Preserved large elastic arterial stiffness and impaired conduit artery endothelial function in patients with endometriosis receiving progestin therapy: A cross‐sectional observational study

OBJECTIVE: To evaluate central arterial stiffness, endothelial function, and circulating vascular biomarkers in women with ovarian endometriosis and to explore their associations compared with age-matched controls. METHODS: This cross-sectional observational study included women aged 18-40 years with Stage III-IV ovarian endometriosis (n = 20) and age-matched controls without endometriosis (n = 30). Of the 20 women with endometriosis, 18 were receiving Dienogest 2 mg/day at the time of assessment. Central arterial stiffness was assessed using carotid-femoral pulse wave velocity (cfPWV) and aortic Augmentation Index standardized to 75 bpm (AIx@75) using the SphygmoCor® XCEL system. Endothelial function was evaluated by brachial artery flow-mediated dilatation (FMD). Circulating biomarkers including high-sensitivity C-reactive protein (hsCRP), E-selectin, and Endothelin-1 were measured using ELISA. Group comparisons were performed using unpaired t-tests or Mann-Whitney U-tests, and correlations were assessed using Pearson or Spearman analyses. RESULTS: Arterial stiffness parameters did not differ significantly between groups. cfPWV was comparable between women with endometriosis and controls (median [interquartile range] 6.6 [6.0-7.0] vs 6.4 [6.1-6.9] m/s; P = 0.749), as was AIx@75 (24.68% ± 8.71% vs 26.7% ± 12.72%; P = 0.547). However, endothelial function was significantly impaired in women with endometriosis, with lower FMD compared with controls (10.80% ± 3.47% vs 15.26% ± 2.59%; P < 0.001). hsCRP levels were significantly higher in women with endometriosis compared with controls (0.0318 [0.0114-0.0631] vs 0.0105 [0.0062-0.0224] mg/L; P = 0.009), whereas Endothelin-1 levels were significantly lower (15.6 [6.4-32.4] vs 30.6 [18.8-53.6] pg/mL; P = 0.045). E-selectin levels did not differ significantly between groups (P = 0.218). No significant correlations were observed between arterial stiffness indices and molecular markers. CONCLUSION: Women with ovarian endometriosis, the majority of whom were receiving Dienogest therapy, demonstrated impaired endothelial function and elevated systemic inflammation despite preserved central arterial stiffness. These findings support the concept of endometriosis as a systemic inflammatory condition associated with early functional vascular impairment.