Incidence and Prevalence of Type 1 Diabetes
The exact number of individuals with type 1 diabetes around the world is not known, but in the U.S., there are estimated to be up to 3 million. Although it has long been called "juvenile diabetes" due to the more frequent and relatively straightforward diagnosis in children, the majority of individuals with type 1 diabetes are adults.
Most children are referred and treated in tertiary centers, where clinical data are more readily captured. The SEARCH for Diabetes in Youth study estimated that, in 2009, 18,436 U.S. youth were newly diagnosed with type 1 diabetes (12,945 non-Hispanic white, 3,098 Hispanic, 2,070 non-Hispanic black, 276 Asian-Pacific Islander, and 47 American Indian). Worldwide, ~78,000 youth are diagnosed with type 1 diabetes annually. Incidence varies tremendously among countries: East Asians and American Indians have the lowest incidence rates (0.1–8 per 100,000/year) as compared with the Finnish who have the highest rates (>64.2 per 100,000/year). In the U.S., the number of youth with type 1 diabetes was estimated to be 166,984.
The precise incidence of new-onset type 1 diabetes in those over 20 years of age is unknown. This may be due to the prolonged phase of onset and the subtleties in distinguishing the different types of diabetes. In one European study of adults aged 30–70 years, ~9% tested positive for GAD antibodies (GADA) within 5 years of a diabetes diagnosis, consistent with other studies.
Adults with type 1 diabetes often receive care in primary care settings rather than with an endocrinologist. Unlike the consolidated care seen in pediatric diabetes management, the lack of consolidated care in adults makes incidence and prevalence rates difficult to characterize, and therefore they are often underestimated. The number of adults living with type 1 diabetes is increasing due to two factors: 1) the rising number of new-onset cases of type 1 diabetes in adults, including those diagnosed with latent autoimmune diabetes in adults (LADA), and 2) individuals with childhood-onset diabetes are living longer.[6,7]
Diabetes Care. 2014;37(7):2034-2054. © 2014 American Diabetes Association, Inc.