Effects of Psychological Stress from a National License Examination on the Urine 8-Hydroxy-Deoxyguanosine Levels in Young Female Students, Taking into Account the Menstrual Cycle

Tadayuki Iida,Hiroaki Ishikawa,Yasuhiro Ito,Miho Kanazashi,Ryoji Teradaira,Asami Tatsumi,Satoko Ezoe

doi:10.4236/ojpm.2018.82003

Abstract

Objective: Urine 8-hydroxy-deoxyguanosine (U8-OHdG) was a marker of oxidative stress-induced DNA damage; it was increased by psychological stress. Since the menstrual cycle may confound or modify the association between psychological stress and U8-OHdG. The aim of this study was to verify the effect of psychological stress from a national license examination on levels of U8-OHdG, which is a biomarker of oxidative stress. And the effects of women’s menstrual cycles, which should be considered in mental and physical assessments, on U8-OHdG, were evaluated. Methods: The subjects were 18 female university students at a medical university in whom Self-rating Depression Scale (SDS) scores, State-Trait Anxiety Inventory (STAI) scores, and U8-OHdG levels were measured in 3 phases of the menstrual cycle, the follicular phase, ovulatory phase, and luteal phase. The mean values were taken for the group during a time of classroom learning. The same measurements were also made one week before and the day after a national license examination and the measurements were compared among the three periods. Results and Conclusion: State anxiety and U8-OHdG levels were significantly higher in those with a week before the national license examination than in those with classroom lecture (State anxiety: p = 0.002, U8-OHdG levels: p = 0.007). The menstrual cycle did not show a significant correlation with U8-OHdG levels. This study demonstrated that levels of the oxidative stress biomarker U8-OHdG are not affected by changes in the menstrual cycle. It also showed that U8-OHdG levels increased with the psychological stress of a national license examination.

Highlights

The percentage of people with work- and life-related anxiety, worry, and stress is increasing every year, and it is said to exceed 60%
U8-OHdG levels were shown to increase with the psychological stress from a national license examination
On the State-Trait Anxiety Inventory (STAI) score, a tool that has often been used as an indicator to evaluate psychological stress, the results showed that state anxiety increased significantly before the national license examination compared with the time of normal classroom learning, and that after the examination, it decreased significantly compared with the time of classroom learning and before the examination

Summary

Introduction

The percentage of people with work- and life-related anxiety, worry, and stress is increasing every year, and it is said to exceed 60%. The relationship between psychological stress and oxidative stress has become a focus of interest, and the mechanism by which psychological stress increases reactive oxygen species (ROS) [1] [2] [3] [4] is slowly being elucidated [5] [6] [7]. Reactive oxygen species oxidize the major biological constituents of DNA, lipids, and proteins, increasing oxidative stress in the body [8]. Oxidized DNA, lipids, and proteins are produced in the blood and urine, and so it is possible that these biomarkers in the body can be used as oxidative stress markers [9]. The focus was on the relationship between psychological stress and U8-OHdG, with the aim of objectively assessing psychological stress with a biomarker

Methods

Results

Discussion

Conclusion