Exposure to Swine Farming and the Lungs: Gene-Environment Interactions

• Author / Creator

  Gao,Zhiwei

• Occupational exposures in swine operations are associated with increased risk of respiratory problems. Although the etiology is not fully understood, genetic and environmental factors play important roles. The primary objective of this thesis is to explore effects of polymorphisms in the Toll-like receptor 2 (TLR2), TLR4 and Nitric Oxide Synthase 3 (NOS3) genes on lung function among workers in swine operations (a high exposure group) and non-farming rural residents (a low exposure group).
  
  The studies considered in this thesis were a cross-sectional study of 374 full-time workers and 411 non-farming rural dwellers in 2003/04, and a longitudinal study of 302 workers and 261 non-farming rural dwellers who were initially studied in 1990/91 and were followed up in 1994/95 (217 workers and 171 rural dwellers) and in 2003/04 (173 workers and 119 rural dwellers). Information on demographic and lifestyle factors and lung function measurements were collected at the three time points and blood samples for genotyping were obtained in 2003/04.
  The important findings in this study were: (1) Workers with TLR2-16933T/A polymorphism (AA) had greater mean values of lung function than workers with the wild-type (AT+TT) (FEV1 (L): 3.7 vs. 3.5, p=0.009; FEF25%-75% (L/s): 3.7 vs. 3.3, p=0.003); similar associations were also observed for the TLR2Arg677Trp polymorphism among workers; (2) Workers with NOS3-786T/C polymorphism (CC) had greater mean values of lung function than workers with the wild-type (TC+TT) (FEV1 (L): 3.75 vs. 3.55, p=0.009; FVC (L): 4.79 vs. 4.56, p=0.03); similar associations were also observed for the NOS3Glu298Asp polymorphism among workers; (3) Workers with NOS3-786T/C polymorphism (CC) had a lower annual decline rates in FEV1 (-30.5 ml/year vs. -58.0 ml/year, p=0.005) and FVC (-16.7 ml/year vs. -50.9 ml/year, p=0.01) than workers with TT genotype; and (4) None of these associations were observed in non-farming rural dwellers.
  In conclusion, TLR2 and NOS3 polymorphisms had significantly protective effects on lung function among workers in swine operations. The results from this study will increase our understanding of environmental and genetic determinants of respiratory dysfunction and ultimately lead to better prevention and intervention measures to improve the respiratory health of workers in swine operations.

• Subjects / Keywords

  • Gene and environment interaction
  • Toll-like receptor 4 (TLR4) gene
  • Swine barns
  • Nitric Oxide Synthase 3 (NOS3) gene
  • Toll-like receptor 2 (TLR2) gene

• Graduation date

  Spring 2013

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3KD1QT60

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.