Triglyceride-glucose Index and Its combination with obesity indicators mediating the association between 2-hydroxyfluorene and the prevalence of cardiovascular disease: Evidence from the NHANES (2005-2018)

Background: Polycyclic aromatic hydrocarbons (PAHs) were increasingly recognized as a group of environmental pollutants associated with various health issues. The rise in their prevalence in the environment was concerning. Yet, the effects of PAH exposure on cardiovascular diseases (CVDs) were still not well understood.

Purpose: This study investigated the impact of exposure to 2-hydroxyfluorene on CVDs prevalence, with a special focus on the mediating role of triglyceride-glucose (TyG) index and its combination with obesity indicators.

Method: Using National Health and Nutrition Examination Survey (NHANES) data from 2005 to 2018, this study assessed how 2-hydroxyfluorene affects CVDs prevalence through various statistical techniques. The investigation began with restricted cubic spline (RCS) analysis to explore the relationship between 2-hydroxyfluorene levels and CVDs prevalence. Logistic regression was then used to examine associations within PAH mixtures, alongside the Bayesian Kernel Machine Regression (BKMR) model. Furthermore, the Quantile G-Computation (QG-comp) model was used to evaluate the influence of weights and directions. A mediation analysis was also performed to assess the mediating role of TyG-related indicators on the relationship between 2-hydroxyfluorene and CVDs prevalence. Besides, the association between 2-hydroxyfluorene and the prevalence of each specific CVDs, congestive heart failure, myocardium infarction, angina pectoris and coronary heart disease, was also assessed and so was the mediated effect. Finally, the subgroup analysis was conducted to assess the association in each specific subgroup.

Result: The study, involving 3645 participants, found a significant positive association between 2-hydroxyfluorene exposure and CVD (OR (95 %CI) = 115.8013 (5.0521 ∼ 2654.3248), P=0.0029), with 2-hydroxyfluorene showing the positive contribution to CVDs prevalence within the phthalate mixture. The positive association also existed between 2-hydroxyfluorene and the prevalence of each specific CVDs. TyG and TyGWC (Triglyceride Glucose-Waist Circumference) were identified as mediators in the link between 2-hydroxyfluorene exposure and the prevalence of total CVD and each specific CVD, while TyGBMI (Triglyceride Glucose-Body Mass Index) can only mediate the association between 2-hydroxyfluorene and the prevalence of total CVD, congestive heart failure and angina pectoris CONCLUSION: The findings highlighted a significant association between 2-hydroxyfluorene exposure and CVDs prevalence, with TyG-related indicators acting as mediators.