Postprandial oxidative stress: influence of sex and exercise training status.
An individual's sex and exercise training status may influence oxidative stress. No study has compared postprandial oxidative stress in exercise-trained and untrained men and women.


OBJECTIVE
To compare oxidative stress biomarkers and triglycerides (TAG) in 16 trained and 16 untrained men and women after ingestion of a high-fat meal.


METHODS
Blood samples were collected before, and at 1, 2, 4, and 6 h after intake of a high-fat meal and analyzed for Trolox-equivalent antioxidant capacity (TEAC), malondialdehyde, hydrogen peroxide, xanthine oxidase activity, protein carbonyls (PC), and TAG. Area under the curve was calculated for each variable.


RESULTS
Sex main effects were noted for all variables (P < 0.01), except for PC and TEAC (P > 0.05), with higher values for men compared with women. A training status main effect was noted for TEAC (P = 0.02), with higher values for trained compared with untrained subjects. No interaction effects were noted (P > 0.05). Regression analysis indicated that TAG explained the greatest degree of variability for oxidative stress variables, and premeal TAG best predicted the TAG response to feeding (R(2) = 0.50).


CONCLUSIONS
With the exception of TEAC, for which higher values were noted for trained compared with untrained subjects, our findings indicate that sex, not exercise training status, influences postprandial oxidative stress. Specifically, women experience a significantly lower oxidative stress response to feeding compared with men. This seems mediated in part by the TAG response to feeding.
Bloomer
Richard J
RJ
Department of Health and Sport Sciences, Cardiorespiratory/Metabolic Laboratory, University of Memphis, Memphis, TN 38152, USA. rbloomer@memphis.edu
Ferebee
David E
DE
Fisher-Wellman
Kelsey H
KH
Quindry
John C
JC
Schilling
Brian K
BK
D000293:Adolescent; D000328:Adult; D019540:Area Under Curve; D001669:Biochemical Phenomena; D015415:Biomarkers / Q000097:blood; D004041:Dietary Fats / Q000008:administration & dosage; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D018384:Oxidative Stress / Q000502:physiology*; D019518:Postprandial Period / Q000502:physiology*; D012737:Sex Factors; D055815:Young Adult
D015415:Biomarkers; D004041:Dietary Fats