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.

Abstract

The epidemiology of insulin-dependent diabetes mellitus (IDDM) was evaluated in a predominantly black population in the U.S. Virgin Islands. 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. 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. The epidemic of IDDM in 1984 provides support for a possible pandemic in the early 1980s.