Bilirubin Concentration in Follicular Fluid Is Increased in Infertile Females, Correlates with Decreased Antioxidant Levels and Increased Nitric Oxide Metabolites, and Negatively Affects Outcome Measures of In Vitro Fertilization

The Association Between Sleep Disorder and Female Infertility: A Mediation Analysis of Inflammatory and Oxidative Markers

Background: Sleep disorder in women of reproductive age may contribute to infertility development, but there is a lack of substantial evidence linking sleep disorder to inflammation and oxidative stress, and the subsequent risk of infertility. Methods: A total of 2365 women aged 18-45 years from the National Health and Nutrition Examination Survey (NHANES) were included in this analysis. Sleep disorder and infertility were assessed according to NHANES questionnaire data module. Inflammatory and oxidative biomarkers such as high-sensitivity C-reactive protein (hs-CRP), white blood cell (WBC), gamma-glutamyl transpeptidase (GGT), albumin, ferritin, and total bilirubin were derived from the laboratory data module, and systemic immune inflammation index (SII), and system inflammation response index (SIRI) were calculated based on complete blood cell counts. A sophisticated multistage sampling design and weighted multivariable adjusted regression models were employed to conduct comprehensive analysis. Mediation models were applied to explicate the mediating role of biomarkers of inflammation and oxidative stress. Results: Compared to the noninfertility group, the infertile participants had a higher incidence of sleep disorder (34% vs. 25%, p < 0.05). In models with fully adjusted covariates, sleep disorder was positively associated with infertility risk (OR: 1.58; 95%CI: 1.01-2.50, p < 0.05), particularly in subgroups of individuals aged over 30 years old (OR: 1.75; 95%CI: 1.00-3.04, p < 0.05) or with a body mass index (BMI) ≥ 30 kg/m2 (OR:2.05; 95%CI: 1.00-4.22, p < 0.05). In terms of mechanisms, there were significant correlations between inflammatory and oxidative markers and both sleep disorder and infertility. Mediation analysis indicated that hs-CRP, SII, SIRI, GGT, and total bilirubin played a significant mediating role in the relationship between sleep disorder and infertility, accounting for 0.4822%, 6.0515%, 1.2485%, 5.1584%, and 0.4738%, respectively. Conclusions: Sleep disorder is a significant risk factor for infertility, particularly in women aged >30 years or with obesity. Furthermore, the presence of inflammation and oxidative stress status in the body, which also significantly mediate the association between sleep disorder and infertility, can be swiftly and repeatedly identified through blood tests. Sleep, as a modifiable behavioral pattern, can be regarded as a new strategy to cope with infertility.

Disturbed Follicular Microenvironment in Polycystic Ovary Syndrome: Relationship to Oocyte Quality and Infertility

Polycystic ovary syndrome (PCOS) is a common endocrine disorder associated with infertility and poor reproductive outcomes. The follicular fluid (FF) microenvironment plays a crucial role in oocyte development. This review summarizes evidence elucidating the alterations in FF composition in PCOS. Various studies demonstrated a pronounced proinflammatory milieu in PCOS FF, characterized by increased levels of cytokines, including but not limited to interleukin-6 (IL-6), tumor necrosis factor α, C-reactive protein, and IL-1β, concomitant with a reduction in anti-inflammatory IL-10. T lymphocytes and antigen-presenting cells are dysregulated in PCOS FF. PCOS FF exhibit heightened reactive oxygen species production and the accumulation of lipid peroxidation byproducts, and impaired antioxidant defenses. Multiple microRNAs are dysregulated in PCOS FF, disrupting signaling critical to granulosa cell function. Proteomic analysis reveals changes in pathways related to immune responses, metabolic perturbations, angiogenesis, and hormone regulation. Metabolomics identify disturbances in glucose metabolism, amino acids, lipid profiles, and steroid levels with PCOS FF. Collectively, these pathological alterations may adversely affect oocyte quality, embryo development, and fertility outcomes. Further research on larger cohorts is needed to validate these findings and to forge the development of prognostic biomarkers of oocyte developmental competence within FF. Characterizing the follicular environment in PCOS is key to elucidating the mechanisms underlying subfertility in this challenging disorder.