On the Use of Migration Studies in the Explanation of Diseases of Multifactorial Causality: The Risk of Non-Insulin-Dependent Diabetes in Japanese-Americans
The study of migrant populations has been employed in epidemiological studies to better characterize the causality of multifactorial disease, where both genetic and environmental factors contribute to the onset of pathological states. By examining migrant populations, groups of individuals sharing a fairly common genetic background—thus exhibiting fairly uniform predispositions toward certain disease processes—can be compared to populations from their countries of origin in order to better understand the environmental factors that precipitate disease. Studies of acculturation of people of Japanese descent have yielded important information on environmental factors that contribute to ailments such as coronary heart disease and non-insulin-dependent diabetes mellitus. However, migration studies may be plagued by confounding factors which detract from the validity of the analysis of data gathered from migrant and native populations. This paper will discuss the complications that arise in migration studies with respect to the work that has been done in acculturation studies comparing Japanese-Americans and natives of Japan.