Increased blood 8-hydroxy-2-deoxyguanosine levels in methamphetamine users during early abstinence

Background: Reactive oxygen species (ROS) are thought to play a role in the adverse physical and mental consequences of methamphetamine usage. The oxidative DNA adduct 8-hydroxy-2'-deoxyguanosine (8-OHdG) is a well-known biomarker of ROS-induced DNA damage. Currently, there is insufficient clinical information about methamphetamine-induced oxidative DNA damage. Objectives: This study examined differences in blood levels of 8-OHdG between methamphetamine users and non-users as well as alterations in 8-OHdG levels after 2 weeks of methamphetamine abstinence. Methods: We recruited 182 methamphetamine users (78.6% of male) and 71 healthy controls (95.8% of male). Baseline serum 8-OHdG levels were measured in both groups using a competitive enzyme-linked immunosorbent assay. In methamphetamine users, 8-OHdG levels were measured again 2weeks after baseline measurement. Results: The results showed that methamphetamine users had significantly higher 8-OHdG levels (0.34 +/- 0.13ng/mL) than healthy controls (0.30 +/- 0.08ng/mL) (p<0.001). The 8-OHdG levels did not alter after 2weeks of methamphetamine abstinence (0.32 +/- 0.12ng/mL, p=0.051 compared to baseline measurement; p=0.12 compared to healthy controls). No significant correlations were observed between baseline 8-OHdG levels in methamphetamine users and post-abstinence interval, age of the first methamphetamine use, duration of methamphetamine use, or history of frequent methamphetamine use. Conclusion: Our findings suggest that methamphetamine users had an enhanced level of oxidative damage, which did not normalize during early abstinence. Future studies are required to determine the effects of long-term methamphetamine abstinence and potential confounders on 8-OHdG levels in methamphetamine users.