TY - JOUR
T1 - Platelet activation status decreases after menopause
AU - Aldrighi, José M.
AU - Oliveira, Rute Loreto S
AU - D'Amico, Élbio
AU - Rocha, Tania R F
AU - Gebara, Otávio E.
AU - Rosano, Giuseppe M C
AU - Ramires, José Antônio F
PY - 2005/5
Y1 - 2005/5
N2 - Objective. The aim of the study was to investigate the impact of the climacterium (before and after menopause) on platelet activation. Background. Platelet activation has been associated to the risk of cardiovascular disease. There is much speculation about the relationship between platelet function and sex steroids, due to peculiarities of platelet action between the genders, including concerns about the influence of low estradiol status in menopausal women. Methods. By means of a cross-sectional study design, 37 female patients divided into two groups were compared. Group A consisted of ten women, mean age 43.9 years, in the premenopausal period, with normal estrogen levels; and Group B comprised 27 patients, mean age 53.0 years, who had all reached menopause. Platelet activation markers, namely P-selectin and glycoprotein IIb-IIIa complex (GPIIb-IIIa), were evaluated by flow cytometry with monoclonal antibodies. A binding index was calculated for both parameters (percentage of positive platelets mean fluorescence of positive platelets). Also, thromboxane A 2 was quantified by means of its main plasma metabolite, thromboxane B2, by enzyme immunoassay. Results. P-selectin and GPIIb-IIIa expression results revealed lower platelet activation status after menopause, as there was a decrease in both the percentage of P-selectin + platelets and of GPIIb-IIIa mean fluorescence of positive platelets, lowering both binding indices. P-selectin binding index differed significantly between Group A (12.3 ± 3, n = 10) and Group B (6.2 + 2.9, n = 27; mean ± standard deviation (SD), p <0.001). GPIIb-IIIa binding index also differed significantly between both groups (Group A: 18.8 ± 2.3, n = 10 vs. Group B: 16.2 ± 3.1, n = 27; mean ± SD, p <0.0018). Plasma concentration of thromboxane B2 was 1.07 ± 0.5 pg/well before menopause (Group A, n = 10) and 1.9 ± 4.1 pg/well after menopause (Group B, n = 27), not significantly different (mean ± SD, baseline × therapy, p = 0.85). Conclusions. After the menopause, climacteric women - whose estradiol status is low - have a decreased activation platelet status compared with premenopausal women. Nevertheless, further studies on a larger sample are necessary for conclusive data regarding cardiovascular disease.
AB - Objective. The aim of the study was to investigate the impact of the climacterium (before and after menopause) on platelet activation. Background. Platelet activation has been associated to the risk of cardiovascular disease. There is much speculation about the relationship between platelet function and sex steroids, due to peculiarities of platelet action between the genders, including concerns about the influence of low estradiol status in menopausal women. Methods. By means of a cross-sectional study design, 37 female patients divided into two groups were compared. Group A consisted of ten women, mean age 43.9 years, in the premenopausal period, with normal estrogen levels; and Group B comprised 27 patients, mean age 53.0 years, who had all reached menopause. Platelet activation markers, namely P-selectin and glycoprotein IIb-IIIa complex (GPIIb-IIIa), were evaluated by flow cytometry with monoclonal antibodies. A binding index was calculated for both parameters (percentage of positive platelets mean fluorescence of positive platelets). Also, thromboxane A 2 was quantified by means of its main plasma metabolite, thromboxane B2, by enzyme immunoassay. Results. P-selectin and GPIIb-IIIa expression results revealed lower platelet activation status after menopause, as there was a decrease in both the percentage of P-selectin + platelets and of GPIIb-IIIa mean fluorescence of positive platelets, lowering both binding indices. P-selectin binding index differed significantly between Group A (12.3 ± 3, n = 10) and Group B (6.2 + 2.9, n = 27; mean ± standard deviation (SD), p <0.001). GPIIb-IIIa binding index also differed significantly between both groups (Group A: 18.8 ± 2.3, n = 10 vs. Group B: 16.2 ± 3.1, n = 27; mean ± SD, p <0.0018). Plasma concentration of thromboxane B2 was 1.07 ± 0.5 pg/well before menopause (Group A, n = 10) and 1.9 ± 4.1 pg/well after menopause (Group B, n = 27), not significantly different (mean ± SD, baseline × therapy, p = 0.85). Conclusions. After the menopause, climacteric women - whose estradiol status is low - have a decreased activation platelet status compared with premenopausal women. Nevertheless, further studies on a larger sample are necessary for conclusive data regarding cardiovascular disease.
KW - Female sex steroids
KW - Glycoprotein IIb-IIIa complex
KW - Menopause
KW - P-selectin
KW - Platelet activation status
KW - Thromboxane
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U2 - 10.1080/09513590500097549
DO - 10.1080/09513590500097549
M3 - Article
C2 - 16019369
AN - SCOPUS:21544484048
VL - 20
SP - 249
EP - 257
JO - Gynecological Endocrinology
JF - Gynecological Endocrinology
SN - 0951-3590
IS - 5
ER -