High preβ 1-HDL levels in hypercholesterolemia are maintained by probucol but reduced by a low-cholesterol diet

Previous study has shown that pre beta 1-HDL levels increase in hypercholesterolemia, or high cholesteryl ester transfer protein (CETP) activity. To determine how pre beta 1-HDL levels change after treatment with probucol or by following a low-cholesterol diet, we randomly assigned 24 hypercholesterolemic patients to either the probucol (P), or low-cholesterol diet group (D), and measured pre beta 1-HDL levels before and after treatments using native two-dimensional gel electrophoresis. We also examined 12 subjects with normolipidemia (N). At baseline, pre beta 1-HDL levels were higher in P (P < 0.05) and D (P < 0.05) than in N (9.2 +/- 4.3, 10.4 +/- 5.5, and 5.9 +/- 2.3 mg/dl apo A-I). After a 4-week treatment, pre beta 1-HDL levels were still high in P (10.5 +/- 4.2 mg/dl apo A-I, N.S.), but reduced in D (7.7 +/- 3.0 mg/dl apo A-I, P < 0.001). Delta pre beta 1-HDL (Y) was positively correlated with Delta CETP mass (X) in P (y = 7.83x-1.93; r = 0.584, P < 0.05). In summary, high prep I-HDL levels in hypercholesterolemia are maintained by probucol but reduced by a low-cholesterol diet. These findings suggest that pre beta 1-HDL levels may be regulated by cholesterol and CETP levels. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.