To the Editor:
Estimates of type 1 diabetes in “All Hispanic” and Mexican-American populations were reported in 2013 using National Health and Nutrition Examination Survey (NHANES) data collected between 1999 and 2010,1 but this study did not examine sufficient numbers of participants from diverse Hispanic/Latino groups to report group-specific estimates. However, there are no estimates of the population prevalence of type 1 diabetes mellitus in diverse Hispanic/Latino groups in the US. The Hispanic Community Health Study/Study of Latinos is a community-based epidemiologic study of health and disease in Hispanic/Latino adults residing in four US communities. Participants included individuals of Cuban, Dominican, Mexican, Puerto Rican, Central American, and South American backgrounds. The study design and implementation have been described in detail,2 each study site and coordinating center received approval from their Institutional Review Board for the study protocol and informed consent was obtained for all participants at the baseline examination visit. Although presence of type 1 diabetes was not specifically ascertained, we differentiated type 1 from type 2 diabetes mellitus using the following methods mirroring NHANES: diagnosis before 30 years of age, currently treated with insulin, and insulin use within 1 year of diagnosis. Of the 16,415 participants examined at baseline (2008–2011), 16,290 participants (ages 18–74 years, 60% male) had complete data on age at diabetes diagnosis, current treatment with insulin and insulin within 1 year of diagnosis. Information on HbA1c was available for 16,091 participants. Data were analyzed using SAS version 9.3 (SAS Institute). All reported estimates were weighted to adjust for sampling probability and non-response using the existing study protocol.
The overall prevalence of type 1 diabetes in this study was 1.8/1000 persons (95% confidence interval [CI] = 0.95, 2.6/1000), i.e., similar to the estimates obtained through NHANES (2.6/1000) and the SEARCH for Diabetes in Youth Study (1.5/1000).3 The prevalence of type 1 diabetes varied by Hispanic/Latino background, with individuals of Dominican backgrounds experiencing the highest prevalence (6.1/1000, 95% CI = 0.0, 12.4/1000) (Table). The authors feel confident that this estimation of type 1 diabetes identified individuals who were likely to have disease based on the measure of glycemic control, HbA1c. Overall, the average HbA1c among those identified as having type 1 diabetes was 9.62 (95% CI = 8.52, 10.71); HbA1c ranged from 11.52 (95% CI = 8.95, 14.08) in persons of Puerto Rican background to 8.22 (95% CI = 7.24, 9.20) in those of Mexican ethnicity. This is consistent with the range of HbA1c values observed in non-Hispanic white and African American individuals with type 1 diabetes.4
Although rare in the general population, type 1 diabetes represents a significant health burden for individuals and populations, and its accurate measurement should be a part of any population-level data collection. This analysis indicates that people of Hispanic/Latino origin with type 1 diabetes may experience poor glycemic control, indicating a potential target for intervention.
Gregory L. Kinney
Kendra A. Young
Molly M. Lamb
Department of Epidemiology, Colorado School of Public Health
Colorado, Aurora, Colorado
Trevor J. Orchard
Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania
Collaborative Studies Coordinating Center
Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel
Hill, North Carolina
Department of Epidemiology & Population
Health, Albert Einstein College of Medicine
Bronx, New York
Oana L. Klein
University of California, San Francisco
Graduate School of Public Health, San Diego State University, San Diego
University of North Carolina, Chapel Hill
Institute of Minority Health Research
University of Illinois at Chicago
1. Menke A, Orchard TJ, Imperatore G, Bullard KM, Mayer-Davis E, Cowie CC. The prevalence of type 1 diabetes in the United States. Epidemiology. 2013;24:773–774.
2. Sorlie PD, Avilés-Santa LM, Wassertheil-Smoller S, et al. Design and implementation of the Hispanic Community Health Study/Study of Latinos. Ann Epidemiol. 2010;20:629–641.
3. Liese AD, D’Agostino RB Jr, Hamman RF, et al. The burden of diabetes mellitus among US youth: prevalence estimates from the SEARCH for Diabetes in Youth Study. Pediatrics. 2006;118:1510–1518.
4. Bergenstal RM, Gal RL, Connor CG, et al.; T1D Exchange Racial Differences Study Group. Racial differences in the relationship of glucose concentrations and hemoglobin A1c levels. Ann Intern Med. 2017;167:95–102.