在发展中国家/地区,缺碘是甲状腺功能减退症的主要病因。虽然在发达国家/地区较为少见,但在一些南欧和西欧国家/地区,轻度至中度缺碘情况常见。[4]Delange F, de Benoist B, Pretell E, et al. Iodine deficiency in the world: where do we stand at the turn of the century? Thyroid. 2001;11:437-447.http://www.ncbi.nlm.nih.gov/pubmed/11396702?tool=bestpractice.com[5]Roberts CG, Ladenson PW. Hypothyroidism. Lancet. 2004;363:793-803.http://www.ncbi.nlm.nih.gov/pubmed/15016491?tool=bestpractice.com[6]Andersson M, Karumbunathan V, Zimmermann MB. Global iodine status in 2011 and trends over the past decade. J Nutr. 2012;142:744-750.http://jn.nutrition.org/content/142/4/744.longhttp://www.ncbi.nlm.nih.gov/pubmed/22378324?tool=bestpractice.com 全球在普及碘盐方面的努力已降低了此问题的严重程度。[4]Delange F, de Benoist B, Pretell E, et al. Iodine deficiency in the world: where do we stand at the turn of the century? Thyroid. 2001;11:437-447.http://www.ncbi.nlm.nih.gov/pubmed/11396702?tool=bestpractice.com 据估计,在英国,原发性甲状腺功能减退症的女性年发病率为 0.41%,男性则为 0.06%。[7]Vanderpump MP, Tunbridge WM, French JM, et al. The incidence of thyroid disorders in the community: a twenty-year follow-up of the Whickham survey. Clin Endocrinol. 1995;43:55-68.http://www.ncbi.nlm.nih.gov/pubmed/7641412?tool=bestpractice.com 在美国,有临床表现的显性原发性甲状腺功能减退症的患病率为 0.3%,而亚临床性甲状腺功能减退症的患病率为 4.3%。[8]Hollowell JG, Staehling NW, Flanders WD, et al. Serum TSH, T(4) and thyroid antibodies in the United States population (1988 to 1994): National Health and Nutrition Examination Survey (NHANES III). J Clin Endocrinol Metab. 2002;87:489-499.http://press.endocrine.org/doi/full/10.1210/jcem.87.2.8182http://www.ncbi.nlm.nih.gov/pubmed/11836274?tool=bestpractice.com 显性及亚临床性甲状腺功能减退症的白人患病率 (5.1%) 高于黑人 (1.7%) 或西班牙人 (4.2%)。[8]Hollowell JG, Staehling NW, Flanders WD, et al. Serum TSH, T(4) and thyroid antibodies in the United States population (1988 to 1994): National Health and Nutrition Examination Survey (NHANES III). J Clin Endocrinol Metab. 2002;87:489-499.http://press.endocrine.org/doi/full/10.1210/jcem.87.2.8182http://www.ncbi.nlm.nih.gov/pubmed/11836274?tool=bestpractice.com 女性患病率较高,并随年龄增长而升高。女性患病率介于 4%(18 至 24 岁)至 21%(74 岁以上)之间,而同年龄组的男性患病率介于 3% 至 16% 之间。[9]Canaris GJ, Manowitz NR, Mayor G, et al. The Colorado thyroid disease prevalence study. Arch Intern Med. 2000 Feb 28;160(4):526-34.http://www.ncbi.nlm.nih.gov/pubmed/10695693?tool=bestpractice.com 英国的患病率与此相似,有 7.5% 的女性和 2.8% 的男性 TSH 水平偏高。[10]Tunbridge WM, Evered DC, Hall R, et al. The spectrum of thyroid disease in the community: the Whickham survey. Clin Endocrinol. 1977;7:481-493.http://www.ncbi.nlm.nih.gov/pubmed/598014?tool=bestpractice.com