The epidemiology of thyroid disorders in a seaport community in southern Sweden

The prevalence of thyroid disorders was studied in two birth cohorts (1928 and 1941) of men and women living in Malmö, a non-iodine deficient area. In the 1928 cohort, the prevalence of thyroid disorders was 11.5% overall (mean 2.4% , women 20.3%), and higher among immigrant women (20.7%) than among women of the native population, e.g. women born in and still living in Malmö (14.7%). In the 1941 cohort, the overall prevalence of thyroid disorders was 7.9% (men 1.5%, women 14.1%); and the prevalence of goiter was lower among immigrant women (9.5%) than among women of the native population (15.0%). Among the native population, the prevalence of goiter did not differ significantly between the two cohorts, whereas among immigrant women it was significantly greater in the 1928 cohort. The findings suggest that, although iodine deficiency is the most probable cause of goiter among immigrants of the 1928 cohort, where the native population is concerned (both men and women), some other goitrogenic factor(s) must be involved.