A study of youth in the United States reveals that the incidence of diabetes mellitus in general, and type 1 disease in particular, is highest among non-Hispanic whites, according to a report presented here Tuesday at a media briefing held by the Journal of the American Medical Association.
Prior to this study, there were only limited population-based estimates of diabetes of various types among youth of all major ethnic groups, lead author Dr. Dana Dabelea, from the University of Colorado Health Sciences Center in Denver, and colleagues note in the report, which is also published today in a special JAMA theme issue of chronic diseases of children.
The SEARCH for Diabetes in Youth Study included 2,435 patients younger than 20 years old who were newly diagnosed with primary diabetes between 2002 and 2003. The study participants were from 10 study locations in the United States, covering a population of more than 10 million person-years, defined as “the number of individuals in the study times the number of years of follow-up per person.”
Overall, the researchers found that the incidence rates were 24.3 cases of diabetes diagnosed per 100,000 person-years. The incidence rate ranged from 16.7 in Asian/Pacific Islanders to 26.1 in non-Hispanic whites.
In terms of age, the highest incidence rate of diabetes was 33.9 in children between 10 and 14 years old. Girls had slightly higher rates of diabetes than boys.
In all ethnic groups, type 1 diabetes was the most common type in children younger than 10 years of age.
Possible genetic susceptibility
As noted, the rate of type 1 diabetes was highest among non-Hispanic white patients. In this group, the incidence rate of type 1 diabetes increased with age, ranging from 18.6 among infants to 4-year-olds — to 32.9 among 10- to 14-year-olds.
American Indian and Asian-Pacific Islander children had the lowest rates of type 1 diabetes.
“I believe the higher rate of type 1 diabetes in white children reflects a greater genetic susceptibility to autoimmunity,” Dabelea told Reuters Health.
However, “there is also evidence that obesity may be an accelerant for type 1 diabetes as it is for type 2 disease” and this may play a role in the ethnic differences seen, she added.
Cases of type 2 diabetes were relatively uncommon. The highest rates were noted in older teens from minority groups, especially American Indians who had an incidence rate of 49.4.
Dabelea added that obesity is likely to partially explain the higher rates of type 2 diabetes in minority groups. However, she added that in her own studies of Pima Indians, the greatest risk factor for type 2 diabetes was having a mother with diabetes.
In a related editorial, Dr. Rebecca B. Lipton, from the University of Chicago, comments that while the “SEARCH project adds some detail to the understanding of the changing nature of diabetes risk in the United States ... there is an urgent need to go beyond studies such as this one by implementing a coordinated approach for childhood diabetes surveillance.”
“Only then can society respond effectively to the serious and increasing challenge of diabetes in youth,” she concludes.
