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N Leboeuf

Publications and source records attributed to N Leboeuf.

4 recordsLinked to original sources
PubMed1994

Short-term response to dietary counseling of hyperlipidemic outpatients of a lipid clinic.

OBJECTIVE: To evaluate the efficacy of a limited dietary intervention delivered by dietitians in a single counseling session on plasma lipid levels in free-living subjects with hyperlipidemia. DESIGN: A 2-month, nonrandomized comparative study of dietary counseling efficacy in subjects with hyperlipidemia. Dietary instruction was conducted in a lipid clinic by dietitians. Subjects were instructed to follow a diet low in saturated fat and cholesterol (National Education Cholesterol Program step 1 or 2 diets) for 2 months with concomitant energy restriction for weight reduction when necessary. Another group of patients who did not receive dietary counseling during the same period served as a control. SUBJECTS: Ambulatory patients were recruited from the Lipid Clinic of the Montreal Clinical Research Institute. INTERVENTION: Dietary counseling was provided to 104 subjects with hypercholesterolemia and 113 subjects with hypertriglyceridemia. They were compared with 72 subjects with hypercholesterolemia and 80 subjects with hypertriglyceridemia who did not receive dietary counseling. RESULTS: In the hypercholesterolemic group, significant reductions in plasma cholesterol (mean +/- standard deviation = -5.7 +/- 11.7%) and low-density lipoprotein cholesterol (LDL-C) (-7.3 +/- 14.2%) and no changes in plasma very-low-density lipoprotein cholesterol (VLDL-C) or high-density lipoprotein cholesterol (HDL-C) were observed after dietary counseling. The LDL-C response to diet was normally distributed, and 20% of the individuals with hypercholesterolemia reached LDL-C levels below 4.1 mmol/L. In patients with hypercholesterolemia and no clinical evidence of familial hypercholesterolemia, (n = 76) the reductions in plasma cholesterol (-6.6 +/- 10.8%) and LDL-C (-8.2 +/- 14%) were more pronounced. Among the latter patients, 27.6% reached LDL-C levels below 4.1 mmol/L. In subjects with hypertriglyceridemia, the reductions in plasma cholesterol (-4.8 +/- 12.8%), triglycerides (-20.7 +/- 33%), and VLDL-C (-19.5 +/- 29%) were associated with an increase in LDL-C (+8.5 +/- 25.7%) and HDL-C (+5.5 +/- 18%). Of the subjects with hypertriglyceridemia, 20% had triglyceride levels below 2.3 mmol/L after treatment. No significant changes were observed in the control groups during the same period. CONCLUSIONS: Dietary counseling of subjects with hypercholesterolemia or hypertriglyceridemia was associated with beneficial changes in plasma lipid levels after 2 months of dietary intervention. However, longer and more controlled dietary interventions are necessary for most patients to achieve lipid goals.

Adult↗
PubMed1993

Influence of probucol on enhanced LDL oxidation after fish oil treatment of hypertriglyceridemic patients.

The susceptibility of low-density lipoprotein (LDL) to oxidation was studied in hypertriglyceridemic men (5 with type III and 5 with type IV) at baseline on a low-saturated-fat, low-cholesterol diet, after 6 weeks of dietary supplementation with fish oil (Promega, 12 g/d), and after 6 weeks of fish oil combined with probucol (500 mg BID). The relative content of n-3 polyunsaturated fatty acids in plasma and LDL was increased during the two treatment periods, and a low alpha-tocopherol to n-3 polyunsaturated fatty acids ratio was observed. Plasma thiobarbituric acid-reactive substances (TBARS) levels were unchanged after 6 weeks of fish oil, but the ratio of lipid peroxides to the reduced triglyceride (TG) levels (MDA:TG) was significantly higher (P < .01). Addition of probucol lowered both absolute levels of TBARS (P < .01) and the MDA to TG ratio (P < .001). The susceptibility of LDL to Cu(2+)-catalyzed oxidation was evaluated over a 5-hour time course by determining TBARS formation, free amino group levels, and changes in LDL electrophoretic mobility. TBARS levels that were higher in native LDL (1.019 < d < 1.050 g/mL) after 6 weeks of fish oil than at baseline (P < .01) were reduced 52.3 +/- 11.3% by the addition of probucol (P < .001). With fish oil alone, TBARS production after exposure of LDL to Cu2+ for 5 hours was increased 17.0 +/- 5.8% compared with corresponding baseline values (P < .001), whereas a 64.1 +/- 14.3% reduction from the previous period was observed with fish oil + probucol (P < .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Apolipoprotein E polymorphism association with lipoprotein profile in endogenous hypertriglyceridemia and familial hypercholesterolemia.

Apolipoprotein (apo) E polymorphism was among the first-reported genetic polymorphisms that explained part of the normal variation in plasma cholesterol concentrations in humans. The aim of this study was to assess the influence of allelic variation at the apo E gene locus on the plasma lipoprotein profile in hyperlipidemia. The lipoprotein levels of hyperlipidemic subjects of the major apo E phenotypes (E3/2, E3/3, and E4/3) were compared. One hundred eighty-two subjects with endogenous hypertriglyceridemia and 98 subjects with familial hypercholesterolemia due to a 10-kb deletion in their low density lipoprotein (LDL) receptor genes were compared with 424 normolipidemic controls from the same environmental background. LDL concentrations were lower in the E3/2 subset than in the E3/3 or E4/3 subset in the control, hypertriglyceridemic, and familial hypercholesterolemic groups. In absolute values, the magnitude of the effect was greatest in the familial hypercholesterolemic group. However, the direction and percentage change were identical in the presence or absence of the LDL receptor defect, indicating that the apo E phenotype effect is independent of LDL receptor status. Triglyceride and very low density lipoprotein (VLDL) cholesterol concentrations were higher in E3/2 than in E3/3 or E4/3 hypertriglyceridemic subjects, but this difference was not found in the familial hypercholesterolemic or control group. Thus, there seems to be a specific interaction between apo E isoforms and VLDL metabolism in hypertriglyceridemia; allelic variation at the apo E gene locus seems to be associated with specific alterations in the plasma lipoprotein profile of subjects with well-defined types of hyperlipidemia.

Adult↗