Endocrine Abstracts

Introduction: Polycystic ovary syndrome (PCOS) is associated with an increased risk of abdominal obesity, what is regulated by numerous genetic, epigenetic, and environmental factors. MicroRNAs (miRNAs) are known regulators of gene expression, involved in the development of metabolic disturbances. Dual-energy X-ray absorptiometry (DXA) is an accurate method of body composition analysis. The aim of the present study was to investigate the association between circulating miRNAs, adipokine concentrations, and body composition in PCOS patients.

Materials and methods: The studied group comprised 102 patients with PCOS (age: 24.3±3.6 years; BMI: 24.7±5.0) and 64 healthy women (age: 25.0±3.4 years; BMI: 23.4±3.7) as a control group. All women underwent anthropometric measurements, body composition analysis with DXA, and transvaginal ultrasound. Concentrations of sex hormones, sex hormone-binding globulin, adiponectin, leptin, lipids, as well as glucose and insulin during oral glucose tolerance test were measured. Serum levels of miR-27a, miR-106b, miR-181a, miR-193b, and miR-320 were assessed with real-time polymerase chain reaction.

Results: The studied groups did not differ in terms of age or BMI. No differences regarding body composition or the concentrations of leptin and adiponectin were observed. Expression levels of miR-27a and miR-193b were higher in PCOS patients, while miR-181a and miR-320 were higher in the control group (all P<0.05). In the PCOS group, significant correlations were observed between adiponectin concentration and the levels of miR-181a (R=0.30; P=0.008) and miR-320 (R=0.24, P=0.031), as well as between miR-106b and leptin concentration (r=−0.25; P=0.045). Additionally, the levels of miR-27a and miR-320 correlated with visceral adipose tissue (VAT) mass (R=0.23, P=0.021; r=−0.25, P=0.013, respectively) and android/gynoid (A/G) ratio (R=0.25, P=0.011; r=−0.21, P=0.040, respectively). The levels of miR-193b were associated with A/G ratio (R=0.29, P=0.003), fat mass index (R=0.22, P=0.024), and lean mass index (R=0.32, P<0.001). No such correlations were observed in healthy women, although in this group, miR-27a correlated with adiponectin concentration (r=−0.37, P=0.010), while miR-106b with leptin concentration (R=0.34, P=0.046) and fat free mass (R=0.37, P=0.002). In linear regression analysis, both miR-181a and miR-320 were associated with VAT mass independent of age, BMI, and waist circumference only in PCOS patients.

Conclusions: The expression levels of circulating miRNAs are altered in PCOS. Body composition, especially visceral adiposity, and adipokine secretion, seem to be associated with the expression of miR-27a, miR-181a, miR-193b, and miR-320 in this group, although functional studies are necessary to verify this hypothesis.