SHIKIMOTO Ryo

写真a

Affiliation

School of Medicine, Center for Supercentenarian Medical Research Center for Supercentenarian Medical Research (Shinanomachi)

Position

Senior Assistant Professor (Non-tenured)/Assistant Professor (Non-tenured)

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Books 【 Display / hide 】

  • Association between dietary fish and PUFA intake in midlife and Dementia in later life: The JPHC Saku mental health study

    Nozaki S., Sawada N., Matsuoka Y.J., Shikimoto R., Mimura M., Tsugane S., Handbook of Prevention and Alzheimer's Disease, 2024.02

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    Background: The relationship between midlife dietary habits and risk of dementia remains unclear. Objective: To investigate the association between dietary fish and n-3 polyunsaturated fatty acid (PUFA) consumption in midlife and risk of dementia in later life. Methods: This population-based cohort study assessed food frequency (average intake in 1995 and 2000) and cognition (2014-2015) in 1,127 participants (aged 45-64 in 1995). We used logistic regression analyses to calculate odds ratios (ORs) for dementia and mild cognitive impairment (MCI) diagnoses for consumption quartiles of fish, PUFA-rich fish, total n-3 PUFAs, total n-6 PUFAs, types of PUFAs, and n-3/n-6 PUFA ratio. Estimated ORs were adjusted for age; sex; education; smoking status; alcohol consumption frequency; physical activity; histories of cancer, myocardial infarction, and diabetes mellitus; and depression. Results: Significantly reduced risks of dementia over non-dementia (MCI plus cognitively normal) were observed in the second (OR = 0.43 (95% CI = 0.20-0.93), third (OR = 0.22 (95% CI = 0.09-0.54), and highest quartiles (OR = 0.39 (95% CI = 0.18-0.86) for fish; the third (OR = 0.39 (95% CI = 0.16-0.92) and highest quartiles (OR = 0.44 (95% CI = 0.19-0.98) for eicosapentaenoic acid (EPA); the second (OR = 0.39 (95% CI = 0.18-0.84), third (OR = 0.30 (95% CI = 0.13-0.70), and highest quartiles (OR = 0.28 (95% CI = 0.12-0.66) for docosahexaenoic acid (DHA); and the third (OR = 0.36 (95% CI = 0.16-0.85) and highest quartiles (OR = 0.42 (95% CI = 0.19-0.95) for docosapentaenoic acid (DPA). Conclusion: High intake of fish in midlife might aid in preventing dementia.

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Papers 【 Display / hide 】

  • Amyloid-β prediction machine learning model using source-based morphometry across neurocognitive disorders

    Momota Y., Bun S., Hirano J., Kamiya K., Ueda R., Iwabuchi Y., Takahata K., Yamamoto Y., Tezuka T., Kubota M., Seki M., Shikimoto R., Mimura Y., Kishimoto T., Tabuchi H., Jinzaki M., Ito D., Mimura M.

    Scientific Reports (Scientific Reports)  14 ( 1 )  2024.12

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    Previous studies have developed and explored magnetic resonance imaging (MRI)-based machine learning models for predicting Alzheimer’s disease (AD). However, limited research has focused on models incorporating diverse patient populations. This study aimed to build a clinically useful prediction model for amyloid-beta (Aβ) deposition using source-based morphometry, using a data-driven algorithm based on independent component analyses. Additionally, we assessed how the predictive accuracies varied with the feature combinations. Data from 118 participants clinically diagnosed with various conditions such as AD, mild cognitive impairment, frontotemporal lobar degeneration, corticobasal syndrome, progressive supranuclear palsy, and psychiatric disorders, as well as healthy controls were used for the development of the model. We used structural MR images, cognitive test results, and apolipoprotein E status for feature selection. Three-dimensional T1-weighted images were preprocessed into voxel-based gray matter images and then subjected to source-based morphometry. We used a support vector machine as a classifier. We applied SHapley Additive exPlanations, a game-theoretical approach, to ensure model accountability. The final model that was based on MR-images, cognitive test results, and apolipoprotein E status yielded 89.8% accuracy and a receiver operating characteristic curve of 0.888. The model based on MR-images alone showed 84.7% accuracy. Aβ-positivity was correctly detected in non-AD patients. One of the seven independent components derived from source-based morphometry was considered to represent an AD-related gray matter volume pattern and showed the strongest impact on the model output. Aβ-positivity across neurological and psychiatric disorders was predicted with moderate-to-high accuracy and was associated with a probable AD-related gray matter volume pattern. An MRI-based data-driven machine learning approach can be beneficial as a diagnostic aid.

  • Serum high-sensitivity C-reactive protein and dementia in a community-dwelling Japanese older population (JPSC-AD)

    Tachibana A., Iga J.I., Ozaki T., Yoshida T., Yoshino Y., Shimizu H., Mori T., Furuta Y., Shibata M., Ohara T., Hata J., Taki Y., Mikami T., Maeda T., Ono K., Mimura M., Nakashima K., Takebayashi M., Ninomiya T., Ueno S.I., Honda T., Akiyama M., Nakaji S., Murashita K., Sawada K., Yokoyama S., Ishizuka N., Akasaka H., Terayama Y., Yonezawa H., Takahashi J., Noguchi-Shinohara M., Iwasa K., Yuki-Nozaki S., Yamada M., Bun S., Niimura H., Shikimoto R., Kida H., Fukada Y., Kowa H., Nakano T., Wada K., Kishi M., Ishikawa T., Yuki S., Fukuhara R., Koyama A., Hashimoto M., Ikeda M., Kokubo Y., Uchida K., Esaki M., Tatewaki Y., Thyreau B., Yonemoto K., Yoshida H., Muto K., Inoue Y., Ri I., Momozawa Y., Terao C., Kubo M., Kiyohara Y.

    Scientific Reports 14 ( 1 )  2024.12

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    In recent years, the association between neuroinflammatory markers and dementia, especially Alzheimer’s disease (AD), has attracted much attention. However, the evidence for the relationship between serum-hs-CRP and dementia including AD are inconsistent. Therefore, the relationships of serum high-sensitivity CRP (hs-CRP) with dementia including AD and with regions of interest of brain MRI were investigated. A total of 11,957 community residents aged 65 years or older were recruited in eight sites in Japan (JPSC-AD Study). After applying exclusion criteria, 10,085 participants who underwent blood tests and health-related examinations were analyzed. Then, serum hs-CRP levels were classified according to clinical cutoff values, and odds ratios for the presence of all-cause dementia and its subtypes were calculated for each serum hs-CRP level. In addition, the association between serum hs-CRP and brain volume regions of interest was also examined using analysis of covariance with data from 8614 individuals in the same cohort who underwent brain MRI. After multivariable adjustment, the odds ratios (ORs) for all-cause dementia were 1.04 (95% confidence interval [CI] 0.76–1.43), 1.68 (95%CI 1.08–2.61), and 1.51 (95%CI 1.08–2.11) for 1.0–1.9 mg/L, 2.0–2.9 mg/L, and ≥ 3.0 mg/L, respectively, compared to < 1.0 mg/L, and those for AD were 0.72 (95%CI 0.48–1.08), 1.76 (95%CI 1.08–2.89), and 1.61 (95%CI 1.11–2.35), for 1.0–1.9 mg/L, 2.0–2.9 mg/L, and ≥ 3.0 mg/L, respectively, compared to < 1.0 mg/L. Multivariable-adjusted ORs for all-cause dementia and for AD prevalence increased significantly with increasing serum hs-CRP levels (p for trend < 0.001 and p = 0.001, respectively). In addition, the multivariable-adjusted temporal cortex volume/estimated total intracranial volume ratio decreased significantly with increasing serum hs-CRP levels (< 1.0 mg/L 4.28%, 1.0–1.9 mg/L 4.27%, 2.0–2.9 mg/L 4.29%, ≥ 3.0 mg/L 4.21%; p for trend = 0.004). This study’s results suggest that elevated serum hs-CRP levels are associated with greater risk of presence of dementia, especially AD, and of temporal cortex atrophy in a community-dwelling Japanese older population.

  • Glucose metabolism and smaller hippocampal volume in elderly people with normal cognitive function

    Shima A., Noguchi-Shinohara M., Shibata S., Usui Y., Tatewaki Y., Thyreau B., Hata J., Ohara T., Honda T., Taki Y., Nakaji S., Maeda T., Mimura M., Nakashima K., Iga J.I., Takebayashi M., Nishijo H., Ninomiya T., Ono K., Kiyohara Y., Kubo M., Terao C., Momozawa Y., Ri I., Inoue Y., Muto K., Yoshida H., Yonemoto K., Esaki M., Uchida K., Kokubo Y., Ikeda M., Hashimoto M., Koyama A., Fukuhara R., Yuki S., Ishikawa T., Ueno S.I., Yoshino Y., Tachibana A., Ozaki T., Kishi M., Wada K., Nakano T., Kowa H., Fukada Y., Kida H., Shikimoto R., Niimura H., Bun S., Yamada M., Yuki-Nozaki S., Iwasa K., Takahashi J., Yonezawa H., Terayama Y., Akasaka H., Ishizuka N., Misawa M., Jung S., Mikami T., Murashita K., Akiyama M., Shibata M.

    npj Aging 10 ( 1 )  2024.12

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    We investigated associations of glycemic measures, and insulin resistance and secretion measures with hippocampal and subfield volumes. In this cross-sectional study, 7400 community-dwelling participants underwent brain MRI and health checkups between 2016 and 2018. Hemoglobin A1c (HbA1c), glycated albumin (GA), homeostasis model assessment for insulin resistance (HOMA-IR), and HOMA of percent β-cell function (HOMA-β) were evaluated. The associations of each measure with a smaller volume of the hippocampus and twelve hippocampal subfields were investigated. As a result, higher HbA1c or GA and lower HOMA-β levels were significantly associated with smaller volumes in multiple hippocampal subfields. Furthermore, even when we analyzed non-diabetic individuals, substantial associations remained between higher GA or lower HOMA-β levels and smaller volumes of the whole hippocampus or the fimbria. Our findings indicate that postprandial glucose fluctuations, postprandial hyperglycemia, and low insulin secretion have a specific effect on the development of smaller hippocampal volume, suggesting that primary prevention of diabetes and/or sufficient glucose control are important for the prevention of dementia.

  • Can the clinical sign “head-turning sign” and simple questions in “Neucop-Q” predict amyloid β pathology?

    Daté Y., Bun S., Takahata K., Kubota M., Momota Y., Iwabuchi Y., Tezuka T., Tabuchi H., Seki M., Yamamoto Y., Shikimoto R., Mimura Y., Hoshino T., Kurose S., Shimohama S., Suzuki N., Morimoto A., Oosumi A., Hoshino Y., Jinzaki M., Mimura M., Ito D.

    Alzheimer's Research and Therapy 16 ( 1 )  2024.12

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    Background: To establish simple screening tests to suspect Alzheimer’s disease (AD) pathology, the clinical sign “head-turning sign” (HTS), which is a patient’s behavior of turning their head towards their partner to seek assistance with questions posed by the examiner during the interview, and the simple screening questionnaire for dementia named “Neucop-Q” were validated in participants diagnosed with amyloid and tau positron emission tomography (PET). Methods: We enrolled 155 patients: 47 cognitive normal, 36 with mild cognitive impairment, 64 with dementia, and 8 with psychiatric disorders. All participants underwent Neucop-Q [three questions: Consciousness/self-awareness of cognitive disabilities (C) normal/impaired (nor/imp), Pleasure/pastime (P) nor/imp, and News/knowledge on current topics (N) nor/imp] and amyloid/tau PET. Additionally, we measured plasma amyloid β (Aβ) 42/40 ratio, phosphorylated tau 181 (pTau181), glial fibrillary acidic protein (GFAP), and neurofilament light (NFL) levels and compared with HTS and Neucop-Q results. Results: The specificity and positive predictive value (PPV) of HTS positivity (HTSpos) were the highest (amyloid PET: 0.930 and 0.870, tau PET: 0.944 and 0.957, respectively), while Cimp and Nimp had a high negative predictive value (NPV) for amyloid PET (negativity) (0.750 and 0.725). Pimp showed high specificity for predicting non-AD tau positivity among non-AD participants without amyloid PET positivity (0.854). To validate these findings with PET results, we examined the correlation between well-established AD blood biomarkers and results obtained from these screening tests. HTSpos, Cimp, and Nimp were strongly associated with Aβ42/40 ratio (P < 0.0001, P = 0.0022, and P = 0.001), pTau181 (P < 0.0001, P = 0.0095, and P = 0.001), GFAP (P = 0.0372, P = 0.0088, and P = 0.0002), and amyloid PET Centiloid (P < 0.0001, P = 0.0210, and P = 0.0006), whereas Pimp increased neuroinflammation (GFAP; P = 0.0061) and was associated with non-AD tauopathy. The combination of Neucop-Q questions showed that Cimp/Pnor/Nimp subjects have the highest specificity and PPV (0.972 and 0.833) and were strongly associated with Aβ42/40 ratio (P = 0.0006), pTau181 (P = 0.0006), and amyloid PET Centiloid (P < 0.0001). Conclusion: HTSpos, Cimp, and Nimp have diagnostic utility in suspecting MCI due to AD and AD, and Pimp has diagnostic value in non-AD tauopathy. HTSpos, Cimp, and Nimp were associated with biomarkers of Aβ pathology. HTS and Neucop-Q may serve as powerful first-line screening in memory clinics. Trial registration: UMIN Clinical Trials Registry (UMIN-CTR) under registration numbers 000032027 (Registration date: 2018/03/31) and 000030248 (Registration date: 2018/01/01).

  • Relationship Between Life Satisfaction and Psychological Characteristics Among Community-Dwelling Oldest-old: Focusing on Erikson's Developmental Stages and the Big Five Personality Traits

    Kida H., Niimura H., Eguchi Y., Suzuki K., Shikimoto R., Bun S., Takayama M., Mimura M.

    American Journal of Geriatric Psychiatry (American Journal of Geriatric Psychiatry)  32 ( 6 ) 724 - 735 2024.06

    ISSN  10647481

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    Objective: To clarify the relationship between life satisfaction and the psychological characteristics of the oldest-old, and explore the factors for achieving mental health and longevity. Design: This cross-sectional study conducted questionnaire surveys and face-to-face interviews as part of a larger prospective cohort study. Setting: Arakawa Ward, a district in Tokyo, Japan. Participants: A total of 247 oldest-old individuals from two age groups, 85+ (aged 85–87 years) and 95+ (aged 95 years or older). Measurements: Life satisfaction was assessed using the Satisfaction with Life Scale (SWLS), developmental stages of the elderly (Erikson's 8th and 9th stages, i.e., ego integrity, and gerotranscendence), and the Big Five personality traits (extraversion, agreeableness, openness, conscientiousness, and neuroticism) using the NEO-Five Factor Inventory. Multiple regression analyses were performed to examine the relationship between the SWLS scores and each assessment, controlling for age, sex, education, activities of daily living, depressive symptoms, and cognitive function. Results: The SWLS scores of 85+ were positively correlated with scores of ego integrity, extraversion, and conscientiousness. Contrastingly, the SWLS scores of 95+ were positively correlated with gerotranscendence scores. Conclusions: Psychological characteristics associated with the level of life satisfaction among community-dwelling oldest-old individuals were identified, but a causal relationship between these factors and life satisfaction was not established. Ego integrity, extraversion, conscientiousness, and gerotranscendence may be associated with enhanced life satisfaction and mental health in the oldest-old. Further, the factors associated with life satisfaction in the 85+ and 95+ age groups varied, suggesting that life satisfaction among the oldest-old has different foundations in different age groups.

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Papers, etc., Registered in KOARA 【 Display / hide 】

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Research Projects of Competitive Funds, etc. 【 Display / hide 】

  • 90歳を超え良好な認知機能を持つスーパーエイジャーの脳神経基盤とライフスタイル

    2024.04
    -
    2027.03

    若手研究, Principal investigator

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Courses Taught 【 Display / hide 】

  • GERIATRICS & ELDERLY SPORTS MEDICINE

    2024

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