Free Fatty Acid Analysis of Plasma from Different Stages of Endometriosis: A Preliminary Study

Background: Endometriosis is a chronic, estrogen-dependent inflammatory disease associated with pelvic pain, dysmenorrhea, dyspareunia, and infertility. This study aimed to characterize serum free fatty acid (FFA) profiles in women with histopathologically confirmed mild and severe endometriosis and explore selected FFAs and FFA ratios as potential markers of disease severity. Methods: This observational study included 20 women with histopathologically confirmed endometriosis, classified as mild (stages I–II; n=10) or severe (stages III–IV; n=10). Serum FFAs were extracted using the Folch method and analyzed by flame ionization detection (FID). Data were normalized and analyzed using Meta-boAnalyst. Univariate and receiver operating characteristic (ROC) analyses were performed to identify potential biomarkers distinguishing disease severity. Statistical significance was set at p<0.05. Results: The identified FFAs included lauric acid (C12:0), capric acid (C10:0), myristic acid (C14:0), stearic acid (C18:0), linoleic acid (C18:2), and dihomo-γ-linolenic acid (DGLA; C20:3). Although relative increases and decreases were observed, individual FFA levels did not differ significantly between the groups. The lauric acid/myristic acid ratio differed significantly between groups (p=0.04; AUC= 0.77), whereas the lauric acid/linoleic acid ratio showed a borderline difference (p= 0.05; AUC=0.75). Conclusion: The lauric acid/myristic acid ratio showed preliminary potential for distinguishing mild from severe endometriosis in women with an established diagnosis. These findings do not establish its utility for primary screening or diagnosis. Larger studies with appropriate control groups, standardized sample collection, and independent validation are needed before clinical application can be considered.