Abstract
OBJECTIVE: The purpose of this study was to examine age of diabetes diagnosis in youth who have a parent with diabetes by diabetes type and whether the parent's diabetes was diagnosed before or after the youth's birth. RESEARCH DESIGN AND METHODS: The cohort comprised SEARCH for Diabetes in Youth Study participants (diabetes diagnosis 2001-2005) with a diabetic parent. SEARCH is a multicenter survey of youth with diabetes diagnosed before age 20 years. RESULTS: Youth with type 2 diabetes were more likely to have a parent with either type 1 or type 2 diabetes (mother 39.3%; father 21.2%) than youth with type 1 diabetes (5.3 and 6.7%, respectively, P < 0.001 for each). Type 2 diabetes was diagnosed 1.68 years earlier among those exposed to diabetes in utero (n = 174) than among those whose mothers' diabetes was diagnosed later (P = 0.018, controlled for maternal diagnosis age, paternal diabetes, sex, and race/ethnicity). Age at diagnosis of type 1 diabetes for 269 youth with and without in utero exposure did not differ significantly (difference 0.96 year, P = 0.403 after adjustment). Controlled for the father's age of diagnosis, father's diabetes before the child's birth was not associated with age at diagnosis (P = 0.078 for type 1 diabetes; P = 0.140 for type 2 diabetes). CONCLUSIONS: Type 2 diabetes was diagnosed at younger ages among those exposed to hyperglycemia in utero. Among youth with type 1 diabetes, the effect of the intrauterine exposure was not significant when controlled for mother's age of diagnosis. This study helps explain why other studies have found higher age-specific rates of type 2 diabetes among offspring of women with diabetes.