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Dive into the research topics where Masahiro Ishizawa is active.

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Featured researches published by Masahiro Ishizawa.


Diabetes & Metabolism | 2017

Impact of glucose tolerance status on the development of coronary artery disease among working-age men.

Kazuya Fujihara; Risa Igarashi; M. Yamamoto; Masahiro Ishizawa; Y. Matsubayasi; Satoshi Matsunaga; Kiminori Kato; C. Ito; M. Koishi; N. Yamanaka; Satoru Kodama; Hirohito Sone

AIMS To examine the impact of glucose tolerance status on the development of coronary artery disease (CAD) in working-age men in Japan. METHODS This population-based retrospective cohort study included 111,621 men aged 31-60 years [63,558 with normal glucose tolerance (NGT); 37,126 with prediabetes; 10,937 with diabetes]. The Cox proportional-hazards regression model was used to identify variables related to the incidence of CAD. RESULTS Multivariate analysis showed that, compared with NGT, diabetes increased the risk of CAD by 17.3 times (95% CI: 6.36-47.0) at ages 31-40 years, by 2.74 times (95% CI: 1.85-4.05) at ages 41-50 years and by 2.47 times (95% CI: 1.69-3.59) at ages 51-60 years. The HRs for CAD in men with diabetes aged 31-40 equaled that of men with NGT aged 51-60 [18.2 (7.15-46.4) and 19.4 (8.28-45.4), respectively]. CONCLUSION The impact of diabetes on CAD was markedly greater in men aged 31-40 years compared with those aged 41-60 years.


Diabetes & Metabolism | 2017

Impact of body mass index and metabolic phenotypes on coronary artery disease according to glucose tolerance status

Kazuya Fujihara; Yasuhiro Matsubayashi; M. Yamamoto; Taeko Osawa; Masahiro Ishizawa; M. Kaneko; Satoshi Matsunaga; Kiminori Kato; H. Seida; N. Yamanaka; Satoru Kodama; Hirohito Sone

OBJECTIVE This study aimed to examine the impact of obesity, as defined by body mass index (BMI), and a metabolically unhealthy phenotype on the development of coronary artery disease (CAD) according to glucose tolerance status. METHODS This population-based retrospective cohort study included 123,746 Japanese men aged 18-72years (normal glucose tolerance: 72,047; prediabetes: 39,633; diabetes: 12,066). Obesity was defined as a BMI≥25kg/m2. Metabolically unhealthy individuals were defined as those with one or more of the following conditions: hypertension, hypertriglyceridaemia and/or low HDL cholesterol. A Cox proportional hazards regression model identified variables related to CAD incidence. RESULTS The prevalences of obese subjects with normal glucose tolerance, prediabetes and diabetes were 21%, 34% and 53%, whereas those for metabolically unhealthy people were 43%, 60% and 79%, respectively. Multivariate analysis showed that a metabolically unhealthy phenotype increases hazard ratios (HRs) for CAD compared with a metabolically healthy phenotype, regardless of glucose tolerance status (normal glucose tolerance: 1.98, 95% CI: 1.32-2.95; prediabetes: 2.91, 95% CI: 1.85-4.55; diabetes: 1.90, 95% CI: 1.18-3.06). HRs for CAD among metabolically unhealthy non-obese diabetes patients and obese diabetes patients with a metabolically unhealthy status were 6.14 (95% CI: 3.94-9.56) and 7.86 (95% CI: 5.21-11.9), respectively, compared with non-obese subjects with normal glucose tolerance and without a metabolically unhealthy status. CONCLUSION A metabolically unhealthy state can associate with CAD independently of obesity across all glucose tolerance stages. Clinicians may need to consider those with at least one or more conditions indicating a metabolically unhealthy state as being at high risk for CAD regardless of glucose tolerance status.


Medicine | 2016

Impact of individual components and their combinations within a family history of hypertension on the incidence of hypertension: Toranomon hospital health management center study 22.

Risa Igarashi; Kazuya Fujihara; Yoriko Heianza; Masahiro Ishizawa; Satoru Kodama; Kazumi Saito; Shigeko Hara; Osamu Hanyu; Ritsuko Honda; Hiroshi Tsuji; Yasuji Arase; Hirohito Sone

AbstractAlthough a family history (FH) of hypertension is a risk factor for the development of hypertension, only a few studies have investigated in detail the impact of individual components of an FH on incident hypertension. We investigated the impact of individual components and their combinations on the presence or development of hypertension considering obesity, smoking habits, physical activity, and other metabolic parameters.Studied were 12,222 Japanese individuals without hypertension (n = 9,766) and with hypertension (n = 2,456) at the baseline examination. The presence or incidence of hypertension during 5 years after a baseline examination was assessed by the presence of systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg or a self-reported history of clinician-diagnosed hypertension. In this prospective study, the odds ratio for incident hypertension was 1.39 (95% confidence interval [CI], 1.22, 1.59) for individuals with any FH of hypertension compared with those without such an FH. Individuals with an FH of hypertension in both parents and one or more grandparents had an odds ratio of 3.05 (95% CI 1.74, 5.36) for hypertension compared with those without an FH of hypertension. FH was associated with incident hypertension independently of other modifiable risk factors such as obesity, smoking, physical inactivity, hyperglycemia, hyperuricemia, and hypertriglyceridemia.A parental history of hypertension was an essential component within an FH for incident hypertension. FH of hypertension over two generations with both parents affected was the most important risk factor for incident hypertension. Although an FH is not a modifiable risk factor, modifying other risk factors could contribute to reducing the risk of hypertension even among individuals with a family history of hypertension.


Pediatric Diabetes | 2018

Relationships among cardiorespiratory fitness, muscular fitness, and cardiometabolic risk factors in Japanese adolescents: Niigata screening for and preventing the development of non-communicable disease study-Agano (NICE EVIDENCE Study-Agano) 2

Sakiko Yoshizawa Morikawa; Kazuya Fujihara; Mariko Hatta; Taeko Osawa; Masahiro Ishizawa; M. Yamamoto; Kazuo Furukawa; Hajime Ishiguro; Satoshi Matsunaga; Yohei Ogawa; Hitoshi Shimano; Hirohito Sone

To examine the independent and combined associations of cardiorespiratory fitness (CRF) and muscular fitness (MF) with cardiometabolic risk factors in Japanese adolescents.


Diabetes & Metabolism | 2018

Association of treatment-achieved HbA1c with incidence of coronary artery disease and severe eye disease in diabetes patients

M. Harada; Kazuya Fujihara; Taeko Osawa; M. Yamamoto; M. Kaneko; Masahiro Ishizawa; Yasuhiro Matsubayashi; Takaho Yamada; N. Yamanaka; H. Seida; Satoru Kodama; W. Ogawa; Hirohito Sone

AIM To examine the association between treatment-achieved HbA1c values and incidence of both coronary artery disease (CAD) and severe eye disease with different diabetes treatments. METHODS Associations of treatment-achieved HbA1c were investigated in various treatment groups [diet only; insulin; sulphonylurea (SU) alone; SU with glinides; and antihyperglycaemic agents other than glinides, SU or insulin] taken from a nationwide claims database of 14,633 Japanese diabetes patients. Coxs regression analysis examined risks over a 5.1-year follow-up. RESULTS A significant linear trend was associated with HbA1c levels and CAD events in the diet-only group, and CAD risks were significantly higher in insulin and SU groups with HbA1c ≤ 7.0% and > 8.0% than in the diet-only group with HbA1c ≤ 7.0%. In contrast to CAD, a linear association was observed regardless of treatment modality between achieved HbA1c levels and risk of severe diabetic eye disease, but with no significant difference in eye disease risk between groups with HbA1c ≤ 7.0% and 7.1-8.0% in those treated with either SU alone, SU with glinides, or insulin. CONCLUSION These findings suggest that the relationship between treatment-achieved HbA1c and incidence of both CAD and severe diabetic eye disease differed according to treatment, based on a large-scale real-life database. More research is now needed to confirm these findings and to further investigate the underlying mechanisms.


Preventive Medicine | 2016

Utility of nonblood-based risk assessment for predicting type 2 diabetes mellitus: A meta-analysis

Sakiko Yoshizawa; Satoru Kodama; Kazuya Fujihara; Hajime Ishiguro; Masahiro Ishizawa; Yasuhiro Matsubayashi; Satoshi Matsunaga; Takaho Yamada; Hitoshi Shimano; Kiminori Kato; Osamu Hanyu; Hirohito Sone

OBJECTIVE Nonblood-based risk assessment for type 2 diabetes mellitus (T2DM) that depends on data based on a questionnaire and anthropometry is expected to avoid unnecessary diagnostic testing and overdiagnosis due to blood testing. This meta-analysis aims to assess the predictive ability of nonblood-based risk assessment for future incident T2DM. METHODS Electronic literature search was conducted using EMBASE and MEDLINE (from January 1, 1997 to October 1, 2014). Included studies had to use at least 3 predictors for T2DM risk assessment and allow reproduction of 2×2 contingency table data (i.e., true positive, true negative, false positive, false negative) to be pooled with a bivariate random-effects model and hierarchical summary receiver-operating characteristic model. Considering the importance of excluding individuals with a low likelihood of T2DM from diagnostic blood testing, we especially focused on specificity and LR-. RESULTS Eighteen eligible studies consisting of 184,011 participants and 7038 cases were identified. The pooled estimates (95% confidence interval) were as follows: sensitivity=0.73 (0.66-0.79), specificity=0.66 (0.59-0.73), LR+=2.13 (1.81-2.50), and LR-=0.41 (0.34-0.50). CONCLUSIONS Nonblood-based assessment of risk of T2DM could produce acceptable results although the feasibility of such a screener needs to be determined in future studies.


Neuropsychiatric Disease and Treatment | 2014

Reversible brain atrophy and cognitive impairment in an adolescent Japanese patient with primary adrenal Cushing's syndrome.

Nobumasa Ohara; Hiroshi Suzuki; Akiko Suzuki; Masanori Kaneko; Masahiro Ishizawa; Kazuo Furukawa; Takahiro Abe; Yasuhiro Matsubayashi; Takaho Yamada; Osamu Hanyu; Takayoshi Shimohata; Hirohito Sone

Endogenous Cushing’s syndrome is an endocrine disease resulting from chronic exposure to excessive glucocorticoids produced in the adrenal cortex. Although the ultimate outcome remains uncertain, functional and morphological brain changes are not uncommon in patients with this syndrome, and generally persist even after resolution of hypercortisolemia. We present an adolescent patient with Cushing’s syndrome who exhibited cognitive impairment with brain atrophy. A 19-year-old Japanese male visited a local hospital following 5 days of behavioral abnormalities, such as money wasting or nighttime wandering. He had hypertension and a 1-year history of a rounded face. Magnetic resonance imaging (MRI) revealed apparently diffuse brain atrophy. Because of high random plasma cortisol levels (28.7 μg/dL) at 10 AM, he was referred to our hospital in August 2011. Endocrinological testing showed adrenocorticotropic hormone-independent hypercortisolemia, and abdominal computed tomography demonstrated a 2.7 cm tumor in the left adrenal gland. The patient underwent left adrenalectomy in September 2011, and the diagnosis of cortisol-secreting adenoma was confirmed histologically. His hypertension and Cushingoid features regressed. Behavioral abnormalities were no longer observed, and he was classified as cured of his cognitive disturbance caused by Cushing’s syndrome in February 2012. MRI performed 8 months after surgery revealed reversal of brain atrophy, and his subsequent course has been uneventful. In summary, the young age at onset and the short duration of Cushing’s syndrome probably contributed to the rapid recovery of both cognitive dysfunction and brain atrophy in our patient. Cushing’s syndrome should be considered as a possible etiological factor in patients with cognitive impairment and brain atrophy that is atypical for their age.


Endocrine Journal | 2010

GH-releasing peptide-2 does not stimulate arginine vasopressin secretion in healthy men.

Kyuzi Kamoi; Shinichi Minagawa; Keita Kimura; Masahiro Ishizawa; Nobumasa Ohara; Yasuyuki Uemura; Junpei Tsuchiya


cardiology research | 2012

Smoking was a Possible Negative Predictor of Incident Hypertension After a Five-Year Follow-up Among a General Japanese Population

Masanori Kaneko; Eiji Oda; Hiromi Kayamori; Satomi Nagao; Hiroshi Watanabe; Takahiro Abe; Masahiro Ishizawa; Yasuyuki Uemura; Yoshifusa Aizawa


Diabetes & Metabolism | 2017

Predictors of the response of HbA1c and body weight after SGLT2 inhibition

Takahiro Abe; Yasuhiro Matsubayashi; A. Yoshida; H. Suganami; T. Nojima; Taeko Osawa; Masahiro Ishizawa; M. Yamamoto; Kazuya Fujihara; Shiro Tanaka; Kohei Kaku; Hirohito Sone

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