of the Hosmer-Lemeshow statistic (HL), respectively, and validated internally through use of Bootstrapping methods.RESULTS:Age, smoking status, alcohol consumption, waist circumference, hypertension status, an-tihypertensive therapy, fasting plasma glucose, diabetes medications, high/low density lipoproteins, urinary albumin/creatinine ratio, history of coronary heart disease/heart failure, atrial fibrillation, or Left ventricular hypertrophy, and parental history of stroke were identified as the significant optimal risk factors for incident stroke.DISCUSSION:The models produced a C = 0.761 and HL = 4.668 (p = 0.792) for women, and a C = 0.765 and HL = 9.171 (p = 0.328) for men, showing good discrimination and calibration.CONCLUSIONS:Our stroke risk prediction models provide a mechanism for stroke risk assessment designed for American Indians. The models may be also useful to other populations with high prevalence of obesity and/or diabetes for screening individuals for risk of incident stroke and designing prevention programs.

Background: Despite growing recognition that asthma is an important cause of morbidity among American Indians, there has been no systematic study of this disease in older adults who are likely to be at high risk of complications related to asthma. Characterization of the impact of asthma among American Indian adults is necessary in order to design appropriate clinical and preventive measures. Methods: A sample of participants in the third examination of the Strong Heart Study, a multicenter, population-based, prospective study of cardiovascular disease in American Indians, completed a standardized respiratory questionnaire, performed spirometry, and underwent allergen skin testing. Participants were > 50 years old. Results: Of 3,197 participants in the third examination, 6.3% had physician-diagnosed asthma and 4.3% had probable asthma. Women had a higher prevalence of physician-diagnosed asthma than men (8.2% vs 3.2%). Of the 435 participants reported in the asthma substudy, morbidity related to asthma was high: among those with physician-diagnosed asthma: 97% reported trouble breathing and 52% had severe persistent disease. The mean FEV1 in those with physician-diagnosed asthma was 61.3% of predicted, and 67.2% reported a history of emergency department visits and/or hospitalizations in the last year, yet only 3% were receiving regular inhaled corticosteroids. Conclusions: The prevalence of asthma among older American Indians residing in three separate geographic areas of the United States was similar to rates in other ethnic groups. Asthma was associated with low lung function, significant morbidity and health-care utilization, yet medications for pulmonary disease were underutilized by this population. (CHEST 2007; 131:1323–1330)

Background: Type 2 diabetes has been associated with an increased risk of several cancers, including liver, colon, breast and gastric cancer. These associations, however, have not been well studied in American Indian populations, which experience a high burden of diabetes. Methods: Prospective cohort study of 4,419 American Indians 45 to 74 years of age followed for up to 20 years. Diabetes was defined by a fasting glucose ≥126 mg/dL or the use of insulin or oral hypoglycemic medication at baseline. Impaired fasting glucose (IFG) was defined as a fasting glucose ≥100 mg/dL and <126 mg/dL without diabetes. Insulin resistance was estimated in non-diabetic participants using the homeostasis model assessment. HbA1c was measured by a high-performance liquid chromatography method. Cancer deaths were assessed by annual mortality surveillance reviews and recorded according to the International Classification of Diseases, 9th Revision. Results: There were 13.7% participants with IFG and 45.7% with diabetes at base...

Purpose The metabolic abnormalities that accompany diabetes mellitus are associated with an increased risk of many cancers. These associations, however, have not been well studied in American Indian populations, which experience a high prevalence of diabetes. The Strong Heart Study is a population-based, prospective cohort study with extensive characterization of diabetes status.Methods Among a total cohort of 4,419 participants who were followed for up to 20 years, 430 cancer deaths were identified.Results After adjusting for sex, age, education, smoking status, drinking status, and body mass index, participants with diabetes at baseline showed an increased risk of gastric (HR 4.09; 95 % CI 1.42-11.79), hepatocellular (HR 2.94; 95 % CI 1.17-7.40), and prostate cancer mortality (HR 3.10; 95 % CI 1.22-7.94). Further adjustment for arsenic exposure showed a significantly increased risk of all-cause cancer mortality with diabetes (HR 1.27; 95 % CI 1.03-1.58). Insulin resistance among participants without diabetes at baseline was associated with hepatocellular cancer mortality (HR 4.70; 95 % CI 1.55-14.26).Conclusions Diabetes mellitus, and/or insulin resistance among those without diabetes, is a risk factor for gastric, hepatocellular, and prostate cancer in these American Indian communities, although relatively small sample size suggests cautious interpretation. Additional research is needed to evaluate the role of diabetes and obesity on cancer incidence in American Indian communities as well as the importance of diabetes prevention and control in reducing the burden of cancer incidence and mortality in the study population.

Background— Stroke prediction models are valuable to physicians in evaluating the risk of their patients so that preventive interventions can be promoted. The Framingham Risk Profile is a widely used stroke prediction equation. However, the contributions of some common risk factors for stroke vary across populations and some risk factors are specific to certain populations. For example, albuminuria is an important risk factor in American Indians (AIs), which is not included in the Framingham equation. The objective of the current study is to develop stroke prediction equations using routinely collected variables in AIs, a population with high rates of diabetes and stroke. Methods— The data used in the analysis are from 4507 stroke free participants at enrollment in the Strong Heart Study (SHS), the largest population-based longitudinal study of cardiovascular disease (CVD) and its risk factors in AIs in Arizona, Oklahoma, and South/North Dakota. As of December 2008, 379/4507 (8.4%) participants suffered a first stroke during an average follow-up of 17 years. Baseline potential risk factors were included in the Cox proportional-hazard models to develop gender-specific prediction equations. Backward selection was used to choose the predictors. Model performance was assessed using Harrell’s C statistics based on bootstrapping methods. Results— Baseline age, untreated systolic blood pressure, treated diastolic blood pressure, HDL-C, current smoking, diabetes, macro-albuminuria, and history of CVD are significant predictors for incident stroke among women. Most of these predictors except HDL-C were also in the prediction equation for men. The equations provided good discrimination ability, as indicated by a C statistic of 0.72 for men and 0.73 for women. Conclusions— Predicted risk of stroke in 10 years can be provided for physicians and their patients. Then appropriate intervention can be implemented. The stroke prediction equations from SHS can be applied to other AIs as well as other ethnic groups with high rates of diabetes and albuminuria.

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.

Very little is known about the alcohol elimination rates of newborns who have had chronic alcohol exposure in utero. In these case reports, blood alcohol levels were taken immediately before delivery, at delivery, and postdelivery for 2 mothers who drank alcohol during their pregnancies and 3 single-birth newborns. Newborn A1 of Mother A had no physical characteristics of fetal alcohol syndrome (FAS). The initial blood alcohol level for this newborn was 38.4 mg/dL 129 minutes after birth, with a subsequent blood alcohol level of 5.5 mg/dL 304 minutes after delivery, resulting in an alcohol elimination rate of 11.3 mg/dL per hour. The blood alcohol level for Mother A was 87.4 mg/dL 66 minutes before delivery. Newborn A2 of mother A had FAS. Sixty minutes after delivery, the blood alcohol level for this newborn was 39.5 mg/dL, and the alcohol level of the mother was 42.1 mg/dL. Newborn B1 of mother B had FAS. At 67 minutes after birth, newborn B1 had a blood alcohol level of 246.5 mg/dL, which dropped to 178.7 mg/dL 302 minutes after birth, resulting in an alcohol elimination rate of 17.3 mg/dL per hour. This alcohol elimination rate is within the metabolism range (15-49 mg/dL per hour) of adults with alcoholism. The maternal blood alcohol level was 265.9 mg/dL 27 minutes before delivery. Blood alcohol levels drawn on both the mother and newborn at delivery and 2 or 3 hourly follow-up levels can provide evidence that fetal alcohol dehydrogenase activity is induced by chronic maternal alcohol use.

OBJECTIVES:Evaluate the quality of care provided patients with acute myocardial infarction and compare with similar national and regional data.DESIGN:Case series.SETTING:The Strong Heart Study has extensive population-based data related to cardiovascular events among American Indians living in three rural regions of the United States.PARTICIPANTS:Acute myocardial infarction cases (72) occurring between 1/1/2001 and 12/31/2006 were identified from a cohort of 4549 participants.OUTCOME MEASURES:The proportion of cases that were provided standard quality of care therapy, as defined by the Healthcare Financing Administration and other national organizations.RESULTS:The provision of quality services, such as administration of aspirin on admission and at discharge, reperfusion therapy within 24 hours, prescription of beta blocker medication at discharge, and smoking cessation counseling were found to be 94%, 91%, 92%, 86% and 71%, respectively. The unadjusted, 30 day mortality rate was 17%.CONCLUSION:Despite considerable challenges posed by geographic isolation and small facilities, process measures of the quality of acute myocardial infarction care for participants in this American Indian cohort were comparable to that reported for Medicare beneficiaries nationally and within the resident states of this cohort.

Differences in utilization of health care services and the quality of those services between geographic regions of the United States exist. Public policy, guidelines, and health care organizations have attempted to address these differences. In 1992 the Healthcare Financing Administration, now the Center for Medicare/Medicaid Services (CMS), initiated the Cooperative Cardiovascular Project with the goal of improving the quality of care for acute myocardial infarction (AMI) nationally. Standards were developed for the evaluation of quality care based on the guidelines of the American College of Cardiology and the American Heart Association. The initial results from this national survey of AMI quality care was presented in 1998 and a follow-up survey reported in 2003. National performance since 1999 has been evaluated primarily on the basis of data from voluntary reporting systems, such as the National Registry of Myocardial Infarction, The National Cardiovascular Data Registry, the CMS and Hospital Quality Alliance Program (begun in 2004), and the American Heart Association’s Get With The Guidelines coronary artery disease program. There have been efforts to use these programs and quality measures to determine the role they play in the known cardiovascular disease disparities among minority populations. Cardiovascular disease accounts for a large proportion of morbidity and mortality among American Indians. Yet, studies of cardiovascular disease quality of care among American Indians are limited. The Strong Heart Study is a longitudinal cohort study of cardiovascular disease and its risk factors in American Indians. It is the longest-running population-based cohort study among American Indians with centers in three primarily rural geographic regions in the United States. It has rich demographic and clinical data including physician adjudicated cardiovascular events. In this study, we describe AMI quality care measures from the Strong Heart Study and then compare them to previously published studies from CMS.

OBJECTIVE To compare fasting plasma glucose (FPG) and HbA1c in identifying and predicting type 2 diabetes in a population with high rates of diabetes. RESEARCH DESIGN AND METHODS Diabetes was defined as an FPG level ≥126 mg/dL or an HbA1c level ≥6.5%. Data collected from the baseline and second exams (1989–1995) of the Strong Heart Study were used. RESULTS For cases of diabetes identified by FPG ≥126 mg/dL, using HbA1c ≥6.5% at the initial and 4-year follow-up diabetes screenings (or in identifying incident cases in 4 years) among undiagnosed participants left 46% and 59% of cases of diabetes undetected, respectively, whereas for cases identified by HbA1c ≥6.5%, using FPG ≥126 mg/dL left 11% and 59% unidentified, respectively. Age, waist circumference, urinary albumin-to-creatinine ratio, and baseline FPG and HbA1c levels were common significant risk factors for incident diabetes defined by either FPG or HbA1c; triglyceride levels were significant for diabetes defined by HbA1c alone, and blood pressure and sibling history of diabetes were significant for diabetes defined by FPG alone. Using both the baseline FPG and HbA1c in diabetes prediction identified more people at risk than using either measure alone. CONCLUSIONS Among undiagnosed participants, using HbA1c alone in initial diabetes screening identifies fewer cases of diabetes than FPG, and using either FPG or HbA1c alone cannot effectively identify diabetes in a 4-year periodic successive diabetes screening or incident cases of diabetes in 4 years. Using both criteria may identify more people at risk. The proposed models using the commonly available clinical measures can be applied to assessing the risk of incident diabetes using either criterion.

Large studies of extended families usually collect valuable phenotypic data that may have scientific value for purposes other than testing genetic hypotheses if the families were not selected in a biased manner. These purposes include assessing population-based associations of diseases with risk factors/covariates and estimating population characteristics such as disease prevalence and incidence. Relatedness among participants however, violates the traditional assumption of independent observations in these classic analyses. The commonly used adjustment method for relatedness in population-based analyses is to use marginal models, in which clusters (families) are assumed to be independent (unrelated) with a simple and identical covariance (family) structure such as those called independent, exchangeable and unstructured covariance structures. However, using these simple covariance structures may not be optimally appropriate for outcomes collected from large extended families, and may under- or over-estimate the variances of estimators and thus lead to uncertainty in inferences. Moreover, the assumption that families are unrelated with an identical family structure in a marginal model may not be satisfied for family studies with large extended families. The aim of this paper is to propose models incorporating marginal models approaches with a covariance structure for assessing population-based associations of diseases with their risk factors/covariates and estimating population characteristics for epidemiological studies while adjusting for the complicated relatedness among outcomes (continuous/categorical, normally/non-normally distributed) collected from large extended families. We also discuss theoretical issues of the proposed models and show that the proposed models and covariance structure are appropriate for and capable of achieving the aim.

Objectives: To examine the relationship between depression and glycemic control in the Strong Heart Study (SHS), a longitudinal study of cardiovascular disease in American Indians. Methods: This cross-sectional analysis focused on the relationship between depression, diabetes and glycemic control among 2832 individuals aged 15 years. Depression was measured by the Center for Epidemiologic Studies of Depression Scale and diabetes by American Diabetes Association criteria. An ordered logit regression model was used to assess whether diabetes was related to level of depression (none, mild, moderate, severe). Multiple logistic regression was used to explore the relationship between Ale and severe depression in participants with diabetes. Results: Rates of depression were higher in men and women with diabetes when compared to those without diabetes, respectively (P<.05). For every I-U increase in Ale, the odds of severe depression increased by 22% (OR 1.22, 95% Cl: 1.05-1.42). Female sex (OR 2.97, 95% Cl: 1.32-6.69) and body mass index (BMI) (OR 1.04, 95% CI: 1.00-1.08) also were significantly associated with increased risk for severe depression. Although BMI appears to be significantly associated with increased risk for severe depression, the magnitude of this effect was small. Conclusions: Individuals with diabetes have higher rates of depression than those without diabetes, consistent with other populations. There is a positive relationship between severity of depression and Ale levels; men and women with severe depression have higher Ale levels than those with moderate-to-no depression. (C) 2010 Published by Elsevier Inc.

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.

OBJECTIVE:Observe and record the demographic and anthropomorphic correlates of health beliefs in American Indians using the multidimensional health locus of control (MHLC) scale.DESIGN:Self-administration or interview rating of Form B of the MHLC scale.SETTING:Arizona, Oklahoma, and Dakota branches of The Strong Heart StudyPARTICIPANTS:3665 participants (1468 men and 2197 women) aged 15 to 93 years (average 39.9) of Phase IV of The Strong Heart Study.MAIN OUTCOME MEASURES:MHLC subscale scores, demographics, anthropometricsRESULTS:DEMOGRAPHICS:Women had higher Chance health locus of control (HLC) than men, but otherwise similar MHLC scores. Age positively correlated with lower Internal HLC and higher Powerful Others HLC. Education was associated with lower Chance HLC. MHLC scores differed by center (AZ, OK, and SD). Anthropometrics: Men with high body fat or high waist-to-hip ratio had higher Powerful Others HLC. Waist-to-hip ratio in women positively correlated to Powerful Others HLC and Chance HLC. BMI was not a strong indicator of differences in MHLC.CONCLUSIONS:To our knowledge, this is the first study to examine health locus of control in American Indians. The health beliefs of American Indians in this study were similar to previous demographic studies in other populations. The associations between certain health beliefs and obesity deserve further exploration to gauge prospective risk. Clinicians should continue to identify psychological issues and counsel American Indian patients in culturally sensitive ways for improved preventive care delivery and increased efficacy of health education.