Increased R2* in the Caudate Nucleus of Asymptomatic Welders

Citation

Lee, Eun-Young; Flynn, Michael R.; Du, Guangwei; Li, Yunqing; Lewis, Mechelle M.; Herring, Amy H.; Van Buren, Eric; Van Buren, Scott; Kong, Lan; & Fry, Rebecca C., et al. (2016). Increased R2* in the Caudate Nucleus of Asymptomatic Welders. Toxicological Sciences, 150(2), 369-377. PMCID: PMC4857156

Abstract

Welding has been associated with neurobehavioral disorders. Welding fumes contain several metals including copper (Cu), manganese (Mn), and iron (Fe) that may interact to influence welding-related neuro-toxicity. Although welding-related airborne Fe levels are about ten-fold higher than Mn, previous studies have focused on Mn and its accumulation in the basal ganglia. This study examined differences in the apparent transverse relaxation rates [R2* (1/T2*), estimate of Fe accumulation] in the basal ganglia (caudate nucleus, putamen, and globus pallidus) between welders and controls, and the dose-response relationship between estimated Fe exposure and R2* values. Occupational questionnaires estimated recent and lifetime Fe exposure, and blood Fe levels and brain MRI were obtained. Complete exposure and MRI R2* and R1 (1/T1: measure to estimate Mn accumulation) data from 42 subjects with welding exposure and 29 controls were analyzed. Welders had significantly greater exposure metrics and higher whole blood Fe levels compared to controls. R2* in the caudate nucleus was significantly higher in welders after controlling for age, body mass index, respirator use, caudate R1, and blood metals of Cu and Mn, whereas there was no difference in R1 values in the basal ganglia between groups. The R2* in the caudate nucleus was positively correlated with whole blood Fe concentration. The present study provides the first evidence of higher R2* in the caudate nucleus of welders, which is suggestive of increased Fe accumulation in this area. Further studies are needed to replicate the findings and determine the neurobehavioral relevance.

URL

http://dx.doi.org/10.1093/toxsci/kfw003

Reference Type

Journal Article

Year Published

2016

Journal Title

Toxicological Sciences

Author(s)

Lee, Eun-Young
Flynn, Michael R.
Du, Guangwei
Li, Yunqing
Lewis, Mechelle M.
Herring, Amy H.
Van Buren, Eric
Van Buren, Scott
Kong, Lan
Fry, Rebecca C.
Snyder, Amanda M.
Connor, James R.
Yang, Qing X.
Mailman, Richard B.
Huang, Xuemei

PMCID

PMC4857156