Endocrine Abstracts

Thyroid dysfunction has been linked to reduced fertility. It is known that changes in SHBG and sex steroids are a consistent feature associated with hyper- and hypothyroidism. It is also has reported that women with polycystic ovary syndrome (PCOS) are more insulin-resistant than it would be expected on the basis of their age and BMI. The mechanisms underlying this phenomenon are still not clarified. Hyperandrogenaemia may play a role, but also other factors such as thyroid function may also be involved. The aim of this study was to estimate the interrelationship between thyroid-stimulating hormone (TSH) levels and insulin resistance (IR) indices in women with PCOS. We included in the study 55 women (age: 32.18±0.63 years; BMI: 25.34±0.59 kg/m²) diagnosed as polycystic ovary syndrome (PCOS) according Rotterdam criteria. Thyroid-stimulating hormone (TSH), oral glucose tolerance testing (OGTT), homeostatic model assessment of insulin resistance (HOMA-IR), androgen levels (total testosterone and androstenedione), free androgen index (FAI) and sex hormone-binding globulin (SHBG) were performed. All women had normal glucose tolerance during OGTT. All women had normal TSH level (conventionally used levels of 4–5 mIU/l as upper limit). Using nonparametric Spearman’s correlation it is showed significant correlation (P<0.05) among TSH level and investigated parameters: SHBG (−0.317), HOMA-IR (0.358); fasting insulin (0.455), insulin at 120 min of OGTT (0.369), FAI (0.466) and androstenedione (0.407) respectively). All correlation was repeated after adjusting for BMI and age and these significant correlations were confirmed. Our data suggested that in patients with PCOS, a significant association between level of TSH and insulin resistance indexes as well as SHBG and androgen levels exist, and this association appeared to be independent of age and BMI.