Shotaro Miyamoto

Dr. Shotaro Miyamoto


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

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

Representative Publications

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16 September 2022 in Medicines
Verified
Journal Article
Open access
PDF file
YOYoshinori Ozeki
Yoshinori Ozeki
TMTakayuki Masaki
Takayuki Masaki
AKAkari Kamata
Akari Kamata
SMShotaro Miyamoto
Shotaro Miyamoto
YYYuichi Yoshida
Yuichi Yoshida
HSHirotaka Shibata
Hirotaka Shibata
Background and Objectives: This study aimed to investigate the changes in obesity severity, glucose metabolism, and body composition in patients with obesity and type 2 diabetes mellitus treated with glucagon-like peptide 1 receptor agonist (GLP1-RA) semaglutide. Materials and Methods: Body weight (BW), metabolic parameters, and body composition were examined before and 3 months after semaglutide administration. The mass of body fat (FM), fat weight percentage (%FM), mass of skeletal muscle (MM), skeletal MM percentage (%MM), and limb muscles were measured using the bioelectrical impedance method. Results: Semaglutide dramatically reduced the weight, the body mass index (BMI), and the levels of the glucose metabolic markers, including fasting blood glucose and hemoglobin A1c, and accelerated the loss of excess BW. FM, MM, and %FM after semaglutide treatment also decreased. Conversely, semaglutide had no effect on the %MM after 3 months. In limb muscle analyses, right upper and lower leg muscle percentages, left upper and lower leg muscles, and the ratios of the lower/upper muscles were maintained by semaglutide treatment. Conclusions: These results suggest that the GLP1-RA semaglutide effectively reduces body adiposity while maintaining the MM in obese type 2 diabetic patients.

4 March 2021 in Diagnostics
Verified
Journal Article
Open access
PDF file
YOYoshinori Ozeki
Yoshinori Ozeki
YTYukie Tanimura
Yukie Tanimura
SNSatoshi Nagai
Satoshi Nagai
TNTakuya Nomura
Takuya Nomura
MKMizuki Kinoshita
Mizuki Kinoshita
HSHirotaka Shibata
Hirotaka Shibata
In the present study, we developed a new chemiluminescent enzyme immunoassay (CLEIA) using a two-step sandwich method to measure aldosterone concentrations. We investigated serum and plasma aldosterone concentrations in 75 blood samples from 27 patients using a radioimmunoassay (RIA) and the CLEIA (with current and newly improved reagents) as well as liquid chromatography-tandem mass spectrometry (LC-MS/MS). Based on the results of the Passing–Bablok regression analysis, the aldosterone levels measured using CLEIA with the new reagents and those measured by LC-MS/MS were found to be significantly correlated (slope, 0.984; intercept, 0.2). However, aldosterone levels varied depending on the measurement method (i.e., CLEIA with the new reagent, CLEIA with the current reagent, and RIA). Aldosterone levels were lower with the improved CLEIA method than with RIA and CLEIA using the current reagent. Therefore, the cutoff values of the screening test as well as those of the confirmatory test for primary aldosteronism (PA) should be adjusted to follow current clinical practice guidelines for PA. The formula that can be used to obtain the aldosterone level (pg/mL) when using CLEIA with the new reagent is 0.765 × RIA (pg/mL) − 33.7. This formula will enable PA cutoff values to be set for provisional screening and confirmatory tests.

4 February 2022 in Metabolites
Verified
Journal Article
Open access
PDF file
TMTakayuki Masaki
Takayuki Masaki
YOYoshinori Ozeki
Yoshinori Ozeki
YYYuichi Yoshida
Yuichi Yoshida
MOMitsuhiro Okamoto
Mitsuhiro Okamoto
SMShotaro Miyamoto
Shotaro Miyamoto
HSHirotaka Shibata
Hirotaka Shibata
We evaluated time-course changes and the relationship between eating behavior and glycemic profile during the treatment of 34 obese type 2 diabetic patients with the glucagon-like peptide-1 receptor agonist (GLP1-RA) semaglutide. Changes in dietary habits were evaluated using the Japan Society for the Study of Obesity questionnaire. Semaglutide improved body weight and hemoglobin A1C (HbA1c) 3 and 6 months after treatment. In addition, semaglutide led to marked improvements in the total scores for eating behavior items on the questionnaire. In particular, changes in the scores regarding the sensation of hunger, food preference, eating style, regularity of eating habits and emotional eating behavior were significantly improved during semaglutide treatment. By contrast, there were no significant changes in the scores for the recognition of weight and constitution and external eating behavior. Furthermore, changes in the scores regarding the sensation of hunger and food preference were correlated with changes in HbA1c after semaglutide treatment. Multivariable regression analyses showed that the change in the sensation of hunger was related to HbA1c during treatment. In conclusion, the GLP1-RA semaglutide regulates eating behavior, and, in particular, the sensation of hunger is closely related to the improvement in HbA1c by semaglutide in obese patients with type 2 diabetes.

18 November 2024 in Nutrients
Verified
Journal Article
Open access
PDF file
YOYoshinori Ozeki
Yoshinori Ozeki
TMTakayuki Masaki
Takayuki Masaki
SMShotaro Miyamoto
Shotaro Miyamoto
YYYuichi Yoshida
Yuichi Yoshida
MOMitsuhiro Okamoto
Mitsuhiro Okamoto
HSHirotaka Shibata
Hirotaka Shibata
Background and Objectives: We analyzed the changes in obesity, glucose metabolism, and body composition over a 3-year period in Japanese patients with obesity following laparoscopic sleeve gastrectomy (LSG). Methods: Body weight, parameters related to diabetes such as glycated hemoglobin (HbA1c), and electrical impedance analysis were used to assess body composition in forty-eight Japanese patients with obesity before surgery and 6 months, 1 year, 2 years, and 3 years after LSG. Results: At 6 months, 1, 2, and 3 years post-LSG, there were significant reductions in body weight, body mass index, blood pressure, fasting plasma glucose, triglyceride, and HbA1c levels. Six months after LSG, fat mass (FM), muscle mass (MM), and %FM all showed a decrease compared to pre-treatment values (all p < 0.05). FM and %FM remained in a decreased state until 3 years had passed. In contrast, %MM increased at 6 months post-LSG and was maintained up to 3 years post-LSG (all p < 0.05). Furthermore, changes in FM and %FM were associated with changes in body weight and A1C. In contrast, change in %MM exhibited a negative correlation with body weight and A1C following LSG. Finally, multivariate regression analyses demonstrated that alterations in FM were independent factors affecting body weight in patients with obesity 3 years after LSG. Conclusions: We observed improvements in FM, fasting plasma glucose, and HbA1c levels over a 3-year period in Japanese patients after LSG. The reduction in FM and maintenance of %MM after LSG were suggested as possible links between the effects of LSG on obesity and diabetes over 3 years.

16 November 2025 in Nutrients
Verified
Journal Article
Open access
PDF file
NMNaoki Matsuda
Naoki Matsuda
YYYuichi Yoshida
Yuichi Yoshida
KGKoro Gotoh
Koro Gotoh
SNSatoshi Nagai
Satoshi Nagai
RKRyo Kurimoto
Ryo Kurimoto
HSHirotaka Shibata
Hirotaka Shibata
Background/Objectives: Sleeve gastrectomy (SG) is the most commonly performed bariatric surgery worldwide. It results in significant weight loss and improves metabolic disorders such as hypertension. Weight loss is thought to be the main factor contributing to blood pressure (BP) reduction after SG. Small-intestinal hormones may also mediate the antihypertensive effects of SG. We aimed to investigate the mechanisms underlying the antihypertensive effects of SG through small-intestinal hormones independently of weight loss. Methods: This study involved male Sprague–Dawley rats that underwent a sham operation or SG, followed by a dietary intervention involving a standard diet, a high-fat and high-salt diet, or pair-feeding with SG. Results: Three weeks postoperatively, SG significantly reduced systolic blood pressure (SBP) and increased urinary sodium excretion. RNA sequencing of the small intestine revealed upregulation of the gene encoding prouroguanylin (proUGN). proUGN is a small-intestinal hormone that inhibits renal sodium reabsorption by converting sodium/hydrogen ion exchanger type 3 (NHE3) in the proximal tubules into the inactive phosphorylated form at Ser552 (pS552-NHE3). Furthermore, SG significantly increased proUGN levels in the ileum and plasma, as well as the levels of pS552-NHE3 in the renal cortex. The administration of exogenous uroguanylin, which is converted from proUGN, resulted in increased renal pS552-NHE3, increased urinary sodium excretion, and decreased SBP without body weight reduction. These effects were similar to those observed with SG. Conclusions: SG increases proUGN secretion from the small intestine, leading to increased blood concentration. This inhibits NHE3 activity in the proximal tubules, promotes natriuresis and reduces BP.

Verified
Journal Article
Open access
PDF file
TNTakaaki Noguchi
Takaaki Noguchi
YYYuichi Yoshida
Yuichi Yoshida
KGKoro Gotoh
Koro Gotoh
SNSatoshi Nagai
Satoshi Nagai
KSKentaro Sada
Kentaro Sada
HSHirotaka Shibata
Hirotaka Shibata
A high-fat diet (HFD) can lead to obesity and skeletal muscle atrophy. Sleeve gastrectomy (SG) improves obesity and increases skeletal muscle mass. This study examined whether SG prevented skeletal muscle atrophy in a diet-induced rat obesity rat model. First, 8-week-old male Sprague-Dawley rats underwent surgical (sham-operated or SG) and dietary (standard, high-fat diet, or same pair feeding as SG [PF]) interventions without exercise. In the second experiment, treadmill exercise was added for 4 weeks post-SG (SG + Ex). In the third experiment, rats received an adiponectin receptor agonist (AdipoRon) injection. The HFD induced weight gain and decreased muscle fiber area. SG + Ex reversed these levels, followed by increases in adiponectin in the blood and skeletal muscle and myoblast determination protein 1 (MyoD) and decreased peri-muscular adipose tissue (PMAT) mass, but SG alone did not. No similar changes were observed in the PF group, with or without exercise. Injection of AdipoRon had a similar effect on skeletal muscle and PMAT as SG + Ex. The combination of SG and exercise, but not calorie restriction alone, had better impacts on skeletal muscle and PMAT than SG or exercise alone.