Life style and urinary 8-hydroxydleoxyguanosine, a marker of oxidative DNA damage: Effects of exercise, working conditions, meat intake, body mass index, and smoking

The urinary levels of 8-hydroxydeoxyguanosine (8-OH-dG), a marker of oxidative DNA damage, of 318 healthy men aged 18-58 were measured with high resolution by a newly developed automated high-pressure liquid chromatography (HPLC) system coupled to an electrochemical detector (ECD). The mean 8-OH-dG level (mug/g creatinine) was 4.12+/-1.73 (SD). An eleven-fold inter-individual variation was observed. The accuracy of the measurement estimated from the recovery of an added 8-OH-dG standard was 90-98%. By univariate analysis, it was found that moderate physical exercise (P=0.0023) and high body mass index (BMI) (P=0.0032) reduced the 8-OH-dG level, while physical labor (P=0.0097), smoking (P=0.032), and low meat intake (less than once/week) (P=0.041) increased its level. Based on a multi-regression analysis of the log-transformed values, moderate physical exercise (P=0.0039), high BMI (P=0.0099), and age (P=0.021) showed significant reducing effects on the 8-OH-dG level, while low meat intake (P=0.010), smoking (P=0.013), and day-night shift work (P=0.044) increased its level. These results suggest that many types of life-style factors that either generate or scavenge oxygen radicals may affect the level of oxidative DNA damage of each individual.