Glycolysis mediates the association between phthalate exposure and the prevalence of childhood asthma: The National Health and Nutrition Examination Survey 2009–2018

Identified as a critical risk factor for childhood asthma, environmental pollution plays a pivotal role. However, research on the effects and mechanisms of phthalates mixture and their interactions in relation to childhood asthma is still lacking. In the National Health and Nutrition Examination Survey (NHANES) conducted from 2009 to 2018, our research explored the link between phthalates in urine and the prevalence of childhood asthma. In this study, which involved 810 participants, we used four different statistical analysis methods to investigate the association between urinary phthalate levels and childhood asthma. Additionally, we conducted a mediation analysis to explore whether the impact mechanism of phthalate exposure on childhood asthma operates through the glycolysis. Among the participants, 525 (64.81 %) individuals were diagnosed with asthma, with 330 (40.74 %) individuals undergoing testing for glycolytic markers. Through Spearman correlation analysis and weighted principal component analysis (W-PCA), it was found that mono-2-ethyl-5-carboxypentyl phthalate (MECPP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-(2-ethyl)-hexyl phthalate (MEHP) and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) are the four most highly correlated phthalates. In addition, comprehensive analysis by the weighted generalized linear models (W-GLM), weighted quantile sum (WQS) and Bayesian kernel machine regression (BKMR) models showed that phthalates mixture were positively associated with the prevalence of childhood asthma, especially MECPP, MEHHP and MEOHP. More importantly, glycolysis participated as a mediator in the relationship between MECPP, MEHHP and MEOHP exposure and the prevalence of childhood asthma, explaining 41.194 %, 38.322 % and 39.871 % of the effects respectively. Therefore, our study revealed that phthalate exposure is a risk factor for asthma in children, and glycolysis may be involved as a potential mediator in this process. This conclusion will be verified through more prospective studies in the future.