Publications by authors named "Tomokazu Oyama"

Objective: Obesity is associated with type 2 diabetes, dyslipidemia and hypertension, contributing to atherogenesis. Weight reduction is the fundamental therapy for obesity. Recently, a novel arterial stiffness parameter called cardio-ankle vascular index (CAVI) has been developed.

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The cardio-ankle vascular index (CAVI) has been proposed as a new noninvasive marker of arterial stiffness independent of blood pressure. Arterial stiffness is closely related to afterload, and elevated afterload aggravates heart failure. We hypothesized that CAVI is a potential marker of afterload in patients with heart failure.

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Aim: Probucol has antioxidant as well as cholesterol-lowering effects. We examined the effect of probucol on the progression of diabetic nephropathy. We named this study 'Sakura Study' after our hospital and city.

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Aim: The cardio-ankle vascular stiffness index (CAVI) is a new parameter that reflects the stiffness of the aorta, femoral artery and tibial artery as a whole. One of its conspicuous features is that CAVI is independent of blood pressure at measuring time, theoretically. But, it has not been experimentally proved yet.

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Postprandial hyperglycemia is known to be associated with increasing cardiovascular mortality in type 2 diabetes mellitus patients. Cardio-ankle vascular index (CAVI) reflects arterial stiffness and is more useful for predicting coronary atherosclerosis than intima-media thickness. Premixed human insulin 30/70 (BHI30) containing rapid-acting insulin has been used conventionally as a biphasic insulin.

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Aim: High cholesterol absorption in the small intestine has been proposed to be a risk factor of atherosclerosis. In this study, we evaluated the effect of ezetimibe monotherapy on arterial stiffness in type 2 diabetic patients.

Methods: Forty type 2 diabetes mellitus patients with high serum low-density lipoprotein cholesterol (LDL-C) were enrolled and treated with ezetimibe 10 mg/day for 6 months.

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Aim: Adipocytes express all components of the renin-angiotensin system (RAS), and adipocyte RAS regulates adipocyte differentiation and metabolism. Plasma angiotensin II (AII) is a putative marker of adipocyte RAS production. The aim of this study was to investigate the effect of pioglitazone on plasma AII in type 2 diabetes (T2D).

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Aim: Recently, a novel device for measuring the cardio-ankle vascular index (CAVI) as an arterial stiffness parameter has been developed. In this study, we evaluated the effect of angiotensin II receptor blocker (ARB) and calcium channel (Ca) blocker on CAVI in type 2 diabetic patients with hypertension.

Methods: Seventy type 2 diabetes mellitus patients with hypertension were enrolled and randomly divided into two groups.

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Aim: A novel device has been developed for measuring the cardio-ankle vascular index (CAVI) as an indicator of arterial stiffness. In this study, we evaluated the effect of pitavastatin on CAVI in type 2 diabetic patients.

Methods: Forty-five type 2 diabetes mellitus patients with low-density lipoprotein cholesterolemia were enrolled and treated with pitavastatin 2 mg/day for 12 months.

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Aim: The three types of calcium channel blocker (CCB), L-, T- and N-type, possess heterogeneous actions on endothelial function and renal microvascular function. In the present study, we evaluated the effects of two CCBs, efonidipine and amlodipine, on renal function and arterial stiffness.

Methods: Forty type 2 diabetic patients with hypertension and nephropathy receiving angiotensin receptor II blockers were enrolled and randomly divided into two groups: the efonidipine group was administered efonidipine hydrochloride ethanolate 40 mg/day and the amlodipine group was admin-istered amlodipine besilate 5 mg/day for 12 months.

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Adipocytes express all components of the renin-angiotensin system, and the renin-angiotensin system is involved in obesity and insulin resistance. Circulating angiotensin II (Ang II) is detectable in blood, but its significance in human obesity remains unknown. The aim of this study was to investigate plasma Ang II in obese patients with type 2 diabetes mellitus (T2D) and the change during weight loss.

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Aim: We analyzed the lipoproteins of a patient with pancreatic cancer causing obstructive jaundice, with marked hypercholesterolemia.

Methods: The patient was a 49-year-old female. Serum total cholesterol, triglyceride, LDL-cholesterol and HDL-cholesterol levels were 1,170 mg/dL, 282 mg/dL, 1,070 mg/dL and 53 mg/dL, respectively.

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Aim: Previous reports indicate that serum lipoprotein lipase mass levels (LPL mass) and common carotid artery intima-media thickness (CCA-IMT) are independent predictors of atherosclerotic diseases. The aim of this study was to examine the effects of combination therapy of sulfonylurea and acarbose on LPL mass and CCA-IMT.

Methods: Eighty-four patients with type 2 diabetes mellitus, who were treated with only sulfonylureas and showed CCA-IMT of more than 0.

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Oxysterols have cytotoxic effects and contribute to the development of atherosclerosis. To examine association between 7-ketocholesterol and diabetes mellitus, and other coronary risk factors, we developed a reliable quantitative method to measure serum 7-ketocholesterol (s-7KCHO) and studied s-7KCHO in patients with type 2 diabetes mellitus (T2DM). The s-7KCHO was detected by gas chromatography-mass spectrometry assay.

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Aim: We investigated the effects of a calorie-restricted low-carbohydrate diet on glucose and lipid metabolism, and body fat distribution, especially on the secretion of leptin and lipoprotein lipase from adipose tissue in Otsuka Long Evans Tokushima Fatty (OLETF) rats.

Methods: Forty-three week-old male OLETF rats were randomized into three groups (n=6 per group): the HC group (HC) was fed a diet with 60% carbohydrate; the LC group (LC) with 30% carbohydrate; and the P-HC group (P-HC) with 60% carbohydrate and pioglitazone (0.1%).

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We previously reported that lipoprotein lipase mass levels in preheparin serum (preheparin LPL mass) was significantly lower in type 2 diabetes mellitus compared to healthy subjects and that low preheparin LPL mass may be a high-risk factor of coronary atherosclerosis. The aim of this study was to clarify the effects of metformin on serum lipoprotein lipase mass levels (preheparin LPL mass), adiponectin and lipid metabolism in patients with type 2 diabetes mellitus. Twenty-eight patients with type 2 diabetes mellitus (HbAlc>7.

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Lipoprotein lipase mass in preheparin serum (preheparin LPL mass) is assumed to reflect some of the LPL production in the whole body and insulin sensitivity. While metabolic syndrome is a common underlying condition for cardiovascular diseases, biological marker of this syndrome has not been fully established. To clarify the characteristics of preheparin LPL mass in metabolic syndrome, 362 Japanese subjects were studied to examine the relationship between symptoms of metabolic syndrome and preheparin LPL mass and compare with plasma adiponectin.

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The effects of combination therapy of angiotensin II receptor blockers (ARBs) and a calcium antagonist, benidipine hydrochloride, on glucose and lipid metabolism and pulse pressure were studied in elderly hypertensive patients with type 2 diabetes mellitus. Twenty-five hypertensive diabetic patients aged 65 years or older, who had been receiving candesartan cilexetil, were administered benidipine hydrochloride (4 mg/day) and followed for 4 months. After 4 months, systolic and diastolic blood pressure decreased significantly from 154/91 mmHg to 139/78 mmHg (p<0.

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Recent studies suggest that blockade of angiotensin type 1 (AT1) receptor may have some effect on glucose and lipoprotein metabolism. Serum level of preheparin lipoprotein lipase (LPL) reflects LPL production mainly in adipocytes and is believed to be related to insulin sensitivity. We studied the effect of a selective AT1 antagonist, valsartan, on glucose, lipid metabolism and the preheparin LPL mass in 55 patients with type 2 diabetes and hypertension.

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To clarify the mechanism by which hyperglycemia in diabetes mellitus causes endothelial cell damages, the effects of high glucose on DNA fragmentation and caspase-3 activity of cultured endothelial cells and on the generation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) were studied. Furthermore, the involvement of the polyol pathway in this process was investigated using aldose reductase inhibitor (SNK-860). Human umbilical vein endothelial cells (HUVECs) were incubated with 5.

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To clarify whether probucol and statins suppress oxidative stress in diabetic patients, we studied the effects of probucol and the statin atorvastatin on urinary 8-hydroxy-2'deoxyguanosine (8-OHdG) levels in diabetics with hypercholesterolemia. A randomized, open study was performed on a total of 36 patients with type 2 diabetes and hypercholesterolemia. The patients were randomly assigned to a probucol group (500 mg/day, n = 18) or an atorvastatin group (10 mg/day, n = 18).

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We previously reported that lipoprotein lipase mass level in preheparin serum (preheparin LPL mass) was significantly lower in type 2 diabetes mellitus compared to healthy subjects and increased by conventional insulin therapy using NPH (intermediate-acting) insulin. The aim of this study was to investigate the effects of intensive insulin therapy on preheparin LPL mass. Thirty-two subjects (total group) with type 2 diabetes receiving treatment by NPH insulin injection twice a day in the morning and evening were switched to basal bolus insulin (BBI) therapy (fast-acting insulin after each meal and NPH insulin before bedtime).

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This study was conducted to clarify the characteristics of colestimide responders. Forty-seven non-diabetic patients with high levels of low-density lipoprotein cholesterol (LDL-C) received colestimide at 3,000 mg/day and were followed up for 4 months. After 4 months, body weight was reduced but the change was not statistically significant.

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It is known that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) enhance the expression- of the low-density lipoprotein (LDL) receptor and lower the level of LDL cholesterol in the blood. But, a triglyceride (TG)-lowering effect is also observed during their administration. To clarify the possibility that statins enhance LPL activity and its mechanism, the effects of statins on the expression of LPL in adipocytes were studied.

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