Are thyroid nodules associated with sex-related hormones? A cross-sectional SPECT-China study

BMJ Open. 2017 Aug 3;7(8):e015812. doi: 10.1136/bmjopen-2016-015812.

Abstract

Objective: Little is known about the association between thyroid nodules (TNs) and endogenous sex hormones. We aimed to investigate the relationship between TNs and sex-related hormones among men in China.

Setting: The data were obtained from a cross-sectional study Survey on Prevalence in East China for Metabolic Diseases and Risk Factors (SPECT-China study, 2014-2015) based on the population.

Participants: In total, 4024 men over 18 years of age who were not using hormone replacement therapy and who underwent complete assays of the serum total testosterone (T), oestradiol (E2), follicle-stimulating hormone (FSH), luteinising hormone (LH) and sex hormone-binding globulin (SHBG) levels as well as thyroid ultrasonography (US) enrolled in this study.

Results: Of the 4024 participants (54.15±13.08 years old), 1667 participants (41.4%) had TNs. Men with TN(s) (TN(+) group) had significantly lower levels of total T and SHBG and higher E2/T levels compared with the men without TN(s) (TN(-) group) (p<0.05). The TN prevalence decreased with the quartiles of the SHBG level (p<0.05). Binary logistic analysis showed that lower quartiles of SHBG had a greater risk of TN(s) (all p for trend <0.05). This association persisted in the fully adjusted model (p for trend=0.017), in which, for the lowest compared with the highest quartile of SHBG, the OR of TN(s) was 1.42 (95% CI 1.07 to 1.89). No statistically significant association was found between sex-related hormones and US characteristics associated with malignancy (nodule >10 mm, microcalcification and a 'taller' than 'wider' shape).

Conclusions: TNs are highly prevalent in men in China. A lower SHBG level was significantly associated with TN among men. The potential role of SHBG in the pathogenesis of the TN remains to be elucidated.

Keywords: SHBG; endogenous sex hormone; male; thyroid nodule.

MeSH terms

  • Adult
  • Aged
  • China / epidemiology
  • Cross-Sectional Studies
  • Estradiol / blood*
  • Follicle Stimulating Hormone / blood
  • Gonadal Steroid Hormones / blood*
  • Humans
  • Luteinizing Hormone / blood
  • Male
  • Middle Aged
  • Prevalence
  • Risk Factors
  • Sex Hormone-Binding Globulin / metabolism*
  • Testosterone / blood*
  • Thyroid Nodule / blood*
  • Thyroid Nodule / epidemiology
  • Thyroid Nodule / etiology
  • Tomography, Emission-Computed, Single-Photon

Substances

  • Gonadal Steroid Hormones
  • Sex Hormone-Binding Globulin
  • Testosterone
  • Estradiol
  • Luteinizing Hormone
  • Follicle Stimulating Hormone