An Examination of the Association of Selected Toxic Metals with Total and Central Obesity Indices: NHANES 99-02

TLDR

Toxic metals may influence obesity by disrupting essential micronutrients and inducing oxidative stress, with zinc deficiency reducing adiposity and deficiencies of chromium, copper, iron, and magnesium increasing it. The study aimed to examine associations between waist circumference, BMI, and body burdens of selected toxic metals in NHANES 99‑02. Using NHANES 99‑02, the authors correlated measured body burdens of nine toxic metals with waist circumference and BMI. They found direct positive associations for barium and thallium, inverse associations for cadmium, cobalt, cesium, and lead, while molybdenum, antimony, and tungsten showed largely insignificant links, indicating that environmental metal exposure may influence weight gain or loss. Future prospective studies are needed to confirm these findings.

Abstract

It is conceivable that toxic metals contribute to obesity by influencing various aspects of metabolism, such as by substituting for essential micronutrients and vital metals, or by inducing oxidative stress. Deficiency of the essential metal zinc decreases adiposity in humans and rodent models, whereas deficiencies of chromium, copper, iron, and magnesium increases adiposity. This study utilized the NHANES 99-02 data to explore the association between waist circumference and body mass index with the body burdens of selected toxic metals (barium, cadmium, cobalt, cesium, molybdenum, lead, antimony, thallium, and tungsten). Some of the associations were significant direct relationships (barium and thallium), and some of the associations were significant inverse relationships (cadmium, cobalt, cesium, and lead). Molybdenum, antimony, and tungsten had mostly insignificant associations with waist circumference and body mass index. This is novel result for most of the toxic metals studied, and a surprising result for lead because high stored lead levels have been shown to correlate with higher rates of diabetes, and obesity may be a key risk factor for developing diabetes. These associations suggest the possibility that environmental exposure to metals may contribute to variations in human weight gain/loss. Future research, such as prospective studies rather than the cross-sectional studies presented here, is warranted to confirm these findings.