title: High prevalence of Hashimoto's thyroiditis in patients with polycystic ovary syndrome: does the imbalance between estradiol and progesterone play a role?
abstract: OBJECTIVE
  Some similar factors, such as genetic susceptibility and subinflammation/autoimmunity, contribute to development of both polycystic ovary syndrome (PCOS) and Hashimoto's thyroiditis (HT), suggesting a potential pathogenic link between the two common disorders. In this study, we investigated the relationship between PCOS and HT, considering the possible effect of PCOS-related hormonal and metabolic factors on thyroid autoimmunity.
  
  
  METHODS
  Eighty-six reproductive-age women diagnosed with PCOS according to Rotterdam criteria and 60 age-BMI matched control women were included in the study. All subjects had thyroid function tests, thyroid peroxidase anti-body (anti-TPO), thyroglobulin anti-body (anti-Tg), LH, FSH, estradiol, progesterone, androgens, fasting glucose, insulin, lipid, homeostasis model assessment insulin resistance (HOMA-IR) levels, thyroid and pelvic ultrasounds.
  
  
  RESULTS
  TSH, anti-TPO (p = 0.017), anti-Tg (p = 0.014), LH, DHEAS, testosterone, and HOMA-IR levels were significantly higher and progesterone were lower in PCOS women than in controls. Free T4, free T3, FSH, estradiol levels and thyroid volume were similar between the two groups. A higher percentage of PCOS patients had elevated TSH (26.7 and 5%; p = 0.001), anti-TPO (26.7 and 6.6%; p = 0.002), and anti-Tg (16.2 and 5%; p = 0.039). HT was more common in PCOS patients compared to controls (22.1 and 5%; p = 0.004). Estradiol (p = 0.003) were higher in anti-TPO positive PCOS women than anti-TPO negative ones. Anti-TPO was correlated positively with estradiol, estradiol/progesterone ratio, and TSH.
  
  
  CONCLUSIONS
  This study demonstrated a higher prevalence of HT, elevated TSH, anti-TPO, and anti-Tg levels in PCOS patients. Increased estrogen and estrogen/progesterone ratio seem to be directly involved in high anti-TPO levels in PCOS patients.
authors.affiliation: a Diabetes, Endocrine and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda , MD , USA .
authors.forename: Ayse
authors.initials: A
authors.lastname: Arduc
authors.affiliation: b Department of Endocrinology and Metabolism .
authors.forename: Bercem
authors.initials: B
authors.lastname: Aycicek Dogan
authors.affiliation: c Department of Internal Medicine , Ministry Of Health, Ankara Numune Research and Training Hospital , Ankara , Turkey , and.
authors.forename: Sevgi
authors.initials: S
authors.lastname: Bilmez
authors.affiliation: b Department of Endocrinology and Metabolism .
authors.forename: Narin
authors.initials: N
authors.lastname: Imga Nasiroglu
authors.affiliation: b Department of Endocrinology and Metabolism .
authors.forename: Mazhar Muslum
authors.initials: MM
authors.lastname: Tuna
authors.affiliation: b Department of Endocrinology and Metabolism .
authors.forename: Serhat
authors.initials: S
authors.lastname: Isik
authors.affiliation: b Department of Endocrinology and Metabolism .
authors.forename: Dilek
authors.initials: D
authors.lastname: Berker
authors.affiliation: d Department of Endocrinology and Metabolism, Faculty of Medicine , Hitit University , Corum , Turkey.
authors.forename: Serdar
authors.initials: S
authors.lastname: Guler
mesh_terms: D000328:Adult; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004958:Estradiol / Q000097:blood*; D005260:Female; D050031:Hashimoto Disease / Q000097:blood* / Q000453:epidemiology / Q000276:immunology*; D006801:Humans; D011085:Polycystic Ovary Syndrome / Q000097:blood* / Q000453:epidemiology; D015995:Prevalence; D011374:Progesterone / Q000097:blood*; D055815:Young Adult
chemical_list: D011374:Progesterone; D004958:Estradiol
keywords: Estradiol; Hashimoto’s thyroiditis; polycystic ovary syndrome; progesterone; thyroid autoantibodies