Decreased oxidant profile and increased antioxidant capacity in naturally postmenopausal women.
Recent works have shown a dual side of estrogens, and research on the relationship between oxidative stress and menopausal status remains unclear and has produced controversial results. In this work, we aimed to evaluate by sensitive methods the oxidant and antioxidant changes that develop after natural menopause. Thirty premenopausal and 28 naturally postmenopausal women volunteered for this study. Blood was collected and plasma used. 17-OH estradiol levels in plasma were estimated. Plasma levels of advanced oxidation protein products (AOPP), lipid peroxidation products (such as hydroperoxides and malondialdehyde (MDA)), and nitrites were measured, and total radical antioxidant parameter testing was performed to determine the oxidant and antioxidant profiles, respectively. Estrogen levels were significantly increased (p < 0.02) in premenopausal women (54.28 ± 9.34 pg/mL) as compared with postmenopausal women (18.10 ± 1.49 pg/mL). Postmenopausal women had lower levels of lipid hydroperoxide oxidation (p < 0.0001), lipid hydroperoxide levels evaluated by the area under the curve (AUC; 1,366,000 ± 179,400 AUC; p < 0.01), and hydroperoxides as measured by the ferrous oxidation-xylenol orange method (31.48 ± 2.7 μM; p < 0.0001). The MDA levels did not differ between pre- and postmenopausal women whether measured by thiobarbituric acid-reactive substances or high-performance liquid chromatography assays. No differences in AOPP and nitrite levels were observed between pre- and postmenopausal women. Postmenopausal women also exhibited a higher total radical antioxidant level (0.89 ± 0.08 μM Trolox; p < 0.0001). Postmenopausal women demonstrated lower levels of oxidative damage and a higher antioxidant capacity than premenopausal women.
Laboratory of Pathophysiology and Free Radicals, Department of General Pathology, State University of Londrina, 86051-990, Londrina, Paraná, Brazil. vanjacob@gmail.com
V J
VJ
Victorino
C
C
Panis
F C
FC
Campos
R C
RC
Cayres
A N
AN
Colado-Simão
S R
SR
Oliveira
A C S A
AC
Herrera
A L
AL
Cecchini
R
R
Cecchini
D000328:Adult; D062107:Advanced Oxidation Protein Products / Q000097:blood*; D000975:Antioxidants / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006861:Hydrogen Peroxide / Q000097:blood; D015227:Lipid Peroxidation; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D016877:Oxidants / Q000097:blood*; D018384:Oxidative Stress / Q000502:physiology*; D017698:Postmenopause / Q000097:blood*; D012189:Retrospective Studies
D062107:Advanced Oxidation Protein Products; D000975:Antioxidants; D016877:Oxidants; D008315:Malondialdehyde; D006861:Hydrogen Peroxide