Secular Trends in Thyroid Disease and Self-Perceived Mental StressAmong Swedish Women: A Comparative Cross-Sectional Study of theTwo Cohorts 1980-1981 and 2004-2005 from the Population Study ofWomen in Gothenburg, Sweden

Abstract

Objective: The aim of this study was to investigate the prevalence of thyroid disease among 38- and 50-year-old Swedish women in 1980-1981 and in 2004-2005. A second aim was to study whether there is any connection between deviant levels of TSH and mental stress or between diagnosed thyroid disease with normalized levels of TSH and mental stress. Design: Prospective study. Setting: Goteborg, Sweden, population about 4,30,000. Subjects: This study is based on material from the Population Study of Women in Gothenburg. The participants are two representative samples of 38- and 50-year-old women who took part in examinations 1980-1981 and 2004-2005. Main outcome measures: Prevalence of thyroid disease as well associations between mental stress and thyroid disease, studied cross-sectionally. Results: The prevalence of thyroid disease has increased in both 38- (with 39%) and 50-year-old (with 56%) women between 1980-1982 and 2004-2005. There was a significant increase in the prevalence, from 0.9% (CI 0.2-2.6) to 3.4% (CI 1.7-6.2) of 50-year-old women with suppressed TSH. No connection was found between high mental stress and deviant levels of TSH. In the 38-year-old women there was a significant connection between high mental stress and diagnosed thyroid disease. Conclusion: The results indicate that the prevalence of suppressed TSH in Swedish women has increased since the early eighties, and that mental symptoms can exist also in successfully treated thyroid disease. However, all of the changes observed consist of relatively few individuals and no certain conclusions can therefore be drawn from the results.