Iodine deficiency and prevalence of nodular goitre in Ukraine

Abstract

More than one tenth of the world population is to some degree affected by goitre and most of these harbour nodules. The large differences in thyroid disease prevalence between populations may be caused by genetic and environmental factors. Among the latter, iodine deficiency seems by far to be the most important risk factor. Thus, nodular goitre is a condition predominantly seen in iodine deficient areas of the world. Large thyroid volumes and high frequencies of goitres have been reported in countries affected by iodine deficiency. In the present review, we evaluated prevalences of thyroid nodules in iodine-deficient countries. In 2016 in Ukraine the prevalence of nodular goiter was 707.8 per 100 thousand population, then after 5 years the figure slowly increased to 891.5 cases, respectively (+25.9%). The existing high indices of newly diagnosed patients with nodular goitre in the country in 2016 were 71.9, and at the end of 2020— 90.2 initially established cases per 100 thousand population, with a positive increase of +25.5%. In the Whickham survey, 20% of women and 5% of men who had goitres in the initial survey showed no evidence of goitre in a follow-up survey. An average growth rate in the multinodular goitre of 5–20% was reported in iodine-sufficient areas. On the basis of the results of the Framingham survey, the estimated lifetime risk for developing a nodule is 5–10%. Thyroid nodule size can increase, decrease, or remain stable, and thyroid nodules may eventually also disappear over time. Solid nodules more frequently increase, whereas cystic nodules can shrink or disappear. If the goitre has been present for some time, autonomous function of the nodules and eventually hyperthyroidism develop. The rate of progression from euthyroidism to subclinical and overt hyperthyroidism is about 10%.