Heterogeneity of Type 1 Diabetes: The Effect of Ethnicity

Background: Most of the current understanding of type 1 diabetes (T1D) etiology and pathogenesis stemmed from studies conducted in majoritarily Non-Hispanic White (NHW) populations. However, evidence is emerging that unique mechanisms of disease may contribute to the development of T1D in individuals of Hispanic ethnicity. Objective: We reviewed the currently available literature on genetic, immunologic, metabolic and clinical characteristics of T1D in Hispanic as compared with NHW individuals. Methods: We searched PubMed, Google Scholar, and authors' bibliographies to collect information from relevant articles on the influence of ethnicity on T1D etiology and pathogenesis. Results: There are significant epidemiological variation based on ethnicity, with consistently higher T1D incidence and prevalence rate in NHWs than Hispanics. The frequencies of T1D high-risk HLA haplotypes and genotypes, as well as their susceptibility or protective effects show considerable ethnic differences. There are conflicting data on immunologic factors (e.g. islet autoantibody positivity) and markers of beta-cell function (e.g., C-peptide levels), as well as in some clinical characteristics (e.g. frequencies of diabetic ketoacidosis and severe hypoglycemia), while age of onset is consistently similar between both groups. Higher prevalence of obesity, less intensive diabetes management, and poorer glycemic control were reported in Hispanics. Accordingly, ethnic disparities in clinical outcomes have been demonstrated as well. Conclusion: There are considerable differences in T1D characteristics between NHWs and Hispanics. Better insight into these ethnic differences would not only affect patient care of patients with T1D, but may also inform the design of future prediction and prevention trials.