Kazushige Ihara

Prof. Kazushige Ihara


Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

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

Representative Publications

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KMKeiko Motokawa
Keiko Motokawa
YMYurie Mikami
Yurie Mikami
MSMaki Shirobe
Maki Shirobe
AEAyako Edahiro
Ayako Edahiro
YOYuki Ohara
Yuki Ohara
HHHirohiko HIRANO
Hirohiko HIRANO
Objectives: This study aimed to determine the relationship between objective chewing ability and the nutritional status of Japanese community-dwelling elders. Design: A cross-sectional study. Participants: A total of 509 community-dwelling elders living in the Tokyo metropolitan area participated in a comprehensive survey conducted in October 2013. Measurements: The basic characteristics were sex, age, and body mass index. Undernutrition was examined through serum albumin levels. Chewing ability was examined through color-changeable xylitol gum by evaluating the color changes in chewing gum. Nutritional intake was examined using the semi-quantitative food frequency questionnaire. Results: In the poor chewing ability group, all nutrient intake levels were significantly low, except for carbohydrates, and intake levels for all food groups were significantly low, except for cereals, confectionery, sugars, seasonings, and spices. Additionally, after adjusting for covariates for sex, age, Tokyo Metropolitan Institute of Gerontology-Index of Competence (TMIG-IC) score, Mini-Mental State Examination (MMSE) score, body mass index (BMI), stroke, number of functional teeth, energy intake, and protein intake, chewing ability was found to be significantly associated with undernutrition. Conclusion: We concluded that chewing ability was closely associated with nutrient and different food groups’ intake, as well as undernutrition, among Japanese community-dwelling elders. Thus, to ensure comprehensive nutritional management, nutritionists and dentists should collaborate when treating the same patients.

Yoshihiro KugimiyaYoshihiro Kugimiya
Yoshihiro Kugimiya
MIMasanori Iwasaki
Masanori Iwasaki
YOYuki Ohara
Yuki Ohara
KMKeiko Motokawa
Keiko Motokawa
AEAyako Edahiro
Ayako Edahiro
HHHirohiko HIRANO
Hirohiko HIRANO
Oral hypofunction, resulting from a combined decrease in multiple oral functions, may affect systemic-condition deterioration; however, few studies have examined the association between oral hypofunction and general health among older adults. In this cross-sectional study, we examined the relationship between oral hypofunction and sarcopenia in community-dwelling older adults. We included 878 adults (268 men and 610 women, mean age 76.5 ± 8.3 years). Tongue coating index, oral moisture, occlusal force, oral diadochokinesis (/pa/,/ta/,/ka/), tongue pressure, mas-ticatory function, and swallowing function were evaluated as indicators of oral hypofunction. Grip strength, gait speed, and skeletal muscle mass index were measured as diagnostic sarcopenia parameters. The association between oral hypofunction and sarcopenia was examined via logistic regression using sarcopenia as the dependent variable. Oral hypofunction prevalence was 50.5% overall, 40.3% in men, and 54.9% in women. The prevalence of sarcopenia was 18.6% overall, 9.7% in men, and 22.5% in women. A logistic regression showed oral hypofunction, age, body mass index, higher-level functional capacity, and serum albumin level were significantly associated with sarcopenia. Sarcopenia occurred at an increased frequency in patients diagnosed with oral hypofunction (odds ratio: 1.59, 95% confidence interval: 1.02–2.47); accordingly, oral hypofunction appears to be significantly associated with sarcopenia.

16 February 2022 in Biology
Verified
Journal Article
Open access
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NONaoki Ozato
Naoki Ozato
TYTohru Yamaguchi
Tohru Yamaguchi
KMKenta Mori
Kenta Mori
MKMitsuhiro Katashima
Mitsuhiro Katashima
MKMika Kumagai
Mika Kumagai
SNShigeyuki Nakaji
Shigeyuki Nakaji
Intestinal microflora has been associated with obesity. While visceral fat is more strongly associated with cardiovascular disorder, a complication linked to obesity, than the body mass index (BMI), the association between intestinal microflora and obesity (as defined in terms of BMI) has been studied widely. However, the link between visceral fat area (VFA) and intestinal microflora has been little studied. In this study, we investigate the association between intestinal microflora and VFA and BMI using a longitudinal study on Japanese subjects with different VFA statuses (N = 767). Principal component analysis of the changes in intestinal microflora composition over the one-year study period revealed the different associations between intestinal microflora and VFA and BMI. As determined by 16S rRNA amplicon sequencing, changes in the abundance ratio of two microbial genera—Blautia and Flavonifractor—were significantly associated with VFA changes and changes in the abundance ratio of four different microbial genera were significantly associated with BMI changes, suggesting that the associated intestinal microbes are different. Furthermore, as determined by metagenomic shotgun sequences, changes in the abundance ratios of two Blautia species—Blautia hansenii and Blautia producta—were significantly and negatively associated with VFA changes. Our findings might be used to develop a new treatment for visceral fat.

19 June 2020 in Nutrients
Verified
Journal Article
Open access
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MMMai Matsumoto
Mai Matsumoto
HSHiroyuki Suganuma
Hiroyuki Suganuma
SSSunao Shimizu
Sunao Shimizu
HHHiroki Hayashi
Hiroki Hayashi
KSKahori Sawada
Kahori Sawada
SNShigeyuki Nakaji
Shigeyuki Nakaji
To confirm the usefulness of noninvasive measurements of skin carotenoids to indicate vegetable intake and to elucidate relationships between skin carotenoid levels and biomarkers of circulatory diseases and metabolic syndrome, we conducted a cross-sectional study on a resident-based health checkup (n = 811; 58% women; 49.5 ± 15.1 years). Skin and serum carotenoid levels were measured via reflectance spectroscopy and high-performance liquid chromatography, respectively. Vegetable intake was estimated using a dietary questionnaire. Levels of 9 biomarkers (body mass index [BMI], brachial-ankle pulse wave velocity [baPWV], systolic and diastolic blood pressure [SBP and DBP], homeostasis model assessment as an index of insulin resistance [HOMA-IR], blood insulin, fasting blood glucose [FBG], triglycerides [TGs], and high-density lipoprotein cholesterol [HDL-C]) were determined. Skin carotenoid levels were significantly positively correlated with serum total carotenoids and vegetable intake (r = 0.678 and 0.210, respectively). In women, higher skin carotenoid levels were significantly associated with lower BMI, SBP, DBP, HOMA-IR, blood insulin, and TGs levels and higher HDL-C levels. In men, it was also significantly correlated with BMI and blood insulin levels. In conclusion, dermal carotenoid level may indicate vegetable intake, and the higher level of dermal carotenoids are associated with a lower risk of circulatory diseases and metabolic syndrome.

1 March 2020 in Archives of Gerontology and Geriatrics
Verified
Journal Article
Closed access
TKTakeshi Kera
Takeshi Kera
HKHisashi Kawai
Hisashi Kawai
HHHirohiko HIRANO
Hirohiko HIRANO
MKMotonaga Kojima
Motonaga Kojima
YWYutaka Watanabe
Yutaka Watanabe
SOShuichi Obuchi
Shuichi Obuchi

23 July 2020 in Scientific Reports
Verified
Journal Article
Open access
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KIKyota Ishibashi
Kyota Ishibashi
ESEiji Sasaki
Eiji Sasaki
SOSeiya Ota
Seiya Ota
DCDaisuke Chiba
Daisuke Chiba
YYYuji Yamamoto
Yuji Yamamoto
YIYasuyuki Ishibashi
Yasuyuki Ishibashi
To investigate synovitis’ influence on early knee osteoarthritis (EKOA) by serum biomarkers and magnetic resonance imaging (MRI) findings in Japanese women. We enrolled 255 women aged 30–70 without radiographic abnormalities (Kellgren–Lawrence grade ≥ 2). Knee injury, OA outcome scores (KOOS), clinical examinations, and standing radiograph were used for classification criteria of EKOA. Participants were classified into normal knee group and EKOA group. All participants underwent MRIs of their right knee. The amount of effusion-synovitis volume was quantified. We compared serum matrix metalloproteinases-3 levels (MMP-3), high-sensitivity C-reactive protein, interleukin-6, and adiponectin between the groups. The relationship between synovitis and EOKA was investigated using multiple linear regression. Fifty-four participants (21%) were classified as EKOA. Serum MMP-3 concentration and effusion-synovitis volume were higher in patients with EKOA (p = 0.025 and p = 0.001, respectively). Effusion-synovitis volume negatively correlated with all KOOS subscales and positively correlated with serum MMP-3 concentration. Serum MMP-3 concentration was associated with effusion-synovitis volume β = 0.60, p < 0.001). There was mildly active but definitive synovitis in EKOA. This was an observational study so that no conclusions can be drawn regarding cause-effect for synovitis and symptoms. Future studies should conduct follow-up of participants with synovitis to assess the progression of knee OA.