The amount of 8-hydroxydeoxyguanosine (8-OH-dG) excreted in urine can be used not only as an indicator of DNA repair capacity, but also as a potential marker of oxidative DNA damage. To clarify the oxidation-related factors, in consideration of cancer risk, this study investigated how urinary 8-OH-dG was associated with occupational and lifestyle factors in 372 healthy workers. The creatinine-adjusted urinary 8-OH-dG level was significantly higher in male subjects, smokers and drinkers compared with their counterparts. There were significant positive correlations of the 8-OH-dG level with average number of working hours, involvement in work, average number of cigarettes smoked, average volume of alcohol consumed and serum cortisol level, and there were significant negative correlations of the 8-OH-dG level with body mass index (BMI) and consumption of soybean products, rice and light-colored vegetables. Multiple regression analysis showed that average number of working hours and average number of cigarettes smoked were significant predictors of increased 8-OH-dG levels, whereas being female and BMI were significant predictors of decreased 8-OH-dG levels. Working hours, BMI and smoking were significant predictors of urinary 8-OH-dG in male subjects, whereas age and BMI were significant predictors in female subjects. We suggest that several occupational and lifestyle factors, particularly long working hours and cigarette smoking, are linked to the formation of 8-OH-dG in workers.
(Cancer Sci 2005; 96: 600 - 606).