Evaluation of Epidemiology and Immunogenetics of IDDM in Spanish- and Portuguese-Heritage Registries: A Key to Understanding the Etiology of IDDM?

There appears to be extraordinary international variation in the incidence of insulin-dependent diabetes mellitus (IDDM), the reasons for which are not known. By evaluating the incidence of IDDM in Spanish- and Portuguese-heritage populations, important insight into reasons for the major worldwide differences in IDDM risk may be gained. The limited data that are available for Hispanic populations suggest that there is at least a 10-fold difference in risk between individuals of Hispanic ancestry in Colorado and Mexicans in Mexico City. Standard methods for assessing IDDM incidence are needed to further elucidate the patterns of risk among populations of Iberian heritage. Therefore, we propose that comparable IDDM registries be established in the Spanish- and Portuguese-speaking world. Once registries are established, further investigation of the characteristics of IDDM among various populations (including seasonal distributions, sex differences, age at onset, and changing trends over time) may help explain the large international incidence differences among not only Spanish- and Portuguese-heritage populations but also among all children.