Associations of Urinary Lead, Cadmium, and Arsenic Exposure with Obesity-Related Indicators Among School-Aged Children: A Longitudinal Study.

To characterize lead, cadmium, and arsenic exposure and examine associations with obesity-related indicators in school-aged children. This study included 1,211 children aged 6-11 years. At baseline, anthropometric measurements and urine samples were collected, and anthropometric measurements were repeated at two 6-month visits. Urinary lead, cadmium, and arsenic were measured by inductively coupled plasma mass spectrometry and adjusted for creatinine.Outcomes included BMI, body fat percentage, waist-to-height ratio, waist circumference, and obesity outcomes. Associations were assessed using regression models and BKMR at baseline, and linear mixed models and generalized estimating equations for repeated measures. Among 1,211 children (mean age, 8.27 ± 0.94 years), detection rates for lead, cadmium, and arsenic were 97.77%, 84.72%, and 99.67%, respectively; creatinine-adjusted geometric mean concentrations were 0.57, 0.12, and 20.99 µg/g Cr. Cadmium was inversely associated with BMI, body fat percentage, waist circumference, and obesity risk (OR = 0.84, 95% CI: 0.73-0.98), whereas arsenic was inversely associated with BMI, body fat percentage, waist-to-height ratio, waist circumference, and both obesity outcomes. BKMR suggested that cadmium and arsenic were the main contributors, although no significant mixture effect was observed. Similar patterns were found in repeated-measures analyses. The third arsenic quartile was associated with lower obesity risk than the first (OR = 0.51, 95% CI: 0.31-0.85). Exposure to lead, cadmium, and arsenic was common, with arsenic showing the highest level. Higher cadmium and arsenic exposures were associated with lower levels of several obesity-related indicators.Although no significant mixture effect was observed, cadmium and arsenic may contribute to obesity-related phenotypes.