In the Journals

Type 1 diabetes rates in black children higher than in white children

Philadelphia registry data reveal highest incidence of type 1 diabetes ever reported in black children aged 5 to 9 years.

Data from a Philadelphia registry show a higher incidence of type 1 diabetes in black children compared with white children aged 0 to 14 years.

In a recent issue of Diabetes Care, Terri H. Lipman, PhD, CRNP, associate professor of nursing of children at the University of Pennsylvania School of Nursing, and colleagues at the Children’s Hospital of Philadelphia and St. Christopher’s Hospital for Children reported on a retrospective, population-based registry that was started in 1985.

The researchers identified all Philadelphia hospitals that admit children and reviewed the charts of all children diagnosed with type 1 diabetes between Jan. 1, 1995, and Dec. 31, 1999. They calculated age-adjusted incidence rates for the population in general and for three subgroups of age, sex and race. Age adjustment was done in five-year intervals (0 to 4 years, 5 to 9 years and 10 to 14 years).

The researchers’ review yielded 234 cases of newly diagnosed type 1 diabetes in Philadelphia children aged 0 to 14 years from 1995 to 1999.

Incidence rates

The overall age-adjusted incidence rate of type 1 diabetes was 14.8 per 100,000/year, according to the report. Although the type 1 diabetes incidence rate remained fairly stable in the Hispanic (15.5 per 100,000/year) and white populations (12.8 per 100,000/year), it rose steadily in the black population (15.2 per 100,000/year). It increased 64% in black children aged 5 to 9 years (14.9 per 100,000/year) and climbed 37% in children aged 10 to 14 years (26.9 per 100,000/year).

“Now, for the first time in Philadelphia, the incidence in black children has surpassed the incidence in white children,” the researchers wrote.

“Although some of our cases in Philadelphia may have been misclassified, it is likely that this cohort represents a true rise in the incidence of type 1 diabetes in black children because of the age and sex distribution,” Lipman told Endocrine Today.

“The incidence of type 1 diabetes in black children 5 to 9 years of age is the highest incidence ever reported in black children in this age group.”

Reason for increase unclear

The cause of this trend remains unknown. “It is unclear why there is a rise in the incidence of type 1 diabetes in black children, in general, and particularly in the older age groups,” Lipman said.

Lipman suggested that the accelerator hypothesis, as proposed by Terry Wilkin, MD, and asserting that obesity is accelerating the age of onset and an increase in incidence of type 1 diabetes as well as type 2 diabetes, may provide a possible explanation. In addition, other not yet identified environmental risk factors could be disproportionately affecting black children.

“Racial disparities exist in the treatment and outcomes of children with type 1 diabetes,” Lipman said. “It has been shown that black children with type 1 diabetes have poorer metabolic control and higher rates of morbidity and mortality. With the rising incidence of type 1 diabetes in the black population, it is crucial that we develop culturally relevant interventions to minimize racial disparities in treatment and outcomes,” she said. – by Colleen Owens

For more information:
  • Lipman T, Jawad A, Murphy K, et al. Incidence of type 1 diabetes in Philadelphia is higher in black than white children from 1995 to 1999. Diabetes Care. 2006;29:2391-2395.