OBJECTIVE: To investigate the prevalence of arthritis and associations with arthritis in American Indian and Alaska Native populations. METHODS: Data on self-reported, doctor-diagnosed arthritis from the baseline visit of 9,968 American Indian and Alaska Native adults from Alaska and the Southwest US were included. The prevalence of arthritis and univariate and multivariate associations between arthritis and demographic characteristics, health-related factors, and treatment are described. RESULTS: The prevalence of self-reported arthritis increased with age. The age-sex adjusted prevalence was high in Alaska (26.1%) and low in the Southwest US (16.5%) as compared with the US population (21.5%). In both centers, arthritis was associated with age, lack of employment, chronic medical conditions, and poorer self-reported overall health. Arthritis was associated with female sex in Alaska only, whereas education, marital status, and urban residency were associated with arthritis in the Southwest US. In both centers, self-reported physical health measured by the Short Form 12 Health Survey was lower in people with arthritis, and mental health was not associated with arthritis. More frequent use of antiinflammatory medications was reported with arthritis in both centers, but increased use of traditional medicine and healers were associated with arthritis only in Alaska. CONCLUSION: Compared with US rates, the prevalence of self-reported arthritis was higher among Alaska Native people and lower in a Southwest American Indian population. Some factors associated with arthritis differ between the 2 populations.
BACKGROUND: Cancer incidence rates vary among American Indian and Alaska Native (AI/AN) populations and often differ from rates among non-Hispanic whites (NHWs). However, the misclassification of race for AI/AN cancer cases in central cancer registries may have led to underestimates of the AI/AN cancer burden in previous reports. METHODS: Cases diagnosed during 1999 through 2004 were identified from population-based cancer registries in the United States. Age-adjusted rates were calculated for the 25 most common sites for AI/ANs and NHWs. To minimize the misclassification of race, cancer registry records were linked with patient registration files from the Indian Health Service (IHS). Analyses were restricted to Contract Health Service Delivery Area (CHSDA) counties and were stratified by IHS region. RESULTS: In CHSDA counties, cancer incidence rates among AI/ANs varied widely by region, whereas rates among NHWs did not. For all cancer sites combined, AI/AN rates were higher than NHW rates among both males and females in the Northern and Southern Plains, and among Alaska Native Females; AI/AN rates were lower than NHW rates in the Southwest, the Pacific Coast, and the East. Lung cancer and colorectal cancer rates for AI/ANs exceeded rates for NHWs in Alaska and the Northern Plains. Rates for stomach, gallbladder, kidney, and liver cancer were higher among AI/ANs than among NHWs overall, in Alaska, in the Plains regions, and in the Southwest. CONCLUSIONS: Regional differences in cancer incidence rates among AI/AN populations were not obvious from nationwide data and highlighted opportunities for cancer control and prevention. It is unlikely that such differences are explained by race misclassification.
BACKGROUND: Assessment of the kidney parenchyma ("kidney") and urinary bladder ("bladder") cancer burden among American Indians and Alaska Natives (AI/AN) has been limited. Using a database with improved classification for AI/AN, the authors described patterns of these 2 cancers among AI/AN and non-Hispanic whites (NHW) in the United States. METHODS: Cases diagnosed during 1999 to 2004 were identified through National Program of Cancer Registries and the Surveillance, Epidemiology and End Results program and linked to the Indian Health Service (IHS) registration records. Age-adjusted incidence rates, rate ratios (RR), annual percent change, and stage at diagnosis were stratified by IHS Contract Health Service Delivery Area (CHSDA) counties to adjust for misclassification. RESULTS: Kidney cancer incidence among AI/AN in CHSDA counties exceeded that among NHW (RR, 1.51; 95% confidence interval [CI], 1.42-1.61), and was highest among AI/AN in the Northern Plains, Southern Plains, Alaska, and Southwest. Average annual increases were highest among AI/AN (5.9%) and NHW (5.9%) males aged 20 to 49 years, although statistically significant only among NHW. Conversely, bladder cancer incidence was significantly lower among AI/AN than NHW (RR, 0.40; 95% CI, 0.37-0.44). For both sites, AI/AN were significantly less likely to be diagnosed at an earlier stage than NHW. CONCLUSIONS: AI/AN have about 50% greater risk of kidney cancer and half the risk of bladder cancer than NHW. Although reasons for these enigmatic patterns are not known, sustained primary prevention efforts through tobacco cessation and obesity prevention are warranted.
OBJECTIVES: The purpose of this study was to develop a dietary instrument (food frequency questionnaire [FFQ]) that measured total dietary intake over 1 year among Alaska Native people in 2 regions. Ways of assessing diet are needed in order to accurately evaluate how the diets of Alaska Natives relate to their health. STUDY DESIGN: Seasonal 24-hour (24-h) diet recalls were collected for developing an FFQ that described the average dietary foods and nutrients consumed. Alaska Native people living in 12 small communities in 2 regions of the state were eligible to participate. METHODS: Each participant was to provide 4 24-h diet recalls, 1 per season. Recalls were used to develop an FFQ using regression techniques. The FFQ was administered to 58 of the 333 original participants. Responses to the FFQ were compared to the averages of their 24-h recalls using the Spearman Correlation Coefficient. RESULTS: Energy-adjusted correlations ranged from 0.15 for protein to 0.49 for monounsaturated fatty acids. Fifteen of 26 nutrients examined were significantly correlated (total carbohydrates, sucrose, fructose, total fat, fatty acids [monounsaturated, polyunsaturated, omega 3, EPA, DHA], folate, vitamins A, C, D, potassium and selenium). CONCLUSIONS: The FFQ can be used to evaluate intakes of Alaska Natives in western Alaska for the correlated nutrients.
Collection of dietary intake in epidemiologic studies involves using methods that are comprehensive yet appropriate for the population being studied. Here we describe a diet history questionnaire (DHQ) that was developed using an audio self-administered computer-assisted interview technique. The DHQ was developed for use in a cohort of American Indians and Alaskan Natives with tribal input and area-specific modules to incorporate local food availability. The DHQ includes 54 main food group questions, specific food items within the main food group, and food preparation and general eating practice questions. The questionnaire was programmed to be self-administered using a computer with a touch screen. The average time for the first 6,604 participants to complete the questionnaire was 36 minutes. Almost 100% of participants had complete DHQ data and the average number of food items selected was 70. The methods developed for collection of dietary data appear to be appropriate for the targeted population and may have usefulness for other populations where collecting dietary data in a self-administered format is desirable.
OBJECTIVES: To calculate the energy and nutrient intake in 2 regions of Alaska and to describe the implications for development of chronic disease among Alaska Native people (AN). STUDY DESIGN: Cross-sectional observation; 10 villages and 2 hub communities in rural Alaska; 333 participants ages 13 to 88 years old. METHODS: Trained interviewers collected 24-hour diet recalls during 4 seasons. RESULTS: In both regions, AN reported a combination of traditional Native foods and store bought foods; most of the energy comes from store-bought foods; a high proportion of nutrients come from Native foods, especially protein, iron and omega-3 fatty acids. Mean intakes of omega-3 fatty acids, from fish and sea mammals, are over twenty times greater than those of the general U.S. population. Mean intakes of protein, iron, selenium, vitamin A, vitamin C (men) and folate (men) met recommended levels; intakes of calcium and fiber were below recommended levels; carbohydrate and saturated fat (% energy) were above. CONCLUSIONS: Traditional foods continue to contribute a significant amount of nutrients to the diet in rural Alaska. Excess simple sugars may be contributing to the rise in obesity and diabetes. Low intakes of calcium, dietary fiber, fruits and vegetables may contribute to the increased incidence of cancers of the digestive system. Emphasis on the positive aspects of Native foods and increased consumption of fruits, vegetables and calcium-rich foods are warranted.
BACKGROUND: Gastric cancer incidence rates for American Indians and Alaska Natives (AI/ANs) historically have exceeded those for non-Hispanic whites (NHWs). Previous reports may have underestimated the true burden of gastric cancer in AI/AN populations because of misclassification of AI/AN race in cancer registries. METHODS: Population-based cancer registry data from 1999 through 2004 were used to describe gastric cancer incidence in AI/ANs and NHWs in the US. To address misclassification of race, registry data were linked with Indian Health Service administrative records, and analyses were restricted to residents of Contract Health Service Delivery Areas (CHSDA). Disease patterns were assessed for 6 geographic regions and for all regions combined. Rates were expressed per 100,000 population and were age-adjusted to the 2000 US standard population. RESULTS: In CHSDA counties, gastric cancer incidence rates for AI/ANs were higher than the rates for NHWs across most regions. For both sexes combined, AI/AN rates ranged from 6.1 in the East region to 24.5 in Alaska; there was relatively little regional variation in NHW rates. Most patients with gastric cancer were diagnosed with late-stage disease, regardless of race, age, or sex. In some regions, cancer rates in the central/distal portions of the stomach were higher among AI/ANs than among NHWs, whereas rates in the proximal stomach were similar between the 2 populations. CONCLUSIONS: AI/ANs are generally at greater risk for gastric cancer than NHWs. Relatively high rates of cancer in the central/distal portions of the stomach among AI/ANs in some geographic regions may indicate a disproportional burden of Helicobacter pylori-associated disease.
BACKGROUND: Previous studies identified disparities in incidence rates of cancers of the oral cavity and pharynx between American Indians/Alaska Natives (AI/AN) and non-Hispanic whites (NHW) and differences between various AI/AN populations. Reporting among AI/AN has been hampered by: 1) heterogeneity among various anatomic sites of oral cavity and pharyngeal cancers obscuring unique patterns of individual anatomic sites; 2) race misclassification and underreporting of AI/AN; and 3) sparseness of data needed to identify regional variations. METHODS: To improve race classification of AI/AN, data from US central cancer registries were linked with Indian Health Service (IHS) records. AI/AN incidence data from 1999 to 2004 were stratified by sex, age, stage at diagnosis, and anatomic subsite for 6 IHS geographic regions and compared with NHW populations. RESULTS: For all oral cavity and pharynx cancers combined, among residents of Contract Health Service Delivery Area counties, AI/AN overall had significantly lower incidence rates than NHW (8.5 vs 11.0). However, AI/AN rates were significantly higher in the Northern Plains (13.9 vs 10.5) and Alaska (16.3 vs 10.6), significantly lower in the Pacific Coast (7.7 vs 11.6) and Southwest (3.3 vs 10.4), and similar in the Southern Plains (11.4). Overall AI/AN males had higher incidence rates than AI/AN women. Nasopharyngeal cancer was more frequent (1.1AI/AN vs 0.4 NHW), and tongue cancer less frequent (1.6 AI/AN vs 2.9 NHW) in AI/AN than NHW populations; however, rates varied by region. Stage distribution was modestly less favorable for AI/AN compared with NHW populations. CONCLUSIONS: Variation by region, anatomic site, and sex indicates a need for research into etiologic factors and attention to regional risk factor profiles when planning cancer control programs.
BACKGROUND: Metabolic syndrome occurs commonly in the United States. The purpose of this study was to measure the prevalence of metabolic syndrome among American Indian and Alaska Native people. METHODS: We measured the prevalence rates of metabolic syndrome, as defined by the National Cholesterol Education Program, among four groups of American Indian and Alaska Native people aged 20 years and older. One group was from the southwestern United States (Navajo Nation), and three groups resided within Alaska. Prevalence rates were age-adjusted to the U.S. adult 2000 population and compared to rates for U.S. whites (National Health and Nutrition Examination Survey [NHANES] 1988-1994). RESULTS: Among participants from the southwestern United States, metabolic syndrome was found among 43.2% of men and 47.3% of women. Among Alaska Native people, metabolic syndrome was found among 26.5% of men and 31.2% of women. In Alaska, the prevalence rate varied by region, ranging among men from 18.9% (western Alaska) to 35.1% (southeast), and among women from 22.0% (western Alaska) to 38.4 % (southeast). Compared to U.S. whites, American Indian/Alaska Native men and women from all regions except western Alaska were more likely to have metabolic syndrome; men in western Alaska were less likely to have metabolic syndrome than U.S. whites, and the prevalence among women in western Alaska was similar to that of U.S. whites. CONCLUSION: The prevalence rate of metabolic syndrome varies widely among different American Indian and Alaska Native populations. Differences paralleled differences in the prevalence rates of diabetes.
BACKGROUND: Early reports of esophageal and gastric cancer in American Indians/Alaska Natives documented high rates. METHODS: Esophageal and gastric cancers in Alaska Natives were reviewed for 1969-2003 using the Alaska Native Tumor Registry database. Alaska Native incidence rates were age-adjusted and compared to rates of several US populations. RESULTS: The incidence of esophageal and gastric cancer has remained relatively stable during the 35-year period. Gastric cancer is higher than that seen in US Whites, Blacks and American Indians of New Mexico and similar US Asian/Pacific Islanders. Esophageal cancer incidence is higher than US Whites, Asian/Pacific Islanders and American Indians of New Mexico but similar to US Blacks. CONCLUSION: The rates of esophageal and gastric cancer in the Alaska Native population have remained high over 35 years. While the rate of gastric cancer has declined among US Whites, a similar decline has not been seen in Alaska Natives.