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This study evaluated the association of arsenic exposure, as measured in urine, with diabetes prevalence, glycated hemoglobin, and insulin resistance in American Indian adults from Arizona, Oklahoma, and North and South Dakota (1989-1991). We studied 3,925 men and women 45-74 years of age with available urine arsenic measures. Diabetes was defined as a fasting glucose level of 126 mg/dL or higher, a 2-hour glucose level of 200 mg/dL or higher, a hemoglobin A1c (HbA1c) of 6.5% or higher, or diabetes treatment. Median urine arsenic concentration was 14.1 µg/L (interquartile range, 7.9-24.2). Diabetes prevalence was 49.4%. After adjustment for sociodemographic factors, diabetes risk factors, and urine creatinine, the prevalence ratio of diabetes comparing the 75th versus 25th percentiles of total arsenic concentrations was 1.14 (95% confidence interval: 1.08, 1.21). The association between arsenic and diabetes was restricted to participants with poor diabetes control (HbA1c ≥8%). Arsenic was positively associated with HbA1c levels in participants with diabetes. Arsenic was not associated with HbA1c or with insulin resistance (assessed by homeostatic model assessment to quantify insulin resistance) in participants without diabetes. Urine arsenic was associated with diabetes control in a population from rural communities in the United States with a high burden of diabetes. Prospective studies that evaluate the direction of the relation between poor diabetes control and arsenic exposure are needed.

We applied Bayesian methods to estimate excess mortality rates by selected causes of death for decedents with diabetes compared to those without diabetes in North Dakota and assessed changes in the excess rate between 1992-1998 and 1999-2003. We report the probability (Pr) of a rate decrease in the age-adjusted excess rate and considered the evidence strong if the probability was 0.90 or higher. Among men with diabetes, the evidence was strong for a probable decrease in excess rate for heart disease (8.7 per 1000 to 6.5), cerebrovascular disease (1.2 per 1000 to 0.75) and arterial disease (0.24 per 1000 to 0.08). Among women with diabetes, the evidence was strong for a probable decrease in excess rates for the overall (total) rate (17.8 per 1000 to 12.6), for heart disease (6.1 per 1000 to 4.4), IHD (4.4 per 1000 to 3.1), cerebrovascular disease (1.4 per 1000 to 0.5), arterial disease (0.17 per 1000 to 0.10) and cancer (2.1 per 1000 to 1.3) as underlying cause of death. The data reflect a high likelihood that cause-specific excess mortality is decreasing for men, and especially for women, with diabetes.

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.

Objective: To estimate incidence rates of diabetes and associated risk factors among participants of the Strong Heart Study., Research Design and Methods: Of the 4,549 Strong Heart Study participants examined at baseline, 3,638 returned for a similar examination after an average of 4 years. The 1985 World Health Organization criteria for diabetes were used to identify new diabetes cases. Rates of diabetes among participants who did not have diabetes at baseline examination were determined. The relationships between the incidence rates of diabetes and a number of risk factors measured at baseline examination were studied., Results: Significant variables associated with the development of diabetes included triglycerides, obesity, fasting plasma glucose, insulin, and degree of American Indian blood among participants with NGT at baseline. For those with IGT at baseline, significant predictors included fasting plasma glucose, 2-h glucose, BMI, degree of American Indian blood, and albuminuria., Conclusions: The high incidence rates found in this study were alarming. To slow down the rapid increase of this disease in the American Indian population, preventive programs must be designed and implemented. Patients with IGT should be treated with diabetes medication or put on a rigid weight-reduction program to reduce the risk of progression to diabetes.

Objectives: Overall and cause-specific mortality among persons with diabetes in North Dakota was estimated and compared with estimates from previous population-based studies., Methods: Data were derived from North Dakota death certificate data, which included unique information on decedents' diabetes status and Behavioral Risk Factor Surveillance System estimates of the diabetic and nondiabetic adult populations of North Dakota., Results: The risk of death among adults with diabetes was 2.6 (2.2, 2.9) times that of adults without diabetes. Relative risks of death among adults with diabetes were at least twice as high for heart disease, cerebrovascular disease, accidents and adverse events, and kidney disease and 70% to 80% higher for pneumonia and influenza, malignant neoplasms, arterial disease, and other causes. Risks remained substantial in the oldest age group. These findings are comparable to results of other population-based studies., Conclusions: Diabetes status information enhanced the usefulness of death certificate data in examining mortality associated with diabetes and confirms that the effect of diabetes on death is substantial.

Objective: In 1997, the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus of the American Diabetes Association (ADA) recommended three new sets of criteria for the diagnosis of diabetes that were different from those established by the World Health Organization (WHO) in 1985. One of these three methods was based on a fasting plasma glucose value only. This article compares ADA criteria with WHO criteria by applying them to three subgroups of American Indians in the Strong Heart Study who had no known diabetes., Research Design and Methods: The Strong Heart Study is a prospective epidemiological study of vascular disease in three American Indian populations aged 45-74 years. During the baseline examination from 1988 to 1991, participants without diagnosed diabetes underwent a fasting glucose test and a 2-h oral glucose tolerance test. These values were used to compare the ADA and WHO diagnostic criteria., Results: By using fasting and 2-h glucose values, prevalence rates of undiagnosed diabetes were 15.9% according to WHO criteria and 14.4% according to ADA criteria. The overall agreement rate was 65%, and the weighted kappa statistic was 0.474, which indicates moderate agreement. The age-specific analysis showed that, among participants between 45 and 54 years of age, the prevalence rates of undiagnosed diabetes were 13.4% according to WHO criteria and 12.7% according to ADA criteria. Among those aged 55-74 years, the rates were 18.7% according to WHO criteria and 16.3% according to ADA criteria. Thus, the difference in the prevalence rates when using WHO and ADA criteria, although generally small in this population, was three times higher in the older group (2.4%) than the difference in the younger group (0.7%)., Conclusions: The Strong Heart Study found that prevalence rates of undiagnosed diabetes determined by ADA criteria and WHO criteria were similar in its American Indian population. The data suggest that the difference between the two criteria may increase as age increases. Longitudinal data will be needed to evaluate further the utility of the two criteria.

Objective: To estimate prevalence rates of diabetes and impaired glucose tolerance (IGT) in three American Indian populations, using standardized diagnostic criteria, and to assess the association of diabetes with the following selected possible risk factors: age, obesity, family history of diabetes, and amount of Indian ancestry., Research Design and Methods: This cross-sectional study involved enrolled members, men and women aged 45-74 years, of 13 American Indian tribes or communities in Arizona, Oklahoma, and South and North Dakota. Eligible participants were invited to the clinic for a personal interview and a physical examination. Diabetes and IGT status were defined by the World Health Organization criteria and were based on fasting plasma glucose and oral glucose tolerance test results. Data on age, family history of diabetes, and amount of Indian ancestry were obtained from the personal interview, and measures of obesity included body mass index, percentage body fat, and waist-to-hip ratio., Results: A total of 4,549 eligible participants were examined, and diabetes status was determined for 4,304 (1,446 in Arizona, 1,449 in Oklahoma, and 1,409 in the Dakotas). In all three centers, diabetes was more prevalent in women than in men. Arizona had the highest age-adjusted rates of diabetes: 65% in men and 72% in women. Diabetes rates in Oklahoma (38% in men and 42% in women) and South and North Dakota (33% in men and 40% in women), although considerably lower than in Arizona, were several times higher than those reported for the U.S. population. Rates of IGT among the three populations (14-17%) were similar to those in the U.S. population. Diabetes rates were positively associated with age, level of obesity, amount of Indian ancestry, and parental diabetes status., Conclusions: Diabetes is found in epidemic proportions in Native American populations. Prevention programs and periodic screening should be implemented among American Indians. Standards of care and intervention have been developed by the Indian Health Service for individuals in whom diabetes is diagnosed. These programs should be expanded to include those with IGT to improve glycemic control or to reduce the risk of development of diabetes as well as to reduce the risk of diabetic complications.

Objective: To evaluate glucose-based community screening for diabetes with regard to detection rate., Research Design and Methods: A retrospective analysis of a community-screening questionnaire data base that included a screening for blood glucose. Referred subjects had fasting glucose levels > 6.4 mM (115 mg/dl) or postprandial levels > or = 8.9 mM (160 mg/dl). An attempt was made to contact referred subjects and to ascertain whether follow-up was undertaken and current status. A random sample of subjects not meeting the glucose criteria (nonreferred) also was contacted in an analogous fashion to referred subjects., Results: In 2,016 questionnaires, glucose-based referral criteria were exhibited by 148 (7.3%) individuals, and subsequent evaluation data were available for 111. Of those 111 individuals, 37 (33%) knew they had diabetes before the screening, and 39 (36%) did not seek further evaluation. Of the remaining 35 subjects, 6 (13%) were told of their new diagnosis of diabetes, and 29 were told they did not have diabetes. Three of 50 nonreferred subjects knew of their diabetes before screening. Thirty percent (14 out of 47) of nonreferred subjects underwent subsequent evaluation, although they were not told to do so. A single new case of diabetes occurred in the nonreferred group., Conclusions: Community screening for diabetes that is based on measured glucose is of low yield. The known problems of glucose-based screening, coupled with its low yield, make a glucose-based approach difficult to justify. These results indicate that glucose-based community screening should be done only under the careful supervision of a health professional who is trained both in glucose measurement instrumentation and in screening.

Objective: To determine the prevalence and incidence rates of diabetes and two specific complications for selected American-Indian tribes in North Dakota, South Dakota, and Nebraska., Research Design and Methods: A descriptive epidemiological study was conducted using ambulatory care data during 1987 for prevalence and diabetes registries and complication case reporting during 1988 from IHS facilities on reservations in these states., Results: The Winnebago and Omaha tribes had the highest age-adjusted diabetes rates, with prevalence 8.8 times and incidence 7.7 times the respective U.S. rates. The diabetes prevalence rate of combined data for the Sioux was 3.7 times the U.S. rate. Among Sioux Indians, the age-adjusted incidence rate for ESRD was 4.8 times the American-Indian/Alaska-Native rate and 13.4 times the rate for U.S. whites. The proportion of new diabetes-related ESRD (86%) was almost 3 times greater than the general U.S. population rate (30%). Also, among the Sioux, the age-adjusted incidence rate for LEA (86.7/10,000 diabetic population) was 1.5 times higher than the U.S. rate; the proportion of diabetes-related LEA (84%) was 1.8 times higher than the general U.S. population rate (45%)., Conclusions: The age-adjusted rates of diabetes and certain complications among these Northern Plains tribes are greater than the U.S. rates. Improved health services to detect and monitor diabetes and its complications and community-based prevention activities directed at the epidemic of diabetes among the various Indian tribes are urgently needed.

The findings from a 1988 audit of medical records of the Three Affiliated Tribes (the Mandan, Arickara, and Hidatsa) at the Fort Berthold, ND, Indian Reservation were compared with the findings from a 1975 audit. The total population served by the IHS clinic there has remained about the same. However, the number of people diagnosed as having diabetes has increased by > 40%. This increase in known cases is caused largely by an increase in the number of women aged > 40 yr who have diabetes. The actual prevalence of diabetes among people aged > 40 yr has increased very little, presumably because the clinic population has aged somewhat over this period of time.