New G, Timmins K L, Duffy S J, Tran B T, O'Brien R C, Harper R W, Meredith I T
Cardiovascular Centre, Monash Medical Centre, Clayton, Melbourne, Australia.
J Am Coll Cardiol. 1997 Jun;29(7):1437-44. doi: 10.1016/s0735-1097(97)00080-6.
This study sought to examine the effects of long-term estrogen therapy on vascular function in male to female transsexuals and to compare the findings with those observed in men and premenopausal women.
Gender differences in coronary artery disease have largely been attributed to the beneficial effects of estrogen on vascular function and plasma lipids in women. However, the effects of estrogen on the male vasculature have not been widely studied.
We compared the effects of estrogen on vascular function in 14 male to female transsexuals, 14 age-matched men and 15 premenopausal women. Flow-mediated vasodilation and response to nitroglycerin were assessed in the brachial artery using noninvasive ultrasound.
Flow-mediated vasodilation was similar in transsexuals and women but greater than that in men ([mean +/- SE] 11.5 +/- 1.3% and 9.4 +/- 1.1% vs. 5.2 +/- 1.0% respectively, p < 0.005). Responses to nitroglycerin were also greater in transsexuals and women than in men (21.6 +/- 1.7% and 21.0 +/- 0.9% vs. 14.5 +/- 1.2%, respectively, p = 0.0005). These differences persisted even after adjusting for vessel size. Despite similar total cholesterol levels, transsexuals had high density lipoprotein cholesterol levels similar to those in women and greater than those observed in men (1.76 +/- 0.12 and 1.82 +/- 0.11 mmol/liter vs. 1.35 +/- 0.07 mmol/liter, respectively, p < 0.005). Moreover, triglyceride levels were greater in transsexuals than in men and women, and low density lipoprotein cholesterol (LDL-C) particle size was smaller (25.7 +/- 0.2 nm vs. 26.2 +/- 0.1 and 26.6 +/- 0.1 nm, respectively, p = 0.0001). Serum testosterone (an index of estrogen therapy in transsexuals) was markedly suppressed in transsexuals and similar to that in women. Univariate analysis revealed that there was a strong inverse correlation between serum testosterone and flow-mediated vasodilation (r(s) = -0.48, p < 0.005). Multivariate analysis revealed that the best combination of predictors of flow-mediated vasodilation was serum testosterone, vessel size and LDL-C (R2 = 0.3, p < 0.005).
Long-term estrogen therapy appears to improve vascular function in male to female transsexuals and occurs despite higher triglyceride levels and the presence of small, dense LDL-C. The beneficial effects of estrogen are not gender specific or solely mediated through endothelium-derived nitric oxide.
本研究旨在探讨长期雌激素治疗对男变女跨性别者血管功能的影响，并将研究结果与男性和绝经前女性进行比较。
冠状动脉疾病的性别差异很大程度上归因于雌激素对女性血管功能和血脂的有益作用。然而，雌激素对男性血管系统的影响尚未得到广泛研究。
我们比较了雌激素对14名男变女跨性别者、14名年龄匹配的男性和15名绝经前女性血管功能的影响。使用无创超声评估肱动脉的血流介导的血管舒张和对硝酸甘油的反应。
跨性别者和女性的血流介导的血管舒张相似，但大于男性（[平均值±标准误]分别为11.5±1.3%和9.4±1.1%，而男性为5.2±1.0%，p<0.005）。跨性别者和女性对硝酸甘油的反应也大于男性（分别为21.6±1.7%和21.0±0.9%，而男性为14.5±1.2%，p = 0.0005）。即使在调整血管大小后，这些差异仍然存在。尽管总胆固醇水平相似，但跨性别者的高密度脂蛋白胆固醇水平与女性相似，且高于男性（分别为1.76±0.12和1.82±0.11 mmol/升，而男性为1.35±0.07 mmol/升，p<0.005）。此外，跨性别者的甘油三酯水平高于男性和女性，低密度脂蛋白胆固醇（LDL-C）颗粒大小较小（分别为25.7±0.2 nm，而男性和女性分别为26.2±0.1和26.6±0.1 nm，p = 0.0001）。跨性别者的血清睾酮（跨性别者雌激素治疗的指标）明显受到抑制，与女性相似。单因素分析显示，血清睾酮与血流介导的血管舒张之间存在强烈的负相关（r(s)= -0.48，p<0.005）。多因素分析显示，血流介导的血管舒张的最佳预测指标组合是血清睾酮、血管大小和LDL-C（R2 =
