Prevalence and Determinants of Elevated Apolipoprotein B and Dense Low-Density Lipoprotein in Youths with Type 1 and Type 2 Diabetes

Objective: The objective of the study was to assess the prevalence and determinants of elevated apolipoprotein B (apoB) and dense low-density lipoprotein (LDL) in United States youth with type 1 or type 2 diabetes. Methods: We conducted cross-sectional analyses of apoB concentrations, LDL density, and prevalence of elevated apoB levels and dense LDL from the SEARCH for Diabetes in Youth study, a six-center U.S.-based study of youth with diabetes onset younger than 20 years of age (2657 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/liter), 8% had dense LDL (relative flotation rate ≤ 0.237), and 12% had elevated LDL-cholesterol (≥130 mg/dl, 3.36 mm/liter). 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 hemoglobin A1c in both types. Among type 1 diabetics in poor glycemic control (hemoglobin A1c ≥ 9.5%), 28% had elevated apoB, and 18% had dense LDL, whereas 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, whereas 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.