Metal (loid) Exposure and Overweight and Obesity in 6–12-Year-Old Spanish Children

Abstract

Epidemiological studies focusing on metal(oid) exposure and excess body weight among children show inconsistent results and the influence of metal(loid) mixtures has been little studied. We aimed to explore the effect of 10 metal(loid)s, individually and in combinations, on overweight and obesity among children aged 6–12. Urinary levels of these metal(oid)s from 92 controls and 51 cases with overweight and obesity were analyzed. Metal(loid) levels were log-transformed and categorized into tertiles according to the control group cutoff points. Two logistic regression models and weighted quantile sum regressions (WQS) were run: model 1 adjusting for age, sex, creatinine, energy intake and physical activity and model 2 additionally adjusting for maternal education, rice and fish consumption. In the single metal(oid) exposure model, there was a trend of significant negative association for urinary cobalt (Co), where children in the third tertile had lower odds of present overweight and obesity than those in the first (Odds Ratio, OR = 0.43; 95% Confidence Interval, CI = 0.20–0.93). Urinary chromium (Cr) levels were borderline-significant negatively associated with overweight and obesity (ORa = 1.70; 95% CI = 0.97–2.98). Molybdemun, Cr and Co had a major contribution to the inverse association between metal(loid) mixture and overweight and obesity as well as lead, cadmium and total arsenic in the positive relationship. Our findings in this explorative study suggested an inverse association of high urinary Co levels with overweight and obesity. Moreover, metal(loid) mixture exposure may have influence on overweight and obesity with an important contribution of Co in the potential negative effect.