ESPE Abstracts

Background: The myokine irisin, is associated with the metabolic and hormonal dysregulation of polycystic ovary syndrome (PCOS) in adult women. Recent studies have shown that circulating irisin levels increase in adult women with PCOS.

Objective and hypotheses: The purpose of this study was to determine serum concentrations of irisin in lean adolescents with PCOS and healthy controls and to evaluate correlations with clinical, sonographic and hormonal parameters.

Method: Lean adolescents aged 13–21 years with PCOS diagnosed according to the Rotterdam criteria, were eligible to enter the study. Exclusion criteria included severe chronic disease, chronic medication or contraceptive use. Anthropometric parameters (weight, height), ovarian volume and serum levels of FSH, LH, estradiol, testosterone, free-testosterone, Δ4-androstenedione, dehydroepiandrosterone sulfate (DHEAS), 17-hydroxyprogesterone and sex hormone-binding globulin (SHBG) were measured and body mass index (BMI), Ferriman-Gallwey (FG) score and Free Androgen Index (FAI) were calculated for each participant. Serum irisin concentrations were measured by ELISA (AdipoGen; assay range 0.001 μg/ml–5 μg/ml).

Results: A total of forty adolescents (median age 17 years, range 13.1–21 years; median BMI 20.7 kg/m², range 17.7–22.5 kg/m²); 23 PCOS patients and 17 age- and BMI-matched controls, were enrolled in the study. Compared with the control group, PCOS patients had significantly increased mean ovarian volume, FG Score, LH, estradiol, testosterone, free-testosterone, Δ4-androstenedione, DHEAS, 17-OHProgesterone and FAI while SHBG was significantly decreased. Serum irisin concentrations in PCOS patients (mean ± S.D.; 1.71±1.03 μg/ml) were significantly elevated (P=0.007) when compared to the control group (mean ± S.D.; 1.04±0.35 μg/ml) (P < 0.001). Serum irisin was positively correlated (spearman’s rho correlation) with height (r_s=0.558, P<0.001) and free-testosterone (r_s=0.681, P<0.001).

Conclusion: Elevated serum irisin concentrations in lean PCOS adolescents were associated with excess of free-testosterone levels, that represent a core feature of the syndrome.