The effect of endurance exercise training on plasma lipoprotein AI and lipoprotein AI:AII concentrations in sedentary adults

The effect of 6 months of endurance exercise training on plasma concentrations of lipoprotein (Lp)AI and LpAI:AII was determined in 39 sedentary subjects (17 men, 22 women, average age, 57 years) with abnormal cholesterol concentrations (total cholesterol [TC] > 200 mg/dL, or high-density lipoprotein-cholesterol [HDL-C] < 35 mg/dL). Following exercise training, plasma LpAI concentrations increased (+5.9 ± 1.2 mg/dL; P <.001), but there was no change in total apolipoprotein (apo) A-I or LpAI:AII concentrations. The change in plasma LpAI concentration was positively correlated to changes in total HDL-C (r =.495, P =.001), the sum of HDL4-C_nmr + HDL5-C_nmr (r =.417, P =.008), and average HDL particle size (r =.415, P =.009), but not to changes in body composition or V̇O₂ max. In the 8 subjects with the greatest change in LpAI concentration following training, the size distribution of LpAI and LpAI:AII particles in plasma also was measured before and after training. In these subjects, the size distribution of LpAI:AII particles did not change with training, but there was a significant increase (0.1 nm; P =.048) in the peak size of the "medium" (7.8 to 9.8 nm) LpAI particles after training. In 7 subjects who served as age- and weight-matched sedentary controls, plasma concentrations of total apo A-I, the LpAI and LpAI:AII subfractions, and plasma lipoprotein-lipids did not differ significantly between baseline and final testing. These data indicate that endurance exercise training increases the average size and plasma concentrations of LpAI, but not LpAI:AII, particles, which may represent possible enhancements of reverse cholesterol transport and may provide insight into the role that exercise plays in reducing cardiovascular disease risk.