Elevated circulating levels of secreted frizzled-related protein 4 in relation to insulin resistance and androgens in women with polycystic ovary syndrome.

PURPOSE: Secreted frizzled-related protein 4 (SFRP4) is an adipokine involving in apoptotic process during ovulation and energy metabolism. Polycystic ovary syndrome (PCOS) is a common reproductive and metabolic disorder associated with insulin resistance and impaired oocyte maturation as well as apoptotic dysfunctions through oocyte development. Our aim was to determine whether there was an alteration in levels of SFRP4 and if there was an association between metabolic or hormonal parameters and SFRP4 in women with PCOS. METHODS: We enrolled 80 subjects with PCOS and 80 age- and body mass index (BMI)-matched subjects with normal menstrual cycle into current case-control study. Metabolic and hormonal parameters of enrolled subjects were determined. Circulating SFRP4 levels were measured with ELISA method. RESULTS: We found that circulating SFRP4 levels were elevated in women with PCOS with respect to controls (5.87 ± 1.91 vs. 3.72 ± 1.29 ng/ml, P < 0.001). We also found a positive association between SFRP4 and insulin resistance, androgens, ovarian follicular number or ovarian volume in women with PCOS. Binary logistic regression analysis revealed that subjects with the highest tertile of SFPR4 levels displayed increased possibility of having PCOS risk compared to those subjects with the lowest tertile of SFRP4 levels. CONCLUSIONS: Increased SFRP4 levels were not only associated with higher possibility of having PCOS but also related to insulin resistance, hyperandrogenism, ovarian follicular number and ovarian volume, suggesting that SFPR4 could be a player in different pathophysiologic pathways of PCOS.

Circulating insulin-like peptide 5 levels and its association with metabolic and hormonal parameters in women with polycystic ovary syndrome.

PURPOSE: Insulin-like peptide 5 (INSL5) is a gut peptide hormone that is a member of relaxin/insulin superfamily. Growing evidence implicates the crucial role of the peptide in some metabolisms including food intake, glucose homeostasis and reproductive system. Polycystic ovary syndrome (PCOS) is involved in both reproductive and metabolic issues. The aim of the study was determination of circulating levels of INSL5 alteration in women with PCOS and evaluation of the relationship between INSL5 and hormonal-metabolic parameters as well as carotid intima media thickness (cIMT). METHODS: A total of 164 subjects were recruited in this cross-sectional study (82 women with PCOS and 82 age- and BMI-matched controls). Circulating INSL5 levels were assessed via ELISA method. High-resolution B-mode ultrasound was used to measure cIMT. The hormonal and metabolic parameters of the recruited subjects were determined. RESULTS: Circulating INSL5 levels were significantly elevated in women with PCOS compared to controls (27.63 ± 7.74 vs. 19.90 ± 5.85 ng/ml, P < 0.001). The mean values of INSL5 were significantly higher in overweight subjects compared to lean weight subjects in both groups. The women with PCOS having insulin resistance have increased INSL5 compared to those of PCOS subjects without insulin resistance. INSL5 is associated with insulin resistance, BMI, luteinizing hormone and free androgen index. Multivariate logistic regression analyses revealed that the odds ratio for having PCOS in the highest tertile of INSL5 was higher than in the lowest tertile. CONCLUSIONS: PCOS subjects exhibited an elevation in circulating INSL5 levels along with a link between INSL5 level induction and metabolic-hormonal parameters.