Association between triclosan exposure and obesity measures among 7-year-old children in northern China

Background: Triclosan (TCS) is a widely used synthetic antibacterial compound with ubiquitous human exposure. Animal studies have suggested the obesogenic effect of TCS exposure, but knowledge regarding its impacts on childhood obesity was limited. Objective: To investigate the associations of TCS exposure with childhood obesity in northern China. Methods: This study included 423 children who participated in the 7-year-old follow-up visits of Laizhou Wan Birth Cohort in Shandong, northern China. Children's TCS exposure were determined in spot urine samples via high performance liquid chromatography-tandem mass. Their height, weight, waist circumference, body fat percentage, body mass index (BMI), and waist-to-height ratio (WHtR) were measured or calculated. BMI z-score >= 85th percentile was defined as overweight/obesity, and WHtR >= 0.5 was considered to be abdominal obesity. Multivariable linear regressions, generalized linear models (GLMs), and multivariable logistic regressions were performed to examine the associations between TCS exposure and obesity measures in children. Results: Linear regressions showed that TCS concentrations, when treated as continuous variables, were positively associated with BMI z-score (beta = 0.12, 95% CI: 0.01, 0.24) and body fat percentage (beta = 0.82, 95% CI: 0.13, 1.52). When TCS concentrations were categorized as a four-level ordinal variable, the results of GLMs were similar those of continuous variables and both of the positive trends were significant (p-trend = 0.049 for BMI z- score; p-trend = 0.023 for body fat percentage). Moreover, the higher TCS levels versus reference group were associated with an approximate 2-3 fold increased risk of abdominal obesity (p-trend = 0.044). Conclusion: Exposure to TCS was positively associated with obesity measures among 7-year-old children in northern, China. Given to the cross-sectional study design, a large prospective study is warranted to confirm our findings.