Twin studies on Tojikomori syndrome in Japanese elderly

• Project/Area Number: 16K15978
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Gerontological nursing
• Research Institution: Kio University
• Principal Investigator: INUI FUJIO 畿央大学, 健康科学部, 准教授 (80469551)
• Co-Investigator(Kenkyū-buntansha): 冨澤 理恵 大阪大学, 医学系研究科, 特任講師(常勤) (20584551) ; 本多 智佳 大阪大学, 医学系研究科, 特任准教授(常勤) (40625498) ; 加藤 憲司 神戸市看護大学, 看護学部, 教授 (70458404) ; 中谷 香江 畿央大学, 健康科学部, 助手 (20524979)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000); Fiscal Year 2018: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2017: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2016: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
• Keywords: 行動遺伝学 / 双生児研究法 / うつ症状 / 疲労 / 自己効力感 / 睡眠時間 / 双生児研究 / 遺伝環境交互作用 / うつ / 閉じこもり

Outline of Final Research Achievements

We conduct the cohort study on middle-aged twins, which has been held every two years since 2008, for investigate depressive symptoms, self-efficacy, lifestyle (including sleeping, eating, living environment), working style, fatigue scale. As a result, the relations between self-efficacy, fatigue, and depressive symptoms were explained by two different genetic factors-a genetic factor related to self-efficacy, fatigue, and depressive symptoms. However, there is another genetic factor that is not associated with self-efficacy.
On sleep duration, we investigated genetic and environmental factors. No evidence was found for the influence of genetic effects on sleep duration in the Japanese population. Instead, common environmental factors explained 44% of the variation of sleep duration. However, it is presumed that some significant environmental factors influence it.

Academic Significance and Societal Importance of the Research Achievements

自己効力感は従来は疾患からの回復に関係すると考えられていた。しかし，身体症状や精神症状そのものと共通する遺伝要因が確認できたことは，疾患の発症メカニズムを解明する上で有用な知見をもたらす。また，今回の結果だけでは明確ではないが，日本人の睡眠時間の分散に影響を与える遺伝要因が極めて小さいことは，遺伝要因が小さいのではなく，それよりもより大きな環境要因が作用していると解釈できる。このことは，日本における近年の睡眠時間の減少が将来的に心身に大きな影響をもたらす可能性を示している。

Research Products

• [Int'l Joint Research] ヘルシンキ大学(フィンランド)
• [Int'l Joint Research]
• [Journal Article] Association of current and former smoking with body mass index: A study of smoking discordant twin pairs from 21 twin cohorts (2018)
  • Author(s): Piirtola Maarit、Jelenkovic Aline、Latvala Antti、Sund Reijo、Honda Chika、Inui Fujio、Watanabe Mikio、et al., Silventoinen Karri
  • Journal Title: PLOS ONE Volume: 13 Issue: 7 Pages: e0200140-e0200140
  • DOI: 10.1371/journal.pone.0200140
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Education in Twins and Their Parents Across Birth Cohorts Over 100 years: An Individual-Level Pooled Analysis of 42-Twin Cohorts (2017)
  • Author(s): Silventoinen Karri、Jelenkovic Aline、et al.
  • Journal Title: Twin Research and Human Genetics Volume: 20 Issue: 5 Pages: 395-405
  • DOI: 10.1017/thg.2017.49
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Differences in genetic and environmental variation in adult BMI by sex, age, time period, and region: an individual-based pooled analysis of 40 twin cohorts (2017)
  • Author(s): Silventoinen Karri、Jelenkovic Aline、et al.
  • Journal Title: The American Journal of Clinical Nutrition Volume: 106 Issue: 2 Pages: 457-466
  • DOI: 10.3945/ajcn.117.153643
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] 健康科学における双生児研究法（Twin study）の可能性について (2016)
  • Author(s): 乾富士男
  • Journal Title: 畿央大学紀要 Volume: 13 Pages: 1-8
  • NAID: 40021052862
  • Peer Reviewed
• [Presentation] No Evidence was Found for the Influence of Genetic Effects on Sleep Duration in the Japanese Population (2019)
  • Author(s): Fujio Inui, Karri Silventoinen, Chika Honda, Rie Tomizawa, Daisuke Matsumoto, Kae Nakatani, Norio Sakai
  • Organizer: 49th Behavior Genetics Association ANNUAL MEETING
  • Int'l Joint Research
• [Presentation] 自己効力感と疲労およびうつ症状の関連について (2018)
  • Author(s): 乾富士男，Karri Silventoinen，本多智佳，冨澤理恵，酒井則夫，中谷香江，松本大輔，加藤憲司，大阪ツインリサーチグループ
  • Organizer: 日本双生児研究学会第32回学術講演会
• [Presentation] Genetic and environmental associations between self-efficacy, fatigue and depression. (2017)
  • Author(s): Fujio Inui, Karri Silventoinen, Chika Honda, Rie Tomizawa, Norio Sakai, Kae Nakatani, Daisuke Matsumoto, Kenji Kato, Osaka Twin Research Group
  • Organizer: Twins2017 (ISTS congress), Madrid
  • Int'l Joint Research
• [Presentation] Genetic and environmental associations between self-efficacy and depressive symptoms in a Japanese population. (2016)
  • Author(s): F.Inui， K.Silventoinen， C.Honda，et al.
  • Organizer: The 16th International Congress on Twin Studies 2016
  • Place of Presentation: Brisbane
  • Year and Date: 2016-06-20
  • Int'l Joint Research
• [Remarks] 研究室について
  • URL: https://bg-lab.org/