Takahisa Ohta

Dr. Takahisa Ohta

Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan
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Research Focus & Metrics

Academic Career Length

36Years (1991-Present)

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

Representative Publications

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TOTakahisa Ohta
Takahisa Ohta
JNJunzo Nagashima
Junzo Nagashima
HSHiroyuki Sasai
Hiroyuki Sasai
NINaokata Ishii
Naokata Ishii
Low cardiorespiratory fitness (CRF) and obesity are independent risk factors for dyslipidemia. We investigated the synergistic effects of CRF and obesity on the incidence of dyslipidemia among Japanese women. Of 7627 participants, 927 normolipidemic Japanese women completed a submaximal exercise test, medical examination, and a questionnaire on smoking and alcohol drinking. The incidence of dyslipidemia was defined as having at least one of the following: high-density lipoprotein cholesterol < 40 mg/dL, low-density lipoprotein cholesterol ≥ 140 mg/dL, fasting triglyceride ≥ 150 mg/dL, or physician-diagnosed dyslipidemia. Multivariable hazard ratios (HRs) and 95% confidence intervals (CI) were calculated using a Cox proportional hazard regression model. During the follow-up period of ≤16 years (median 1 year), 196 (21.1%) women developed dyslipidemia. Compared with those in the body mass index (BMI)-specific (< or ≥25.0 kg/m2) lowest CRF tertile, the multivariable HRs for dyslipidemia in the highest CRF tertile were 1.36 (95% CI, 0.75–2.48) for women with BMI ≥ 25 kg/m2 and 0.70 (95% CI, 0.45–1.09) for those with BMI < 25 kg/m2 (p < 0.01 for interaction). These results suggest that CRF and BMI are interdependent and, together, they affect the incidence of dyslipidemia among Japanese women. CRF is inversely related to a lower incidence of dyslipidemia with low BMI.

16 April 2024 in Nutrients
Verified
Journal Article
Open access
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TOTakahisa Ohta
Takahisa Ohta
YOYosuke Osuka
Yosuke Osuka
TSTakashi Shida
Takashi Shida
KDKaori Daimaru
Kaori Daimaru
NKNarumi Kojima
Narumi Kojima
HSHiroyuki Sasai
Hiroyuki Sasai
Smartphone applications aimed at enhancing physical, cognitive, and social activities through mobile health (mHealth) technology are of increasing interest. Their feasibility and acceptability, alongside impacts on frailty phenotype scores and step counts among older adults with frailty, remain to be fully validated. This study presents a 13-week preliminary intervention trial assessing an mHealth app’s feasibility in a cohort of 34 eligible older adults, including 5 frail and 29 pre-frail participants. The intervention entailed a 6-week course on app usage, followed by 7 weeks of observation, with four participants withdrawing early. Feasibility was determined by login and active use rates, with a target login rate of 60% or higher. Post-intervention, 100% session attendance and a median login rate of 88.4% were observed. Acceptability was high, with 73% affirming the app’s health benefits. Notably, frailty scores and step counts improved post-intervention, underscoring the app’s potential for supporting older adults with frailty.

4 April 2023 in Frontiers in Public Health
Verified
Journal Article
Open access
TOTakahisa Ohta
Takahisa Ohta
HSHiroyuki Sasai
Hiroyuki Sasai
YOYosuke Osuka
Yosuke Osuka
NKNarumi Kojima
Narumi Kojima
TATakumi Abe
Takumi Abe
IIIRIDE Cohort Study Investigators
IRIDE Cohort Study Investigators
Introduction: This study examined whether the association between sarcopenia severity and cognitive function differed according to sex and age in community-dwelling older adults in Japan.Methods: This is a cross-sectional study of older adults (age ≥ 65 years) consisting of five regional cohorts integrated as the Integrated Research Initiative for Living Well with Dementia (IRIDE) Cohort Study. Sarcopenia severity was determined based on the Asian Working Group for Sarcopenia 2019, which assessed grip strength, walking speed, and skeletal muscle mass index. Poor cognitive function was defined as a Mini-Mental State Examination score of ≤ 23. Odds ratios (ORs) and 95% confidence intervals (CIs) for poor cognitive function were calculated by sex and age group (65–74 and ≥75 years) using binomial logistic regression models, which were adjusted for age, educational attainment, history of non-communicable diseases, smoking and drinking habits, living alone, frequency of going outdoors, exercise habits, and depressive symptom.Results: Of the 8,180 participants, 6,426 (1,157 men aged 65–74 and 1,063 men aged 75 or older; 2,281 women aged 65–74 and 1,925 women aged 75 or older) were analyzed. The prevalence ratio of sarcopenia and severe sarcopenia were 309 (13.9%) and 92 (4.1%) among men and 559 (13.3%) and 166 (3.7%) among women, respectively. A total of 127 (5.8%) men and 161 (3.9%) women had a poor cognitive function. Setting non-sarcopenia as a reference, the adjusted ORs (95% CI) of poor cognitive function were 2.20 (1.54, 3.15) for sarcopenia and 3.56 (2.20, 5.71) for severe sarcopenia. A similar trend was observed in analyses stratified by sex and age, with linear associations (P for trend <0.05) in both categories. Furthermore, there was a significant interaction (P < 0.05) between sex and sarcopenia severity, indicating a stronger linear association of sarcopenia severity with poor cognitive function in women compared with men.Discussion and conclusion: Sarcopenia severity was linearly associated with poor cognitive function in adults aged ≥ 65 years, with a stronger association in women compared with men.

NKNaoki Kikuchi
Naoki Kikuchi
TOTakahisa Ohta
Takahisa Ohta
YHYuto Hashimoto
Yuto Hashimoto
YMYukina Mochizuki
Yukina Mochizuki
MSMika Saito
Mika Saito
Takanobu OkamotoTakanobu Okamoto
Takanobu Okamoto
Purpose: This study investigated the effect of online home-based resistance exercise training on fitness, depression, stress, and well-being. A total of 67 individuals participated. Of them, 28 participants (13 men and 15 women, average age: 45.1 ± 12.2 years) performed the same exercise training online (n = 17), using Zoom, or in person (n = 11) in 2020 (Study 1). In addition, 39 participants (15 men and 24 women; average age: 47.6 ± 10.8 years) performed eight weeks of online home-based resistance exercise training in 2021 (Study 2). The participants performed low-load resistance exercises twice a week for eight weeks (16 sessions). Muscle strength, thigh muscle cross-sectional area, fitness parameters, blood pressure, mental health (Center for Epidemiologic Studies-Depression Scale—CES-D; and Kessler Psychological Distress scale—K6), and well-being (Well-Being Index—WHO-5) were measured pre-and post-resistance training. In Study 1, eight weeks of online home-based resistance training improved CES-D (p = 0.003), and a similar tendency was observed in resistance training (RT) with the in-person group (p = 0.06). There was a significant improvement in CES-D symptoms after the online home-based resistance training in Study 2 (p = 0.009). However, there were no significant changes in the WHO-5 and K6. Our results suggest that online low-load resistance training improves fitness parameters and curbs depressive status.

3 April 2024 in Nutrition
Verified
Journal Article
Closed access
TSTakashi Shida
Takashi Shida
SHSho Hatanaka
Sho Hatanaka
TOTakahisa Ohta
Takahisa Ohta
YOYosuke Osuka
Yosuke Osuka
NKNarumi Kojima
Narumi Kojima
HSHiroyuki Sasai
Hiroyuki Sasai

1 February 1991 in Journal of Liquid Chromatography
Verified
Journal Article
Closed access
NCNobutoshi Chikazumi
Nobutoshi Chikazumi
TOTakahisa Ohta
Takahisa Ohta
Hydrodynamic volume was estimated by using high-performance size-exclusion chromatography (SEC) with a silica-based column and intrinsic viscosity ([η]) measurement, for native proteins and those reduced in sodium dodecyl sulphate (SDS) or guanidine hydrochloride (Gu-HCl). In solutions of 6M Gu-HCl, proteins in their reduced state behaved hydrodynamically as randomly coiled linear homopolymers and exhibited good linearity between an