Prevalence and Incidence of Type 1 Diabetes Among Children and Adults in the United States and Comparison With Non-U.S. Countries

Type 1 diabetes is one of the most common chronic diseases of childhood in the United States, accounting for nearly 98% of all cases of diabetes in children age <10 years and over 87% of all cases in youth age 10–19 years. However, the disease can occur at any age. Type 1 diabetes primarily results from an immune attack to the insulin-producing beta cells of the pancreas, which results in insulin deficiency and high blood glucose concentrations. If left untreated, this disease is fatal. The optimal treatment of type 1 diabetes includes basal and multiple doses of insulin using injections or an insulin pump, frequent checking of blood glucose concentrations, and adjusting insulin doses for carbohydrate intake and physical activity. Individuals with type 1 diabetes are at risk of acute complications (e.g., severe hypoglycemia, diabetic ketoacidosis) and chronic complications, including both macrovascular and microvascular diseases, and may experience a shorter life expectancy than the U.S. general population. Estimates of the prevalence and incidence of type 1 diabetes in U.S. youth age <20 years in all major U.S. race/ethnicity groups come from the SEARCH for Diabetes in Youth study (SEARCH). SEARCH reported that in the United States, in 2009, an estimated 167,000 youth lived with type 1 diabetes. The overall prevalence (cases/1,000) was 1.93. It was similar in boys and girls and increased with age from 0.82 in children age 0–9 years to 2.97 in youth age 10–19 years. In 2008–2009, among youth age <20 years, the incidence of type 1 diabetes was 22.0 per 100,000 per year. By applying age-, sex-, and race/ethnicity-specific incidence rates to the U.S. youth population, SEARCH estimated that each year approximately 18,000 new cases of type 1 diabetes occur in youth age <20 years. Data on the prevalence and incidence of type 1 diabetes in U.S. adults are very limited. Using data collected by the National Health and Nutrition Examination Surveys in 1999–2010, the estimated overall prevalence of type 1 diabetes, defined as being on insulin since diagnosis, current insulin use, and age of onset <30 or <40 years, was 2.6 per 1,000 and 3.4 per 1,000, respectively, corresponding to 740,000 to 970,000 people of the U.S. civilian, noninstitutionalized population. During 1990–2005, among U.S. military personnel age 18–44 years, the overall age-adjusted incidence of insulin-requiring diabetes was 17.5 per 100,000 person-years in men and 13.6 per 100,000 person-years in women. Diabetes registries in the United States have reported that the incidence of type 1 diabetes in children is increasing. Data from the SEARCH study showed that among non-Hispanic white youth, the incidence (per 100,000 per year) increased from 24.4 in 2002 to 27.4 in 2009, a relative increase of 2.7% per year. Type 1 diabetes surveillance is crucial for understanding the disease burden at the population level, for identifying subgroups most at risk, for planning health care delivery, and for advancing the understanding of the pathogenesis of the disease both in childhood and adulthood. However, surveillance efforts of type 1 diabetes encounter a number of challenges, including distinguishing types of diabetes both in youth and in adults and the lack of common case definition and ascertainment methodology. Surveillance strategies based on large administrative databases and electronic health records might be useful to fill these gaps. However, the feasibility, accuracy, and costs of these approaches need to be evaluated.