Thomas A. Burch

Gallbladder disease in pima indians. Demonstration of high prevalence and early onset by cholecystography.

Abstract An American Indian population was investigated to determine the true prevalence of gallbladder disease, to examine its relation to suggested etiologic factors and to identify high-risk persons. From an age–sexstratified random sample of 596 Pima Indians 15 to 74 years of age. subjects with clinically documented gallbladder disease were identified by review of medical records. An attempt was then made to examine the remainder of the sample by cholecystography. The overall prevalence of gallbladder disease was 48.6 per cent, which greatly exceeded that based on clinical diagnosis alone. The prevalence was significantly higher in females and increased with age in both sexes. No association was demonstrated between gallbladder disease and obesity, serum cholesterol level, diabetes or parity. Pima females 15 to 20 years of age were shown to be at high risk of early development of gallbladder disease and to offer unusual opportunities for further epidemiologic and clinical studies.

Diabetes in the Pima Indians: Evidence of Bimodality in Glucose Tolerance Distributions

Venous plasma glucose levels two hours after a 75 gm. carbohydrate load were determined on over 2,900 Pima Indians, a population known to have an extremely high prevalence of diabetes mellitus. In each sex and in each decade above twenty-five years of age, the frequency distributions of the logarithms of the glucose levels were clearly bimodal, but below this age a single symmetrical unimodal distribution was found. A maximum likelihood procedure was used to derive the best fitting theoretical gaussian distributions for each group of data, together with the parameters of each distribution. The observed bimodal distributions were found to be in satisfactory agreement with a model of two overlapping gaussian distributions, indicating that a logical separation between those with normal and high levels of glucose is possible, although the presence of overlap indicates that some misclassification will occur if any finite level is used to subdivide the population. The data indicate that among the Pima: 1. The frequency distributions of two-hour glucose tolerance levels can be used to identify objectively and describe a hyperglycemic population without recourse to other criteria for diabetes. 2. There are small changes in the parameters of “normal” glucose tolerance between the ages of twenty-five and sixtyfour years. 3. The increase in mean glucose level found with rising age in this population is mainly the result of an increasing proportion of subjects who are in the group characterized by marked glucose intolerance. The bimodal distributions of plasma glucose levels The bimodal distributions of plasma glucose levels among the Pima Indians contrast with those described so far in other groups. It seems likely that differences are attributable to the lower prevalence of diabetes elsewhere which would obscure the identification of bimodality.

Congenital Anomalies and Diabetes in the Pima Indians of Arizona

Medical records of 1,207 Pima Indian children were examined for reported congenital anomalies. Anomalies occurred in eight (38.1 per cent) of twenty-one offspring born after the onset of diabetes to mothers whose disease was diagnosed before age twenty-five, but in only 3.7 per cent of the offspring of all other women. Children born after the onset of diabetes to mothers whose disease started at or after age twenty-five, and those born to prediabetic mothers had anomalies no more frequently than the children of nondiabetic mothers. Congenital anomalies were not related to paternal diabetes. Anomalies were more frequent in children from “diabetic” pregnancies during which the mother required hypoglycemic medication than from those during which medication was not required. Although a genetic mechanism cannot be completely excluded, the data better support the hypothesis that diabetes produced fetal anomalies among the Pima Indians by its influence upon the intrauterine environment during early pregnancy.

Hyperglycemia in Washoe and Northern Paiute Indians

The prevalence of hyperglycemia in two American Indian tribes, the Washoe and Northern Paiute, was evaluated by determining the number of individuals aged fifteen years and older with a history of concurrently treated diabetes or with a plasma glucose level of at least 160 mg./100 ml. (Auto Analyzer) two hours after a 75-gm. glucose equivalent load. One hundred and twelve Washoe Indians, representing 74.2 per cent of the Washoe study population, and 131 Paiute Indians, 60.6 per cent of the Paiute study population, were examined. The prevalence of hyperglycemia was 10.7 per cent for the Washoe and 11.5 per cent for the Paiute group. These rates, when adjusted for age and sex, did not differ significantly from each other or from that reported for the Cocopah Indians. The adjusted rates for these three tribes were significantly lower than the adjusted rate for the Pima. In both the Washoe and Paiute populations, the prevalence of hyperglycemia increased with age, but was not related to parity.