Changes in urinary levels of 8‐hydroxy‐2′‐deoxyguanosine due to aging and smoking

Background: Oxidative DNA damage and oxidative stress have been recognized to participate in the pathogenesis of cancer or aging, and 8-hydroxy-2′-deoxyguanosine (8-OHdG) is currently one of the most popular markers for the evaluation of this. To measure the 8-OHdG level in urine, the 8-OHdG Check kit using a monoclonal antibody has been developed in Japan. The purpose of the present study was to evaluate this check kit and determine the influences of aging and smoking on oxidative DNA damage. Methods: Levels of 8-hydroxy-2′-deoxyguanosine/creatinine (8-OHdG/cre) in spot urine were measured in 120 healthy persons aged 25–88 years (78 non-smokers and 42 smokers) and 24 cancer patients aged 54–89 years. Results: In the healthy people there were no sex differences in urinary levels of 8-OHdG/cre in both non-smokers and smokers. The urinary levels of 8-OHdG/cre increased with age in non-smokers, but not in smokers. There was a tendency for the urinary levels of 8-OHdG/cre to be higher in smokers than in non-smokers, but smokers over 70 years of age showed the lowest urinary levels of 8-OHdG/cre among all age groups. In cancer patients there was a tendency for the urinary levels of 8-OHdG/cre to be higher compared with age-matched healthy persons (n = 51) in both smokers and non-smokers. Conclusion: Aging and smoking are associated with oxidative DNA damage, and the 8-OHdG Check kit, which uses a monoclonal antibody specific for 8-OHdG, may be a useful tool for evaluating the influences of various factors on oxidative DNA damage.