HDL concentration, lipid transfer to HDL, and HDL size in normolipidemic nonobese menopausal women.

OBJECTIVE: To determine the impact of menopause on lipid transfer from donor lipoproteins to high-density lipoproteins (HDLs) -- a process that is related to the protective function of HDL -- and the size of HDL particles. METHOD: Plasma from 22 premenopausal and 18 postmenopausal nonobese, normolipidemic women paired for age (40-50 years) was incubated in an artificial nanoemulsion labeled with radioactive lipids. Then the HDL fraction was assessed for radioactivity; the percentage of radioactive lipids transferred from the nanoemulsion to HDL was determined; and the size of HDL particles was measured by laser light scattering. RESULTS: There were no differences between the 2 groups in serum concentration of HDL cholesterol (61+/-12 mg/dL vs 61+/-14 mg/dL) or apolipoprotein A(1) (1.5+/-0.3 g/L vs 1.5+/-0.2 g/L); lipid transfer to HDL; or size of HDL particles (8.8+/-0.8 vs 9.0+/-0.5 nm). CONCLUSION: Menopause was not found to affect HDL cholesterol plasma concentration, lipid transfer to HDL, or size of HDL particles in normolipidemic nonobese women.