Children of African, African Caribbean, and South Asian descent show precursors of type 2 diabetes risk that reflect the elevated risk patterns of adults in those ethnic groups, according to a new study of nearly 5,000 9- and 10-year-old schoolchildren living in three U.K. cities.
“The new epidemic of early onset type 2 diabetes occurring in many Western societies affects all sections of the population, and key preventive measures in childhood … are likely to be widely desirable. However, there is a particularly urgent need for preventive measures in high-risk ethnic groups, in which the benefits of prevention are potentially greater,” the study investigators reported (PLoS Medicine 2010 April 20 [doi:10.1371/journal.pmed.1000263]).
Peter Whincup, Ph.D., of St. George's, University of London, and colleagues took body measurements and blood samples from primary school students of 1,153 white European, 1,306 South Asian, and 1,215 African or African Caribbean descent, along with 294 children with roots in other parts of Asia and 828 mixed-race children, using ethnicity data reported by their parents. A total of 80% of the children in the three largest groups were U.K. born; all lived in Leicester, Birmingham, or London. The researchers measured the children's adiposity and recorded the socioeconomic status and immigration history of the children's families.
Children of South Asian descent, compared with their white peers, had significantly higher levels of glycated hemoglobin (2.1% higher), fasting insulin (30%), triglyceride (12.9%), and C-reactive protein (43%), along with lower levels of HDL cholesterol (2.9% lower). Children of African or African Caribbean descent had higher levels of glycated hemoglobin (1.9% higher), insulin (22.9%), C-reactive protein (21%), and—“paradoxically”—HDL cholesterol (1.9%), with lower levels of triglyceride (10.6% lower), they reported.
The remaining ethnic and mixed-race groups were not included in the comparative analysis.
The patterns seen among South Asian children closely mirrored those of adults in that U.K. ethnic group, which has roughly triple the diabetes risk of white U.K. citizens. The African and Caribbean children's patterns mirrored those of adult African Caribbeans, who also bear a risk significantly higher than that of white Europeans, the researchers noted.
The higher insulin and glycated hemoglobin levels seen among the black and South Asian children were particularly worrisome, Dr. Whincup said in an interview. “These are predictors in long-term diabetes risk, and the fact that the patterns are corresponding closely with the adult experience suggests that these new generations will be affected as well.”
None of the differences in risk profiles could be attributed to variations in adiposity among ethnic groups or to socioeconomic status.
Dr. Whincup said he did not view the differences in risk precursors as entirely hereditary. “It may be a complex interaction between genetics and environment.” He said his team hopes to study how childhood nutrition and physical activity, and early life factors, may influence ethnic differences in diabetes risk.
The research was funded by the Wellcome Trust and the British Heart Foundation. Dr. Whincup and his colleagues declared no conflicts of interest.