Hyperlipidemias: Biro S

Teramoto T, Sasaki J, Ueshima H, Egusa G, Kinoshita M, Shimamoto K, Daida H, Biro S, Hirobe K, Funahashi T, Yokote K, Yokode M, Anonymous00494. · Committee for Epidemiology and Clinical Management of Atherosclerosis. · J Atheroscler Thromb. · Pubmed #18480589 links to  free full text

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Eto H, Miyata M, Shirasawa T, Akasaki Y, Hamada N, Nagaki A, Orihara K, Biro S, Tei C. · Department of Cardiovascular, Respiratory and Metabolic Medicine, Graduate School of Medicine, Kagoshima University, Kagoshima, Japan. · Hypertens Res. · Pubmed #18971539 No free full text.

Abstract: Angiotensin II type 1 receptor may contribute to atherogenesis by facilitating the proliferative and inflammatory response to hypercholesterolemia. In the present study, we investigated the long-term effect of angiotensin II type 1a receptor (AT1a) deficiency on hypercholesterolemia-induced atherosclerosis by the use of AT1a-knockout (AT1a-KO) mice and apolipoprotein E-knockout (apoE-KO) mice. AT1a-KO were crossed with apoE-KO, generating double-knockout (D-KO) mice. Mice were fed a standard diet and analyzed at 25- or 60-weeks-old. The quantification of atherosclerotic volume in the aortic root revealed that the atherosclerotic lesions of D-KO mice were significantly smaller than those of apoE-KO mice at 25-week-old (0.81+/-0.16 mm2 vs. 1.05+/-0.21 mm2, p<0.001) and at 60-week-old (0.89+/-0.11 mm2 vs. 2.44+/-0.28 mm2, p<0.001). Surprisingly, there was no significant difference in atherosclerotic lesion size of D-KO mice at 25- and 60-week-old, suggesting that AT1a deficiency completely protected against the age-related progression of atherosclerosis. The amounts of collagen and elastin, the expression of p22phox, serum amyloid P (SAP), matrix metalloproteinase (MMP)-2, and MMP-9, and the number of apoptotic cells of D-KO mice were lower than those of apoE-KO mice. Furthermore, we confirmed that the expression of procollagen alpha1(I), procollagen alpha1(III), tropoelastin, p22phox, SAP, MMP-2, and MMP-9 decreased in cultured vascular smooth muscle cells from D-KO mice compared with those of apoE-KO mice. In conclusion, AT1a deficiency reduces atherosclerotic lesion size of apoE-KO mice and protects against the age-related progression of atherosclerosis. Reduction of oxidative stress, apoptosis, and MMP expression in atherosclerotic lesions by AT1a deficiency may contribute to plaque size.

Sasaki J, Ikeda Y, Kuribayashi T, Kajiwara K, Biro S, Yamamoto K, Ageta M, Kobori S, Saikawa T, Otonari T, Kono S. · International University of Health and Welfare Graduate School of Public Health Medicine, Tagawa Municipal Hospital, Fukuoka, Japan. · Clin Ther. · Pubmed #18640465 No free full text.

Abstract: BACKGROUND: Statin therapy has been found to produce substantial reductions in low-density lipoprotein cholesterol (LDL-C) levels, resulting in a reduced risk for cardiovascular events. Recently, research interest has focused on modification of high-density lipoprotein cholesterol (HDL-C) levels for the potential prevention of cardiovascular events. The effects of pitavastatin and atorvastatin on HDL-C have not been directly compared. OBJECTIVES: This study compared the effects of pitavastatin and atorvastatin on HDL-C and other lipids and glucose metabolism in Japanese patients with elevated LDL-C levels and glucose intolerance. The tolerability of the 2 treatments was also compared. METHODS: This was a multicenter, open-label, parallel-group trial. Patients with LDL-C levels>or=140 mg/dL and glucose intolerance (defined according to Japanese criteria for borderline diabetes and World Health Organization criteria for impaired fasting glucose and impaired glucose tolerance) were randomly assigned to receive either pitavastatin 2 mg/d or atorvastatin 10 mg/d for 52 weeks. Levels of serum lipids and lipoproteins and measures of glucose metabolism (fasting insulin, fasting glucose, glycosylated hemoglobin, and homeostasis model assessment for insulin resistance) were obtained at baseline and at 8, 26, and 52 weeks of treatment. The effect of study drug on glucose metabolism was evaluated as a tolerability outcome. Tolerability was further assessed based on adverse events, either spontaneously reported or elicited by questioning; physical examination findings; and clinical laboratory test results. Study physicians rated the relationship of adverse events to study medication as unrelated, suspected, or probable. RESULTS: Two hundred seven patients were enrolled in the study, and efficacy was evaluated in 173 patients (88 pitavastatin, 85 atorvastatin). Thirty-four patients were excluded for reasons including failure to start medication or lack of >or=6 months of follow-up. Women accounted for 62% (108/173) of the evaluable population, which had a mean age of 63.3 years and a mean weight of 63.0 kg; 89% (154/173) had diabetes mellitus. The percent change in HDL-C levels was significantly greater in the pitavastatin group compared with the atorvastatin group (8.2 vs 2.9, respectively; P=0.031), as was the percent change in apolipoprotein (Apo) A-I (5.1 vs 0.6; P=0.019). The percent change in LDL-C levels was significantly lower with atorvastatin compared with pitavastatin (-40.1 vs -33.0, respectively; P=0.002), as were the percent changes in non-HDL-C (-37.4 vs -31.1; P=0.004), Apo B (-35.1 vs -28.2; P<0.001), and Apo E (-28.1 vs -17.8; P<0.001). The significant results for these parameters were unchanged when all 189 subjects who received>or=1 dose of study medication were included in the analysis, using last-value-carried-forward methodology. There were no significant differences between treatments with respect to the measures of glucose metabolism. Both statins appeared to be well tolerated. Adverse events occurred in 9% (9/96) of the pitavastatin group and 14% (13/93) of the atorvastatin group (P=NS). Two patients in the pitavastatin group and none in the atorvastatin group had an alanine aminotransferase value>3 times the upper limit of normal (P=NS). CONCLUSIONS: In these patients with elevated LDL-C levels and glucose intolerance, 52 weeks of treatment with pitavastatin 2 mg/d was associated with significantly greater increases in HDL-C and Apo A-I levels than atorvastatin 10 mg/d. Both treatments were well tolerated.

Ogawa M, Abe S, Saigo M, Biro S, Toda H, Matsuoka T, Torii H, Minagoe S, Maruyama I, Tei C. · First Department of Internal Medicine, Faculty of Medicine, Kagoshima University, 8-35-1 Sakuragaoka, 890-8520, Kagoshima, Japan. · Thromb Res. · Pubmed #12818247 No free full text.

Abstract: INTRODUCTION: Hyperhomocysteinemia is a coronary risk factor, but its pathophysiologic mechanism remains unclear. MATERIALS AND METHODS: The importance of hyperhomocysteinemia in the pathogenesis of early myocardial infarction, was determined in case-control study of 127 men with a first early myocardial infarction <or=45 years and 150 age-matched male controls. We measured plasma concentrations of homocysteine, fibrinogen, antithrombin, tissue factor, tissue factor pathway inhibitor, tissue plasminogen activator, plasminogen activator inhibitor-I, plasminogen, alpha(2)-antiplasmin, lipoprotein(a), protein C, protein S, factor VII, and activated factor VII. RESULTS: Homocysteine concentrations were higher in patients with early myocardial infarction than in controls (11.2+/-5.3 and 8.3+/-5.0 micromol/l, respectively, P<0.001). Hyperhomocysteinemia was associated with early myocardial infarction (odds ratio=2.22, P<0.001) by multivariate logistic regression analysis. Tissue factor, antithrombin, plasminogen, tissue plasminogen activator, plasminogen activator inhibitor-I, lipoprotein(a), diabetes, and smoking also had associations. In a stepwise logistic regression analysis, hyperhomocysteinemia was the strongest predictor of early myocardial infarction (R(2)=0.19, P<0.001). Hyperhomocysteinemia also had positive correlations with tissue factor (rho=0.26, P=0.009), tissue factor pathway inhibitor (rho=0.23, P=0.020), and tissue plasminogen activator (rho=0.25, P=0.011) in patients with early myocardial infarction, but not in controls. CONCLUSIONS: Hyperhomocysteinemia is an independent risk factor for early myocardial infarction, and is associated with a hypercoagulable state mediated by the extrinsic coagulation cascade.