Laboratory of Molecular Endocrinology, Division of Endocrinology, Department of Medicine, Escola Paulista de Medicina, Federal University of São Paulo, Rua Pedro de Toledo 669, São Paulo, Brazil.
Thyroid. 2010 Oct;20(10):1151-6. doi: 10.1089/thy.2009.0424.
It has been suggested that the female preponderance for autoimmune thyroid disease might be associated with hormonal differences, abortion, and fetal microchimerism. Findings emerging from the few epidemiological studies on this matter, however, are controversial. In this study, we investigated the hypothesis whether parity, abortion, and the use of estrogens are associated with a higher risk for thyroid autoimmunity.
This cross-sectional population-based study examined 675 women from a Japanese-Brazilian population aged above 30 years. Thyroid peroxidase antibodies (TPOAbs), thyroglobulin antibodies (TgAbs), thyrotropin, and free T₄ were measured by immunofluorimetric assays. Urinary iodine concentration was measured using a colorimetric method. Data were analyzed in logistical regression models to obtain the odds ratio (OR) and 95% confidence intervals.
TPOAbs and TgAbs were present in 11.6% and 13.6% of women, respectively. After adjustment for age, smoking, and urinary iodine concentration, the OR for positive TPOAb (OR, 1.22 [95% confidence interval, 0.73–2.02]) and for positive TgAb (OR, 1.01 [0.63–1.62]) among women who had one or more parities did not differ from those who had never given birth. In addition, we found no association between the presence of thyroid antibodies and previous abortions or the use of estrogens.
Parity, abortion, and the use of estrogens are not associated with thyroid autoimmunity in this population. These findings reinforce previous reports that advocated against a key role of fetal microchimerism in the pathogenesis of autoimmune thyroid disease.
有人认为，女性自身免疫性甲状腺疾病的高发可能与激素差异、流产和胎儿微嵌合体有关。然而，关于这个问题的少数几项流行病学研究结果存在争议。在这项研究中，我们调查了假设，即生育、流产和雌激素的使用是否与更高的甲状腺自身免疫风险相关。
这项基于人群的横断面研究调查了 675 名年龄在 30 岁以上的日本-巴西人群中的女性。甲状腺过氧化物酶抗体 (TPOAb)、甲状腺球蛋白抗体 (TgAb)、促甲状腺激素和游离 T₄ 均采用免疫荧光分析进行测量。尿碘浓度采用比色法测量。数据采用逻辑回归模型进行分析，以获得比值比 (OR) 和 95%置信区间。
TPOAb 和 TgAb 分别存在于 11.6%和 13.6%的女性中。在调整年龄、吸烟和尿碘浓度后，有一次或多次生育的女性中 TPOAb 阳性的 OR（OR，1.22[95%置信区间，0.73-2.02]）和 TgAb 阳性的 OR（OR，1.01[0.63-1.62]）与从未生育的女性无差异。此外，我们没有发现甲状腺抗体的存在与既往流产或雌激素使用之间存在关联。
在该人群中，生育、流产和雌激素的使用与甲状腺自身免疫无关。这些发现进一步证实了先前的报告，即不支持胎儿微嵌合体在自身免疫性甲状腺疾病发病机制中的关键作用。
