Incidence of childhood-onset IDDM in black African-heritage populations in the Caribbean. The Caribbean African Heritage IDDM Study (CAHIS) Group.

OBJECTIVE: To compare incidence rates of childhood-onset IDDM among black African-heritage populations age 0-19 years in the Caribbean region. RESEARCH DESIGN AND METHODS: Population-based registries for IDDM were established on the eastern Caribbean islands of Antigua, Barbados, Dominica, St. Croix, St. Kitts, St. Thomas, and Tortola using standardized criteria from the World Health Organization (WHO) Multinational Project for Childhood Diabetes (DiaMond). Average annual incidence rates (IR) with 95% CI for 0-19 years olds were computed using the DiaMond Registry program for the 5-year period from 1989 to 1993. Poisson regression analysis was used to determine differences in incidence rates. RESULTS: The highest incidence rate for 0-19 year olds was for the black African-heritage population of St. Croix (IR 10.09 per 100,000; 95% CI 4.35-19.89), one of the U.S. Caribbean islands. A significant (P < 0.05) 3.9 variation in IDDM incidence across the registries was found when the IR for St. Croix was compared to the IR for Barbados (IR 2.57 per 100,000; 95% CI 0.90-4.64). CONCLUSIONS: The variation in childhood-onset IDDM incidence rates among the black populations of the eastern Caribbean islands is consistent with the geographic variation in IDDM incidence seen among African Americans in the U.S. Variation in incidence rates of childhood diabetes in black populations may reflect differences in level of white genetic admixture or exposure to environmental diabetogenic agents.