Response of Lipoprotein Particle Diameters and Distributions Following Aerobic Exercise and Omega-3 Fatty Acid Supplementation

Abstract

Small, dense LDL particles have been associated with an increased cardiovascular disease risk. Both aerobic exercise and omega-3 fatty acid (ω-3fa) supplementation have been shown to favorably alter lipid and lipoprotein concentrations. Little data exist documenting the combined effects of aerobic exercise and ω-3fa supplementation on lipoprotein particle diameters and relative cholesterol distributions. The poly acrylamide gel electrophoresis (PAGE) technique has been shown to quantify both the peak particle diameters and the percent or relative distribution of LDL and HDL cholesterol among LDL and HDL subfractions, respectively. PURPOSE: To determine the independent and combined effect of aerobic exercise and ω-3fa supplementation on LDL and HDL particle diameters and relative cholesterol distributions. METHODS: Moderately active, non-smoking men (n=11; mean±SD, agey 30.5±10.0 yrs, Ht=179.3±10.9 cm, Wt=85.4±11.2 kg, BMI=26.7±3.8 kgm−2, VO2peak=40.8±6.5 mL-kg-min1) were recruited. Each participant performed four randomized trials: rest-no-supplement, exercise-no-supplement, rest±supplement, and exercise±supplement. Exercise consisted of three consecutive days of treadmill exercise at ∼70%VO peak for 60 minutes, and rest consisted of three consecutive days of no exercise. Supplementation consisted of 42 d of 4.55 g-d1 of ω-3fa. Fasting (10h) blood samples were collected 14–16 h following the third exercise and rest sessions in both of the supplement and no supplement trials. Using a 2–31% non-denaturing PAGE, LDL, HDL, HDL, HDL, and HDL peak diameters were quantified. The > relative distribution of cholesterol was quantified by measuring the area under the lipoprotein peaks. A 2 × 2 (exercise × supplement) ANO VA with repeated measures with a Bonferroni post hoc test were employed. The criterion reference for statistical significance was set at a p<0.05. RESULTS: Exercise promoted a significant increase in LDL diameter (26.1 nm to 26.4 nm), but not in HDL diameter. The relative distribution of cholesterol in LDL subfractions was not altered. Supplementation of the ω-3fa resulted in a significant shift in the distribution of cholesterol carried by HDL2 (12.3%) and HDL3 (−22.8%). The majority of this shift was noted inHDL2b (17.4%) and HDL3a (−30.8%). There were no combined effects of exercise and ω-3fa supplementation on lipoprotein particles. CONCLUSION: These data suggest that three consecutive days of aerobic exercise will promote a favorable change in LDL particle diameter. In addition, ω-3fa supplementation may promote a change in the distribution of cholesterol between HDL3 and HDL2 particles.