RT Journal Article SR Electronic T1 Application of linear mixed-effects model with LASSO to identify metal components associated with cardiac autonomic responses among welders: a repeated measures study JF Occupational and Environmental Medicine JO Occup Environ Med FD BMJ Publishing Group Ltd SP 810 OP 815 DO 10.1136/oemed-2016-104067 VO 74 IS 11 A1 Jinming Zhang A1 Jennifer M Cavallari A1 Shona C Fang A1 Marc G Weisskopf A1 Xihong Lin A1 Murray A Mittleman A1 David C Christiani YR 2017 UL http://oem.bmj.com/content/74/11/810.abstract AB Background Environmental and occupational exposure to metals is ubiquitous worldwide, and understanding the hazardous metal components in this complex mixture is essential for environmental and occupational regulations.Objective To identify hazardous components from metal mixtures that are associated with alterations in cardiac autonomic responses.Methods Urinary concentrations of 16 types of metals were examined and ‘acceleration capacity’ (AC) and ‘deceleration capacity’ (DC), indicators of cardiac autonomic effects, were quantified from ECG recordings among 54 welders. We fitted linear mixed-effects models with least absolute shrinkage and selection operator (LASSO) to identify metal components that are associated with AC and DC. The Bayesian Information Criterion was used as the criterion for model selection procedures.Results Mercury and chromium were selected for DC analysis, whereas mercury, chromium and manganese were selected for AC analysis through the LASSO approach. When we fitted the linear mixed-effects models with ‘selected’ metal components only, the effect of mercury remained significant. Every 1 µg/L increase in urinary mercury was associated with −0.58 ms (−1.03, –0.13) changes in DC and 0.67 ms (0.25, 1.10) changes in AC.Conclusion Our study suggests that exposure to several metals is associated with impaired cardiac autonomic functions. Our findings should be replicated in future studies with larger sample sizes.