Exercised-induced increase in lipid peroxidation parameters in amenorrheic female athletes.

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 E2. 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 E2 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 E2 levels in this group, considering the strong free radical scavenging ability of estrogens identified recently.