Murdoch J C, Ratcliffe W A, McLarty D G, Rodger J C, Ratcliffe J G
J Clin Endocrinol Metab. 1977 Mar;44(3):453-8. doi: 10.1210/jcem-44-3-453.
The thyroid status of 82 institutionalized adults with Down's syndrome has been assessed. Compared to age and sex matched control subjects, these patients had significantly lower mean total serum thyroxine (T4) and triiodothyronine (T3) concentrations (T4; 69.1+/-22.2 nmol/1; (mean+/-SD) vs. 100.1+/-19.1, P less than 0.001; T13; 1.61+/-0.47 nmol/1 vs. 1.76+/-0.34, P less than 0.025), lower free thyroxine index (FTI), (FTI; 66.1+/-22.4 vs. 95.1+/-20.2, P less than 0.001), and higher basal serum thyrotrophin (TSH) concentrations (TSH; 7.6+/-10.7 mU/1 vs. 3.8+/-1.5, P less than 0.001). These changes were not related to age or sex. Abnormalities in one or more test of thyroid function were demonstrated in at least 38 (46%) of the 82 patients. Two main patterns of abnormality were defined: 1) subnormal T4, FTI and elevated basal TSH levels (primary hypothyroidism) in 13 (16%). All seven of the 13 patients in whom TRH tests were performed showed the expected exaggerated TSH response, and seven out of the 13 patients (54%) had positive thyroid antibodies, 2) Subnormal T4, subnormal or low normal FTI, and basal TSH levels within the normal range in 18 (22%). The mean basal TSH concentration was, however, significantly higher than in patients with normal T4 and FTI levels, suggesting a minor degree of thyroid failure. Only two of the 18 patients (11%) had positive thyroid antibodies. Of the 17 patients in the group tested, 13 showed a normal TSH response to TRH, three an exagerrated response (all females), and one had an impaired response. Other patterns of abnormal thyroid function were observed occasionally: one female patient had biochemical T3 toxicosis; another had the biochemical pattern of subclinical hypothyroidism, four patients with normal basal T4, FTI and TSH levels showed an exaggerated TSH response to TRH and one patient had an impaired response. These data indicate that htyroid dysfunction, in particular hypothyroidism, is common in adults with Down's syndrome, though specific tests are usually required to make the diagnosis. The general reduction in thyroid function in Down's syndrome may be due to impaired development of the thyroid gland. However, frank chemical hypothyroidism may occur only when thyroiditis is superimposed on preexisting diminished thyroid reserve.
对82名患有唐氏综合征的机构收容成年人的甲状腺状况进行了评估。与年龄和性别匹配的对照受试者相比，这些患者的血清总甲状腺素（T4）和三碘甲状腺原氨酸（T3）平均浓度显著降低（T4：69.1±22.2nmol/L；（均值±标准差），对照组为100.1±19.1，P＜0.001；T3：1.61±0.47nmol/L，对照组为1.76±0.34，P＜0.025），游离甲状腺素指数（FTI）较低（FTI：66.1±22.4，对照组为95.1±20.2，P＜0.001），基础血清促甲状腺激素（TSH）浓度较高（TSH：7.6±10.7mU/L，对照组为3.8±1.5，P＜0.001）。这些变化与年龄或性别无关。82名患者中至少38名（46%）在一项或多项甲状腺功能测试中出现异常。定义了两种主要的异常模式：1）13名（16%）患者T4、FTI低于正常水平，基础TSH水平升高（原发性甲状腺功能减退）。在进行促甲状腺激素释放激素（TRH）试验的13名患者中，所有7名患者的TSH反应均如预期那样过度增强，13名患者中有7名（54%）甲状腺抗体呈阳性；2）18名（22%）患者T4低于正常水平，FTI低于正常水平或略低于正常范围，基础TSH水平在正常范围内。然而，其基础TSH平均浓度显著高于T4和FTI水平正常的患者，提示存在轻度甲状腺功能减退。18名患者中只有2名（11%）甲状腺抗体呈阳性。在该组接受测试的17名患者中，13名对TRH的TSH反应正常，3名反应过度增强（均为女性），1名反应受损。偶尔还观察到其他甲状腺功能异常模式：1名女性患者有生化性T3中毒；另1名有亚临床甲状腺功能减退的生化模式，4名基础T4、FTI和TSH水平正常的患者对TRH的TSH反应过度增强，1名患者反应受损。这些数据表明，甲状腺功能障碍，尤其是甲状腺功能减退，在唐氏综合征成年人中很常见，不过通常需要进行特定检查才能做出诊断。唐氏综合征患者甲状腺功能普遍降低可能是由于甲状腺发育受损。然而，只有当甲状腺炎叠加在先前已减少的甲状腺储备之上时，才可能发生明显的化学性甲状腺功能减退。
