Association of computed variables with anthropometric indices in north indian children exposed to Bisphenol-A and heavy metals

Obesity and underweight-associated environmental risk factors pose significant health challenges for the public, especially among children at an early stage of life. This study evaluates the association and potential role of combined exposure to Bisphenol-A (BPA) and heavy metals with anthropometric indices among North Indian children. This study also demonstrates the possibility of reverse causality, where obesity or underweight may result from BPA and heavy metals exposure among children. A total of 301 children were enrolled, grouped into obese, non-obese, and underweight. Urinary BPA and blood heavy metal levels were measured using LC–MS/MS and ICP-MS. Both quantitative variables, BPA and metals, were combined using the computed feature of SPSS, followed by linear regression analysis to identify the association with anthropometric indices (height, weight, BMI, waist and hip circumference, waist-to-stature ratio, and waist-to-hip ratio). A positive association was found among obese children for computed variables of combined exposure to BPA*Zn (WB) and a negative association with BPA*Fe (WB) for weight, height, and BMI. Similarly, a positive association was observed among underweight children for the computed variable of BPA*U (WB) with weight, height, and BMI. Significant negative associations were also observed for the BPA*Mg (WB) and BPA*Hg (WB) with WHR among obese and BPA*Cu (WB) with weight and BPA*Hg (WB) with WHR among underweight children. This study found a positive association for BPA*Se (WB) and BPA*Cd (S) with WC and WHR, respectively, among non-obese children. Our analysis suggests that BPA, combined with metals, is associated with both obesity and underweight. Both BPA and heavy metals are endocrine disruptive pollutants that may affect the metabolic pathways by substituting vital metals and inducing oxidative stress. This extends the scope for future research to address obesity and underweight among children. However, these results should be interpreted cautiously, considering the potential for reverse causality due to the exposure source and duration.