Fluorine may intensify the mechanisms of polycystic ovary syndrome (PCOS) development via increased insulin resistance and disturbed thyroid-stimulating hormone (TSH) synthesis even at reference levels.

We were interested whether fluorine, at the concentrations regarded as normal, can play a role in PCOS pathogenesis. The effect was not described in PCOS. Women with PCOS were diagnosed according to Rotterdam's criteria. The average age of 40 examined women with PCOS was 26.3 ± 5.5 years, BMI-29.16 ± 0.8, WHR-0.91 ± 0.08. Main Outcome Measures: ECLIA was used to analyse testosterone, FSH, LH, oestradiol, TSH, prolactin, insulin and SHBG. Fluorine content was analysed by potentiometry using ion selective electrode. Fluorine content in serum of women with PCOS did not statistically significantly differ from that of the control group and amounted to 0.224 ± 0.043 and 0.228 ± 0.023 ppm, respectively. There were significant differences in the levels of TSH and HOMA-IR between the groups. Based on the correlation matrix, a negative correlation with the level of SHBG protein and the level of glucose on fasting was showed for the group with a lower of fluorine, and a positive correlation with HDL level was observed in the group with higher concentration of fluorine. In the phenotype with a higher level of androgens, there was a negative correlation with triglycerides level and a positive correlation with HDL. Fluorine, even in concentrations regarded as proper, takes part in PCOS pathogenesis. It increases the synthesis of TSH and increases insulin resistance. Higher insulin resistance leads to the reduced synthesis of SHBG transport protein. Therefore, the key factor in PCOS pathogenesis is testosterone, but fluorine facilitates disruptions in carbohydrates and lipids metabolism leading to increased levels of androgens in blood.