The gap in disease incidence among ethnic groups demands a policy response, say experts who weighed in on the SEARCH data.
Results from the first decade a major study by the CDC and the National Institutes of Health (NIH) show diabetes incidence is rising rapidly among US youth, but especially among racial and ethnic minorities.
The findings from the Search for Diabetes in Youth Study (SEARCH), which began in 2000 and will continue until at least 2020,1 were published in the New England Journal of Medicine (NEJM) in mid-April,2 and were consistent with a claims study reported by FAIR Health earlier this year.
The study is the first to analyze trends in new cases of both type 1 diabetes (T1D) and type 2 diabetes (T2D) among US youth younger than age 20 across 5 ethnic groups: non-Hispanic whites, non-Hispanic blacks, Hispanics, Asian Americans/Pacific Islanders, and Native Americans.
While the findings were not quite a surprise, the gap in disease incidence among ethnic groups, and the trends in the Hispanic population in particular, demand policy responses and increased levels of research, according to several experts who contacted Evidence-Based Diabetes Management™ (EBDM™).
The current findings report data from 2002-2003 to 2011-2012, and found the unadjusted incidence of T1D cases rose significantly by about 1.4% per year, but rates varied by demographic characteristics. For instance, new cases increased much more among boys than girls. After adjusting for age, sex, and race or ethnic group, the researchers found a 1.8% relative annual increase in T1D incidence. They also found that Hispanic youths had a significantly higher increase in new T1D cases per year (4.2%) compared with white youths (1.2%).
T1D is known to be caused by a combination of genetic and environmental factors, according to Jessica Dunne, MD, director of Discovery Research for JDRF. The rise in cases of T1D in ethnic groups beyond those Northern European countries associated with the disease suggests that the genetics could be changing, “or that there is a larger interplay of what those environmental factors may be,” Dunne said in an interview with EBDM™.
When looking at unadjusted T2D incidence, the researchers observed a 7.1% increase in new cases each year among youths aged 10 to 19. After adjusting for demographics, they found white youths had a significantly lower increase in incidence compared with each of the other ethnic or racial groups. In other comparisons, Native Americans had a significantly higher average increase in incidence rates at 8.9% than Hispanics at 3.1%, but the CDC press release cautioned that the sample of Native American youths in this study was not representative of all Native American youths nationwide.
According to study authors, the findings, particularly those concerning T1D, indicate that racial and ethnic minorities are shouldering most of the burden of increasing youth diabetes rates. As such, the results “highlight the critical need to identify approaches to reduce disparities among racial and ethnic groups.”2
SEARCH found that obesity had increased among Hispanic girls and black boys from 2003 to 2012, but had not increased for American youths overall. Along with further research on insulin resistance in children of different races and ethnicity, the researchers suggested that these disparities in risk factors like obesity might provide an opportunity to control the growing numbers of children developing diabetes, which the CDC described as a serious public health concern.
“Because of the early age of onset and longer diabetes duration, youth are at risk for developing diabetes related complications at a younger age. This profoundly lessens their quality of life, shortens their life expectancy, and increases health care costs,” Giuseppina Imperatore, MD, PhD, epidemiologist in CDC’s division of diabetes translation, National Center for Chronic Disease Prevention and Health Promotion, said in a statement.3
Ongoing efforts to clarify the drivers of diabetes rates include The Environmental Determinants of Diabetes in the Young (TEDDY) study4 and the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study.5 In addition to funding projects like TEDDY and TODAY that target the youth population, NIH is also conducting initiatives such as the Type 1 Diabetes TrialNet, which collects outcomes data and conducts research on preventing diabetes in Americans of all ages.6
Dunne said diabetes researchers are waiting for the data from TEDDY to better understand what the viral triggers are that lead to the development of T1D. The overall rise of diabetes in the Hispanic and African American population suggests a complex mix of environmental factors are at work. “There hasn’t been a single smoking gun, and I don’t anticipate there will be,” she said.
William T. Cefalu, MD, chief scientific and medical officer for the American Diabetes Association, said in an email that the SEARCH study and another study in the NEJM April 13, 2017, issue, “Mortality and cardiovascular disease in type 1 and type 2 diabetes,”7 highlight both “the concerns about the increasing prevalence of diabetes, and the positive impact of research in managing the disease.”
“Seeing the rate of diagnosis rise among youth should draw everyone’s attention to this epidemic,” he said. “At the same time, we’ve been able to improve the lives of millions of people who are living with diabetes around the world through research leading to fewer incidences of complications.”
Ted Kyle, RPh, MBA, founder of ConscienHealth and an advocate for people living with obesity, said in an email that while the NEJM articles did not include assessments for body mass index, there was little doubt that the current, historically high levels of childhood obesity—especially severe obesity—“will contribute to further growth of type 2 diabetes for years to come. The best hope for blunting this trend is better utilization of evidence-based obesity care, such as the Diabetes Prevention Program.”
Kyle called for health plans to make smarter use of both diabetes prevention and obesity care for at-risk populations.
1. Search for Diabetes in Youth website. https://www.searchfordiabetes.org/dspHome.cfm. Accessed May 16, 2017.
2. Mayer-Davis EJ, Lawrence JM, Dabelea D, et al. Incidence trends of type 1 and type 2 diabetes among youths, 2002-2012. N Engl J Med. 2017; 376(15):1419-1429. doi: 10.1056/NEJMoa1610187.
3. Rates of new diagnosed cases of type 1 and type 2 diabetes on the rise among children, teens [press release]. Atlanta, GA: CDC Newsroom; April 12, 2017. https://www.cdc.gov/media/releases/ 2017/p0412-diabtes-rates.html. Accessed April 13, 2017.
4. The Environmental Determinants of Diabetes in the Young (TEDDY) Study website. https://teddy.epi.usf.edu/TEDDY/index.htm. Accessed May 16, 2017.
5. Linder BL, Fradkin JE, Rodgers GP. The TODAY study: an NIH perspective on its implications for research. Diabetes Care. 2013;36(6):1775-1776. doi: 10.2337/dc13-0707.
6. TrialNet website. https://www.trialnet.org/. Accessed May 16, 2017.
7. Rawshani A, Rawshani A, Franzen S, et al. Mortality and cardiovascular disease in type 1 and type 2 diabetes. N Engl J Med. 2017;376:1407-1418. DOI: 10.1056/NEJMoa1608664.