Alcohol drinking, obesity, and reduced physical activity are commonly related to oxidative stress, which induces plasma membrane-bound protein damage in hepatic cells and elevates serum gamma-GTP. We have a hypothesis that a long commuting time may induce oxidative stress. This study was undertaken to investigate the relationship between commuting time and serum gamma-GTP level.

Questionnaires were administered to 717 male workers who had worked at Kimpo airport until the year 2000,and had then moved to Incheon airport and were working there in 2002. The questionnaire included items concerning commuting time, sleeping time and alcohol consumption. Physical examination and laboratory data were also collected.

Serum gamma-GTP level was significantly and positively correlated with commuting time, body mass index, systolic blood pressure,diastolic blood pressure, hemoglobin, glucose, total cholesterol, AST, ALT and alcohol consumption. Multivariate regression analysis demonstrated that serum gamma-GTP level is significantly associated with commuting time, after considering the other covariates.

Commuting time is one of the factors that affects serum gamma-GTP level in male workers.