Type 1 Diabetes in Immigrant and Nonimmigrant Black Youth

Thesis (Ph.D.)--University of Washington, 2013University of Washington Abstract Type 1 Diabetes in Immigrant and Nonimmigrant Black Youth M. Rebecca O'Connor Chair of the Supervisory Committee: Associate Professor Ardith Doorenbos School of Nursing Type 1 diabetes (T1D) affects nearly 500,000 children globally and the incidence for T1D has been rising steadily at a rate of 3% a year for the last few decades. While the causes of T1D are thought to include both genetic and environmental factors, the exact mechanisms remain elusive. Differences in both prevalence rates and health outcomes related to T1D have been reported between populations from different races and groups of mixed immigrants and native populations. However, it is not known whether T1D-related differences exist between two populations within the same race classification. This dissertation explores whether T1D-related differences exist between East African immigrant and nonimmigrant Black youth in the Seattle area through three separate papers. The first paper explores genetic and autoimmune biomarkers involved in diabetes affecting pediatric populations. Specifically, this paper examines the role of autoimmune biomarkers in the diagnosis of T1D. A search of PubMed identified reviews that were published from 2008-2011 and included the topics of etiology, epidemiology, genetics, epigenetics, pathogenesis and/or immunology related to diabetes in youth. A total of 19 reviews were included in this clinical update. The second paper summarizes a retrospective descriptive study that compares demographic and clinical characteristics of immigrant and nonimmigrant youth at the time of T1D diagnosis. All Black youth diagnosed with T1D and treated at Seattle Children's Hospital (SCH) from 1/1/2000 to 7/31/2011 were identified using primary and secondary ICD-9 codes. Demographic and clinical data were obtained from existing electronic medical records. Additional data were obtained from the United States Census Bureau for use in estimating T1D prevalence rates. Results from the study revealed that T1D prevalence rates in King County, Washington were nearly 4 times higher for immigrant Black youth than nonimmigrant Black youth (6.76/1,000 vs. 1.74/1,000). Immigrant youth had a slightly lower mean age of T1D onset diagnosis (7.63, SD 4.42 vs. 8.29, SD 3.50), were more likely to have subsidized health insurance (75.0% vs. 58.5%), and almost twice as likely to have a family history of T1D (13.3% vs. 7.5%) compared to nonimmigrant Black youth. Immigrant Black youth also tested positive less frequently for T1D-related autoimmune biomarkers and if diabetic ketoacidosis (DKA) was present at diagnosis, immigrant youth were more likely to be in severe DKA. Both groups were approximately 60% female, in contrast to much of the literature which suggests that T1D affects both genders equally. The third paper compared glycemic control (measured by hemoglobin A1c [HbA1c]) at 12, 24, and 36 months after T1D diagnosis in immigrant and nonimmigrant Black youth. Case ascertainment and data collection utilized existing electronic medical records as described in the second paper. HbA1c levels were obtained from the clinic visit most closely corresponding to each time point. Immigrant youth had lower mean HbA1c s at each time point. Analyses of variance indicated that the effect of ethnicity (immigrant vs. nonimmigrant) on glycemic control approached statistical significance at the 36 month time point and when comparing the extreme time points (12 and 36 months). Results from these papers suggest that there are several clinically significant differences between two pediatric populations diagnosed with T1D within the same race classification and in particular, East African immigrants may be at greater risk for developing T1D. Nurses and other diabetes care providers should be aware that T1D affects populations differently and use this knowledge to educate and advocate for diabetes patients and their families