Inverse association between cardiometabolic index and endometriosis in women of reproductive age: A cross-sectional, population-based study

Objective This study aimed to investigate the relationship between the cardiometabolic index and the prevalence of endometriosis among reproductive-age women in the United States. This cross-sectional population-based study used data from the National Health and Nutrition Examination Survey (NHANES) 2003–2006. Methods We conducted a cross-sectional analysis using data from 1156 women aged 20–54 years who participated in NHANES 2003–2006. Cardiometabolic index was calculated as the product of the waist-to-height ratio and the triglyceride-to-high-density lipoprotein cholesterol ratio. Logistic regression models adjusted for demographic, reproductive, and lifestyle factors were used to assess the association between cardiometabolic index and self-reported endometriosis. Structural equation modeling was applied to explore potential mediating and moderating effects. Results A significant inverse association between cardiometabolic index and endometriosis was observed. In the fully adjusted model, each one-unit increment in cardiometabolic index corresponded to a 42% reduction in the odds of self-reported endometriosis (odds ratio = 0.58, 95% confidence interval = 0.38–0.91, p < 0.05). Compared with women in the lowest cardiometabolic index quartile, those in the highest quartile exhibited a 51% (precise value: 50.6%) lower prevalence of endometriosis (odds ratio = 0.49, 95% confidence interval = 0.29–0.83). Additionally, the use of oral contraceptives significantly moderated the cardiometabolic index–endometriosis relationship p for interaction <0.05. Conclusions Cardiometabolic index is significantly and inversely associated with endometriosis among US women of reproductive age. However, given the cross-sectional design of this study, these findings should be considered preliminary, and causal inferences cannot be drawn.