Postprandial concentrations and distribution of apo C-III in type 2 diabetic patients. Effect Of bezafibrate treatment.
Apo C-III plays a key role in the metabolism of triglyceride-rich lipoproteins. It has recently been implicated as a potential determinant of the triglyceride (TG) lowering effect of fibrates, which down-regulate its expression. This hypothesis has been explored in ten moderately hypertriglyceridemic (TG 4.50+/-2.40 mmol/l) male type 2 diabetic patients tested with a lipid load before and after 4 weeks of treatment with 400 mg bezafibrate daily. Treatment lowered apo C-III concentrations by 20%, mainly in VLDL. Postprandially, apo C-III was transferred to chylomicrons in proportion to their TG content exclusively from HDL. VLDL retained their apo C-III and the apo C-III:TG ratio decreased as TG contents increased. At the end of the absorptive period (8 h) HDL did not recover the totality of their apo C-III (net loss 19 and 28% respectively before and after treatment, P<0.0001 for time effect). Bezafibrate lowered apo E by 33% (P<0.03). The apo C-III:apo E ratio did not vary significantly under treatment but underwent a postprandial decrease: 13% before and 18% (P=0.01) after treatment. These results indicate that repression of apo C-III expression and lowering of the apo C-III:E ratio are not likely mechanisms for the lipid-lowering effects of fibrates in type 2 diabetic patients. The potent effects on postprandial lipemia are suggestive of an apo C-III-independent stimulation of lipolysis.
Attia
N
N
Département des Sciences de la Vie, Faculté des Sciences de Bizerte, Bizerte, Tunisia.
Durlach
V
V
Cambilleau
M
M
Roche
D
D
Girard-Globa
A
A
D000368:Aged; D000704:Analysis of Variance; D053305:Apolipoprotein C-III; D001056:Apolipoproteins C / Q000187:drug effects* / Q000378:metabolism; D001057:Apolipoproteins E / Q000187:drug effects* / Q000378:metabolism; D001629:Bezafibrate / Q000008:administration & dosage*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy*; D005260:Female; D006801:Humans; D000960:Hypolipidemic Agents / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period; D011336:Probability
D053305:Apolipoprotein C-III; D001056:Apolipoproteins C; D001057:Apolipoproteins E; D000960:Hypolipidemic Agents; D001629:Bezafibrate