Polycystic Ovary Syndrome May Be an Autoimmune Disorder
Abstract
Polycystic ovarian syndrome (PCOS) is the most prevalent endocrine disorder affecting females. It is a common cause of menstrual irregularities and infertility during reproductive age. Genetic and hormonal factors play crucial role in the pathogenesis of PCOS. Low level of progesterone in PCOS causes overstimulation of immune system that produces more estrogen which leads to various autoantibodies. Different autoantibodies have been documented in PCOS, for example, anti-nuclear (ANA), anti-thyroid, anti-spermatic, anti-SM, anti-histone, anti-carbonic anhydrase, anti-ovarian, and anti-islet cell antibodies. There is an association between PCOS and autoimmune diseases such as ANA and anti-TPO that have been documented in systemic lupus erythematosus and Hashimoto thyroiditis, respectively, and it is suspected that there are autoantibodies that might affect the long term clinical management of these patients. Therefore fluctuating levels of autoantibodies in different PCOS patients give us the way to open new chapter for future research on molecular level. This may lead to discovery of better treatment options for PCOS in near future.
High prevalence of Hashimoto’s thyroiditis in patients with polycystic ovary syndrome: does the imbalance between estradiol and progesterone play a role?
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.
Prevalence of autoimmune thyroiditis in patients with polycystic ovary syndrome
Abstract
Introduction
Hypothyroidism is associated with pregnancy complications both for the mother and progeny and it should be considered in reproductive age. Thyroid autoimmunity is stated to be the main cause of hypothyroidism in iodine sufficient areas. Polycystic ovary syndrome (PCOS) is known as the most common endocrine disorder affecting women in reproductive age. Early diagnosis and treatment of hypothyroidism in PCOS may reduce the rate of infertility and pregnancy-related morbidity. In the present study we evaluated thyroid autoimmunity in PCOS patients.
Methods
Over a period of 12 months, 78 patients with PCOS were recruited to this case–control study. Three hundred and fifty age-matched women were studied as a control group. PCOS was defined according to the revised 2003 Rotterdam criteria. Thyroid size was estimated by inspection and palpation. Serum thyroid stimulating hormone (TSH), anti-thyroperoxidase antibody (anti-TPO Ab), and anti-thyroglobulin antibody (anti-Tg Ab) were measured.
Results
The mean ± SD of serum anti-TPO Ab in PCOS patients and subjects in the control group was 216 ± 428 and 131 ± 364 IU/mL, respectively (P = 0.04). Prevalence of goiter in PCOS patients was higher than that in control subjects (62.3 vs. 35.7%, P = 0.0001). Serum TSH and anti-Tg Ab in PCOS patients and control subjects did not differ significantly.
Conclusion
In this case–control study, anti-thyroid antibodies and goiter prevalence were significantly higher in PCOS patients. These data suggest that thyroid exam and evaluation of thyroid function and autoimmunity should be considered in such patients.