Relationship of Phospholipid Transfer Protein Activity to HDL and Apolipoprotein B–Containing Lipoproteins in

Patients with type 1 diabetes have greatly increased phospholipid transfer protein (PLTP) activity and have an altered HDL subclass distribution. In 195 patients with type 1 diabetes and in 194 men and women aged 30–55 years, we examined the relationship of PLTP activity to HDL and examined whether PLTP activity contributes to differences in HDL found in type 1 dia-betes. PLTP activity was measured using an exogenous substrate assay. Average HDL particle size and HDL subclasses were measured using nuclear magnetic reso-nance spectroscopy. Apolipoprotein AI (apoAI) and apoAII were measured by immunoturbidimetry. The amount of apoAI present in LpAI was measured using a differential electroimmunoassay, and the amount of apoAI in LpAIAII was inferred from the apoAI and LpA