研究者業績

飯塚 勝美

イイヅカ カツミ  (Katsumi Iizuka)

基本情報

所属
藤田医科大学 臨床栄養学講座 教授
学位
医学博士(大阪大学)

研究者番号
40431712
ORCID ID
 https://orcid.org/0000-0002-9837-6238
J-GLOBAL ID
200901050808238794
researchmap会員ID
6000005331

栄養関連疾患の発症予防(老化予防)を目指して、過栄養(メタボリック症候群)および低栄養(サルコペニア・フレイル)の予防・重症化抑制に資する栄養療法に関する研究に精力的に取り組んでいます。臨床研究では、遺伝素因や腸内細菌叢を考慮した上で、栄養素摂取と過栄養・低栄養疾患の関連を明らかにし、”体質”を考慮した栄養療法の質の向上につながる研究を推進したいと考えます。基礎研究では、グルコースセンサーChREBP欠失マウス、老化促進マウス、糖尿病性腎症マウスなどを用いて、栄養素と疾患発症(メタボリック症候群、サルコペニア・フレイル)の関連を明らかにし、栄養療法を行う際の基盤となる基礎研究を展開したいと思います。以上から、食事による疾患発症(老化)予防法の開発を目指します。代謝学に基づいて、栄養学を理詰めで考えたい医師、管理栄養士の参加を歓迎します。


主要な学歴

 4

論文

 103
  • Katsumi Iizuka, Kanako Deguchi, Chihiro Ushiroda, Kotone Yanagi, Yusuke Seino, Atsushi Suzuki, Daisuke Yabe, Hitomi Sasaki, Satoshi Sasaki, Eiichi Saitoh, Hiroyuki Naruse
    Nutrients 16(11) 1742 2024年6月  査読有り筆頭著者責任著者
  • Katsumi Iizuka, Kazuko Kobae, Kotone Yanagi, Yoshiko Yamada, Kanako Deguchi, Chihiro Ushiroda, Yusuke Seino, Atsushi Suzuki, Eiichi Saitoh, Hiroyuki Naruse
    Healthcare 2024年2月13日  査読有り筆頭著者責任著者
  • 篠原 彩恵理, 村岡 真理, 石浦 里織, 中村 洸佑, 平野 好, 一丸 智美, 伊藤 明美, 清野 祐介, 鈴木 敦詞, 飯塚 勝美
    日本病態栄養学会誌 27(Suppl.) S-26 2024年1月  
  • 淺井 志歩, 伊藤 明美, 川部 直人, 葛谷 貞二, 清野 祐介, 廣岡 芳樹, 鈴木 敦詞, 飯塚 勝美
    日本病態栄養学会誌 27(Suppl.) S-30 2024年1月  
  • Katsumi Iizuka, Kanako Deguchi
    Frontiers in Endocrinology 14 2023年11月1日  筆頭著者責任著者
  • Katsumi Iizuka, Daisuke Yabe
    Nutrients 15(20) 4314-4314 2023年10月10日  筆頭著者責任著者
  • Shinji Ueno, Yusuke Seino, Shihomi Hidaka, Masashi Nakatani, Keisuke Hitachi, Naoya Murao, Yasuhiro Maeda, Haruki Fujisawa, Megumi Shibata, Takeshi Takayanagi, Katsumi Iizuka, Daisuke Yabe, Yoshihisa Sugimura, Kunihiro Tsuchida, Yoshitaka Hayashi, Atsushi Suzuki
    Journal of diabetes investigation 14(9) 1045-1055 2023年6月9日  
    AIMS/INTRODUCTION: Glucagon is secreted from pancreatic α-cells and plays an important role in amino acid metabolism in liver. Various animal models deficient in glucagon action show hyper-amino acidemia and α-cell hyperplasia, indicating that glucagon contributes to feedback regulation between the liver and the α-cells. In addition, both insulin and various amino acids, including branched-chain amino acids and alanine, participate in protein synthesis in skeletal muscle. However, the effect of hyperaminoacidemia on skeletal muscle has not been investigated. In the present study, we examined the effect of blockade of glucagon action on skeletal muscle using mice deficient in proglucagon-derived peptides (GCGKO mice). MATERIALS AND METHODS: Muscles isolated from GCGKO and control mice were analyzed for their morphology, gene expression and metabolites. RESULTS: GCGKO mice showed muscle fiber hypertrophy, and a decreased ratio of type IIA and an increased ratio of type IIB fibers in the tibialis anterior. The expression levels of myosin heavy chain (Myh) 7, 2, 1 and myoglobin messenger ribonucleic acid were significantly lower in GCGKO mice than those in control mice in the tibialis anterior. GCGKO mice showed a significantly higher concentration of arginine, asparagine, serine and threonine in the quadriceps femoris muscles, and also alanine, aspartic acid, cysteine, glutamine, glycine and lysine, as well as four amino acids in gastrocnemius muscles. CONCLUSIONS: These results show that hyperaminoacidemia induced by blockade of glucagon action in mice increases skeletal muscle weight and stimulates slow-to-fast transition in type II fibers of skeletal muscle, mimicking the phenotype of a high-protein diet.
  • Katsumi Iizuka, Hiroko Sato, Kazuko Kobae, Kotone Yanagi, Yoshiko Yamada, Chihiro Ushiroda, Konomi Hirano, Satomi Ichimaru, Yusuke Seino, Akemi Ito, Atsushi Suzuki, Eiichi Saitoh, Hiroyuki Naruse
    Nutrients 15(9) 2216-2216 2023年5月7日  査読有り筆頭著者責任著者
  • Katsumi Iizuka
    Nutrients 15(7) 1778-1778 2023年4月5日  査読有り招待有り筆頭著者責任著者
  • 劉 彦言, 土田 宏美, 飯塚 勝美, 窪田 創大, 堀川 幸男, 桑田 仁司, 藤原 結花, 清野 祐介, 林 良敬, 清野 裕, 矢部 大介
    糖尿病 66(Suppl.1) S-32 2023年4月  
  • 劉 彦言, 土田 宏美, 飯塚 勝美, 窪田 創大, 堀川 幸男, 桑田 仁司, 藤原 結花, 清野 祐介, 林 良敬, 清野 裕, 矢部 大介
    糖尿病 66(Suppl.1) S-213 2023年4月  
  • 後田 ちひろ, 亀井 優香, 今度 匡祐, 土田 宏美, 清野 祐介, 長尾 静子, 矢部 大介, 鈴木 敦詞, 飯塚 勝美
    糖尿病 66(Suppl.1) S-183 2023年4月  
  • 飯塚 勝美, 土田 宏美, 鷹尾 賢, 劉 彦言, 窪田 創大, 窪田 紗希, 今泉 俊則, 加藤 丈博, 鈴木 渓, 富田 弘之, 堀川 幸男, 矢部 大介
    糖尿病 66(Suppl.1) S-183 2023年4月  
  • Iizuka K, Yabe D, Abu-Farha M, Abubaker J, Al-Mulla F
    Frontiers in endocrinology 14 2023年1月18日  査読有り招待有り筆頭著者責任著者
  • Abu-Farha M, Iizuka K, Yabe D, Al-Mulla F, Abubaker J
    Frontiers in endocrinology 13 2023年1月5日  査読有り招待有り
  • Katsumi Iizuka
    Nutrients 14(21) 4446-4446 2022年10月22日  査読有り招待有り筆頭著者最終著者責任著者
    Artificial sweeteners have been developed as substitutes for sugar. Sucralose, acesulfame K (ACE K), aspartame, and saccharin are artificial sweeteners. Previously, artificial sweeteners were thought to be effective in treating obesity and diabetes. Human meta-analyses have reported that artificial sweeteners have no effect on body weight or glycemic control. However, recent studies have shown that artificial sweeteners affect glucose absorption in the intestinal tract as well as insulin and incretin secretion in humans and animals. Moreover, artificial sweeteners alter the composition of the microbiota and worsen the glycemic control owing to changes in the gut microbiota. The early intake of ACE K was also shown to suppress the taste response to sugar. Furthermore, a large cohort study showed that high artificial sweetener intake was associated with all-cause mortality, cardiovascular risk, coronary artery disease risk, cerebrovascular risk, and cancer risk. The role of artificial sweeteners in the treatment of diabetes and obesity should be reconsidered, and the replacement of sugar with artificial sweeteners in patients will require the long-term tracking of not only intake but also changes in blood glucose and weight as well as future guidance based on gut bacteria data. To utilize the beneficial properties of artificial sweeteners in treatment, further studies are needed.
  • Katsumi Iizuka
    Frontiers in Endocrinology 13 2022年9月13日  査読有り筆頭著者責任著者
  • Katsumi Iizuka, Takuma Ishihara, Mayuka Watanabe, Akemi Ito, Masayoshi Sarai, Ryoji Miyahara, Atsushi Suzuki, Eiichi Saitoh, Hitomi Sasaki
    Nutrients 14(18) 3754 2022年9月11日  査読有り筆頭著者責任著者
    Mobile food records are currently used to determine the nutrition of healthy subjects. To determine the accuracy of such records, we evaluated the nutritional composition of a test meal (noodles and fruit juice) and a hospital meal (Japanese set meal) using two types of mobile food records. Eighteen healthy subjects (2 males and 16 females) were enrolled. Using these diets and validated nutrient-composition information, we evaluated the accuracy of the dietary assessments made by two dietary-record applications, Asken® and Calomeal®, over 5 days. For the test meal, the values provided by the two applications were close to the actual values. In contrast, for the hospital meal, the values provided by the two applications were approximately 1.5 times higher than the actual values. A linear-mixed-model analysis showed that the total energy, carbohydrate, and salt contents were significantly overestimated in the hospital meal. Protein also tended to be overestimated, while the fat content was not significantly overestimated. Furthermore, the total energy and fat contents increased significantly over time. No association with age was observed. A comparison of the coefficients of variation (CVs) for each nutrient in the hospital meal indicated that the fat levels were significantly higher than those in the test meal. In conclusion, the accuracy of mobile food records depends on the type of meal. Our data will provide lessons for the use of meal-recording applications in special cases, such as hospital food.
  • Akira Sumida, Katsumi Iizuka, Takehiro Kato, Yanyan Liu, Sodai Kubota, Saki Kubota-Okamoto, Teruaki Sakurai, Toshinori Imaizumi, Yoshihiro Takahashi, Masami Mizuno, Ken Takao, Takuo Hirota, Tetsuya Suwa, Yukio Horikawa, Mayumi Yamamoto, Yusuke Seino, Atsushi Suzuki, Daisuke Yabe
    BMC endocrine disorders 22(1) 164-164 2022年6月22日  査読有り責任著者
    BACKGROUND: Familial hypocalciuric hypercalcemia (FHH) is a rare autosomal dominant disease, which requires differential diagnosis from relatively common primary hyperparathyroidism (PHPT) in order to avoid unnecessary surgery. CASE PRESENTATION: A 16-year-old female had been followed by the department of psychosomatic medicine at our institution. Throughout the follow-up period, her plasma calcium levels were high, plasma Pi levels were relatively low, and plasma intact PTH was relatively high. She was referred to our department to determine the cause of her hypercalcemia. Her 24 h urinary calcium excretion was as low as 100 mg/day, and calcium creatinine clearance ratio was below 0.01. Moreover, she had a family history of hypercalcemia (proband, her brother, and her father). The genetic testing for her family revealed that she, her brother, and her father were definitively diagnosed with FHH type 1 due to the heterozygous calcium-sensing receptor mutation (NM_00388:4:c.164C > T:p.Pro55Leu). CONCLUSION: We experienced a 16-year-old female with FHH, in whom genetic testing identified the heterozygous calcium-sensing receptor mutation (NM_00388:4:c.164C > T:p.Pro55Leu) as pathogenic, permitting a definitive diagnosis of FHH type 1. The genetic testing for calcium sensing receptor is beneficial to distinguish asymptomatic primary hyperparathyroidism from FHH.
  • 隅田 旭, 飯塚 勝美, 加藤 丈博, 劉 彦言, 窪田 創大, 窪田 紗希, 櫻井 瑛章, 今泉 俊則, 高橋 佳大, 水野 正巳, 鷹尾 賢, 廣田 卓男, 諏訪 哲也, 堀川 幸男, 山本 眞由美, 清野 祐介, 鈴木 敦詞, 矢部 大介
    日本内分泌学会雑誌 98(1) 324-324 2022年4月  
  • 隅田 旭, 飯塚 勝美, 加藤 丈博, 劉 彦言, 窪田 創大, 窪田 紗希, 櫻井 瑛章, 今泉 俊則, 高橋 佳大, 水野 正巳, 鷹尾 賢, 廣田 卓男, 諏訪 哲也, 堀川 幸男, 山本 眞由美, 清野 祐介, 鈴木 敦詞, 矢部 大介
    日本内分泌学会雑誌 98(1) 324-324 2022年4月  
  • Daichi Tsukada, Katsumi Iizuka, Ken Takao, Yanyan Liu, Sodai Kubota, Saki Okamoto-Kubota, Teruaki Sakurai, Toshinori Imaizumi, Mayu Sakai, Takehiro Kato, Masami Mizuno, Takuo Hirota, Tetsuya Suwa, Yukio Horikawa, Mayumi Yamamoto, Sumihisa Kubota, Daisuke Yabe
    Internal medicine (Tokyo, Japan) 61(18) 2753-2757 2022年2月26日  査読有り責任著者
    We treated a 22-year-old woman suffering from Graves' disease and thymic hyperplasia. She was referred to our institution for a close investigation of thyrotoxicosis and thymic mass. Thyroid tests and magnetic resonance imaging resulted in a diagnosis of Graves' disease and thymic hyperplasia. The thyroid function and thyroid-stimulating hormone receptor antibody (TRAb) were normalized one and five months after thiamazole initiation, respectively. The thymic size began to decrease after 1 month and was further decreased after 5 months; it was normalized after 12 months. The correlation between TRAb titers and the thymic size (R2=0.99) suggested that the patient's autoimmunity might have contributed to the thymic hyperplasia.
  • 飯塚 勝美, 石原 琢磨, 鷹尾 賢, 劉 彦言, 窪田 創大, 加藤 丈博, 水野 正巳, 廣田 卓男, 諏訪 哲也, 堀川 幸男, 矢部 大介
    日本病態栄養学会誌 24-25(Suppl.) S-31 2022年1月  
  • Shunsuke Tominari, Megumi Yasuda, Takehiro Kato, Mayu Sakai, Sodai Kubota, Kenta Nonomura, Tokuyuki Hirose, Ken Takao, Yanyan Liu, Masami Mizuno, Takuo Hirota, Katsumi Iizuka, Tetsuya Suwa, Yukio Horikawa, Daisuke Yabe
    Diabetology international 13(1) 295-299 2022年1月  
    Background: Elderly adults with diabetes are at increased risk of severe hypoglycemia and hypoglycemic coma due to various conditions including decline in cognitive function, reduced activity of daily living (ADL) and reduced renal function; special cautions are, therefore, recommended to avoid these life-threatening events. Case presentation: A 92-year-old female was admitted to our institution because of severe coma. Upon arrival, her serum C-peptide was 1.64 ng/mL despite low plasma glucose (24 mg/dL) and serum glimepiride (40.85 ng/mL). She had past history of compression fracture of her lumbar spine, which substantially affected her ADL. Her score on the dementia assessment sheet for community-based integrated care system-8 items (DASC-8) was 26 points. She had been receiving 12 oral medications for diabetes, essential hypertension, chronic gastritis and constipation from her nearby clinic. Her physician-in-charge had found that she was not taking her medications properly and simplified her prescription regimen to 3 oral medications with vildagliptin 50 mg twice daily replaced by glimepiride 3 mg once daily and asked her son to assist in taking the drugs 6 days before her admission to our hospital. While her consciousness level was improved to some extent, she was transferred to a long-term care bed hospital because it had become too difficult to care for her at home. Conclusions: It is important to note that anti-diabetes drugs should be carefully selected based on each patient's cognitive function and ADL, and that the reasoning should be shared with the general practitioners involved to avoid severe hypoglycemic events. Supplementary Information: The online version contains supplementary material available at 10.1007/s13340-021-00510-9.
  • Nao Nomura, Katsumi Iizuka, Eiichi Goshima, Kazuyoshi Hosomichi, Atsushi Tajima, Sodai Kubota, Yanyan Liu, Ken Takao, Takehiro Kato, Masami Mizuno, Takuo Hirota, Tetsuya Suwa, Yukio Horikawa, Daisuke Yabe
    Endocrine journal 69(4) 473-477 2021年11月19日  査読有り責任著者
    Glucokinase has an important role in regulating glycolysis as a glucose sensor in liver and pancreatic β cells. Glucokinase-maturity onset diabetes in young (GCK-MODY also known as MODY2) is caused by autosomal dominant gene mutation of the GCK gene; it is characterized by mild fasting hyperglycemia and small 2-h glucose increment during 75 g-oral glucose tolerance test (OGTT) as well as near-normal postprandial glucose variabilities. A 10-year-old girl with family history of diabetes visited her physician after being found positive for urinary glucose by school medical checkup. She received a diagnosis of diabetes based on the laboratory data: 75 g-OGTT (mild fasting hyperglycemia and small 2-h glucose increment) and factory-calibrated glucose monitoring (mild elevation of average glucose level and near-normal glycemic variability), which raised suspicion of GCK-MODY. She was then referred to our institution for genetic examination, which revealed a GCK heterozygous mutation (NM_000162: exon10: c.1324G>T: p.E442X) in the proband as well as in her mother and maternal grandmother, who had been receiving anti-diabetes medications without knowing that they had GCK-MODY specifically. GCK-MODY cases show incidence of microvascular and macrovascular diseases similar to that of normal subjects, and their glucose levels are adequately controlled without anti-diabetes drug use. Thus, early and definitive diagnosis of MODY2 by genetic testing is important to avoid unnecessary medication.
  • Daisuke Yabe, Katsumi Iizuka, Mike Baxter, Daisuke Watanabe, Hideaki Kaneto
    Journal of Diabetes Investigation 12(11) 1992-2001 2021年11月19日  
    INTRODUCTION: Treatments for type 2 diabetes (T2D) targeting baseline glucose levels but not postprandial glucose can result in normalized fasting blood glucose but suboptimal overall glycemic control (high glycated hemoglobin); residual hyperglycemia. In Japanese patients with T2D the predominant pathophysiology is lower insulin secretory capacity, and residual hyperglycemia is common with basal insulin treatment. Single-injection, fixed-ratio combinations of glucagon-like peptide-1 receptor agonists and basal insulin have been developed. iGlarLixi (insulin glargine 100 unit/mL [iGlar]: lixisenatide ratio of 1 U:1 µg) is for specific use in Japan. Post-hoc analysis of the LixiLan JP-L trial (NCT02752412) compared the effect of iGlarLixi with iGlar on this specific subpopulation with residual hyperglycemia. MATERIALS AND METHODS: Outcomes at week 26 (based on last observation carried forward) were assessed in patients in the modified intent-to-treat population with baseline residual hyperglycemia. RESULTS: Overall, 83 (32.5%) patients in the iGlarLixi group and 79 (30.7%) patients in the iGlar group had baseline residual hyperglycemia. The proportion of patients with residual hyperglycemia at week 26 decreased to 15.7% in the iGlarLixi group, and increased to 36.9% in the iGlar group. Patients in the iGlarLixi group had significantly greater reductions in glycated hemoglobin compared with the iGlar group (-0.72% difference between groups; P < 0.0001). CONCLUSIONS: New data from this post-hoc analysis of the JP-L trial show that treatment with fixed-ratio combination iGlarLixi reduced the proportion of Japanese patients with residual hyperglycemia from baseline to week 26 and significantly reduced glycated hemoglobin versus similar doses of iGlar alone.
  • Katsumi Iizuka
    International Journal of Molecular Sciences 22(21) 2021年11月8日  査読有り招待有り筆頭著者責任著者
    Carbohydrates are macronutrients that serve as energy sources. Many studies have shown that carbohydrate intake is nonlinearly associated with mortality. Moreover, high-fructose corn syrup (HFCS) consumption is positively associated with obesity, cardiovascular disease, and type 2 diabetes mellitus (T2DM). Accordingly, products with equal amounts of glucose and fructose have the worst effects on caloric intake, body weight gain, and glucose intolerance, suggesting that carbohydrate amount, kind, and form determine mortality. Understanding the role of carbohydrate response element binding protein (ChREBP) in glucose and lipid metabolism will be beneficial for elucidating the harmful effects of high-fructose corn syrup (HFCS), as this glucose-activated transcription factor regulates glycolytic and lipogenic gene expression. Glucose and fructose coordinately supply the metabolites necessary for ChREBP activation and de novo lipogenesis. Chrebp overexpression causes fatty liver and lower plasma glucose levels, and ChREBP deletion prevents obesity and fatty liver. Intestinal ChREBP regulates fructose absorption and catabolism, and adipose-specific Chrebp-knockout mice show insulin resistance. ChREBP also regulates the appetite for sweets by controlling fibroblast growth factor 21, which promotes energy expenditure. Thus, ChREBP partly mimics the effects of carbohydrate, especially HFCS. The relationship between carbohydrate intake and diseases partly resembles those between ChREBP activity and diseases.
  • Katsumi Iizuka
    Nutrients 13(11) 2021年10月22日  
    Diet composition determines the risk of obesity, cardiovascular disease, malignant tumors, and type 2 diabetes mellitus [...].
  • 酒井 麻有, 加藤 丈博, 諏訪 哲也, 堀谷 愛美, 窪田 創大, 廣瀬 徳之, 鷹尾 賢, 水野 正巳, 廣田 卓男, 飯塚 勝美, 酒々井 夏子, 堀川 幸男, 山本 眞由美, 宮崎 龍彦, 矢部 大介
    日本内分泌学会雑誌 97(2) 504-504 2021年10月  
  • Yusuke Seino, Katsumi Iizuka, Atsushi Suzuki
    Journal of diabetes investigation 12(10) 1759-1761 2021年10月  
    Carbohydrates, otherwise known as saccharides, are a macronutrient that is found in a wide variety of natural and processed foods. Carbohydrates include sugars, starch, and cellulose (insoluble dietary fiber), and can be categorized as monosaccharides, disaccharides, oligosaccharides, and polysaccharides. Monosaccharides such as glucose and fructose, and disaccharides such as sucrose, are together referred to as sugars.
  • Sakiho Imaki, Katsumi Iizuka, Yukio Horikawa, Megumi Yasuda, Sodai Kubota, Takehiro Kato, Yanyan Liu, Ken Takao, Masami Mizuno, Takuo Hirota, Tetsuya Suwa, Kazuyoshi Hosomichi, Atsushi Tajima, Yuuka Fujiwara, Yuji Yamazaki, Hitoshi Kuwata, Yutaka Seino, Daisuke Yabe
    Journal of diabetes investigation 12(10) 1914-1918 2021年10月  査読有り責任著者
    Heterozygous RFX6 mutation has emerged as a potential cause of maturity-onset diabetes mellitus of the young (MODY). A 16-year-old female was diagnosed with diabetes by her family doctor and was referred to our institution for genetic examination. Genetic testing revealed a novel RFX6 heterozygous mutation (NM_173560: exon17: c.1954C>T: p.R652X) in the patient and in her mother and brother. She had no islet-specific autoantibodies and showed a reduced meal-induced response of insulin, glucose-dependent insulinotropic polypeptide, and glucagon-like peptide-1, which is consistent with the phenotype of MODY due to heterozygous RFX6 mutation. In conclusion, we report a case of MODY due to a novel heterozygous mutation, p.R652X.
  • Katsumi Iizuka, Mike Baxter, Daisuke Watanabe, Daisuke Yabe
    Diabetes, obesity & metabolism 23(12) 2795-2803 2021年9月2日  査読有り筆頭著者責任著者
    AIMS: To compare the benefits of iGlarLixi, a fixed-ratio combination of insulin glargine 100 U/mL and lixisenatide (iGlarLixi), over insulin glargine (iGlar) for reducing residual hyperglycaemia (defined as glycated haemoglobin [HbA1c] ≥7% despite fasting plasma glucose [FPG] <130 mg/dL) in Japanese people with type 2 diabetes (T2D) inadequately controlled on oral antidiabetic drugs. MATERIALS AND METHODS: The open-label LixiLan JP-O2 study compared iGlarLixi with iGlar over 26 weeks in 521 people with T2D. This post-hoc analysis assessed the proportions of participants with residual hyperglycaemia in the overall population, and in subgroups defined by age and dipeptidyl-peptidase 4 inhibitor (DPP4i) use at screening. RESULTS: At 26 weeks, significantly fewer participants had residual hyperglycaemia in the iGlarLixi versus the iGlar arm (8.1% vs. 19.6%; P = 0.0002). There was also less residual hyperglycaemia with iGlarLixi than iGlar in all subgroup analyses: 9.0% versus 16.8% in participants aged <65 years (P = 0.0369); 6.5% versus 24.2% in participants aged ≥65 years (P = 0.0008); 10.1% versus 20.5% (P = 0.0202) in participants with DPP4i use; and 6.2% versus 18.8% in those without DPP4i use (P = 0.0024). The proportion reaching both HbA1c <7% and FPG <130 mg/dL was higher with iGlarLixi versus iGlar in the overall population (50.8% vs. 31.5%; P < 0.0001), and in all studied subgroups. CONCLUSIONS: iGlarLixi reduced the prevalence of residual hyperglycaemia in Japanese people with uncontrolled T2D compared with iGlar, both in the overall population and in subgroups defined by age and DPP4i use at screening. This article is protected by copyright. All rights reserved.
  • 今泉 俊則, 飯塚 勝美, 大洞 尚司, 矢部 大介
    The Lipid 32(1) 16-25 2021年4月  
    インクレチンと総称されるglucagon-like peptide-1(GLP-1)、glucose-dependent insulinotropic polypeptide(GIP)は、栄養素摂取に応答し消化管から分泌され、全身の糖・脂質代謝を制御することから、糖尿病や肥満に代表される生活習慣病の発症・重症化予防の標的として注目される。GLP-1、GIPは、膵β細胞に作用して血糖依存的にインスリン分泌を促進する。さらに、GLP-1は膵α細胞からのグルカゴン分泌を抑制するとともに、胃内容物排出時間を遅延させることで食後高血糖を是正する。また、GLP-1は消化管からの脂質吸収を抑制するとともに、肝臓の脂肪酸代謝を制御することで脂肪肝を是正する。加えて、GLP-1は中枢に作用して食欲を抑制し、減量効果を発揮する。GIPは、低血糖時に膵α細胞からのグルカゴン分泌を促進し、血糖値を正常範囲に保つ。また、GIPは骨形成を促進することから、骨折やサルコペニア、フレイルの観点からも注目されている。一方、GIPは、高脂肪食に対して脂肪組織へのエネルギー蓄積を促進するため、インスリン抵抗性を惹起し、耐糖能を悪化させうる。GLP-1、GIP共に、食事に含まれるさまざまな栄養素の量や内容、さらには摂取の順番により分泌量が変化することから、糖尿病や肥満に代表される生活習慣病の発症・重症化予防に資する食事療法を考える上で、インクレチンが注目される。(著者抄録)
  • Ken Takao, Katsumi Iizuka, Yanyan Liu, Teruaki Sakurai, Sodai Kubota, Saki Kubota-Okamoto, Toshinori Imaizumi, Yoshihiro Takahashi, Yermek Rakhat, Satoko Komori, Tokuyuki Hirose, Kenta Nonomura, Takehiro Kato, Masami Mizuno, Tetsuya Suwa, Yukio Horikawa, Masakatsu Sone, Daisuke Yabe
    The Journal of endocrinology 248(3) 317-324 2021年3月  査読有り責任著者
    Carbohydrate response element binding protein (ChREBP) is critical in the regulation of fatty acid and triglyceride synthesis in the liver. Interestingly, Chrebp-/- mice show reduced levels of plasma cholesterol, which is critical for steroid hormone synthesis in adrenal glands. Furthermore, Chrebp mRNA expression was previously reported in human adrenal glands. Thus, it remains to be investigated whether ChREBP plays a role directly or indirectly in steroid hormone synthesis and release in adrenal glands. In the present study, we find that Chrebp mRNA is expressed in mouse adrenal glands and that ChREBP binds to carbohydrate response elements. Histological analysis of Chrebp-/- mice shows no adrenal hyperplasia and less oil red O staining compared with that in wild-type mice. In adrenal glands of Chrebp-/- mice, expression of Fasn and Scd1, two enzymes critical for fatty acid synthesis, was substantially lower and triglyceride content was reduced. Expression of Srebf2, a key transcription factor controlling synthesis and uptake of cholesterol and the target genes was upregulated, while cholesterol content was not significantly altered in the adrenal glands of Chrebp-/- mice. Adrenal corticosterone content and plasma adrenocorticotropic hormone and corticosterone levels were not significantly altered in Chrebp-/- mice. Consistently, expression of genes related to steroid hormone synthesis was not altered. Corticosterone secretion in response to two different stimuli, namely 24-h starvation and cosyntropin administration, were also not altered in Chrebp-/- mice. Taking these results together, corticosterone synthesis and release were not affected in Chrebp-/- mice despite reduced plasma cholesterol levels.
  • Ken Takao, Ayaka Tani, Tetsuya Suwa, Yayoi Kuwabara-Ohmura, Kenta Nonomura, Yanyan Liu, Takehiro Kato, Masami Mizuno, Takuo Hirota, Mayumi Enya, Katsumi Iizuka, Yukio Horikawa, Chiemi Saigo, Yusuke Kito, Tatsuhiko Miyazaki, Naoyuki Ohe, Toru Iwama, Daisuke Yabe
    BMC endocrine disorders 21(1) 13-13 2021年1月11日  査読有り
    BACKGROUND: Primary central nervous system lymphoma is a rare extra-nodal lymphoma of the central nervous system. Primary central nervous system lymphoma lesions usually appear in the vicinity of the ventricle, and there are few reports of primary central nervous system lymphoma with hypothalamic-pituitary lesions. CASE PRESENTATION: We treated a 56-year-old male with primary central nervous system lymphoma with the primary lesion in the hypothalamus, which was found by magnetic resonance imaging after sudden onset of endocrinological abnormalities. Initially, he was hospitalized to our department for hyponatremia. Endocrinological examination in conjunction with head magnetic resonance imaging and endoscopic biopsy revealed hypothalamic hypopituitarism and tertiary hypoadrenocorticism caused by a rapidly growing, diffuse large B-cell lymphoma in the hypothalamus. Remission of the tumor was achieved by high-dose methotrexate with whole brain radiotherapy, and some of the hormone responses were normalized. CONCLUSIONS: While primary central nervous system lymphoma is rare, it is important to note that hypopituitarism can result and that the endocrinological abnormalities can be partially restored by its remission.
  • 野田 かおる, 加藤 丈博, 酒井 麻有, 窪田 創大, 鷹尾 賢, 水野 正巳, 廣田 卓男, 飯塚 勝美, 堀川 幸男, 安福 至, 杉山 佐織, 西村 佳代子, 舘 英里, 近藤 和樹, 山本 眞由美, 青木 隆明, 塩入 俊樹, 吉田 和弘, 矢部 大介
    日本内分泌学会雑誌 96(3) 730-730 2021年1月  
  • Yangyang Liu, Sodai Kubota, Katsumi Iizuka, Daisuke Yabe
    Journal of diabetes investigation 11(6) 1422-1425 2020年11月  査読有り
    Cardiovascular disease (CVD) is one of the most serious health-related problems in patients with type 2 diabetes, especially in western countries. Basic and clinical research on how to prevent CVD onset and progression in patients with type 2 diabetes have been an urgent task for decades. Glucagon-like peptide-1 (GLP-1) is one of two incretins that are responsible for ≥50% of postprandial insulin secretion and subsequent glucose excursion, and has been intensively investigated from the perspective of CVD due to its cardiovascular benefits in preclinical studies1, 2 .
  • Yayoi Kuwabara-Ohmura, Katsumi Iizuka, Yanyan Liu, Ken Takao, Kenta Nonomura, Takehiro Kato, Masami Mizuno, Kazuyoshi Hosomichi, Atsushi Tajima, Tatsuhiko Miyazaki, Yukio Horikawa, Daisuke Yabe
    Endocrine journal 67(9) 981-988 2020年9月28日  査読有り責任著者
    Pancreatic tail hypoplasia is a common manifestation of maturity onset diabetes of the young (MODY) 5 that can cause reno-genito-urinary malformations such as renal cysts and bicornuate uterus. A 69-year-old female was admitted to our hospital for consultation on her relatively high HbA1c value. At age 20, she was diagnosed with uterus bicornis. At age 68, she was diagnosed with pancreas tail hypoplasia, renal cysts and non-functioning pancreatic neuroendocrine tumor (NET) in addition to right hydronephrosis due to multiple ureteral bladder carcinomas. She received total right nephrectomy, ureterectomy and partial cystectomy for multiple ureteral bladder carcinomas [non-invasive papillary urothelial carcinoma, low grade (G1), pTa, LV10, u-rtx, RM0, and pN0 (0/8)]. She also received distal pancreatomy for pancreatic NET [NET G1]. She then was referred to our department at age 69 due to increase in her HbA1c value from 6.2 to 7.2%; 75 g oral glucose tolerance test revealed impaired glucose tolerance. Her clinical characteristics (uterus bicornis, pancreas hypoplasia, and renal cysts) closely resembled the phenotype of MODY5, in which mutations in the HNF1B gene have been reported. Our genetic testing failed to detect any mutation or microdeletion in the coding or minimal promoter regions of the HNF1B gene. Although there remains a possibility that genetic mutations in introns and regulatory regions of the HNF1B gene might cause the MODY5-like manifestations in this patient, these results might suggest involvement of genes other than HNF1B in the pathogenesis of our patient's disease.
  • Sodai Kubota, Yanyan Liu, Katsumi Iizuka, Hitoshi Kuwata, Yutaka Seino, Daisuke Yabe
    Nutrients 12(9) 2020年8月19日  査読有り
    While adjustment of total energy and nutritional balance is critically important, meal sequence, a relatively simple method of correcting postprandial hyperglycemia, is becoming established as a practical dietary approach for prevention and management of diabetes and obesity. Meal sequence, i.e., consumption of protein and/or fat before carbohydrate, promotes secretion of glucagon-like peptide-1 (GLP-1) from the gut and ameliorates secretions of insulin and glucagon and delays gastric emptying, thereby improving postprandial glucose excursion. GLP-1 is known to suppress appetite by acting on the hypothalamus via the afferent vagus nerve. Thus, enhancement of GLP-1 secretion by meal sequence is expected to reduce body weight. Importantly, consumption of a diet rich in saturated fatty acids such as meat dishes before carbohydrate increases secretions of not only GLP-1 but also glucose-dependent insulinotropic polypeptide (GIP), which promotes energy storage in adipose tissue and may lead to weight gain in the long term. Dietary fiber intake before carbohydrate intake significantly reduces postprandial glucose elevation and may have a weight loss effect, but this dietary strategy does not enhance the secretion of GLP-1. Thus, it is suggested that their combination may have additive effects on postprandial glucose excursion and body weight. Indeed, results of some clinical research supports the idea that ingesting dietary fiber together with meal sequence of protein and/or fat before carbohydrate benefits metabolic conditions of individuals with diabetes and obesity.
  • 窪田 創大, 岡本 紗希, 松原 実穂, 桑田 仁司, 表 孝徳, 浜本 芳之, 劉 彦言, 飯塚 勝美, 田中 大祐, 矢部 大介, 稲垣 暢也, 清野 裕
    日本内分泌学会雑誌 96(1) 368-368 2020年8月  
  • 岡本 紗希, 浜本 芳之, 松原 実穂, 窪田 創大, 桑田 仁司, 表 孝徳, 劉 彦言, 飯塚 勝美, 田中 大祐, 矢部 大介, 稲垣 暢也, 清野 裕
    糖尿病 63(Suppl.1) S-163 2020年8月  
  • 劉 彦言, 飯塚 勝美, 鷹尾 賢, 加藤 丈博, 野々村 健太, 水野 正巳, 堀川 幸男, 藤原 結花, 桑田 仁司, 清野 祐介, 鈴木 敦詞, 山田 祐一郎, 清野 裕, 矢部 大介
    糖尿病 63(Suppl.1) S-157 2020年8月  
  • Kenta Nonomura, Katsumi Iizuka, Yayoi Kuwabara-Ohmura, Daisuke Yabe
    Internal medicine (Tokyo, Japan) 59(12) 1535-1539 2020年6月15日  査読有り責任著者
    A 72-year-old man had type 2 diabetes (T2D) that had been diagnosed at 54 years old. Macroalbuminuria was first detected at age 64. While his HbA1c had been kept below 7%, his estimated glomerular filtration rate (eGFR) was declining rapidly. At 70 years old, his eGFR dropped below 50 ml/min/1.73 m2. A renal biopsy revealed diabetic nephropathy. sodium glucose transporter 2 inhibitors (SGLT2i)/glucagon-like peptide-1 receptor agonists (GLP-1RA) combination therapy substantially improved his eGFR and urinary albumin level, and the renoprotective effect persisted for the two-year study period. These findings suggest that SGLT2i and GLP-1RA can additively improve the renal function in patients with T2D.
  • Katsumi Iizuka, Daisuke Yabe
    Nutrients 12(6) 1668-1668 2020年6月4日  査読有り招待有り筆頭著者責任著者
    Conventional recommendations for dietary intervention have been generally based on population groups divided by gender and age [...]
  • Yasuda M, Iizuka K, Kato T, Liu Y, Takao K, Nonomura K, Mizuno M, Yabe D
    Journal of diabetes investigation 11(3) 745-747 2020年5月  査読有り責任著者
  • Katsumi Iizuka, Ken Takao, Daisuke Yabe
    Frontiers in endocrinology 11 587189-587189 2020年  査読有り招待有り筆頭著者責任著者
    Carbohydrate response element-binding protein (ChREBP) plays an important role in the development of type 2 diabetes, dyslipidemia, and non-alcoholic fatty liver disease, as well as tumorigenesis. ChREBP is highly expressed in lipogenic organs, such as liver, intestine, and adipose tissue, in which it regulates the production of acetyl CoA from glucose by inducing Pklr and Acyl expression. It has recently been demonstrated that ChREBP plays a role in the conversion of gut microbiota-derived acetate to acetyl CoA by activating its target gene, Acss2, in the liver. ChREBP regulates fatty acid synthesis, elongation, and desaturation by inducing Acc1 and Fasn, elongation of long-chain fatty acids family member 6 (encoded by Elovl6), and Scd1 expression, respectively. ChREBP also regulates the formation of very low-density lipoprotein by inducing the expression of Mtp. Furthermore, it plays a crucial role in peripheral lipid metabolism by inducing Fgf21 expression, as well as that of Angptl3 and Angptl8, which are known to reduce peripheral lipoprotein lipase activity. In addition, ChREBP is involved in the production of palmitic-acid-5-hydroxystearic-acid, which increases insulin sensitivity in adipose tissue. Curiously, ChREBP is indirectly involved in fatty acid β-oxidation and subsequent ketogenesis. Thus, ChREBP regulates whole-body lipid metabolism by controlling the transcription of lipogenic enzymes and liver-derived cytokines.
  • Iizuka K, Mizuno M, Nonomura K, Yabe D
    BMJ case reports 12(5) 2019年5月27日  査読有り筆頭著者責任著者
  • Masami Mizuno, Katsumi Iizuka, Takuma Ishihara, Shusaku Fukaya, Shunji Yoshida, Jun Takeda
    Diabetes therapy : research, treatment and education of diabetes and related disorders 10(1) 269-276 2019年2月  査読有り責任著者
    INTRODUCTION: Glycated hemoglobin (A1c) and glycated albumin (GA) are often used as indicators of glycemic control. In this study, we determined whether prednisolone (PSL) administration lowers plasma GA. METHODS: We investigated the factors affecting GA using multivariate analysis in 48 subjects with connective tissue diseases (CTDs). RESULTS: Multiple regression analysis of GA showed that the dose of PSL [β = - 1.36; 95% confidence interval (CI) - 2.59 to - 0.14; p = 0.03], age (β = 0.06; 95% CI 0.03-0.09; p < 0.001), body mass index (BMI) (β = - 0.14; 95% CI - 0.28 to - 0.01; p = 0.042), and A1c (β = 1.4; 95% CI 0.38-2.42; p = 0.008) significantly correlated with GA (adjusted R2 = 0.518). Moreover, GA levels adjusted for age, sex, BMI, plasma albumin (Alb) and creatinine (Cre), and A1c in the subjects taking ≥ 5 mg PSL was significantly lower than those in those taking < 5 mg PSL. Finally, the dose of PSL (as a continuous variable) was negatively correlated with GA adjusted for age, sex, BMI, Alb, Cre, and A1c. CONCLUSION: High dose (≥ 5 mg) PSL reduces GA concentration more than glycemia.
  • Teruaki Sakurai, Katsumi Iizuka, Takehiro Kato, Jun Takeda
    Internal medicine (Tokyo, Japan) 58(2) 259-262 2019年1月15日  査読有り責任著者
    A 60-year-old male patient with type 1 diabetes mellitus (T1DM) was admitted for glycemic control. The patient exhibited abdominal adiposity, osteoporosis, and high insulin requirement (>100 U), and we suspected hypogonadism. A physical examination revealed small testes and thin pubic hair, laboratory examination found high luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels and low testosterone levels, and a chromosome analysis (47, XXY) indicated hypogonadism due to Klinefelter syndrome (KS). KS is associated with autoimmune diseases and patients positive for diabetes related auto-antibodies. In male patients with T1DM and abdominal adiposity, the concurrence of KS should be taken into consideration.
  • Iizuka, K.
    Molecular Nutrition Carbohydrates 2019年  

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