Analysis of 2-Arachidonoylglycerol Levels in Polycystic Ovary Syndrome in the Context of Hormonal and Metabolic Alterations and Across the Classical Phenotypes

Abstract

Introduction:

Ovarian folliculogenesis requires a fine balance between extra- and intra-ovarian factors. Endocannabinoids are found in the female reproductive system and are essential for a normal follicular growing process and ovulation. First, our study aimed to analyze levels of the endocannabinoid—2-arachidonoylglycerol (2-AG)—in patients with polycystic ovary syndrome (PCOS) and to compare with healthy controls. In addition, the study aimed to explore the association of 2-AG with hormonal and metabolic alterations, ovulatory dysfunction, and the presence of polycystic ovarian morphology (PCOM) across the classical PCOS phenotypes.

Methods:

Fifty-four women with PCOS were compared with 26 healthy controls. PCOS patients were diagnosed and phenotyped according to the Rotterdam criteria. Further analyses were performed with the classical PCOS phenotypes A and B comprising hyperandrogenism with oligo-anovulation with or without PCOM, respectively. Full medical history, clinical investigations, anthropometric measurements, laboratory tests, and ultrasound investigations were carried out in the follicular phase. Serum levels of 2-AG were measured by enzyme-linked immunosorbent assay.

Results:

PCOS patients (n=54) and healthy controls (n=26) showed similar metabolic parameters and anthropometric characteristics. PCOS patients were more hirsute than healthy women (p=0.001). Luteinizing hormone/follicle-stimulating hormone ratio and serum levels of androgens were significantly higher in the patient than in the control group (p=0.035, p<0.001, respectively). Free androgen index was also higher in the patient group (p=0.002). Serum levels of 2-AG did not significantly differ when comparing all PCOS patients versus healthy controls; however, further analysis of individual phenotype groups revealed that 2-AG levels in PCOS patients with phenotyope A (n=30) were significantly lower when compared with PCOS patients with phenotype B (n=20) and healthy controls (n=26).

Conclusion:

Serum levels of 2-AG were similar between PCOS patients and healthy controls. Nevertheless, phenotype A PCOS patients had significantly lower levels of the endocannabinoid compared with phenotype B patients and healthy controls. Collectively, these results suggest that overall serum levels of 2-AG are not a diagnostic marker for PCOS; however, their altered secretion or activity may influence normal follicular processes.