Efeitos do estradiol sobre a função endotelial, sensibilidade insulínica e viscosidade sanguínea em mulheres na pós-menopausa com excesso de peso

Abstract

The action that estrogen plays on the endothelium depends on its integrity and consequently on the clinical characteristics of each individual. The use of menopausal hormone therapy (MHT) in women with low cardiovascular risk usually results in beneficial effects, since it is started in a period close to menopause. In contrast, its use often results in harmful effects in women at high cardiovascular risk, such as diabetic ones or those with established atherosclerotic lesions, and even in those that the beginning of MHT exceeds ten years from menopause. Our goal is to evaluate the effects of estrogen on endothelial function in overweight women, ie, individuals at intermediate cardiovascular risk. For this purpose, 44 postmenopausal women, aged 47-55 years with body mass index (BMI) from 27.5 to 34.9 kg / m², were randomized into placebo (P) and transdermal estrogen (TE) groups. The intervention consisted of using transdermal estradiol 1mg per day for a period of three months. Participants underwent endothelial reactivity assessment at rest and after ischemia [by venous occlusion plethysmography (VOP), with assessment of forearm blood flow (FBF) and dynamic nailfold videocapillaroscopy (DNV), with assessment of red blood cell velocity (RBCV)], measurements of soluble adhesion molecules [E-selectin, intercellular adhesion molecule (ICAM-1) and vascular cell adhesion molecule (VCAM-1)], measurement of insulin sensitivity [by homeostatic model assessment of insulin resistance (HOMA-IR) and area under the curve (AUC) of insulin during the oral glucose tolerance test (OGTT)] and measurements of blood and plasma viscosities. The participants aged 51.77 ± 2.3 years, BMI 31.52 ± 2.54 kg/m² and had a time since menopause of 3 [2-5] years. P group showed no significant change in any variable. After intervention, the TE group compared to the baseline presented in DNV lower time taken to reach RBCV during post-occlusive reactive hyperemia (PORH) (4,0 [3,25-5,0] vs. 5,0 [4,0-6,0] s, P<0.05) and also higher RBCV at rest (0.316 [0.309 to 0.326] vs. 0.303 [0.285-0.310] mm/s, P<0.001) and during PORH (0.374 [0.353 to 0.376] vs. 0.341 [0.334 to 0.373] mm/s, P<0.001 ), at POV we also noticed a higher FBF at rest (2.46 [1.81-3.28] vs. 1.89 [1.46 to 2.44] ml/min.100mltecido-1, P<0.01) and during PORH (6.39 [5.37 to 9.39] vs. 5.23 [4.62 to 7.47] ml/min.100mltecido-1, P<0.001). The TE group also showed a decrease in the levels of soluble E-selectin (68.95 [50.18 to 102.8] vs. 58.4 [44.53 to 94.03] ng/ml, P<0.05) and ICAM-1 (188 [145-212] vs. 175 [130-200] ng/ml, P<0.01). Compared to baseline, the ET group had a decrease in HOMA-IR (3.35 ± 1.67 vs. 2.85 ± 1.60, P<0.05) and insulin AUC during OGTT (152 [117-186] vs. 115 [85-178], P<0.01), and decreased blood viscosity with native hematocrit (3.72 ± 0.21 vs. 3.57 ± 0.12 mPa.s; P<0.01) and in plasma (1.49 ± 0.10 vs. 1.45 ± 0.08 mPa.s, P<0.05). In conclusion the use of transdermal estradiol in overweight and recently menopausal women improves endothelial function and protection to other cardiovascular risk factors.