Neighborhood level risk factors for type 1 diabetes in youth: the SEARCH case-control study

Controlling for individual risk factors (age, gender, race/ethnicity, infant feeding, birth weight, maternal age, number of household residents, parental education, income, state), higher neighborhood household income (p = 0.005), proportion of population in managerial jobs (p = 0.02), with at least high school education (p = 0.005), working outside the county (p = 0.04) and vehicle ownership (p = 0.03) were each independently associated with increased odds of type 1 diabetes. Conversely, higher percent minority population (p = 0.0003), income from social security (p = 0.002), proportion of crowded households (0.0497) and poverty (p = 0.008) were associated with a decreased odds.Our study suggests that neighborhood characteristics related to greater affluence, occupation, and education are associated with higher type 1 diabetes risk. Further research is needed to understand mechanisms underlying the influence of neighborhood context.Although type 1 diabetes mellitus is one of the leading chronic diseases of childhood and youth, little is known about its causes. Type 1 diabetes has been previously known as insulin-dependent or juvenile-onset diabetes. It results from the destruction of pancreatic beta cells which leads to insulin deficiency and lifelong dependency on insulin therapy. Type 1 diabetes risk is influenced by both genetic and environmental risk factors, but the rapid worldwide increase in incidence suggests that strong environmental influences interact with a common genetic risk set [1,2]. A multitude of environmental risk factors are being studied, including infectious agents, environmental toxins in water or foods, dietary exposures, and exposures to immunizations and pets [3,4]. The Environmental Determinants of Diabetes in Youth (TEDDY) study, a large, international cohort project, was explicitly designed to explore these and other factors with respect to their impact on the development of islet cell autoimmunity and the incidence of type 1 diabetes a