Association of childhood multiple essential and toxic trace elements with longitudinal cardiometabolic risk factors

Abstract

Background/Aim: Trace elements concentrations have been implicated in cardiometabolic risk in children. Previously, studies have largely focused on individual elements, however, more akin to the real word, children are simultaneously exposed to multiple elements. We aimed to evaluate the longitudinal association of childhood exposure to mixtures of trace elements with levels of serum lipids and blood pressure in 300 children from the RHEA pregnancy cohort in Crete, Greece.Methods: Concentrations of 5 essential (Mg, Mo, Co, Cu, Se,) and 4 toxic trace elements (As, Cd, Hg, Pb) were determined in whole blood at the age of 4 years. Blood pressure and serum lipids (total cholesterol, triglycerides, LDL and HDL cholesterol) were measured repeatedly at the ages of 4, 6 and 11 years. We used linear mixed models for single element associations and hierarchical Bayesian Kernel Machine Regression (BKMR) to assess mixtures. All models were adjusted for relevant covariates. Results: In linear mixed models, higher total cholesterol levels (mg/dl) were observed per each doubling of magnesium (beta 3.3, 95% CI: 0.6, 6.0), selenium (beta 4.3, 95% CI: 1.6, 7.0), molybdenum (beta 3.3, 95% CI: 0.7, 6.0) and arsenic (beta 3.1, 95% CI: 0.4, 5.9) concentrations. Similar associations were observed for LDL. Higher levels of arsenic were also associated with increased systolic blood pressure (beta 0.9 mmHg, 95% CI: 0.0, 1.8 mmHg). The BKMR for essential elements showed that increased levels of all essential elements were associated with higher cholesterol levels with selenium being the main driver of the mixture effect. No association was observed between trace elements mixture and blood pressure. The observed associations were similar among boys and girls. Conclusions: Exposure to trace elements in childhood and especially selenium might play a role in later cardiometabolic risk.