Suguru Nakajima

Dr. Suguru Nakajima

orcid

Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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7 November 2024 in Behavioral Sciences
Verified
Journal Article
Open access
PDF file
YOYuichiro Otsuka
Yuichiro Otsuka
YKYoshitaka Kaneita
Yoshitaka Kaneita
SNSuguru Nakajima
Suguru Nakajima
YMYuuki Matsumoto
Yuuki Matsumoto
YKYoshitaka Kaneita
Yoshitaka Kaneita
Few studies have examined the relationship between teleworking practices and presenteeism. This study determined the association between teleworking practices and presenteeism among teleworkers in Japan. A cross-sectional online survey was administered to 2687 teleworkers from five companies in Japan, collecting data on demographic variables, teleworking practices, frequency and duration of teleworking, presenteeism, and various lifestyle- and health-related factors. A logistic regression analysis was performed. Teleworkers with full-time employment and less teleworking experience exhibited higher presenteeism rates. Key practices negatively associated with presenteeism included creating a dedicated workspace, chatting with colleagues, and setting daily work goals. Gender differences were significant: for men, additional practices, such as determining their work hours, were beneficial; while for women, chatting with colleagues was particularly important. A sensitivity analysis indicated that specific teleworking practices can mitigate presenteeism. Certain teleworking practices, such as creating a workspace, chatting with colleagues, and setting work goals, were associated with lower presenteeism among teleworkers. These findings highlight the need for organizations to support telework ergonomics, promote social interaction, and encourage goal setting to enhance teleworker productivity and health. Training for employees and supervisors to raise awareness of their own and their subordinates’ health while teleworking is advised.

13 February 2025 in Clocks & Sleep
Verified
Journal Article
Open access
PDF file
SNSuguru Nakajima
Suguru Nakajima
YOYuichiro Otsuka
Yuichiro Otsuka
YKYoshitaka Kaneita
Yoshitaka Kaneita
YKYoshitaka Kaneita
Yoshitaka Kaneita
YKYuki Kuwabara
Yuki Kuwabara
YOYoneatsu Osaki
Yoneatsu Osaki
It is unclear whether patterns of alcohol consumption are associated with sleep disturbance. We aimed to investigate the relationship between comprehensive alcohol-related factors and insomnia symptoms, as well as sleep quality, among adult women in Japan. Responses to an online cross-sectional survey were gathered from 12,000 women. The survey items included demographic characteristics, alcohol consumption (Alcohol Use Disorders Identification Test, nightcaps, years of drinking), sleep-related factors (sleep duration, insomnia symptoms, sleep quality), lifestyle-related factors, and mental health. Binary logistic regression was used to investigate the relationship between alcohol consumption and both insomnia symptoms and sleep quality. A total of 10,233 women were included in the final analysis. The results revealed that several alcohol-related behaviors, including the consumption of nightcaps and years of drinking, were significantly associated with insomnia symptoms and poor sleep quality. Specifically, nightcaps were significantly associated with all types of insomnia symptoms and poor sleep quality, with a higher odds ratio than other alcohol-related items. Our findings suggest that specific alcohol-related behaviors, particularly the consumption of nightcaps, are associated with insomnia symptoms and poor sleep quality among women. Intervention programs for alcohol consumption should be provided to prevent sleep problems among women.

26 June 2025 in Clocks & Sleep
Verified
Journal Article
Open access
PDF file
YTYuki Tanaka
Yuki Tanaka
YOYuichiro Otsuka
Yuichiro Otsuka
SNSuguru Nakajima
Suguru Nakajima
YKYoshitaka Kaneita
Yoshitaka Kaneita
TMTomomi Miyoshi
Tomomi Miyoshi
YKYoshitaka Kaneita
Yoshitaka Kaneita
Worsening adolescent mental health is a significant social issue. Although dreams may reflect one’s mental state, few studies have focused on adolescents. Therefore, this study investigated the relationship between dream content and mental health, specifically anxiety disorder and depressive symptoms, among Japanese adolescents. This cross-sectional study obtained data on gender, grade, age, lifestyle habits, weekday sleep duration, anxiety disorder symptoms, depressive symptoms, and dreams from Japanese high school students. The data were analyzed via multiple logistic regression analyses. The prevalence of anxiety and depressive symptoms increased with the frequency of “rumination at bedtime”, “memory of dreams”, “emotional carryover”, and “awakening by frightening”, “unpleasant”, “film-like”, “fantastical”, and “recurring” dreams. However, this was not the case for “pleasant dreams”. Furthermore, “rumination at bedtime” (anxiety disorder symptoms: adjusted odds ratio: 10.60; 95% confidence interval: 5.92–18.97; depressive symptoms: 8.79, 5.58–13.87) and “unpleasant dreams” (anxiety disorder symptoms: 5.25, 2.86–9.64; depressive symptoms: 10.13, 5.57–18.44) exhibited particularly high odds ratios. “Rumination at bedtime” and “unpleasant dreams” may serve as early indicators of declining mental health. School- and parent-led interventions aimed at improving mental well-being may help prevent the progression or exacerbation of anxiety and depressive symptoms among adolescents.

16 December 2025 in Traditional & Kampo Medicine
Verified
Journal Article
Closed access
TMTomomi Miyoshi
Tomomi Miyoshi
YOYuichiro Otsuka
Yuichiro Otsuka
YTYuki Tanaka
Yuki Tanaka
SNSuguru Nakajima
Suguru Nakajima
YKYoshitaka Kaneita
Yoshitaka Kaneita