Koichiro Oka

Prof. Koichiro Oka

Faculty of Sport Sciences, Waseda University, 2‐579‐15, Mikajima, Tokorozawa, Saitama 359‐1192, Japan
orcid

Research Focus & Metrics

Academic Career Length

34Years (1993-Present)

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

Representative Publications

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18 July 2016 in Journal of Medical Internet Research
Verified
Journal Article
Open access
SMSeigo Mitsutake
Seigo Mitsutake
ASAi Shibata
Ai Shibata
KIKaori Ishii
Kaori Ishii
KOKoichiro Oka
Koichiro Oka
Journal of Medical Internet Research - International Scientific Journal for Medical Research, Information and Communication on the Internet

19 July 2017 in British Journal of Sports Medicine
Verified
Journal Article
Open access
PDF file
JCJennifer Copeland
Jennifer Copeland
MAMaureen C Ashe
Maureen C Ashe
Stuart BiddleStuart Biddle
Stuart Biddle
WBWendy J Brown
Wendy J Brown
MBMatthew Buman
Matthew Buman
SDShilpa Dogra
Shilpa Dogra
Sedentary time (ST) is an important risk factor for a variety of health outcomes in older adults. Consensus is needed on future research directions so that collaborative and timely efforts can be made globally to address this modifiable risk factor. In this review, we examined current literature to identify gaps and inform future research priorities on ST and healthy ageing. We reviewed three primary topics:(1) the validity/reliability of self-report measurement tools, (2) the consequences of prolonged ST on geriatric-relevant health outcomes (physical function, cognitive function, mental health, incontinence and quality of life) and(3) the effectiveness of interventions to reduce ST in older adults. Methods A trained librarian created a search strategy that was peer reviewed for completeness. Results Self-report assessment of the context and type of ST is important but the tools tend to underestimate total ST. There appears to be an association between ST and geriatric-relevant health outcomes, although there is insufficient longitudinal evidence to determine a dose–response relationship or a threshold for clinically relevant risk. The type of ST may also affect health; some cognitively engaging sedentary behaviours appear to benefit health, while time spent in more passive activities may be detrimental. Short-term feasibility studies of individual-level ST interventions have been conducted; however, few studies have appropriately assessed the impact of these interventions on geriatric-relevant health outcomes, nor have they addressed organisation or environment level changes. Research is specifically needed to inform evidence-based interventions that help maintain functional autonomy among older adults. This consensus statement has been endorsed by the following societies: Academy of Geriatric Physical Therapy, Exercise & Sports Science Australia, Canadian Centre for Activity and Aging, Society of Behavioral Medicine, and the National Centre for Sport and Exercise Medicine.

13 November 2012 in Journal of Medical Internet Research
Verified
Journal Article
Open access
SMSeigo Mitsutake
Seigo Mitsutake
ASAi Shibata
Ai Shibata
KIKaori Ishii
Kaori Ishii
KOKoichiro Oka
Koichiro Oka
Association of eHealth Literacy With Colorectal Cancer Knowledge and Screening Practice Among Internet Users in Japan

7 April 2017 in PLOS ONE
Verified
Journal Article
Open access
PDF file
SAShiho Amagasa
Shiho Amagasa
NFNoritoshi Fukushima
Noritoshi Fukushima
HKHiroyuki Kikuchi
Hiroyuki Kikuchi
KOKoichiro Oka
Koichiro Oka
TTTomoko Takamiya
Tomoko Takamiya
SIShigeru Inoue
Shigeru Inoue
The most effective type of social participation against psychological distress in older adults is not well documented. The aim of this study was to examine whether different types of social participation are associated with changes in psychological distress level in older men and women in Japan. Two thousand seven hundred community-dwelling older adults (aged 65–74 years, 50% women) were randomly selected from the resident registry of three cities. Of these, participants who reported social participation and psychological distress level in the baseline survey in 2010 were followed up. Psychological distress was evaluated based on K6 scales at baseline and follow-up (in 2015). Social participation level was examined using question items from the National Health and Nutrition Survey in Japan. Exploratory factor analysis was used to derive the underlying factor structure. Multiple linear regression analysis was used to examine the association between social participation and changes in psychological distress level after adjusting for covariates stratified by both gender and age group or living arrangement. Data from 825 community-dwelling older adults (45.3% women) were analyzed. Social participation was categorized into two types using factor analysis: community involvement (volunteer activities, community events, clubs for the elderly) and individual relationship (friendship, communication with family and friends, hobbies). During the 5-year follow-up, 29.5% of participants reported a deterioration in psychological distress. Higher community involvement was independently associated with lower risk of psychological distress for older women (β = 0.099, p = 0.047), whereas there were no associations with individual relationship for either gender. Furthermore, in older women living with others, higher community involvement was also associated with lower risk of psychological distress (β = 0.110, p = 0.048). Community involvement provides older women with mental health benefits regardless of individual relationship level. Promoting community involvement may be an effective strategy for healthy mental aging.

1 October 2014 in Preventive Medicine
Verified
Journal Article
Closed access
HKHiroyuki Kikuchi
Hiroyuki Kikuchi
SIShigeru Inoue
Shigeru Inoue
TSTakemi Sugiyama
Takemi Sugiyama
NONeville Owen
Neville Owen
KOKoichiro Oka
Koichiro Oka
TSTeruichi Shimomitsu
Teruichi Shimomitsu

18 December 2015 in BMC Public Health
Verified
Journal Article
Open access
PDF file
KIKaori Ishii
Kaori Ishii
ASAi Shibata
Ai Shibata
MAMinoru Adachi
Minoru Adachi
KNKeiko Nonoue
Keiko Nonoue
KOKoichiro Oka
Koichiro Oka
Physical activity levels in childhood have decreased, making the promotion of children’s physical activity an important issue. The present study examined gender and grade differences in objectively measured sedentary behavior, physical activity, and physical activity guideline attainment among Japanese children and adolescents. In total, 329 boys and 362 girls age 3–15 years completed the survey. School grade, gender, height, and weight were collected by questionnaires and physical activity objectively measured using an accelerometer (Lifecorder Suzuken Co.). Physical activity level (in MET) was classified as sedentary (<1.5), light (≥1.5 to <3), moderate (≥3 to 600 min/day total wear time. Two-way analysis of covariance and logistic regression analyses, adjusted for weight status and accelerometer wear time, were used to examine gender and grade differences in physical activity variables and the likelihood of physical activity guideline attainment by gender and grade level. Participants were sedentary 441.4 (SD, 140.1) min/day or 53.7 % of the average daily accelerometer wear time of 811.2 (118.7) min, engaged in light physical activity 307.1 (70.0) min or 38.4 % of wear time, moderate physical activity 34.6 (14.8) min (4.3 %), vigorous physical activity 28.3 (19.1) min (3.6 %), and took 12462.6 (4452.5) steps/day. Boys were more physically active and took more steps/day than girls. Students in higher grades were less active than those in lower grades. Boys were significantly more likely to meet physical activity guidelines than girls (OR: 2.07, 95 % CI: 1.45–2.96). Preschoolers (6.66, 4.01–11.06), lower-grade elementary school students (17.11, 8.80–33.27), and higher-grade elementary school students (7.49, 4.71–11.92) were more likely to meet guidelines than junior high school students. Boys and lower-grade students engaged in more physical activity and were more likely to attain guidelines than girls and higher-grade students. These findings highlight the need for effective and sustainable strategies to promote physical activity in Japanese school children.