The relationship between circulating estradiol and thyroid autoimmunity in males

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 432-458-Thyroid Autoimmunity
Basic/Clinical
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-449
La-or Chailuekit*1, Wicha Aekplakorn1 and Boonsong Ongphiphadhanakul2
1Mahidol University, Bangkok, Thailand, 2Ramathibodi Hospital, Bangkok, Thailand
Introduction: Autoimmune disease including autoimmune thyroid disease is more common in females. Although autoimmune thyroid disease in males is less common, it is unclear if estrogen contributes to the difference in susceptibility among males. In the present study, we therefore examined if circulating estradiol is related to thyroid autoimmunity in males.

Methods: Subjects consisted of 1,263 males aged 14-94 years. Serum levels of 17β- estradiol (E2), thyroid stimulating hormone receptor (TRAb), thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb), free
thyroxine (FT4) and thyroid-stimulating hormone (TSH) were measured by electrochemiluminescence immunoassay.

Results: Circulating E2 varied widely in males ranging from 5-110 pg/mL with a mean value of 37.1 ± 14.1 pg/mL. E2 increased with age (r = 0.18, p < 0.001). No relationship between E2 and BMI was found. When comparing the difference in E2 according to the test results for TRAb, TPOAb or TgAb, it was found that E2 was significantly higher in subjects with positive TRAb (TRAb-positive, E2 = 46.4 ± 16.3 pg/mL; TRAb-negaitive, E2 = 36.5 ± 13.8 pg/mL; p < 0.001). No difference in E2 was demonstrated according to TPOAb or TgAb results. Logistic regression analysis showed that E2 was a determinant of positive TRAb independent of age and BMI. In addition, there was no relationship between serum E2 and TSH or FT4. However, E2 was negatively related to TSH (r -0.45, p < 0.01) in subjects whose TSH fell below the reference range (0.3 - 4.2 IU/L).

Conclusion: Higher circulating estradiol is related to thyroid autoimmunity in males as reflected by positive TRAb.

Nothing to Disclose: LOC, WA, BO

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