Comparison of Urinary Levels of 8-Hydroxy-2′-deoxyguanosine between Young Females with and without Depressive Symptoms during Different Menstrual Phases

This study aimed to clarify the association between depressive symptoms and a marker of oxidative stress-induced DNA damage in young females. Since the menstrual cycle may confound or modify this association, depressive symptoms and urinary levels of 8-hydroxy-2' deoxyguanosine (8-OHdG) were evaluated during each menstrual phase. A total of 57 female fourth-year students (aged 21.6 +/- 0.8) from a Japanese health science university were studied. The menstrual cycle was divided into 3 phases: menstrual (days 1 to 3 after the onset of menses); proliferative (days 13 to 15); and secretory (days 24 to 26). Depressive symptoms were assessed by the self-rating depression scale (SDS). Positive depressive symptoms were defined as a score of 53 or more during 2 different menstrual phases. The association between the presence of depressive symptoms and 8-OHdG levels adjusting for the menstrual cycle was examined by two-way analysis of variance with the menstrual cycle (menstrual, proliferative, and secretory phases) as the within-individual factor. The menstrual cycle did not show a significant correlation with urinary 8-OHdG levels. On the other hand, the menstrual cycle-adjusted 8-OHdG level was significantly higher in those with depressive symptoms (7.01ng/mL) than in those without them (3.98 ng/mL). The ROC curve analysis showed that urinary 8-OHdG levels had reasonably high discriminative performance throughout all the menstrual cycles (0.73-0.81; all p < 0.05). These results indicated the presence of oxidative stress in subjects with depressive symptoms independent of the menstrual cycle.