The relations between insulinemia, insulin resistance, and blood pressure differ among racial groups and may be mediated by mechanisms active in whites, but not in Pima Indians or blacks.

The incidence of fatal coronary heart disease (CHD) was determined in a population of Pima Indians from the Gila River Indian Community in Arizona. Between 1975 and 1984, 394 deaths occurred among 4,828 subjects aged 5 years or older, and 199 of these occurred in the 1,093 persons with non-insulin-dependent diabetes. Only 28 deaths were attributed to CHD; all occurred among the 689 diabetic persons 45 years of age or older. No CHD deaths occurred among the 419 nondiabetic subjects 45 years of age or older. The rate of fatal CHD among the diabetic subjects was higher in men than in women and increased with advancing age and duration of diabetes. A higher incidence of fatal CHD was associated with proteinuria, renal insufficiency, medial arterial calcification, diabetic retinopathy, insulin therapy, and an abnormal electrocardiogram. In Pima Indians aged 50-79 years, the incidence of fatal CHD was less than half that found in the Framingham population after controlling for age, sex, and diabetes (incidence rate ratio, 0.4; 95% confidence interval, 0.2-0.7). Factors protecting Pima Indians from fatal CHD may include racial heritage, low serum concentrations of total and low density lipoprotein cholesterol, and rarity of heavy smoking. Among the diabetic subjects, mortality from diabetic renal disease, which shows many of the same risk factors, may selectively compete and remove those at risk for fatal CHD. This would not, however, explain the lack of fatal CHD among the nondiabetic subjects. Fatal CHD shares many of the risk factors associated with the specific microvascular complications of diabetes, and diabetes and its associated attributes are the major predictors of fatal CHD in this population. (Circulation 1990;81:987-995) A therosclerotic coronary heart disease (CHD) occurs more frequently in persons with diabetes mellitus than in those without it1,2 and is the most common underlying cause of death in diabetic adults in the United States.2 Although the Pima Indians of the Gila River Indian Community in Arizona have the world's highest reported prevalence of non-insulin-dependent diabetes,3 they have a low frequency of clinically apparent myocardial infarction4 and a low prevalence of electrocardiographic (ECG) and necropsy-proven CHD.4-6 In the present study, the incidence of CHD as an underlying cause of death was determined in the Pima Indians with and without non-insulindependent diabetes. Risk factors for CHD death were identified, and the incidence of fatal CHD was compared with that of the primarily caucasian population participating in the Framingham study.7Methods A longitudinal study of diabetes and its complications has been conducted in the Gila River Indian

High blood pressure, abnormal glucose tolerance, and obesity are frequently associated with each other, but the mechanism of these associations is poorly understood. Studying them in children may help in understanding the pathogenesis of hypertension. Blood pressure, height, weight, and plasma glucose and serum insulin concentrations during a 75-g oral glucose tolerance test were measured in 1,698 Pima Indian children aged 6-17 years who participated in an ongoing epidemiologic study. Weight relative to height was used as an index of obesity. The parents of many of the children were also examined. Fasting and 2-hour glucose and insulin concentrations, adjusted for age, sex, and relative weight, were positively related to systolic blood pressure but not to diastolic blood pressure. Relative weight, 2-hour glucose, and fasting insulin concentrations were independently and significantly associated with systolic blood pressure in a stepwise regression analysis that included age and sex. After parental hypertension was taken into account, maternal but not paternal non-insulin-dependent diabetes mellitus, controlled for the child's relative weight and glucose and insulin concentrations, was significantly associated with higher blood pressure in children. The stronger association with maternal diabetes suggests a greater sharing of environmental factors between mother and child than between father and child, but familial similarities in obesity and glucose and insulin concentrations, the diabetic intrauterine milieu, and shared environmental factors probably all contribute to this association.