['Offspring of mothers with diabetes are at risk of obesity and glucose intolerance in later life. In adults, markers of subclinical inflammation (C-reactive protein [CRP] and interleukin [IL]-6) and endothelial activation (intracellular adhesion molecule [ICAM]-1) are associated with obesity and higher risk for incident type 2 diabetes. We examined whether these biomarkers were elevated at birth in offspring of type 1 diabetic mothers (OT1DM).', 'Umbilical cord plasma CRP, IL-6, and ICAM-1 were measured in 139 OT1DM and 48 control offspring, with analysis relative to fetal lipids and hormonal axes.', 'OT1DM had higher median (interquartile range) CRP (OT1DM 0.17 mg/l [0.13-0.22] vs. control subjects 0.14 mg/l [0.12-0.17], P < 0.001) and ICAM-1 (OT1DM 180 ng/ml [151-202] vs. control subjects 166 ng/ml [145-187], P = 0.047). IL-6 was not different after necessary adjustment for mode of delivery. Birth weight was unrelated to inflammatory indexes; however, leptin was correlated with CRP (control subjects r = 0.33, P = 0.02; OT1DM r = 0.41, P < 0.001) and with IL-6 (r = 0.23, P < 0.01) and ICAM-1 (r = 0.29, P < 0.001) in OT1DM. In OT1DM, CRP correlated with maternal glycemic control (A1C at 35-40 weeks; r = 0.28, P = 0.01). In multivariate analysis, leptin was a determinant of CRP (P < 0.001), ICAM-1 (P = 0.003), and IL-6 (P = 0.02) in OT1DM. Inflammatory measures demonstrated positive relationships with triglycerides in OT1DM (CRP, IL-6, and ICAM-1 P < 0.05) and control subjects (ICAM-1 P = 0.001).'] Is inflammation and endothelial activation evident at birth in offspring of mothers with type 1 diabetes?