Exercised-induced increase in lipid peroxidation parameters in amenorrhelc female athletes

Abstract

Objective: To determine plasma lipid peroxidation parameters in eumenorrheic and amenorrheic athletes and to evaluate differences in their response to exercise-induced oxidative stress. In female athletes, intense physical exercise has been shown to be associated with an increased occurrence of menstrual dysfunction with lower levels of E 2. Recently, a protective role has been demonstrated for estrogens as free radical scavengers. Design: Comparison of eumenorrheic and amenorrheic athletes before and after an acute bout of exercise. Setting: Academic Research Environment. Patient(s): Seven eumenorrheic (normally menstruating) and seven amenorrheic (<3 menses/year) female athletes aged 18 to 35 years participating in regular training. Main Outcome Measure(s): Plasma and low-density lipoprotein oxidation parameters, plasma E 2 and vitamin E levels, and creatine kinase activity. Result(s): Both the amenorrheic and eumenorrheic athletes demonstrated a significant decrease in the lag time of conjugated diene formation after exercise ( P < 0.01), with greater magnitude of change occurring in the amenorrheic athletes ( P < 0.05). In addition, postexercise samples from amenorrheic (but not eumenorrhic) athletes showed a significant ( P < 0.01) increase in oxysterol formation as compared to baseline values. Amenorrheic athletes also demonstrated a significantly higher baseline creatine kinase activity and a nonsignificant ( P = 0.04) trend of an increase in creatine kinase activity after exercise. Conclusion(s): The results of this study shows that amenorrheic female athletes demonstrate an increased potential for lipid peroxidation after exercise. This could be related to lower plasma E 2 levels in this group, considering the strong free radical scavenging ability of estrogens identified recently.