Aims: To assess the prevalence and determinants of elevated apolipoprotein B (apoB) and dense LDL in United States youth with type 1 or type 2 diabetes.

Methods: Cross-sectional analyses of apoB concentrations, LDL density, and prevalence of elevated apoB levels and of dense LDL from the SEARCH for Diabetes in Youth study, a six-center United States-based study of youth with diabetes onset < 20 years of age (2,657 with type 1 and 345 with type 2).

Results: Among youth with type 1 diabetes, 11% had elevated apoB ( 100 mg/dL, 1.95 mM/L), 8% had dense LDL [relative flotation rate (Rf) 0.237], and 12% had elevated LDL-cholesterol ( 130 mg/dL, 3.36 mM/L). In contrast, among youth with type 2 diabetes, 36% had elevated apoB, 36% had dense LDL, but only 23% had elevated LDL-cholesterol. Dense LDL and apoB each increased with HbA1c in both types. Among type 1 diabetics in poor glycemic control (HbA1c 9.5%), 28% had elevated apoB and 18% had dense LDL, while 72% of poorly controlled type 2 diabetics had elevated apoB and 62% had dense LDL.

Conclusions: In youth with type 1 diabetes, elevated apoB and dense LDL were not highly prevalent, while elevated apoB and dense LDL were common lipoprotein abnormalities in youth with type 2 diabetes. The prevalence of these risk factors substantially increased with poor glycemic control in both groups, stressing the importance of achieving and maintaining an optimal glucose control.