Association Between Atherogenic Index of Plasma and Endometriosis: Evidence from NHANES 1999–2006

Due to its association with various diseases, atherogenic index of plasma (AIP) has garnered increasing attention. Exploration of the relationship between AIP and endometriosis risk has not been thorough. This nationwide study will attempt to explore this association. This cross-sectional study aimed to investigate this association using a nationally representative sample. We utilized a nationally representative dataset from the 1999-2006 NHANES, including 1817 participants. AIP was defined as log10 (triglycerides/high-density lipoprotein cholesterol). An examination of the relationship between AIP and endometriosis utilized methods including weighted multivariable logistic regression, restricted cubic splines, and subgroup analyses. The relative significance of various lipid indicators was evaluated with the Extreme Gradient Boosting (XGBoost) algorithm. This study analyzed 1817 participants, among whom 146 were diagnosed with endometriosis. Upon full adjustment for relevant covariates, the continuous model through multivariable logistic regression demonstrated a notable association between heightened AIP levels and the risk of endometriosis (OR = 2.578, 95% CI: 1.232-5.394, P = 0.013). In the categorical model, the incidence of endometriosis in the highest AIP quartile was 1.762 times that in the lowest AIP quartile (OR = 1.762, 95% CI: 1.056-3.103), P = 0.047). Interaction tests in subgroup analyses did not significantly affect this association. A linear correlation between AIP and endometriosis was observed within the constraints of the restricted cubic spline regression model. The machine learning results indicate that AIP is the most critical lipid indicator. Our analysis confirms a positive correlation between elevated AIP levels and the frequency of endometriosis cases. This indicates that therapeutic strategies aimed at reducing AIP levels might have a beneficial impact on the management of endometriosis.