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.

The Relationship Between Adverse Life Events and Endogenous Inhibition of Pain and Spinal Nociception: Findings From the Oklahoma Study of Native American Pain Risk (OK-SNAP)

Adverse life events (ALEs) are a risk factor for chronic pain; however, mechanisms underlying this association are not understood. This study examined whether cumulative ALE exposure impairs endogenous inhibition of pain (assessed from pain report) and spinal nociception (assessed from nociceptive flexion reflex; NFR) in healthy, pain-free Native Americans (n = 124) and non-Hispanic Whites (n = 129) during a conditioned pain modulation (CPM) task. Cumulative ALE exposure was assessed prior to testing by summing the number of potentially traumatic events experienced by each participant across their lifespan. Multilevel modeling found that ALEs were associated with NFR modulation during the CPM task even after controlling for general health, body mass index, sex, age, blood pressure, sleep quality, stimulation intensity, stimulus number, perceived stress, and psychological distress. Low exposure to ALEs was associated with NFR inhibition, whereas high exposure to ALEs was associated with NFR facilitation. By contrast, pain perception was inhibited during the CPM task regardless of the level of ALE exposure. Race/ethnicity did not moderate these results. Thus, ALEs may be pronociceptive for both Native Americans and non-Hispanic Whites by impairing descending inhibition of spinal nociception. This could contribute to a chronic pain risk phenotype involving latent spinal sensitization. PERSPECTIVE: This study found that adverse life events were associated with impaired descending inhibition of spinal nociception in a sample of Native Americans and non-Hispanic Whites. These findings expand on previous research linking adversity to chronic pain risk by identifying a proximate physiological mechanism for this association.

Effect Modification of the Association Between Race and Stage at Colorectal Cancer Diagnosis by Socioeconomic Status

OBJECTIVES

To compare risks of distant-stage colorectal cancer (CRC) diagnosis between whites and American Indian/Alaska Natives (AI/ANs) and to explore effect modification by area-based socioeconomic status (SES).

DESIGN

Retrospective cohort study using data from the Oklahoma Central Cancer Registry.

SETTING

Oklahoma.

PARTICIPANTS

White and AI/AN cases of CRC diagnosed in Oklahoma between 2001 and 2008 (N = 8 438). A subanalysis was performed on the cohort of those aged 50 years and older (N = 7 728).

MAIN OUTCOME MEASURE

Risk of distant-stage CRC diagnosis stratified by SES score.

RESULTS

Race and SES were independently associated with distant-stage diagnosis. In SES-stratified analyses, AI/ANs in the 2 lowest SES groups experienced increased risks in the overall cohort and among those aged 50 years and older. In multivariable models, risks remained significant among those aged 50 years and older in the lowest SES groups (Adjusted risk ratio SES score of 2: 1.31, 95% confidence interval: 1.06-1.63 and adjusted risk ratio SES score of 1: 1.21, 95% confidence interval: 1.01-1.44).

CONCLUSION

Socioeconomic status is an effect modifier in the association between race/ethnicity and stage at CRC diagnosis. Disparities in stage at CRC diagnosis exist between AI/ANs and whites with lower estimated SES. Efforts are needed to increase CRC screening among lower SES AI/ANs.

The Effect of Pain Catastrophizing on Endogenous Inhibition of Pain and Spinal Nociception in Native Americans: Results From the Oklahoma Study of Native American Pain Risk

BACKGROUND

Conditioned pain modulation (CPM) is a task that involves measuring pain in response to a test stimulus before and during a painful conditioning stimulus (CS). The CS pain typically inhibits pain elicited by the test stimulus; thus, this task is used to assess endogenous pain inhibition. Moreover, less efficient CPM-related inhibition is associated with chronic pain risk. Pain catastrophizing is a cognitive-emotional process associated with negative pain sequelae, and some studies have found that catastrophizing reduces CPM efficiency.

PURPOSE

The current study examined the relationship between catastrophizing (dispositional and situation specific) and CPM-related inhibition of pain and the nociceptive flexion reflex (NFR; a marker of spinal nociception) to determine whether the catastrophizing-CPM relationship might contribute to the higher risk of chronic pain in Native Americans (NAs).

METHODS

CPM of pain and NFR was assessed in 124 NAs and 129 non-Hispanic Whites. Dispositional catastrophizing was assessed at the beginning of the test day, whereas situation-specific catastrophizing was assessed in response to the CS, as well as painful electric stimuli.

RESULTS

Situation-specific, but not dispositional, catastrophizing led to less NFR inhibition but more pain inhibition. These effects were not moderated by race, but mediation analyses found that: (a) the NA race was associated with greater situation-specific catastrophizing, which led to less NFR inhibition and more pain inhibition, and (b) situation-specific catastrophizing was associated with greater CS pain, which led to more pain inhibition.

CONCLUSIONS

Catastrophizing may contribute to NA pain risk by disrupting descending inhibition.

Characterizing Discrimination Experiences by Race among Homeless Adults

Objectives: Among domiciled samples, racial discrimination is a known stressor linked with poorer quality of life. However, homeless adults may be particularly vulnerable to discrimination due to multiple factors beyond race. In this study, we characterized perceived discrimination and its reported impact on quality of life in a sample of adults who were homeless. Methods: Homeless adults recruited from Oklahoma City self-reported their socio-demographics, past discrimination experiences, and their impact on quality of life via the MacArthur Major Experiences of Discrimination Questionnaire. Descriptive statistics and frequencies were used to characterize perceived discrimination experiences and impact. Racial differences were examined using ANO- VAs/Kruskal-Wallis tests and chi-square tests. Results: Discrimination experiences attributed to homelessness were common and consistent between the races. Black adults perceived significantly more lifetime discrimination experiences than white adults, and attributed the majority to race. Relative to Whites and American Indians, black adults were more likely to endorse links between discrimination and having a harder life. Conclusions: Results suggest that black homeless adults may represent the most vulnerable racial subgroup for hardships in life as a conse- quence of perceived discrimination among homeless adults.

"Gay Equals White"? Racial, Ethnic, and Sexual Identities and Attitudes Toward LGBT Individuals Among College Students at a Bible Belt University

While past research has certainly explored a variety of correlates of attitudes toward lesbian, gay, bisexual, and transgender (LGBT) individuals, the current study is among the first in an emerging line of inquiry that examines attitudes toward each of these groups separately utilizing an intersectional framework with special attention to racial, ethnic, and sexual identities. Using a college sample of students from the Bible Belt of the United States (N = 1,940), I investigated the roles of racial and ethnic identities (Caucasian/White, African American/Black, Asian/Pacific Islander, Native American/Alaskan Native, other race, and Hispanic/Latinx), religiosity, patriarchal gender norms, parental perspectives, and the intersections among these identities and experiences as they relate to attitudes toward LGBT individuals among heterosexual (n = 1,551) and LGB respondents (n = 389). This moves beyond explorations of White heterosexual people's attitudes about "homosexuals" (i.e., away from a focus only on gayness and Whiteness) and expands to include non-White LGB people's LGBT attitudes. Overall, results indicate that racial, ethnic, and sexual identities play a significant role in southern college students' LGBT attitudes, and these patterns are further complicated by interacting cultural experiences with religiosity, patriarchy, and family dynamics. Campus policy and program implications are provided.

Plasminogen activator inhibitor-1 is associated with leukocyte telomere length in American Indians: findings from the Strong Heart Family Study

Essentials Plasminogen activator inhibitor-1 (PAI-1) advanced cellular senescence in experiment studies. No population study exists on the association between PAI-1 and biological aging in American Indians. We found cross-sectional and longitudinal associations between higher PAI-1 and shorter telomere length. Our findings suggest a pathway linking PAI-1 with biological aging beyond metabolic factors.

SUMMARY

Background Plasminogen activator inhibitor-1 (PAI-1) promotes cellular aging both in vitro and in vivo. Telomere length is a marker of biological aging. Objectives To examine the cross-sectional and longitudinal associations between plasma PAI-1 and leukocyte telomere length in a large-scale epidemiological study of American Indians. Methods We measured leukocyte telomere length (LTL) and plasma PAI-1 in 2560 American Indians who were free of overt cardiovascular disease (CVD) and participated in the Strong Heart Family Study (SHFS) clinical examination in 2001-2003. LTL and PAI-1 were repeatedly measured in 475 participants who attended SHFS clinical visits in both 2001-2003 and 1998-1999. A generalized estimating equation model was used to examine the cross-sectional and longitudinal associations between PAI-1 and LTL, adjusting for known risk factors. Results A higher level of plasma PAI-1 was negatively associated with shorter age-adjusted LTL (β = -0.023; 95% CI, -0.034 to -0.013). This association was attenuated (β = -0.015; 95% CI, -0.029 to -0.002) after adjustments for demographics, study site, lifestyle (smoking, drinking and physical activity) and metabolic factors (obesity, blood pressure, fasting glucose, insulin, lipids and kidney function). Further adjustment for hsCRP did not change this association (β = -0.015; 95% CI, -0.029 to -0.001). Longitudinal analysis revealed that change in plasma PAI-1 was also inversely associated with change in LTL after adjusting for demographics, follow-up years, lifestyle factors, changes in metabolic factors, baseline levels of PAI-1 and LTL (β = -0.0005; 95% CI, -0.0009 to -0.0001). Conclusions A higher level of plasma PAI-1 was associated with shorter LTL in American Indians. This finding may suggest a potential role of PAI-1 in biological aging among American Indians.

Comparison of American Indian and Non-Native BASC-2 Self-Report-Adolescent Scores

BASC-2 SRP-A scores of 162 American Indian (AI) youth were compared with those of an ethnically diverse sample (N = 200) to explore group equivalence. A MANOVA indicated group differences among the five composites. AIs outscored non-Natives in Inattention/Hyperactivity. We examined AIs' ADHD scores in relation to their acculturation strategies, measured using the Bicultural Ethnic Identity Scale. Culturally marginalized AIs (low White and low Indian acculturation) reported stronger ADHD symptoms than bicultural, assimilated, or separated youth. The potential impact of culture on clinical measures is discussed.

THE EFFECT OF A CULTURALLY TAILORED SUBSTANCE ABUSE PREVENTION INTERVENTION WITH PLAINS INDIAN ADOLESCENTS

PURPOSE

To examine the effects of incorporating tribal specific cultural beliefs into a tailored substance abuse prevention intervention for at risk rural Oklahoma Native American Indian (NAI) Plains adolescents.

RESEARCH DESIGN

The 10 hour Native American Talking Circle Intervention, a school-based, group substance abuse prevention program, was implemented over a 8.5 week period and evaluated using a one group, pretest-posttest design. Measurements were from the Native Self-Reliance Questionnaire and the Substance Problems Scale from Global Appraisal of Individual Needs-Quick (GAIN-Q).

FINDINGS

One-tailed, paired sample t-tests demonstrated significant increase in self-reliance, from 86.227 to 92.204 (t (43) = -2.580, p = .007) and a decrease in substance abuse/use, from 2.265 to 1.265 (t (33) = 1.844, p = .007).

CONCLUSIONS

The Native Talking Circle Intervention based on tribal-specific values and beliefs was shown to be effective with substance abuse/use at-risk NAI Plains tribal adolescents.

Cultural identity and patient trust among older American Indians

BACKGROUND

Patients' trust in healthcare providers and institutions has been identified as a likely contributor to racial-ethnic health disparities. The likely influence of patients' cultural characteristics on trust is widely acknowledged but inadequately explored.

OBJECTIVE

To compare levels of patients' trust in primary care provider (interpersonal trust) with trust in healthcare organizations (institutional trust) among older American Indians (AIs), and determine associations with cultural identity.

DESIGN

Patient survey administered following primary care visits.

PARTICIPANTS

Two-hundred and nineteen American Indian patients ≥ 50 years receiving care for a non-acute condition at two clinics operated by the Cherokee Nation in northeastern Oklahoma.

MAIN MEASURES

Self-reported sociodemographic and cultural characteristics. Trust was measured using three questions about interpersonal trust and one measure of institutional trust; responses ranged from strongly agree to strongly disagree. Finding substantial variation only in institutional trust, we used logistic generalized estimating equations to examine relationships of patient cultural identity with institutional trust.

KEY RESULTS

Ninety-five percent of patients reported trusting their individual provider, while only 46 % reported trusting their healthcare institution. Patients who strongly self-identified with an AI cultural identity had significantly lower institutional trust compared to those self-identifying less strongly (OR: 0.6, 95 % CI: 0.4, 0.9).

CONCLUSIONS

Interpersonal and institutional trust represent distinct dimensions of patients' experience of care that may show important relationships to patients' cultural characteristics. Strategies for addressing low institutional trust may have special relevance for patients who identify strongly with AI culture.

Different disparities of gender and race among the thrombotic thrombocytopenic purpura and hemolytic-uremic syndromes

Thrombotic thrombocytopenic purpura (TTP) and hemolytic-uremic syndrome (HUS) represent multiple disorders with diverse etiologies. We compared the gender and race of 335 patients enrolled in the Oklahoma TTP-HUS Registry across 21 years for their first episode of TTP or HUS to appropriate control groups. The relative frequency of women and white race among patients with TTP-HUS-associated with a bloody diarrhea prodrome and the relative frequency of women with quinine-associated TTP-HUS were significantly greater than their control populations. The relative frequency of women and black race among patients with idiopathic TTP and TTP-associated with severe ADAMTS13 deficiency was significantly greater than their control populations. The relative frequency of black race among patients who had systemic lupus erythematosus (SLE) preceding TTP was significantly greater than among a population of patients with SLE, and the relative frequency of black race among patients with other autoimmune disorders preceding TTP was significantly greater than their control population. No significant gender or race disparities were present among patients with hematopoietic stem cell transplantation-associated thrombotic microangiopathy, TTP associated with pregnancy, or TTP associated with drugs other than quinine. The validity of these observations is supported by the enrollment of all consecutive patients across 21 years from a defined geographic region, without selection or referral bias. These observations of different gender and race disparities among the TTP-HUS syndromes suggest the presence of different risk factors and may serve as starting points for novel investigations of pathogenesis.

Urban Indian voices: a community-based participatory research health and needs assessment

This community-based participatory research (CBPR) project utilized a mixed-methods survey design to identify urban (Tulsa, OK) American Indian (AI) strengths and needs. Six hundred fifty AIs (550 adults and 100 youth) were surveyed regarding their attitudes and beliefs about their community. These results were used in conjunction with other community research efforts to inform program development, support proposals for external funding, and develop a comprehensive service system model to be implemented in the community.

Evaluation of C1q genomic region in minority racial groups of lupus

Complement cascade plasma proteins play a complex role in the etiopathogenesis of systemic lupus erythematosus (SLE). Hereditary C1q deficiency has been strongly related to SLE; however, there are very few published SLE studies that evaluate the polymorphisms of genes encoding for C1q (A, B and C). In this study, we evaluated 17 single nucleotide polymorphisms (SNPs) across 37 kb of C1QA, C1QB and C1QC in a lupus cohort of individuals of the African-American and Hispanic origin. In a case-only analysis, a significant association at multiple SNPs in the C1QA gene was detected in African Americans with kidney nephritis (best P=4.91 x 10(-6)). In addition, C1QA was associated with SLE in African Americans with a lack of nephritis and accompanying photosensitivity when compared with that in normal controls (P=6.80 x 10(-6)). A similar trend was observed in the Hispanic subjects (P=0.003). Quantitative analysis showed that some SNPs in C1q genes might be correlated with C3 complement levels in an additive model among African Americans (best P=0.0001). The C1QA gene is associated with subphenotypes of lupus in the African-American and Hispanic subjects. Further studies with higher SNP densities in this region and other complement components are necessary to elucidate the complex genetics and phenotypic interactions between complement components and SLE.

Bereavement rituals in the Muscogee Creek tribe

A qualitative, collective case study explores bereavement rituals in the Muscogee Creek tribe. Data from interviews with 27 participants, all adult members of the tribe, revealed consensus on participation in certain bereavement rituals. Common rituals included: (a) conducting a wake service the night before burial; (b) never leaving the body alone before burial; (c) enclosing personal items and food in the casket; (d) digging graves by hand; (e) each individual throwing a handful of dirt into the grave before covering, called giving a "farewell handshake"; (f) covering the grave completely by hand; (g) building a house over the grave; (h) waiting 4 days before burial; (i) using medicine/purification; and (j) adhering to socialized mourning period. Cultural values of family, community, religion, importance of the number 4, Indian medicine, and the meaning of death contributed to the development of these rituals.

Asthma in American Indian adults: the Strong Heart Study

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 > or = 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 FEV(1) 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.

Body mass index and blood pressure screening in a rural public school system: the Healthy Kids Project

INTRODUCTION

All students (N = 2053) in Anadarko public schools, grades kindergarten through 12, were invited to be screened for height, weight, and blood pressure to assess the health status of this multiracial, multiethnic (American Indian, white, African American, and Hispanic) population in southwestern Oklahoma.

METHODS

The Centers for Disease Control and Prevention's 2000 growth charts were used to determine body mass index (BMI) percentiles, and standards from the National High Blood Pressure Education Program Working Group on Hypertension Control in Children and Adolescents were used to assess blood pressure.

RESULTS

Seven hundred sixty-nine students with active consent participated in the screening. Of these, approximately 28% were overweight. American Indians were at significantly greater risk of being overweight or at risk for overweight than whites (relative risk [RR], 1.4; 95% confidence interval [CI], 1.1-1.7) as were African Americans (RR, 1.5; 95% CI, 1.1-2.0), whereas Hispanics (RR, 1.3; 95% CI, 0.9-2.0) did not have a statistically significant increased risk compared with whites. BMI at or above the 95th percentile was strongly associated with elevated blood pressure (> or =90th percentile) (RR, 3.8; 95% CI, 2.6-5.4).

CONCLUSION

Students who participated in this BMI screening in the Anadarko public school system evidenced high rates of excess weight, with American Indians and African Americans at greatest risk. Elevated BMI was strongly associated with elevated blood pressure.

Prediction of coronary heart disease in a population with high prevalence of diabetes and albuminuria: the Strong Heart Study

BACKGROUND

The present article presents equations for the prediction of coronary heart disease (CHD) in a population with high rates of diabetes and albuminuria, derived from data collected in the Strong Heart Study, a longitudinal study of cardiovascular disease in 13 American Indian tribes and communities in Arizona, North and South Dakota, and Oklahoma.

METHODS AND RESULTS

Participants of the Strong Heart Study were examined initially in 1989-1991 and were monitored with additional examinations and mortality and morbidity surveillance. CHD outcome data through December 2001 showed that age, gender, total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein cholesterol, smoking, diabetes, hypertension, and albuminuria were significant CHD risk factors. Hazard ratios for ages 65 to 75 years, hypertension, LDL cholesterol > or = 160 mg/dL, diabetes, and macroalbuminuria were 2.58, 2.01, 2.44, 1.66, and 2.11 in men and 2.03, 1.69, 2.17, 2.26, and 2.69 in women, compared with ages 45 to 54 years, normal blood pressure, LDL cholesterol <100 mg/dL, no diabetes, and no albuminuria. Prediction equations for CHD and a risk calculator were derived by gender with the use of Cox proportional hazards model and the significant risk factors. The equations provided good discrimination ability, as indicated by a c statistic of 0.70 for men and 0.73 for women. Results from bootstrapping methods indicated good internal validation and calibration.

CONCLUSIONS

A "risk calculator" has been developed and placed on the Strong Heart Study Web site, which provides predicted risk of CHD in 10 years with input of these risk factors. This may be valuable for diverse populations with high rates of diabetes and albuminuria.

Apolipoprotein E4 and tau allele frequencies among Choctaw Indians

Apolipoprotein genotyping and tau haplotyping were carried out on a series of cases with dementia and controls from the Choctaw Nation of Oklahoma. Both the Apolipoprotein E4 allele frequency and the tau H2 haplotype frequency were low in the Choctaw compared with Caucasians and there was the possibility that the association between dementia and the E4 allele was weaker than in Caucasians.

Differences in echocardiographic findings and systemic hemodynamics among non-diabetic American Indians in different regions: The Strong Heart Study

PURPOSE

This study was undertaken to determine whether differences in left ventricular (LV) and systemic hemodynamic findings exist between American Indians in different regions that might contribute to known differences in cardiovascular morbidity rates among American Indians.

METHODS

We compared echocardiography results in 290 non-diabetic Strong Heart Study (SHS) participants in Arizona, 595 in Oklahoma and 572 in North/South Dakota (ND/SD).

RESULTS

Participants in the 3 regions were similar in age and gender but those in Arizona had the highest body mass indices and lowest heart rates while those in ND/SD had the lowest diastolic blood pressures (BP). In analyses that adjusted for significant covariates, ND/SD participants had larger aortic (Ao) anular, Ao root, and LV chamber size as well as higher cardiac output and lower peripheral resistance, whereas Arizona participants had increased LV wall thickness and mass and reduced LV myocardial contractility. These findings may contribute to the known high rates of cardiovascular events in ND/SD Indians and to the proportionately higher rate of cardiovascular death than of non-fatal cardiovascular events that has been recently documented in Arizona Indians.

CONCLUSIONS

Application of echocardiography to non-diabetic SHS participants reveals that LV chamber and arterial size are larger in ND/SD Indians and that LV wall thicknesses and mass are higher and LV myocardial contractility lower in Arizona Indians, possibly contributing to the higher than expected rates of cardiovascular morbidity and mortality among Indians in Arizona.

Rheumatoid arthritis in a United States Public Health Service Hospital in Oklahoma: serologic manifestations in rheumatoid arthritis vary among tribal groups

OBJECTIVE

To study the serologic manifestations of rheumatoid arthritis (RA) at a United States Public Health Service Hospital that serves numerous tribes in Oklahoma.

METHODS

Forty-five patients with RA were identified, and serologic studies for antinuclear antibody (ANA), rheumatoid factor, and antibodies to extractable nuclear antigens were performed. Extraarticular manifestations of RA were also evaluated.

RESULTS

Twelve of the 45 patients with RA were Kiowa. These patients were significantly more likely to have a positive ANA (75%) than the other patients with RA (28%). In addition, anti-Ro was significantly more common among Kiowa (33%) than among members of other tribes (3%). There was no difference in the extraarticular manifestations of the Kiowa compared with the other Native American tribes.

CONCLUSION

RA can be distinctly characterized by serology among groups of American Indians living in the same geographic area.