INFLUENCE OF STRENUOUS ENDURANCE EXERCISE ON CHOLESTERYL ESTER TRANSFER PROTEIN AND HDL METABOLISM IN SERUM 169

Abstract

This study was conducted to clarify the effect of a single bout of strenuous endurance exercise on reverse cholesterol transport through HDL. Thirty-two male triathletes (35.7±8.3yr.) who participated in the '95 Ironman Japan in Lake Biwa (3.8km swim, 180.2km bike, 42.2km run, average duration time: 10hr. 24min.) were examined. Blood samples were taken before, immediately after and one day after the race. Significant increase in serum HDL cholesterol (HDL-C) was observed immediately after the race (66.4 ± 16.6mg/dl to 70.1 ± 17.6mg/dl: p<0.01). However, there was a significant plasma volume change immediately and one day after the race (-7.0% and +4.6%, respectively). If the plasma volume changes were normalized, HDL-C revealed a significant increase one day after the race (+5.5%). HDL-C/(apoA-I+apoA-II) also showed a significant increase one day after the race. This indicates that strenuous exercise altered HDL to a cholesterol rich particle. Serum cholesteryl ester transfer protein (CETP) activity decreased significantly immediately and one day after the race.Table Moreover, there were significant negative correlations between serum CETP activity and HDL-C/(apoA-I+apoA-II) immediately after and one day after the race (p<0.05). These results suggest that CETP mediated cholesterol transfer was obstructed, therefore, cholesterol might accumulate in HDL after strenuous exercise. We conclude that a single bout of strenuous endurance exercise hindered HDL in its reverse cholesterol transport activity by reduction of CETP.