This retrospective cohort study examined the relationship of birth weight, family history of diabetes (FamHx), and current weight to insulin resistance in Black girls and boys on the Caribbean island of Barbados. A cohort of 56 low birth weight (LBW) and 120 normal birth weight (NBW) adolescents born between January 1, 1986, and December 31, 1988, were recruited for study participation in 2002. FamHx was ascertained by questionnaire. Body mass index (BMI) and waist circumference (WC) were used to assess fat distribution. Fasting blood glucose and insulin were measured from blood samples drawn from each adolescent participant. Insulin resistance was estimated by the homeostasis model assessment (HOMA) technique. These data show that only among LBW girls was a positive (+) FamHx associated with higher HOMA (FamHx "Yes"=1.22 +/- 0.298 vs "No"=0.811 +/- 0.452; P=.032). No significant relationships were observed among boys. Further analyses revealed that compared to their NBW counterparts, LBW girls without FamHx, had a smaller WC (69.70 +/- 9.88cm vs 76.70 +/- 15.64cm, respectively; P=.055). In contrast, LBW girls with a (+) FamHx had similar mean WC (77.71 +/- 16.46cm) to those of NBW girls with (+) FamHx (WC=71.50 +/- 10.38cm; P=.405). These data indicate that along with a family history of diabetes, catch-up weight may be important in assessing diabetes risk in Black Caribbean LBW adolescent girls.