Yu Koyama

Prof. Dr. Yu Koyama

Niigata University Graduate School of Health Sciences, Niigata, Japan
orcid

Research Focus & Metrics

Academic Career Length

24Years (2003-Present)

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

Representative Publications

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1 December 2003 in Clinical Breast Cancer
Verified
Journal Article
Closed access
YKYu Koyama
Yu Koyama
KKKouji Kaneko
Kouji Kaneko
KAKohei Akazawa
Kohei Akazawa
CKChizuko Kanbayashi
Chizuko Kanbayashi
TKTatsuo Kanda
Tatsuo Kanda
KHKatsuyoshi Hatakeyama
Katsuyoshi Hatakeyama

27 October 2018 in Nutrients
Verified
Journal Article
Open access
PDF file
HAHansani Madushika Abeywickrama
Hansani Madushika Abeywickrama
YKYu Koyama
Yu Koyama
MUMieko Uchiyama
Mieko Uchiyama
USUtako Shimizu
Utako Shimizu
YIYuka Iwasa
Yuka Iwasa
YMYuta Mitobe
Yuta Mitobe
Micronutrients include vitamins, minerals and, trace elements that are required in minute quantities but play a vital role in normal human growth, development and physiological functioning. Micronutrient deficiencies, also known as hidden hunger, are a global issue, with particularly high prevalence rates in developing countries. Currently, Sri Lanka is experiencing the double burden of over- and undernutrition. This review describes the micronutrient status of Sri Lanka based on results of national surveys and related articles published from 2000. The available data suggest a higher prevalence of iron, zinc, calcium, folate, and vitamin A deficiencies. The prevalence of iodine deficiency has declined gradually following the implementation of a universal salt iodization program. Iron deficiency is the most common cause of anemia and low red blood cell indices. Females are more vulnerable to micronutrient deficiencies than males. The coexistence of multiple micronutrient deficiencies and concurrent macro- and micronutrient deficiencies is common. Studies have shown an association between micronutrient deficiencies and different demographic, socioeconomic, and dietary factors. Therefore, there is a need for comprehensive studies, nutritional policies, and nationwide intervention programs in Sri Lanka to improve the micronutrient status of the population.

1 January 2019 in Journal of Clinical Medicine Research
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Journal Article
Open access
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YMYuta Mitobe
Yuta Mitobe
SMShinichiro Morishita
Shinichiro Morishita
KOKazuki Ohashi
Kazuki Ohashi
SSSayuri Sakai
Sayuri Sakai
MUMieko Uchiyama
Mieko Uchiyama
YKYu Koyama
Yu Koyama
Skeletal Muscle Index at Intensive Care Unit Admission Is a Predictor of Intensive Care Unit-Acquired Weakness in Patients With Sepsis

7 August 2023 in Nutrition Reviews
Verified
Journal Article
Open access
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HAHansani Madushika Abeywickrama
Hansani Madushika Abeywickrama
MUMieko Uchiyama
Mieko Uchiyama
TSTomoko Sumiyoshi
Tomoko Sumiyoshi
AOAkiko Okuda
Akiko Okuda
YKYu Koyama
Yu Koyama
Background: Zinc (Zn) deficiency, malnutrition, sarcopenia, and frailty are prevalent among older adults and are prominent factors contributing to disability and mortality. Objective: This scoping review was conducted to aid understanding of the extent and types of research addressing the role of Zn in nutritional status, sarcopenia, and frailty, among older individuals. Method: A systematic search was performed in August 2022 of 3 electronic databases (PubMed, Web of Science, and ProQuest) using predefined search terms. The review was conducted referring to the Arksey and O’Malley framework and PRISMA-ScR. Results: The search retrieved 16 018 records, and a total of 49 studies were included in this review after the screening. Of those, 30 were based on dietary Zn intake, 18 on tissue Zn levels, and 1 on both. Most studies were based on cross-sectional data from community-dwelling older adults. Studies addressing the associations between Zn status and individual anthropometric and sarcopenia-related variables reported inconsistent results. However, most studies reported inverse associations between malnutrition, frailty, and Zn status. Conclusion: There was more consistent evidence of the relationship of Zn status with malnutrition, sarcopenia, and frailty rather than with individual nutritional parameters. Validated screening and assessment tools and criteria and prospective studies are required to elucidate the relationship of Zn with sarcopenia and frailty in the older population.

HAHansani Madushika Abeywickrama
Hansani Madushika Abeywickrama
SWSwarna Wimalasiri
Swarna Wimalasiri
YKYu Koyama
Yu Koyama
MUMieko Uchiyama
Mieko Uchiyama
USUtako Shimizu
Utako Shimizu
NNNishantha Nanayakkara
Nishantha Nanayakkara
Symptom burden and health-related quality of life (HRQOL) are important predictors of how a disease affects patients’ lives, especially for endemic health problems such as chronic kidney disease of uncertain etiology (CKDu). Our study describes symptom burden, HRQOL, and associated demographic and clinical variables in CKDu patients in the Girandurukotte area, Sri Lanka. A cross-sectional study included 120 CKDu patients attending the renal clinic in the endemic area. The instruments applied were the Kidney Disease Quality of Life—Short Form (KDQOL-SFTM) version 1.3 and CKD Symptom Index—Sri Lanka. Socio-demographic, disease-related, and anthropometric variables were also investigated. The mean age of patients was 61.87 (SD 11.31), while 69.2% were male. The mean glomerular filtration rate was 28.17 (SD 14.03) mL/min/1.73 min2, and 70.8% were anemic. Bone/joint pain was the most experienced symptom while the median number of symptoms reported by patients was 5 (IQR 3–7). The mean symptom burden, physical component summary, mental component summary, and kidney-disease-specific component scores were 12.71 (SD 10.45), 68.63 (SD 19.58), 78.53 (SD 18.78), and 81.57 (SD 5.86), respectively. Age was found to be a significant predictor of HRQOL, while hemoglobin level and being a farmer were significant predictors of symptom burden. Our data indicate that CKDu patients in all stages experience at least one symptom affecting all aspects of HRQOL.

3 September 2013 in Nutrients
Verified
Journal Article
Open access
PDF file
KKKazuaki Kobayashi
Kazuaki Kobayashi
YKYu Koyama
Yu Koyama
SKShin-Ichi Kosugi
Shin-Ichi Kosugi
TITakashi Ishikawa
Takashi Ishikawa
KSKaoru Sakamoto
Kaoru Sakamoto
TWToshifumi Wakai
Toshifumi Wakai
We retrospectively examined esophageal cancer patients who received enteral nutrition (EN) to clarify the validity of early EN compared with delayed EN. A total of 103 patients who underwent transthoracic esophagectomy with three-field lymphadenectomy for esophageal cancer were entered. Patients were divided into two groups; Group E received EN within postoperative day 3, and Group L received EN after postoperative day 3. The clinical factors such as days for first fecal passage, the dose of postoperative albumin infusion, differences of serum albumin value between pre- and postoperation, duration of systematic inflammatory response syndrome (SIRS), incidence of postoperative infectious complication, and use of total parenteral nutrition (TPN) were compared between the groups. The statistical analyses were performed using Mann-Whitney U test and Chi square test. The statistical significance was defined as p < 0.05. Group E showed fewer days for the first fecal passage (p < 0.01), lesser dose of postoperative albumin infusion (p < 0.01), less use of TPN (p < 0.01), and shorter duration of SIRS (p < 0.01). However, there was no significant difference in postoperative complications between the two groups. Early EN started within 3 days after esophagectomy. It is safe and valid for reduction of albumin infusion and TPN, for promoting early recovery of intestinal movement, and for early recovery from systemic inflammation.