Galanin-like peptide and its correlation with androgen levels in patients with polycystic ovary syndrome

Introduction: We aimed to investigate serum galanin-like peptide (GALP) levels and their correlation with hormonal and metabolic parameters in patients with polycystic ovary syndrome (PCOS).

Material and methods: The study included 48 women (age range, 18-44 years) with a diagnosis of PCOS, and a control group that included 40 healthy females (age range, 18-46 years). Waist circumference, body mass index (BMI), and Ferriman-Gallwey score were evaluated and plasma glucose, lipid profile, oestradiol, progesterone, total testosterone, prolactin, insulin, dehydroepiandrosterone sulphate (DHEA-S), follicle-stimulating hormone (FSH), luteinizing hormone (LH), thyroid-stimulating hormone (TSH), 25-hydroxyvitamin D (25(OH)D), fibrinogen, d-dimer, C-reactive protein (CRP), and GALP levels were measured in all study subjects.

Results: Waist circumference (p = 0.044) and Ferriman-Gallwey score (p = 0.002) were significantly higher in patients with PCOS compared to the control group. Among the metabolic and hormonal parameters studied, only total testosterone was significantly higher in patients with PCOS (p = 0.002). Also, the serum 25(OH)D level was significantly lower in the PCOS group (p = 0.001). CRP, fibrinogen, and D-dimer levels were all similar between the 2 groups. Serum GALP level was significantly higher in PCOS patients (p = 0.001). GALP was negatively correlated with 25(OH)D (r = -0.401, p = 0.002) and positively correlated with total testosterone values (r = 0.265, p = 0.024). Multiple regression analysis revealed that both total testosterone and 25(OH)D significantly contributed to GALP levels.

Conclusions: Our study is the first in the literature to evaluate serum GALP levels in patients with PCOS. Increased GALP levels in PCOS and its association with total testosterone levels might show that GALP can act as an intermediary in increased GnRH-mediated LH release, which is one of the underlying pathogenetic mechanism of PCOS.