[Effects of raloxifene on endothelial function and hemostasis in women with ischemic heart disease]. / Efecto del raloxifeno en la función endotelial y la hemostasia en mujeres con enfermedad coronaria.

INTRODUCTION AND OBJECTIVES: Modulation of vascular tone is one of the most relevant estrogen effects. A beneficial effect on endothelial function in postmenopausal women has also been proposed for the selective estrogen receptor modulator raloxifene. However, its effects in women with established cardiovascular disease have not been fully elucidated. In addition, recent trials have generated controversy regarding thromboembolic risk with raloxifene use. The aim of the study was to assess the effect of raloxifene on: a) endothelial function and b) coagulation and fibrinolysis pathways. METHODS: The MERCED trial was a prospective, randomized clinical trial. Thirty-three postmenopausal women with ischemic heart disease were enrolled in the study. Raloxifene treatment was administered for a 3-month period, according to a double-blind crossover design. Assessment of vascular function and biologic parameters related to coagulation pathways were conducted at various pre-established time-points. RESULTS: Flow-mediated dilatation was severely impaired in the study population, and raloxifene had no effect on endothelial function. Treatment with raloxifene was associated to decreased levels of fibrinogen (3.41 [3.11-3.74] vs. 3.69 [3.40-4.00], P<.05); prothrombin fragments F(1+2) (0.93 [0.77-1.12] vs. 0.94 [0.78-1.15], P<.05); and plasmin/antiplasmin complexes (211 [166-267] vs. 242 [199-295], P<.01). CONCLUSIONS: The present study provides evidence that in postmenopausal women with demonstrated endothelial dysfunction and ischemic heart disease, mid-term treatment with raloxifene does not affect endothelial function. In the MERCED trial, no increased thrombotic risk was observed, but a decreased thrombotic and fibrinolytic activity was observed with raloxifene. Further studies are required to determine whether thrombotic risk is associated with specific clinical characteristics or subgroups of postmenopausal women with cardiovascular disease. Full English text available from: www.revespcardiol.org.

Effect of surgical menopause and Paget's disease of bone on the isomerization of type I collagen carboxyterminal telopeptide: evolution after antiresorptive therapy.

The objective of this study was to analyze the effect of surgical menopause and Paget's disease of bone, as well as the influence of therapy, on the isomerization of the carboxyterminal telopeptide of type I collagen (CTX). Fourteen women who had undergone surgical menopause and had begun hormone replacement therapy (HRT) after surgery were recruited. Results for these women were compared with those of 29 patients with Paget's disease of bone treated with tiludronate (400 mg/day) for 3 months, and with those of a group of 21 healthy premenopausal women (control group I). In addition, 14 healthy individuals with an age range similar to that of the pagetic patients (control group II) were included in the study. Urine samples were analyzed for levels of nonisomerized and beta-isomerized CTX (alpha-CTX and beta-CTX). Biochemical determinations were performed 3 months after surgical menopause and after 3 and 9 months of HRT, and at baseline, and 1 and 6 months after tiludronate treatment in the pagetic patients. The average levels of alpha-CTX and beta-CTX were higher in patients than in controls. In patients after surgical menopause, because of their greater increase of beta-CTX, the alpha-CTX/beta-CTX ratio was lower than that of control group I (0.881 +/- 0.3 vs 1.515 +/- 0.8; P < 0.05). In contrast, at baseline, pagetic patients showed marked increases in alpha-CTX levels, resulting in a higher alpha-CTX/beta-CTX ratio than that of control group II (2.879 +/- 1.3 vs 0.96 +/- 0.25; P < 0.0001). The average percent decrease in both markers after therapy was similar in both conditions (-60% for alpha-CTX and -44% for beta-CTX after 3 months of HRT in the surgical menopause group, vs -66% for alpha-CTX and -41% for beta-CTX in the pagetic group, 1 month after finishing tiludronate therapy; P, NS), resulting in a significant decrease of the alpha-CTX/beta-CTX ratio in pagetic patients (2.879 +/- 1.3 vs. 1.614 +/- 0.8; P < 0.001). In conclusion, surgical menopause is associated with a decrease in the urinary alpha-CTX/beta-CTX ratio because of the higher increase in the beta-CTX level after menopause. Pagetic patients show an increase in this ratio, compared with the control value, and the ratio decreases after bisphosphonate treatment. The response to therapy was similar in both conditions, with a comparable decrease of both markers. These findings show how bone markers may contribute to the understanding of pathophysiologic mechanisms in bone diseases.