Overtime work and occurance of health disorder

• Project/Area Number: 26350847
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Applied health science
• Research Institution: Tokyo Medical University
• Principal Investigator: Odagiri Yuko 東京医科大学, 医学部, 講師 (90276907)
• Co-Investigator(Kenkyū-buntansha): 高宮 朋子 東京医科大学, 医学部, 准教授 (40366133)
• Project Period (FY): 2014-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000); Fiscal Year 2016: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2015: ¥260,000 (Direct Cost: ¥200,000、Indirect Cost: ¥60,000); Fiscal Year 2014: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
• Keywords: 過重労働 / 疲労 / 微量元素 / 鉄 / 亜鉛 / 8-OHdG / ミネラル / 長時間過重労働 / 生体内微量元素

Outline of Final Research Achievements

Factors related to high fatigue, indicator of overwork, are examined for 240 workers (161 men and 79 women). Low work control and long working hours were associated with high fatigue. Results shows that VAS fatigue is weakly negatively correlated with iron in tissues, and weakly positively correlation with urinary 8-OHdG. Other biological trace elements such as zinc and silicon were also examined, but no significant association with fatigue was found. The fatigue level and the trace element were measured twice for 66 subjects, and the relationship between the change in the trace element and the fatigue level was examined, but there was no significant association.

Academic Significance and Societal Importance of the Research Achievements

日本人の潜在的亜鉛欠乏が諸外国に比べて多く10～30％と推定されていることから、これに過重な労働負担が加わり、過労による身体不調を引き起こしている可能性を疑い検討を行ったが、本研究では過労と亜鉛との間に関連は見いだせなかった。他の日本人で不足が指摘されいてる元素についても疲労との明らかな関連は認められなかった。亜鉛は免疫機能の維持や精神健康に関連するという報告があり亜鉛の摂取は重要と考えられるが、疲労予防や精神健康の向上は今後の検討課題である。
疲労との間に酸化ストレス指標である尿中8-OHdGが弱い正の関連を示したことから酸化ストレスの予防は重要かもしれない。