Lind P, Langsteger W, Molnar M, Gallowitsch H J, Mikosch P, Gomez I
Department of Nuclear Medicine & Endocrinology LKH Klagenfurt, Austria.
Thyroid. 1998 Dec;8(12):1179-83. doi: 10.1089/thy.1998.8.1179.
Epidemiology of thyroid diseases in iodine-sufficient areas (ISA) deals with sporadic goiter, thyroid autoimmune diseases, and thyroid cancer. A comparison between the different studies performed is difficult because methods have changed over time and selection criteria and definitions such as prevalence or incidence were not used consistently by some authors. Sporadic goiter: in ISA, autoimmune processes play a major role in the development of sporadic goiter. In adults, sporadic diffuse goiter is most frequent in young women (16%), perhaps due to additional relative iodine deficiency especially in pregnancy, and declines with age (<10%). Sporadic nodular goiter increases from 5% in young women to 9% in older women. Autoimmune thyroid disease (AITD): thyroid autoantibodies (TAb) and histopathological lymphocytic infiltration of the thyroid is much more common in ISA (4.6% in women; 1.1% in men) than in iodine-deficient areas (IDA). The prevalence and incidence of hypothyroidism and hyperthyroidism varies, depending on whether overt and subclinical forms are included and whether newly or previously diagnosed dysfunction is considered. In an overview of the literature, the prevalence is 2 in 1000 for overt and 6 in 1000 for subclinical hyperthyroidism in ISA. The values for hypothyroidism are 5 in 1000 and 15 in 1000, respectively. Change from IDA to ISA: in former IDA, the percentage of hyperthyroidism increases up to 4 years after salt iodination. Whereas this effect is transient for Plummer's disease, a change from IDA to ISA seems to lead to a permanent increase in overt and subclinical Graves' disease. Thyroid cancer: most studies demonstrate that the histopathological types of thyroid cancer are different in IDA and ISA. There is a tendency toward an increase in differentiated and decrease of anaplastic cancer. The ratio of papillary to follicular thyroid cancer ranges from 6.5:1 to 3.4:1 in areas with high iodine intake, decreases 3.7:1 to 1.6:1 in areas with moderate iodine intake, and ranges from 1.7:1 to 0.19:1 in IDA.
碘充足地区（ISA）甲状腺疾病的流行病学涉及散发性甲状腺肿、甲状腺自身免疫性疾病和甲状腺癌。由于研究方法随时间发生了变化，且部分作者对诸如患病率或发病率等选择标准和定义的使用并不一致，因此对不同研究进行比较存在困难。散发性甲状腺肿：在碘充足地区，自身免疫过程在散发性甲状腺肿的发生中起主要作用。在成年人中，散发性弥漫性甲状腺肿在年轻女性中最为常见（16%），这可能是由于额外的相对碘缺乏，尤其是在孕期，且其发生率会随年龄增长而下降（<10%）。散发性结节性甲状腺肿在年轻女性中的发生率从5%升至老年女性中的9%。自身免疫性甲状腺疾病（AITD）：在碘充足地区，甲状腺自身抗体（TAb）和甲状腺组织病理学淋巴细胞浸润比碘缺乏地区（IDA）更为常见（女性为4.6%；男性为1.1%）。甲状腺功能减退症和甲状腺功能亢进症的患病率和发病率各不相同，这取决于是否纳入显性和亚临床形式，以及是否考虑新诊断或既往诊断的功能障碍。在一篇文献综述中，碘充足地区显性甲状腺功能亢进症的患病率为千分之二，亚临床甲状腺功能亢进症的患病率为千分之六。甲状腺功能减退症的相应数值分别为千分之五和千分之十五。从碘缺乏地区转变为碘充足地区：在既往的碘缺乏地区，甲状腺功能亢进症的百分比在食盐碘化后4年内会升高。虽然这种效应对于普拉默病是短暂的，但从碘缺乏地区转变为碘充足地区似乎会导致显性和亚临床格雷夫斯病的永久性增加。甲状腺癌：大多数研究表明，碘缺乏地区和碘充足地区甲状腺癌的组织病理学类型有所不同。分化型甲状腺癌有增加趋势，未分化癌有减少趋势。在高碘摄入地区，乳头状甲状腺癌与滤泡状甲状腺癌的比例为6.
