Details of a Researcher

Sato, Koryu

写真a

Affiliation: Faculty of Policy Management (Shonan Fujisawa)

Position: Assistant Professor/Senior Assistant Professor

Page Top ▲

Career 【 Display / hide 】

2009.04

-

2021.03

厚生労働省
2021.04

-

2024.03

京都大学, 大学院医学研究科, 助教
2024.04

-

Present

慶應義塾大学, 総合政策学部, 専任講師

Page Top ▲

Academic Degrees 【 Display / hide 】

Master of Public Health, Harvard University, Coursework, 2018.03
博士（経済学）, Waseda University, Coursework, 2024.03

Page Top ▲

Papers 【 Display / hide 】

Sedentary behavior and the combination of physical activity associated with dementia, functional disability, and mortality: A cohort study of 90,471 older adults in Japan

Du Z., Sato K., Tsuji T., Kondo K., Kondo N.

Preventive Medicine (Preventive Medicine) 180 2024.03

ISSN 00917435

　View Summary

Objective: To examine the associations of sedentary behavior (SB) and the combination of moderate-to-vigorous intensity physical activity (MVPA) with dementia, functional disability, and mortality in older adults, and the heterogeneity in different subpopulations. Methods: Nation-wide cohort with 90,471 individuals aged ≥65 years in Japan. SB (<3, 3–<8, and ≥ 8 h per day [h/d]) and MVPA (0, 0 < MVPA<1, and ≥ 1 h/d) were measured in 2016. Long-term care registry-based incidence of outcomes was ascertained through 2021. Cox proportional hazard models were performed. Results: Compared with SB < 3 h/d group, SB ≥ 8 h/d was associated with higher risks of dementia, functional disability, and mortality with hazard ratios (95% confidence interval) of 1.36 (1.22–1.52), 1.32 (1.19–1.48), and 1.31 (1.18–1.45). The combination of MVPA and SB demonstrated a dose-respond trend of increasing risks of dementia, functional disability, and mortality with increased SB and decreased MVPA, where participants who spent no MVPA with SB ≥ 8 h/d had the highest risks. High MVPA attenuated but didn't eliminate the risks. Participants who spent MVPA≥1 h/d with SB ≥ 8 h/d had comparable risks to those who spent no MVPA with SB < 3 h/d. No heterogeneity was found by MVPA levels, sex, education, comorbidity, and depression conditions. Conclusions: Prolonged daily SB was associated with higher risks of dementia, functional disability, and mortality in older adults, regardless of MVPA, sex, education, and chronic conditions. Individuals with high MVPA also face considerable risks when engaging in high SB. High MVPA with high SB revealed a comparable risk to no MVPA with low SB.
- Access to Document (DOI)
Estimating the joint association of adverse childhood experiences and asthma with subsequent depressive symptoms: a marginal structural modelling approach

Takemura Y., Sato K., Liang R., Isobe M., Kondo N., Inoue K.

BMJ mental health (BMJ mental health) 27 ( 1 ) 2024.02

　View Summary

BACKGROUND: The relationship between adverse childhood experiences (ACEs) and depression risk has been well documented. However, it remains unclear whether stress-related chronic conditions associated with ACEs, such as asthma, increase the long-term mental health burden of ACEs. OBJECTIVE: To investigate the joint association of ACEs and asthma with subsequent depressive symptoms among US adults. METHODS: This study used data from the Behavioural Risk Factor Surveillance System 2010, including 21 544 participants over 18 years old from four states where participants were questioned about ACEs. We used logistic regression models to calculate the adjusted OR (aOR) for elevated depressive symptoms evaluated by Patient Health Questionnaire-8 according to ACEs and asthma, along with marginal structural models (MSM) to consider ACE-related confounders between asthma and depression. We evaluated the additive interaction between ACEs and asthma on depressive symptoms with the relative excess risk due to interaction (RERI). FINDINGS: Of the 21 544 participants (mean age: 56, women: 59.5%), 52.3% reported ≥1 ACEs, 14.9% reported a history of asthma and 4.0% had depressive symptoms. ACEs and asthma were independently associated with elevated depressive symptoms (aORs (95% CI) were 2.85 (2.30 to 3.55) and 2.24 (1.50 to 3.27), respectively). Furthermore, our MSM revealed an additive interaction between ACEs and asthma for depressive symptoms (RERI (95% CI)=+1.63 (0.54 to 2.71)). CONCLUSIONS: These findings suggest that asthma amplifies the risk of depressive symptoms associated with ACEs. CLINICAL IMPLICATIONS: Prevention and treatment of asthma, along with establishing preventive environments and services against ACEs, are effective in mitigating the potential burden of ACEs on mental health.
- Access to Document (DOI)
Family Pharmacy and Medication Adherence Among Older Adults in Japan: A Cross-Sectional Study of JAGES 2019

Tamura M., Takasugi T., Nakamura M., Yanagi N., Nakagomi A., Sato K., Kondo K., Ojima T.

The journals of gerontology. Series B, Psychological sciences and social sciences (The journals of gerontology. Series B, Psychological sciences and social sciences) 78 ( 12 ) 2122 - 2130 2023.12

　View Summary

OBJECTIVES: Poor medication adherence among older adults is a global concern as it causes adverse drug interactions and inappropriate dosing. This study aimed to assess the association between family pharmacy and medication adherence among older adults. METHODS: The Japan Gerontological Evaluation Study was a cross-sectional study of 18,792 people aged ≥65 years living in 61 municipalities in 25 prefectures who participated in a survey conducted in 2019 and did not require long-term care. Self-reported questionnaires were administered to evaluate whether the participants "always received medicines from the same pharmacy" and whether they had unused medicines. Modified Poisson regression was used to examine the association after adjusting for confounders. RESULTS: Unused medicines were present in 89.9% of the "have group" (individuals who always received their medicines from the same pharmacy). This group had a lower prevalence of unused medicines (prevalence ratio [PR] = 0.87, 95% confidence interval [CI]: 0.82-0.92) than the "none group" (individuals who did not always receive their medicines from the same pharmacy). In the stratified analysis by education level, the prevalence of unused medicines was lower among those with low levels of education (≤9 years: PR = 0.82, 95% CI: 0.71-0.96; 10-12 years: PR = 0.81, 95% CI: 0.74-0.88). DISCUSSION: Older adults who "always received medicines from the same pharmacy" had a lower prevalence of unused medicines, especially those with low levels of education. Thus, "always receiving medicines from the same pharmacy" may be effective in reducing the proportion of unused medicines and improving medication adherence.
- Access to Document (DOI)
Association of frailty with influenza and hospitalization due to influenza among independent older adults: a longitudinal study of Japan Gerontological Evaluation Study (JAGES)

Iwai-Saito K., Sato K., Aida J., Kondo K.

BMC Geriatrics (BMC Geriatrics) 23 ( 1 ) 2023.12

　View Summary

Background: It is unknown that whether frailty is a risk factor of influenza and the hospitalization among older adults, although it has been shown that frailty was associated with poor recovery from the hospitalization among those. We examined the association of frailty with influenza and the hospitalization and the effect by sex among independent older adults. Methods: We used the longitudinal data from the Japan Gerontological Evaluation Study (JAGES), performed in 2016 and 2019 and conducted in 28 municipalities in Japan. The target population comprised 77,103 persons aged ≥ 65 years who did not need assistance from the public long-term care insurance. Primary outcome measures were influenza and hospitalization due to influenza. Frailty was evaluated with the Kihon check list. We estimated the risk of influenza, the hospitalization, those risks by sex, and the interaction for frailty and sex using Poisson regression adjusting for covariates. Results: Frailty was associated with both influenza and the hospitalization among the older adults compared with nonfrail individuals after adjusting for covariates (influenza, frail: risk ratio {RR}: 1.36, 95% confidence interval {95% CI}: 1.20 − 1.53, and prefrail: RR: 1.16, 95% CI: 1.09 − 1.23; the hospitalization, frail: RR: 3.18, 95% CI: 1.84 − 5.57, and prefrail: RR: 2.13, 95% CI: 1.44 − 3.16). Male was associated with the hospitalization, but not associated with influenza compared to female (the hospitalization: RR: 1.70, 95% CI: 1.15 − 2.52 and influenza: RR: 1.01, 95% CI: 0.95 − 1.08). The interaction for frailty and sex was significant neither in influenza nor in the hospitalization. Conclusion: These results suggest that frailty is a risk of influenza and the hospitalization, that risks of the hospitalization are different by sex, but that the sex difference does not cause the effect heterogeneity of frailty on the susceptibility and severity among independent older adults.
- Access to Document (DOI)
Does disaster-related relocation impact mental health via changes in group participation among older adults? Causal mediation analysis of a pre-post disaster study of the 2016 Kumamoto earthquake

Matsuoka Y., Haseda M., Kanamori M., Sato K., Amemiya A., Ojima T., Takagi D., Hanazato M., Kondo N.

BMC Public Health (BMC Public Health) 23 ( 1 ) 2023.12

　View Summary

Background: Disaster-related relocation is associated with depression and post-traumatic stress disorder, especially in older adults. Disaster-related relocation often deprives survivors of opportunities for social group participation, potentially deteriorating their mental health. On the contrary, the relocation could also be an opportunity for optimizing social relationships, ending/reducing unwanted participation. This study examined the potential mediation effects of changing participation for the link of disaster-related relocation to mental health. Methods: We analyzed a pre-post disaster dataset of functionally independent older adults from the Japan Gerontological Evaluation Study. Following the 2013 survey, a follow-up survey was conducted seven months after the 2016 Kumamoto earthquake (n = 828). Results: The causal mediation analyses indicated that compared to no relocation, the relative risk for experiencing major depressive episodes among those relocating to temporary housing was 3.79 [95% confidence interval: 1.70–6.64] (natural direct effect). By contrast, the relative risk for those renewing (either ceased or started) group participation was 0.60 [95% CI: 0.34–0.94] (natural indirect effect). Conclusions: Optimization of social ties according to a renewal of group participation status might have protected older adults in temporary housing against depression.
- Access to Document (DOI)