Role Of Melatonin In Regulation Of Menstrual Cycle In Women With Polycysic Ovarian Syndrom (PCOS)

Abstract

Background: Polycystic Ovary Syndrome (PCOS) is increasingly strongly linked to circadian biology disruptions and sleep and wake cycle issues, though clinical data regarding endogenous melatonin status remains contradictory. Understanding this specific relationship is crucial for effectively managing ovulatory dysfunction within this complex endocrine disorder involving the HPO axis. Objective: This study aimed to evaluate the correlation between endogenous serum melatonin levels and the severity of menstrual cycle irregularity in women diagnosed with PCOS. Methodology: An observational case-control study was conducted involving 236 participants stratified into healthy controls, PCOS with regular cycles, and PCOS with irregular cycles. Standardized morning trough blood samples were analyzed for melatonin, reproductive hormones, and oxidative stress markers using ELISA. Data were analyzed using comprehensive ANOVA and multivariable linear regression adjusting for confounders. Results: Analysis revealed a significant stepwise reduction in serum melatonin concentrations, with the lowest levels observed in the irregular cohort (14.2±4.9 pg/mL) compared to controls (24.3±6.8 pg/mL; p<0.001). Melatonin levels negatively correlated with menstrual cycle length (r=-0.62) and LH/FSH ratio. Multivariable regression confirmed melatonin as an independent predictor of cycle length (β=-0.41), independent of BMI and insulin resistance. Additionally, oxidative stress markers like MDA were statistically significantly elevated in the irregular group (p<0.05). Conclusion: Endogenous melatonin deficiency is significantly associated with menstrual irregularity and oxidative stress in women with PCOS, independent of adiposity. Restoring melatonin homeostasis may represent a viable therapeutic strategy to further improve ovulatory function and metabolic health in this specific population.