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.