Inappropriate Suppression of Thyrotropin Concentrations in Young Patients with Thyroid Nodules Including Thyroid Cancer: The Fukushima Health Management Survey

Program: Abstracts - Orals, Poster Previews, and Posters
Session: SAT 270-310-Thyroid Neoplasia (posters)
Clinical/Translational
Saturday, April 2, 2016: 1:15 PM-3:15 PM
Exhibit/Poster Hall (BCEC)

Poster Board SAT 271
Satoru Suzuki*, Izumi Nakamura, Satoshi Suzuki, Sanae Midorikawa, Toshihiko Fukushima, Yuko Ito, Hiroki Shimura, Akira Ohtsuru, Masafumi Abe, Shunichi Yamashita and Shinichi Suzuki
Fukushima Medical University, Fukushima-shi, Japan
Background: The serum thyroid hormone concentration is regulated through the hypothalamus-pituitary-thyroid axis. The aim of this study was to clarify the relationship between thyroid hormone regulation and ultrasonographic findings in subjects with thyroid nodules based on the thyroid ultrasound examination for the Fukushima Health Management Survey.

Methods: A total of 296,253 children who lived in Fukushima Prefecture at the time of the Fukushima nuclear power plant accident and who were aged 18 years or younger on March 11, 2011, participated in two concurrent screening programs as of October 31, 2014. A total of 2,241 children who were mainly presumed to have a thyroid nodule in the primary screening until October 31, 2014. 2,004 children underwent a second confirmatory thyroid ultrasound examination and blood sampling for thyroid function tests were examined in the study. The subjects were re-assessed and classified into disease-free subjects (Group1), subjects with only cysts (Group2), subjects with nodules (Group3), and subjects with suspected malignancy or malignancy (Group4). Serum concentrations of FT3, FT4, thyrotropin (TSH), thyroglobulin, and the FT3/FT4 ratio were classified according to the diagnoses.

Results: The inverse relationships between the age and its values of log TSH (Spearman’s correlation r=-0.311, P=0.015), serum FT3 concentration (r=-0,688, P<0.001), and the FT3/FT4 ratio (r= -0.520, P<0.001) were observed in the group without nodules and cysts. When ANCOVA with Bonferroni post-hoc comparisons was used in the four groups, the value of log TSH was significantly lower in either subjects with nodules or those with suspected malignancy or malignancy compared to either disease-free or only cysts after correction for age. (ANCOVA P<0.001, Group1 vs. Group3; P=0.016, Group1 vs. Group4; P=0.022, Group2 vs. Group3; P=0.001, Group2 vs Group4; P= 0.008). While, no significant diffrences were observed among the four groups studied in the levels of the FT3, FT4, FT3/FT4 ratio, and thyroglobulin (ANCOVA P= 0.304, 0.340, 0.208, and 0.583, respectively).

Conclusion: Inappropriate suppression of thyrotropin concentration might be present in response to illness, including thyroid nodules, in young subjects. Low TSH levels may be related to the development of not only papillary thyroid cancer, but also thyroid nodules, in children and adolescents.

Nothing to Disclose: SS, IN, SS, SM, TF, YI, HS, AO, MA, SY, SS

*Please take note of The Endocrine Society's News Embargo Policy at https://www.endocrine.org/news-room/endo-annual-meeting/pr-resources-for-endo

Sources of Research Support: This survey was conducted as part of Fukushima Prefecture’s post-disaster recovery plans and was supported by the national “Health Fund for Children and Adults Affected by the Nuclear Incident”.