Epidemiology of childhood IDDM in U.S. Virgin Islands from 1979 to 1988: Evidence of an Epidemic in Early 1980s and Variation by Degree of Racial Admixture

OBJECTIVE: The epidemiology of insulin-dependent diabetes mellitus (IDDM) was evaluated in a predominantly black population in the U.S. Virgin Islands. RESEARCH DESIGN AND METHODS: Primary ascertainment of diabetic subjects was by retrospective review of hospital and clinic records, and IDDM was defined by Diabetes Epidemiology Research International Group criteria. RESULTS: For the period 1979-1988, 28 children less than 15 yr of age were diagnosed with IDDM resulting in an average annual IDDM incidence rate (IR) of 7.5/100,000 (95% confidence interval 4.7-10.3). A significant increase in IDDM incidence (P less than 0.01) was observed when the IR rose to 28.4/100,000 in 1984. White children had the highest IR (28.9/100,000). The IR for Hispanics (7.2/100,000) was slightly higher than that for blacks (5.9/100,000). Among black children, a slight but nonsignificant male excess in incidence was observed (male-female ratio 1.5). When black or Hispanic patients were compared with age-matched control subjects with respect to grandparental race, the diabetic subjects had a greater percentage of white ancestry (P less than 0.02 and P less than 0.05, respectively). The incidence of IDDM in Caribbean blacks (West Indians) in the U.S. Virgin Islands was similar to blacks in the U.S. CONCLUSIONS: The epidemic of IDDM in 1984 provides support for a possible pandemic in the early 1980s.