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Dive into the research topics where Akira Kurozumi is active.

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Featured researches published by Akira Kurozumi.


Journal of Diabetes Investigation | 2017

Factors influencing inter-day glycemic variability in diabetic outpatients receiving insulin therapy.

Yosuke Okada; Akira Kurozumi; Manabu Narisawa; Yoshiya Tanaka

The aim of the present study was to determine the actual state of inter‐day glycemic variability and identify the factors that affect glycemic variability in diabetic outpatients on insulin therapy.


Journal of UOEH | 2015

Prednisolone Dosing Regimen for Treatment of Subacute Thyroiditis.

Tadashi Arao; Yosuke Okada; Keiichi Torimoto; Akira Kurozumi; Manabu Narisawa; Sunao Yamamoto; Yoshiya Tanaka

The rate of recurrence of subacute thyroiditis (SAT) during prednisolone (PSL) therapy is approximately 10 to 20%. However, there is little or no information on the time period to relapse following administration of a tapered dose of PSL and the factors associated with such relapse. The aim of this study was to determine the correlation between SAT recurrence and PSL tapering regimen used in the treatment of SAT. This study was a medical record-based retrospective study and involved 26 patients (3 men, 23 women) who received PSL therapy for SAT. The primary endpoint was the association between recurrence and number of days required to taper daily PSL dose to 5 mg. The secondary endpoint was the relationship between recurrence and several variables including age, clinical score, free thyroxine, inflammatory reaction, thyroglobulin, total treatment time, total dose of PSL and presence or absence of creeping thyroiditis. The SAT recurrence rate was 15.3%. There was no significant difference in the initial PSL dose between the non-recurrence and recurrence groups (27.5 mg vs 24.5 mg, P = 0.302). However, for the primary endpoint, significant differences were found between the two groups in time required for tapering PSL to 5 mg/day (non-recurrence: 44.3 ± 15.3 days, recurrence: 19.0 ± 11.9 days, P = 0.012). None of the clinical variables evaluated correlated significantly with SAT relapse. In conclusion, to prevent recurrence of SAT, consideration should be given to the period required for PSL tapering to 5 mg/day.


Endocrine Journal | 2017

Comparative analysis of the effects of alogliptin and vildagliptin on glucose metabolism in type 2 diabetes mellitus

Kenichi Tanaka; Yosuke Okada; Megumi Miyazaki; Fumi Kuno; Satomi Sonoda; Kei Sugai; Maiko Hajime; Akira Kurozumi; Manabu Narisawa; Keiichi Torimoto; Tadashi Arao; Shinichiro Mine; Yoshiya Tanaka

The aim of this 24-week, prospective randomized open-label study was to compare the effects of alogliptin and vildagliptin on glucose control, renal function, and lipid metabolism. In Study 1, DPP-4 inhibitor-naive type 2 diabetes (T2DM) were randomly assigned to alogliptin 25 mg/day or vildagliptin 50 mg twice daily. In Study 2, T2DM on treatment with 50 mg/day sitagliptin were switched to either 25 mg/day alogliptin or 50 mg twice daily vildagliptin. The primary endpoint was change in glycosylated hemoglobin (HbA1c) level at 24 weeks, while the secondary endpoints were changes in urinary albumin excretion and low-density lipoprotein cholesterol (LDL-C) levels at 24 weeks. In Study 1, HbA1c levels changed at 24-week by -0.5±0.7% in the alogliptin group (p=0.002, relative to baseline) and -0.7±0.9% in the vildagliptin group (p=0.001, relative to baseline), and the extent of these changes were comparable between the two groups (p=0.219). The decrease in log urinary albumin excretion was more significant in the vildagliptin group (p=0.008). In Study 2, HbA1c levels at 24-week changed by 0.2±0.7% in the switch-to-alogliptin group (p=0.007) and 0.0±0.6% in the switch-to-vildagliptin group (p=0.188), indicating a significant difference between the groups (p=0.003). In both studies, the changes in LDL-C levels were comparable between the two groups. The two drugs had comparable glucose-lowering effects in DPP-4 inhibitor-naive patients but the effect was more pronounced for vildagliptin in patients switched from sitagliptin. The results may point to subtle yet important differences between the two DPP-4 inhibitors. This trial was registered with UMIN (no. #000019022).


Endocrine Journal | 2016

Detrimental effects of high-fat diet loading on vascular endothelial function and therapeutic efficacy of ezetimibe and statins in patients with type 2 diabetes

Akira Kurozumi; Yosuke Okada; Takuya Kobayashi; Daisaku Masuda; Shizuya Yamashita; Yoshiya Tanaka

Several recent reports from large clinical trials have described the role of postprandial hyperlipidemia in the onset of atherosclerosis. In this pilot study, the effects of postprandial lipid abnormalities induced by high-fat diet loading on vascular endothelial function in type 2 diabetes were investigated and the effects of ezetimibe and statins on endothelial function were compared. In 20 patients in Study 1, peripheral arterial tonometry tests were performed before and 4h after loading to measure the reactive hyperemia index (RHI). In Study 2, the same patients were randomly allocated to ezetimibe or rosuvastatin. After 1 week of treatment, loading tests were conducted in the same manner. In Study 1, the RHI decreased from 1.86 to 1.60. There were no significant correlations between changes in RHI and the area under the curve (AUC) or coefficient of variation (CV) of each metabolic marker. In Study 2, ezetimibe treatment resulted in a significant improvement in RHI. The two drugs had comparable effects on changes in AUC. There were no significant correlations between changes in RHI and changes in AUC or changes in CV. When age, sex, drug, hemoglobin A1c, and changes in each lipid were evaluated as independent variables with RHI improvement as the dependent variable, drug differences were found to exert the greatest effect on RHI improvement using a stepwise procedure. The results of this study suggest that the progression of atherosclerosis is due to abnormalities in postprandial lipid metabolism and that ezetimibe can potentially inhibit the aggravation of vascular endothelial dysfunction after high-fat diet loading.


Journal of Diabetes Investigation | 2018

Comparison of effects of anagliptin and alogliptin on serum lipid profile in type 2 diabetes mellitus patients

Akira Kurozumi; Yosuke Okada; Tadashi Arao; Takuya Kobayashi; Daisaku Masuda; Shizuya Yamashita; Yoshiya Tanaka

Anagliptin (ANA) improves dyslipidemia in addition to blood glucose levels. However, there are no comparative studies on the effects of ANA and other dipeptidyl peptidase‐4 inhibitors on serum lipid profile. We compared the effects of ANA on serum lipid profile with those of alogliptin (ALO) in type 2 diabetes mellitus outpatients.


Internal Medicine | 2017

Clinical Features of Patients with Basedow's Disease and High Serum IgG4 Levels

Keiichi Torimoto; Yosuke Okada; Akira Kurozumi; Manabu Narisawa; Tadashi Arao; Yoshiya Tanaka

Objective IgG4-related disease is a recently characterized condition presenting with high blood IgG4 levels, swelling of organs, and hypertrophic lesions. This disease is associated with thyroid disease, Hashimotos disease, and Riedels thyroiditis. However, there is little information on the association between IgG4-related disease and Basedows disease. We herein defined the clinical features of patients with Basedows disease and high IgG4 levels. Methods We compared two groups of patients with Basedows disease (n=72) who had either normal IgG4 levels (<135 mg/dL; n=67) or high IgG4 levels (≥135 mg/dL; n=5 [6.9%], mean IgG4: 206±116 mg/dL, IgG4/IgG ratio: 10.6%±3.3%). Patients Seventy-two newly diagnosed, untreated patients with Basedows disease. Results Compared to the normal IgG4 group, patients in the high IgG4 group were predominantly male and showed a significantly higher thyroid low-echo score (1.8±0.4 vs. 1.2±0.5) and eosinophil count (363±354/mm2 vs. 136±122/mm2). Five patients had high IgG4 levels: one had a pancreatic lesion, and four had thyroid lesions. Conclusion Patients with Basedows disease and high IgG4 levels may represent a new subtype of Basedows disease. Further studies with larger sample sizes are needed.


Endocrinology, Diabetes & Metabolism Case Reports | 2016

Pancreas-protective effect of rituximab for acute-onset type 1 diabetes in the honeymoon period: a case report

Akira Kurozumi; Yosuke Okada; Tadashi Arao; Yusuke Miyazaki; Maiko Yoshikawa; Keiichi Torimoto; Satoshi Kubo; Shingo Nakayamada; Yoshiya Tanaka

Summary A randomized controlled study of rituximab demonstrated that the drug protects pancreatic function in patients with acute-onset type 1 diabetes mellitus (AOT1DM). However, the mechanism of this protective effect is poorly understood. We examined the effects of rituximab in two patients with AOT1DM in the honeymoon period and the mechanism of these effects. Case 1 was a 40-year-old man and Case 2 was a 45-year-old man, both diagnosed with AOT1DM. Various tests indicated intact capacity for endogenous insulin secretion and that they were in the honeymoon phase of AOT1DM. Treatment with rituximab protected against pancreatic β-cell damage and maintained somewhat the endogenous insulin secretion. In Case 2, HbA1c level was maintained below 6.5% up to 24 months after treatment. However, in Case 1, the patient showed a gradual increase in HbA1c level starting around 9 months but fell at 12 months to >9.0% and required an insulin dose about twice greater than that of Case 2. High spleen tyrosine kinase (Syk) levels were recorded in the two patients before rituximab administration and after the treatment, the levels were further increased in Case 1, but decreased in Case 2. Both patients require continuous careful follow-up for glycemic control, insulin secretion capacity, and adverse reactions in the future. Although the clinical relevance of high Syk levels in AOT1DM patients remains unclear, the difference in the change in Syk level between the two patients may explain the different clinical courses. Learning points We described the pancreas-protective effect of rituximab in two patients with acute-onset type 1 diabetes mellitus in the honeymoon period and investigated the possible mechanism of action. The present study demonstrated that treatment with rituximab maintained endogenous insulin secretion capacity for 2 years in the two patients. The phosphorylated-spleen tyrosine kinase (p-Syk) data suggest that the differences in HbA1c level and the required insulin dose between the two patients could be due to reactivation or nonreactivation of β-cells.


Journal of UOEH | 2018

Association Between Diabetic Microangiopathies and Glycemic Variability Assessed by Continuous Glucose Monitoring

Satomi Sonoda; Yosuke Okada; Fumi Uemura; Kei Sugai; Maiko Hajime; Kenichi Tanaka; Akira Kurozumi; Manabu Narisawa; Keiichi Torimoto; Yoshiya Tanaka

The aim of this retrospective study was to elucidate the association between glucose profile using the continuous glucose monitoring system (CGMS) and microvascular complications in patients with type 2 diabetes mellitus (T2DM). The subjects were 160 inpatients with T2DM. The mean blood glucose (MBG) level, percentage of time in a 24-hour period spent with blood glucose level higher than 180 mg/dl (time at >180 mg/dl), standard deviation (SD), and mean amplitude of glycemic excursions (MAGE) were measured continuously over 48 hours using the CGMS. The primary outcome was the association between microvascular complications and glycemic variability. The secondary outcome was the association between microangiopathies and MBG. The SD and MAGE were not associated with presence of microangiopathies or number of complications. There were also no associations between abnormal vibratory sensation in the bilateral lower extremities, coefficient of variation of the R-R interval (CVRR), retinopathy stage, nephropathy stage, or microalbuminuria. MBG was associated, however, with retinopathy, retinopathy stage, and number of complications. Time at >180 mg/dl correlated with abnormal vibratory sensation in the bilateral lower extremities and presence or stage of retinopathy. MBG and time at >180 mg/dl were not associated with presence or stage of nephropathy. Our findings suggest that broad glycemic variability was not associated with microvascular complications, the number of which increased in patients with a high mean glucose level and long time spent with hyperglycemia. It is important, therefore, to reduce the mean glucose level and time spent with hyperglycemia to prevent future microangiopathies.


Journal of UOEH | 2018

Comparison of the Effects of Teneligliptin and Sitagliptin, Two Dipeptidyl Peptidase 4 Inhibitors with Different Half-Lives, on Glucose Fluctuation and Glucagon-Like Peptide-1 in Type 2 Diabetes Mellitus

Akira Kurozumi; Yosuke Okada; Kei Sugai; Keiichi Torimoto; Yoshiya Tanaka

Our purpose was to determine the effects of teneligliptin and sitagliptin, two dipeptidyl peptidase 4 inhibitors (DPP4-Is) with different half-lives, on glycemic variability and glucagon-like peptide-1 (GLP-1) levels in Japanese patients with type 2 diabetes mellitus (T2DM). The study subjects were 14 drug-naïve patients with T2DM who were allocated to either a 20 mg/day teneligliptin group (n = 7) or a 50 mg/day sitagliptin group (n = 7) for 7 days, then switched to the other treatment for another 7 days. Meal tolerance tests were performed at the time of no treatment, and after treatment with each DPP4-Is at supper. We evaluated the effects of each drug on glucose fluctuation using continuous glucose monitoring (CGM). There was no significant difference between the two groups in the primary endpoint (maximum glucose level after supper), nor in the secondary endpoint: area under the curve (AUC) for plasma glucose (≥140 mg/dl) after supper (18:00 - 24:00). Teneligliptin significantly improved the AUC for plasma glucose (≥140 mg/dl) after supper (20:00-24:00) (P = 0.048), and also significantly increased the GLP-1 level at 30 minutes after the meal load (P = 0.030). No serious adverse effects were noted in either group, apart from a few episodes of asymptomatic hypoglycemia. A daily dose of teneligliptin improved the AUC for plasma glucose at 20:00 to 24:00 (≥140 mg/dl) after the meal tolerance test, and also significantly increased the levels of activated GLP-1 after the test meal.


Journal of Diabetes Investigation | 2018

Twenty-four-hour variations in blood glucose level in Japanese type 2 diabetes patients based on continuous glucose monitoring

Maiko Hajime; Yosuke Okada; Takashi Otsuka; Mayuko Kawaguchi; Megumi Miyazaki; Fumi Kuno; Kei Sugai; Satomi Sonoda; Kenichi Tanaka; Akira Kurozumi; Manabu Narisawa; Keiichi Torimoto; Tadashi Arao; Yoshiya Tanaka

High fluctuations in blood glucose are associated with various complications. The correlation between glycated hemoglobin (HbA1c) level and fluctuations in blood glucose level has not been studied in Japanese patients with type 2 diabetes. In the present study, blood glucose profile stratified by HbA1c level was evaluated by continuous glucose monitoring (CGM) in Japanese type 2 diabetes patients.

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Yosuke Okada

University of Occupational and Environmental Health Japan

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Yoshiya Tanaka

University of Occupational and Environmental Health Japan

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Tadashi Arao

University of Occupational and Environmental Health Japan

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Keiichi Torimoto

University of Occupational and Environmental Health Japan

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Manabu Narisawa

University of Occupational and Environmental Health Japan

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Sunao Yamamoto

University of Occupational and Environmental Health Japan

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Kei Sugai

University of Occupational and Environmental Health Japan

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Kenichi Tanaka

University of Occupational and Environmental Health Japan

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Maiko Hajime

University of Occupational and Environmental Health Japan

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Fumi Kuno

University of Occupational and Environmental Health Japan

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