Carotid intima media thickness is related positively to plasma pre ß-high density lipoproteins in non-diabetic subjects.

Background: Lipid-poor or lipid-free high density lipoprotein (HDL) particles, designated pre ß-HDL, stimulate removal of cell-derived cholesterol to the extracellular compartment, which is an initial step in the reverse cholesterol transport pathway. Pre ß-HDL levels may be elevated in subjects with established cardiovascular disease. We determined the relationship of carotid intima media thickness (IMT), a marker of subclinical atherosclerosis, with pre ß-HDL in subjects without clinically manifest cardiovascular disease.

Methods: IMT and plasma pre ß-HDL, assayed by crossed immuno-electrophoresis, were determined in 70 non-diabetic subjects (aged 56±9 years; non-smokers only; 27 women).

Results: IMT was correlated positively with pre ß-HDL, both expressed as plasma apolipoprotein (apo) A-I concentration (r=0.271, p=0.023) and as% of apo A-I (r=0.341, p=0.004). In contrast, IMT was correlated inversely with HDL cholesterol (r=-0.253, p=0.035). IMT was also related positively to pre ß-HDL after adjustment for age, sex, systolic blood pressure (in apoA-I concentration, ß=0.203, p=0.043; in% of plasma apoA-I, ß=0.235, p=0.023). IMT remained associated with pre ß-HDL after additional adjustment for either body mass index, plasma glucose, cholesterol, triglycerides, HDL cholesterol, apoA-I and apoB.

Conclusion: Subclinical atherosclerosis may relate to higher plasma pre ß-HDL independently of apoA-I and HDL cholesterol levels.