Exposure to Metal Fume Particulate Matter and Advance Glycation End Products in Welding Workers: A Longitudinal Study

Abstract

Previous studies have demonstrated the association of exposure to air pollution and the diabetes mellitus (DM). Insulin resistance has been regarded as an underlying mechanism of type 2 DM. Studies have shown transition metal ions play important roles in the Maillard reaction. The objective of this study was to assess the effects of metal fume particulate matter and nickel (Ni) on insulin resistance among the welders and to understand its association with advanced glycation end products (AGEs) formation.This study was in a longitudinal design. Study subjects consisted of 74 welders and 28 office workers from a shipyard of northern Taiwan at baseline Oct, 2014 and followed up annually on Oct to Nov, 2015 and 2016. Participants were asked to wear a PM2.5 sampler during their working hours on the first weekday (Monday) and collected urine and fasting blood samples on the next day (Tuesday) morning.A total of 233 measurements were collected and included in the subsequent statistical analyses. Urinary Ni was assayed as biomarkers of internal dose of nickel exposure. Plasma adiponectin and AGEs were measured as biomarkers of cardiovascular effects. Urinary 1-hydroxypyrene (1-OHP) was used as a biomarker of exposure to polycyclic aromatic hydrocarbons (PAHs).Personal PM2.5 exposure levels were significantly associated with urinary 1-OHP concentrations according to the generalized estimating equation (GEE) analysis after adjusting for confounds. Log(Ni) was negatively associated with log(Insulin)(β= -0.056, 95% CI -0.110 to -0.001, p<0.05). Log(Ni) was positively associated with log(adiponectin)(β= 0.160, 95% CI 0.080 to 0.238, p<0.001). Log(Ni) was positively associated with log(AGEs)(β= 0.119, 95% CI 0.041 to 0.197, p<0.01).Urinary Ni levels are associated decreasing insulin levels. Urinary Ni levels are positively associated with formation of AGE. Exposure to metal fume particulate matter may increase advance glycation end products in welding workers.