Aim: Adipokines are protein products of adipose tissue with paracrine and endocrine actions, which have been implicated in the pathogenesis of cardiovascular disease. Locally produced adipokines, especially by periadventitial adipose tissue, may affect vascular physiology and pathology. We investigated the expression of adiponectin, visfatin, leptin and novel adipokines chemerin and vaspin in human periaortic and epicardial adipose tissue, as well as their correlation to aortic and coronary atherosclerosis. Methods: Standard immunohistochemical staining for the adipokines was performed on samples of human periaortic, pericoronary and apical epicardial adipose tissue. Atherosclerotic lesions of the adjacent vascular wall were assessed using the AHA classification. Results: Adipokines were expressed in periadventitial and apical epicardial adipose tissue and - except for adiponectin - in vascular smooth muscle cells and foam cells in atherosclerotic lesions. Aortic atherosclerosis was positively correlated with chemerin, vaspin, visfatin and leptin periaortic fat expression. Coronary atherosclerosis was positively correlated with chemerin and visfatin pericoronary fat expression. Adipose tissue adiponectin expression was negatively correlated to atherosclerosis in both locations. Expression of adipokines in apical epicardial fat was not associated with atherosclerosis. Conclusions: Our results show: a) a different expression pattern of adiponectin, visfatin, leptin, chemerin and vaspin in periaortic, pericoronary and apical epicardial adipose tissue, b) a correlation of these adipokines with either aortic or coronary atherosclerosis or both in a pattern characteristic for each adipokine and suggest that locally produced adipokines might differently affect the atherosclerotic process in different locations.
Aim: The autosomal recessive hypercholesterolemia (ARH) gene is located on chromosome 1p35 and encodes a 308-amino acid protein containing a phosphotyrosine-binding domain. Several researchers have identified mutations of ARH that cause autosomal recessive hypercholesterolemia; however, it remains unknown whether this gene is involved in common hypercholesterolemia. Methods and Results: We searched for polymorphisms of the ARH gene by denaturing high-performance liquid chromatography and direct sequencing. We identified 18 single nucleotide polymorphisms of the gene, including 9 novel polymorphisms, and determined 2 haplotype blocks. No association was observed between common hypercholesterolemia and any polymorphisms or haplotypes of the ARH gene; however, we newly identified a rare Thr56Met missense mutation located in the phosphotyrosine-binding domain, which is the functional domain responsible for cholesterol metabolism. Among 1,800 Japanese individuals enrolled in the Suita study, only 4 were heterozygous for Thr56Met and all had hypercholesterolemia. The total cholesterol level and low-density lipoprotein cholesterol level of diabetic patients with the Thr56Met missense mutation was 276.3±13.8mg/dL and 185.3±7.37mg/dL, respectively. Conclusions: Because the Thr56Met missense mutation occurs in an orthologously conserved functional domain and all subjects with the mutation had hypercholesterolemia resembling familiar hypercholesterolemia, it may be a cause of familial hypercholesterolemia.
Aim: A recent clinical study using coronary intravascular ultrasound showed that rimonabant, a cannabinoid 1 (CB1) receptor antagonist, significantly reduced total atheroma volume, suggesting that CB1 receptor blockade could be beneficial in anti-atherogenic therapy. The reverse cholesterol transport (RCT) system plays important roles in atherogenesis. We investigated whether CB1 receptor blockade could modulate atherogenesis in mice. Methods and Results: Oral administration of rimonabant (8 mg/kg/day) to apolipoprotein E-deficient mice for 3 months significantly reduced the relative area of atherosclerotic lesions in the aorta (vehicle; 12.6±4.0% vs. rimonabant; 9.7±2.3, n=12 each, p<0.05) with an increase in serum adiponectin levels (15.6±2.3 µg/mL vs. 12.2±2.1, n=12 each, p<0.001), without affecting body weight or serum cholesterol levels. Rimonabant tended to increase serum high-density lipoprotein cholesterol (HDL-C) (p=0.05). The relative area of atherosclerotic lesions in the aorta correlated inversely with serum HDL-C levels (r=-0.45, n=24, p<0.05). Rimonabant upregulated the mRNA expression levels of various components of the RCT system on THP-1 cell-derived macrophages (scavenger receptor B1: 1.15±0.12 fold, n=6; p<0.05, ATP-binding cassette [ABC] transporter G1: 1.23±0.11 fold, n=6; p<0.01), but not ABCA1 (1.13±0.20 fold, n=6; p=0.13). Conclusion: CB1 receptor blockade reduced atherosclerosis in apoE-deficient mice through an increase in serum adiponectin levels and activation of the RCT system. CB1 receptor blockade may be therapeutically beneficial for atherogenesis by increasing the serum adiponectin level and enhancing of the RCT system.
Aim: There are few data focusing on the effect of insulin resistance on a new risk category of prehy-pertension (120-139 mmHg systolic and/or 80-89 mmHg diastolic blood pressure) recently estab-lished by The Seventh Report of the Joint National Committee on High Blood Pressure (JNC-7). We aimed to determine whether insulin resistance was associated with a risk for prehypertension and hypertension. Methods: Of 3,164 (34.6% of 9,133 adults aged 19 to 90 years) adults at the community-based annual medical check-up, study participants without a clinical history of stroke, transient ischemic attack, myocardial infarction, angina, or renal failure (567 men aged 57±14 (mean±standard devia-tion); range, 20-84) years and 702 women aged 59±12; 21-88 years) were recruited. We examined the cross-sectional relationship between insulin resistance, which was evaluated by homeostasis of minimal assessment of insulin resistance (HOMA-IR) and normotension, prehypertension, or hyper-tension using the JNC-7 criteria. Results: The HOMA-IR correlated significantly with systolic (r=0.171) and diastolic (r=0.170) blood pressures. Triglycerides ≥150 mg/dL, HDL-C <40 mg/dL, metabolic syndrome, serum uric acid ≥7.0 mg/dL, and HOMA-IR ≥2.5 showed the highest crude odds ratio (OR) for progression from normotension to prehypertension, and ≥65 years, FBG ≥110 mg/dL, metabolic syndrome, and HOMA-IR ≥2.5 showed the highest crude OR for progression from normotension to hypertension. Multivariate logistic regression analysis showed that HOMA-IR was independently associated with the presence of prehypertension and hypertension. Conclusions: Insulin resistance was significantly associated with prehypertension as well as hyperten-sion in the general population.
Aim: A previous phase 2 study of patients undergoing non-urgent PCI treated with SCH530348 plus aspirin and clopidogrel tended to reduce MACE without increased bleeding. This study evaluated the safety of SCH530348 in Japanese patients with NSTE ACS. Methods: Subjects (117), in whom PCI was planned, received standard-of-care (aspirin, ticlopidine, and heparin) and were randomized 4:1 to receive either SCH530348 (20 or 40 mg loading dose followed by 1 mg/d or 2.5 mg/d for 60 days) or placebo. The key safety endpoint was TIMI major and minor bleeding in the PCI cohort (n=92). The key exploratory efficacy endpoint was MACE and death within 60 days. Addition of SCH530348 to standard-of-care did not significantly increase the rate of TIMI major and minor bleeding (or non-TIMI bleeding) in the primary cohort. Results: Incidence (non-MACE) and discontinuation of AEs were similar across groups. PCI subjects treated with SCH530348 plus standard-of-care experienced a significant reduction in periprocedural MI compared with standard-of-care alone (16.9% vs 42.9%, respectively; p=0.013). There were no deaths or any other MACE. Conclusion: SCH530348 added to standard-of-care did not result in excess bleeding in Japanese subjects with NSTE ACS but significantly reduced the incidence of periprocedural MI in subjects undergoing urgent PCI.
Aim: Cerebrovascular disease (CVD) is a major determinant of the prognosis in end-stage renal diseases (ESRD). The purpose of this study was to examine whether factors associated with arterial stiffness contributed to the development of CVD in patients with ESRD. Methods: CVD (lacunes and carotid/intracranial artery stenosis) was evaluated with brain magnetic resonance imaging (MRI), and carotid/intracranial artery magnetic resonance angiography (MRA) in 44 pre-dialytic patients. The severity of CVD was evaluated by the number of lacunes and the degree of stenosis, respectively. The association between CVD and atherosclerotic parameters was evaluated. Results: Patients with severe lacunes (n=18) manifested older age, lower diastolic blood pressure, serum creatinine and albumin, and higher CRP and serum calcium than those with absent-moderate lacunes (n=26). When assessed by multivariate analysis, only baPWV was adopted as an independent risk factor for severe lacunes. Furthermore, baPWV and i-PTH were associated with the severity of carotid/intracranial artery stenosis, both of which were independent of other risk factors, including age and diabetes. Conclusions: Arterial stiffness may constitute a novel determinant predicting the severity of CVD in pre-dialytic patients besides classical risk factors.
Aim: Ezetimibe, an inhibitor of Niemann-Pick C1-like 1 protein, has been shown to reduce the intestinal absorption of cholesterol. We investigated whether it also has beneficial effects on metabolic disorder and/or renal insufficiency in patients with hypercholesterolemia. Methods: Ezetimibe was administered to 38 Japanese patients with hypercholesterolemia to obtain appropriate low-density lipoprotein cholesterol (LDL-chol) levels. Age- and sex-matched patients with hypercholesterolemia (n=38) were the controls. We evaluated the effects of ezetimibe before and 4 to 8 weeks after ezetimibe treatment. Results: Ezetimibe significantly decreased LDL-chol levels and metabolic syndrome-related factors, including body weight, waist circumference, blood pressure; homeostasis model assessment insulin resistance (HOMA-IR), and urinary albumin excretion, were significantly reduced. In addition, it decreased the level of high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor (TNF)-α, the urinary excretion of 8-hydroxy-2'-deoxyguanosine, a parameter of oxidative stress, and increased the urinary excretion of nitrate and nitrite (NOx). In the controls we observed no such changes. Excepting the decrease in the serum TNF-α level, the effects of ezetimibe were not correlated with decreased LDL-chol levels. Conclusion: Ezetimibe ameliorated the status of metabolic syndrome and microalbuminuria, reduced inflammation and oxidative stress, and increased nitric oxide bioavailability in a LDL-chol reduction-dependent and -independent manner.
Aim: Cardiovascular disease is becoming increasingly more problematic in Mongolia. The cardioankle vascular index (CAVI) and circulating C-reactive protein (CRP) are new atherosclerosis-related parameters, but no comparative studies of atherosclerotic parameters including CAVI and CRP are available between Mongolian and Japanese populations, such as disease populations of hypertension (HT) and diabetes mellitus (DM). Our study objective was to examine atherosclerotic profiles in HT and DM patients in both countries. Methods: From a hospital-based population, 156 Mongolian outpatients with HT and DM (men: 46%, mean age: 57.1 years) and 156 age- and sex-matched Japanese outpatients with HT and DM (men: 46%, age: 57.7) were recruited. Body mass index (BMI), heart rate (HR), blood pressure (BP), pulse pressure (PP), ankle-brachial index (ABI), ultrasonographic carotid intima-media thickness (IMT), blood total cholesterol (T-Cho), glucose, insulin and homeostasis model assessment of insulin resistance (HOMA-IR) were measured, in addition to CAVI and CRP. Results: The levels of BMI, HR, BP, PP, insulin and IMT were significantly higher and T-Cho and glucose were significantly lower in the Mongolian patients in comparison to the Japanese patients. Particularly, the levels of CAVI (mean±SD) (8.1±1.1 vs. 8.8±1.2) and CRP(median[interquartile range])(0.05[0.03-0.12]vs. 0.19[0.09-0.42]mg/dL)were significantly higher in Mongolian than Japanese patients. These significant differences remained unchanged, even after taking into account multiple variables, including BP and HOMA-IR. In addition, except for CAVI in the subgroup of DM, generally similar trends regarding atherosclerotic parameters were seen in the subgroup by sex and disease (HT, DM and HT plus DM). Conclusion: These findings suggest that Mongolian patients with HT and DM may be at higher risk for cardiovascular disease than Japanese patients.
Aim: To evaluate the prevalence of prehypertension among middle-aged and elderly people in Taiwan and to explore the evolutionary changes of blood pressure in 5-year follow-up period. Methods: In 2000, people aged over 40 participating in annual health examinations at local health stations in I-Lan County were invited to join the study. Past medical histories were reviewed, physical examinations and serial laboratory tests were performed for participants. All participants were followed in 2005 by a medical record review, telephone survey or personal visit. Subjects with prehypertension were sorted for further analysis. Results: Overall, 1053 people (mean age=64.4±11.4 years, 44.4% males) were enrolled in the primary cohort. The prevalence of hypertension and prehypertension was 40.4% and 35.8%, respectively. In 2005, 677 subjects (mean age: 68.8±10.4 years, 42.5% males) were successfully followed, which revealed a significant increase of systolic blood pressure (3.7±16.8 mmHg, p<0.001), but not diastolic blood pressure (0.3±11.5 mmHg, p=0.758) in prehypertensive subjects; however, both systolic blood pressure (14.3±17.4 mmHg, p<0.001) and diastolic blood pressure (7.7±13.3 mmHg, p<0.001) were significantly increased among normotensive subjects. The cumulative incidence of prehypertensive subjects becoming hypertensive was 31.3%, and those who became hypertensive were significantly older (65.3±8.6 vs. 62.2±12.3 years, p=0.024), having higher pulse pressure in 2000 (49.6±10.6 vs. 45.1±11.6 mmHg, p=0.001), serum total cholesterol (214.3±31.7 vs. 204.0±37.2 mg/dL, p=0.020) and low-density lipoprotein-cholesterol (141.7±29.2 vs. 132.7±34.7 mg/dL, p=0.042). Conclusions: The prevalence of prehypertension among older Taiwanese was 35.8% and the 5-year cumulative incidence of hypertension from prehypertension was 31.3%. Older prehypertensive subjects with higher pulse pressure, higher serum total cholesterol and higher low-density lipoproteincholesterol were more likely to become hypertensive within 5 years.
Aim: Gamma-glutamyltransferase (GGT) is known to correlate well with alcohol consumption; however, the relation between GGT and diabetes and that between alcohol consumption and diabetes mellitus (DM) is inconsistent. Thus, several questions, such as whether light to moderate drinkers can be considered as low risk for diabetes incidence irrespective of their GGT level, is unresolved. In this study, we investigated the relation of GGT or alcohol drinking with DM incidence considering the body mass index (BMI) in healthy Japanese workers. Methods: We followed 3095 men who did not have DM at baseline for 4 years. Incident diabetes was defined as a fasting (non-fasting) plasma glucose level of ≥7.0 (11.1) mmol/L, or treatment of diabetes. Multiple adjusted hazard ratios (HR) were calculated using Cox proportional models. Results: Participants with higher GGT (GGT ≥27 IU/L) showed an increased risk of diabetes incidence even when their BMI level was low. Although a U-shaped relation between alcohol drinking and incident diabetes was observed, the risk to light to moderate drinkers (alcohol <23 g/day) was not low if they were either overweight (BMI ≥25 kg/m2) or had higher GGT (HR=2.60, p=0.08) or both overweight and higher GGT (HR=3.16, p=0.07) compared with never drinkers without higher GGT and overweight. Conclusions: Higher GGT was associated with a higher incidence of DM irrespective of drinking status or obesity. Although a U-shaped relation between alcohol drinking and incident diabetes was observed, the risk to light to moderate drinkers was not low if they were either overweight or had higher GGT.
C-reactive protein (CRP) is a pluripotent mediator of inflammation and is present at sites of vascular injury and in atherosclerotic lesions. CRP stimulates endothelial cell adhesion molecule expression and monocyte migration, thereby contributing to the development and progression of vascular lesion formation. In addition, chronic exposure to CRP is known to inhibit angiogenesis and endothelial cell (EC) proliferation. Aim: Whether CRP also affects EC migration, however, has yet to be determined. The present study investigates how long-term exposure to CRP interacts with vascular endothelial growth factor (VEGF) -induced EC migration. Methods and Results: Using a Transwell chamber migration assay, VEGF (20 ng/mL, 5 h incubation) -induced migration of human umbilical vein EC was significantly inhibited in cells pretreated with CRP (10μg/mL) for 24 h by more than 75%. EC migration in response to VEGF is known to require activation of the proteinkinase B (Akt)/endothelial NO synthase (eNOS)- and the extracellular signal-regulated protein kinase 1/2 (ERK1/2) pathway. We therefore investigated the long-term effects of CRP on these signalling events. Immunoblotting with phosphospecific antibodies revealed rapid and transient activation/phosphorylation of the protein kinase Akt within 20 minutes after stimulation with VEGF, which was inhibited by 86% in EC pretreated with CRP (10μg/mL, 24 h, p<0.05). Subsequent VEGF-induced phosphorylation of eNOS downstream of Akt was completely inhibited in CRP-treated EC. In contrast, CRP-pretreatment did not affect VEGF-induced phosphorylation of ERK1/2. Interestingly, stimulation of EC with CRP for 16-24 h induced marked expression of the phosphatase and tensin homolog (PTEN), which functions as a negative regulator of phosphatidylinositol 3 kinase (PI3K) →Akt signalling. Conclusion: The observed time course for CRP-mediated PTEN upregulation corresponds to the exposure time needed for inhibition of Akt phosphorylation and migration and may therefore constitute a potential mechanism by which CRP inhibits inducible Akt phosphorylation and EC migration.
Aim: Dietary fats may affect coronary artery disease risk by influencing factors other than serum cholesterol. The effect of diets containing coconut oil and sunflower oil without cholesterol supplementation on oxidative stress and lipid peroxidation were studied in male New Zealand White rabbits. Methods: Animals assigned to four groups (control, cholesterol-fed, coconut oil-fed and sunflower oil-fed), given an isocaloric diet and studied for 6 months. The lipid profile, reduced glutathione, glutathione peroxidase, superoxide dismutase, vitamin C and lipid peroxidation were evaluated at the beginning of the study, at the third month and at the end of the study period. Results: Serum lipid values did not show significant variation between animals fed coconut oil and sunflower oil, but total cholesterol, triglycerides and LDL-cholesterol were significantly higher and HDL-cholesterol was reduced in cholesterol-fed animals. Lipid peroxidation was higher in choles-terol-fed and sunflower oil-fed rabbits compared to controls and coconut oil-fed rabbits. Though other parameters such as reduced glutathione, glutathione peroxidase, superoxide dismutase and ascorbate did not vary between the two oil-fed rabbit groups, cholesterolfed rabbits showed severe oxidative stress. Conclusion: We conclude that in the absence of cholesterol supplementation, coconut oil intake up to 30% of daily energy supply did not cause hypercholesterolemia or oxidative stress in rabbits.