Abstract 10022: Effects of Therapeutic Lifestyle Change Diets High and Low in Dietary Fish-Derived Fatty Acids on Apolipoprotein B Metabolism in Moderately Hypercholesterolemic Middle-Aged and Older Subjects
Introduction: Nutritional and lifestyle modifications are the cornerstones of therapy for the treatment of dyslipidemia to prevent and treat coronary heart disease.
Hypotheses: We hypothesized that the Therapeutic Lifestyle Change (TLC) diets, low (2 meals/wk) and high (8 meals/wk) in dietary fish intake, would increase the catabolism of apolipoprotein (apo) B containing lipoproteins and that the TLC high-fish diet would confer added benefits by decreasing the production of these lipoproteins.
Methods: 20 subjects (mean ± SEM; age 66 ± 2 yr, BMI 26 ± 0.5 kg/m2) were provided with a Western diet for 6 wk and then with one of two TLC diets for 24 wk (10/group). At the end of each diet phase, subjects received a primed, constant infusion of d3-leucine for 15 h with hourly feeding. Very low-density lipoprotein (VLDL), intermediate-density lipoprotein and low-density lipoprotein (LDL) apoB-100, and triglyceride-rich lipoprotein (TRL) apoB-48 kinetics were determined using gas chromatography mass spectrometry and compartmental modeling.
Results: Both TLC diets decreased LDL apoB-100 concentration and increased its fractional catabolic rate (FCR) compared with the Western diet (all p<0.05). Compared with the Western diet, the high-fish diet decreased VLDL apoB-100 concentration (-27%) and production rate (PR; 26.7 ± 3.2 vs 22.1 ± 2.1 mg/kg/d) and increased VLDL apoB-100 FCR (6.5 ± 0.8 vs 8.3 ± 1.1 pools/d) and VLDL to LDL conversion (47.8 ± 6.9 vs 71.3 ± 7.9 %) (all p<0.05). The high-fish diet also decreased TRL apoB-48 concentration (-28%), PR (1.5 ± 0.4 vs 0.9 ± 0.4 mg/kg/d) and FCR (5.0 ± 0.5 vs 3.7 ± 0.5 pools/d) (all p<0.05). No changes to VLDL apoB-100 or TRL apoB-48 concentration or kinetics were observed with the low-fish diet. In the high-fish diet group, changes in VLDL apoB-100 PR were negatively correlated with changes in plasma eicosapentanoic (EPA) and docosahexaenoic acids concentrations while changes in VLDL to LDL apoB-100 conversion were positively correlated with changes in EPA (p<0.05).
Conclusions: The TLC diets decreased LDL apoB-100 concentration by increasing LDL apoB-100 catabolism. The TLC high-fish diet, but not the low-fish diet, decreased VLDL apoB-100 and TRL apoB-48 concentrations primarily by decreasing the production of these particles.
- © 2011 by American Heart Association, Inc.