Urinary metals and metal mixtures and oxidative stress biomarkers in an adult population from Spain: The Hortega Study. (February 2019) - Domingo-Relloso, Arce
Abstract: Introduction: Few studies have investigated the role of exposure to metals and metal mixtures on oxidative stress in the general population. Objectives: We evaluated the cross-sectional association of urinary metal and metal mixtures with urinary oxidative stress biomarkers, including oxidized to reduced glutathione ratio (GSSG/GSH), malondialdehyde (MDA), and 8‑oxo‑7, 8‑dihydroguanine (8-oxo-dG), in a representative sample of a general population from Spain (Hortega Study). Methods: Urine antimony (Sb), barium (Ba), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), molybdenum (Mo), vanadium (V) and zinc (Zn) were measured by ICPMS in 1440 Hortega Study participants. Results: The geometric mean ratios (GMRs) of GSSG/GSH comparing the 80th to the 20th percentiles of metal distributions were 1.15 (95% confidence intervals [95% CI]: 1.03–1.27) for Mo, 1.17 (1.05–1.31) for Ba, 1.23 (1.04–1.46) for Cr and 1.18 (1.00–1.40) for V. For MDA, the corresponding GMRs (95% CI) were 1.13 (1.03–1.24) for Zn and 1.12 (1.02–1.23) for Cd. In 8-oxo-dG models, the corresponding GMR (95% CI) were 1.12 (1.01–1.23) for Zn and 1.09 (0.99–1.20) for Cd. Cr for GSSG/GSH and Zn for MDA and 8-oxo-dG drove most of the observed associations. Principal component (PC) 1 (largely reflecting non-essential metals) was positively associated with GSSG/GSH. The association of PC2 (largely reflecting essential metals) was positive for GSSG/GSH but inverse for MDA. Conclusions: Urine Ba, Cd, Cr, Mo, V and Zn were positively associated with oxidative stress measures at metal exposure levels relevant for the general population. The potential health consequences of environmental, including nutritional, exposure to these metals warrants further investigation. Highlights: Barium, cadmium, chromium, molybdenum, vanadium and zinc levels were positively associated with oxidative stress measures The associations seemed to be driven by chromium for GSSG/GSH, and by zinc for MDA and 8-oxo-dG Findings support that oxidative damage may partly explain the associations of elevated metals with adverse health outcomes The results raise questions regarding the safety of unnecessary supplementation in well-nourished population