Toxic multinodular goiter (MNG) accounts for about 5% to 15% of patients with endogenous hyperthyroidism, but the proportion is higher in iodine-deficient regions (around 50%).[2]Gabriel EM, Bergert ER, Grant CS, et al. Germline polymorphism of codon 727 of human thyroid-stimulating hormone receptor is associated with toxic multinodular goiter. J Clin Endocrinol Metab. 1999;84:3328-35.
https://academic.oup.com/jcem/article/84/9/3328/2864599?login=true
http://www.ncbi.nlm.nih.gov/pubmed/10487707?tool=bestpractice.com
[3]De Leo S, Lee SY, Braverman LE. Hyperthyroidism. Lancet. 2016 Aug 27;388(10047):906-18.
http://www.ncbi.nlm.nih.gov/pubmed/27038492?tool=bestpractice.com
In areas where low iodine intake is prevalent, the incidence of toxic MNG is 18.0 cases per 100,000 per year compared with 1.5 cases per 100,000 per year in high-iodine-intake areas.[4]Taylor PN, Albrecht D, Scholz A, et al. Global epidemiology of hyperthyroidism and hypothyroidism. Nat Rev Endocrinol. 2018 May;14(5):301-16.
http://www.ncbi.nlm.nih.gov/pubmed/29569622?tool=bestpractice.com
In iodine-sufficient parts of the world, the prevalence of palpable nodular thyroid disease is approximately 5% in women and 1% in men.[5]Thiruvengadam S, Luthra P. Thyroid disorders in elderly: A comprehensive review. Dis Mon. 2021 Nov;67(11):101223.
https://www.doi.org/10.1016/j.disamonth.2021.101223
http://www.ncbi.nlm.nih.gov/pubmed/34154807?tool=bestpractice.com
Toxic MNG is the most frequent cause of thyrotoxicosis in elderly individuals, especially those in iodine-deficient areas.[4]Taylor PN, Albrecht D, Scholz A, et al. Global epidemiology of hyperthyroidism and hypothyroidism. Nat Rev Endocrinol. 2018 May;14(5):301-16.
http://www.ncbi.nlm.nih.gov/pubmed/29569622?tool=bestpractice.com
Toxic nodular disease in children is rare, and evidence is limited.[6]Guille JT, Opoku-Boateng A, Thibeault SL, et al. Evaluation and management of the pediatric thyroid nodule. Oncologist. 2015 Jan;20(1):19-27.
https://www.doi.org/10.1634/theoncologist.2014-0115
http://www.ncbi.nlm.nih.gov/pubmed/25480825?tool=bestpractice.com
The epidemiology of iodine intake is influenced by natural sources of iodine in the food chain and implementation of public health measures, such as salt iodization programs.[7]Zimmermann MB, Boelaert K. Iodine deficiency and thyroid disorders. Lancet Diabetes Endocrinol. 2015 Apr;3(4):286-95.
http://www.ncbi.nlm.nih.gov/pubmed/25591468?tool=bestpractice.com
[8]Li M, Eastman CJ. The changing epidemiology of iodine deficiency. Nat Rev Endocrinol. 2012 Apr 3;8(7):434-40.
https://www.doi.org/10.1038/nrendo.2012.43
http://www.ncbi.nlm.nih.gov/pubmed/22473332?tool=bestpractice.com
Iodine Global Network: Global scorecard of iodine nutrition in 2021 in the general population based on school-age children (SAC)
Opens in new window
[Figure caption and citation for the preceding image starts]: Goiter due to a dietary iodine deficiencyCenters for Disease Control and Prevention; used with permission [Citation ends].