Impact of overnight 1 mg dexamethasone on vascular function in patients with nonfunctioning adrenal adenomas.

The purpose of this study was to evaluate the effects of administration of overnight 1 mg dexamethasone on vascular function in patients with nonfunctioning adrenal adenomas (NFA). Flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation (NID) were measured to assess vascular function in 22 patients with NFA who had hypertension and/or diabetes mellitus (DM) and 272 patients without adrenal incidentalomas who had hypertension and/or DM (control patients with hypertension and/or DM). FMD and NID were measured in the morning before and after administration of 1 mg of dexamethasone at 2300 h in 18 patients with NFA. There were no significant differences in FMD and NID between control patients with hypertension and/or DM and patients with NFA who had hypertension and/or DM (3.4 ± 2.8% vs. 2.9 ± 1.9% and 11.5 ± 5.7% vs. 11.4 ± 4.3%, P = 0.46, and P = 0.99, respectively). There were no significant differences in vascular function between control patients with hypertension and/or DM and patients with NFA who had hypertension and/or DM even after adjustment for cardiovascular risk factors. Overnight 1 mg dexamethasone increased FMD from 2.4 ± 1.9% to 5.3 ± 3.2% (P < 0.01) and increased NID from 12.1 ± 4.2% to 14.0 ± 2.8% (P < 0.01) in patients with NFA. The overnight 1 mg dexamethasone suppression test does not impair FMD and NID in patients with NFA. Decreases in circulating levels of cortisol may improve vascular function.Clinical Trial Registration: This study was approved by principal authorities and ethical issues in Japan (URL for Clinical Trial: http://www.umin.ac.jp/ctr/index.htm Registration Number for Clinical Trial: UMIN000039512).

KCNJ5 mutation is a predictor for recovery of endothelial function after adrenalectomy in patients with aldosterone-producing adenoma.

The relationship of KCNJ5 mutation with vascular function and vascular structure in aldosterone-producing adenoma (APA) patients before and after adrenalectomy remains unclear. The purpose of this study was to evaluate the influence of KCNJ5 mutation on vascular function and vascular structure in APA and the effects of adrenalectomy on vascular function and vascular structure in APA patients with and those without KCNJ5 mutation. Flow-mediated vasodilation (FMD), nitroglycerine-induced vasodilation (NID), brachial artery intima-media thickness (IMT), and brachial-ankle pulse wave velocity (baPWV) were measured to assess vascular function and vascular structure in 46 APA patients with KCNJ5 mutation and 23 APA patients without KCNJ5 mutation and in 69 matched pairs of patients with essential hypertension (EHT). FMD, NID, brachial IMT and baPVW were evacuated before adrenalectomy and at 12 weeks after adrenalectomy in APA patients with KCNJ5 mutation and APA patients without KCNJ5 mutation. FMD and NID were significantly lower in APA patients than in patients with EHT. There was no significant difference in FMD or NID between patients with and those without KCNJ5 mutation. In APA patients with KCNJ5 mutation, FMD and NID after adrenalectomy were significantly higher than those before adrenalectomy. In APA patients without KCNJ5 mutation, only NID after adrenalectomy was significantly higher than that before adrenalectomy. Endothelial function in APA patients with KCNJ5 mutation was improved by adrenalectomy in the early postoperative period. KCNJ5 mutation is a predictor for early resolution of endothelial function by adrenalectomy. This study was approved by principal authorities and ethical issues in Japan (URL for Clinical Trial: http://www.umin.ac.jp/ctr/index.htm Registration Number for Clinical Trial: UMIN000003409).

Endothelial Function Is Preserved in Patients with Wild-Type Transthyretin Amyloid Cardiomyopathy.

Heart failure (HF) is associated with endothelial dysfunction. Vascular function per se plays an important role in cardiac function, whether it is a cause or consequence. However, there is no information on vascular function in patients with wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM). The purpose of this study was to evaluate vascular function in patients with ATTRwt-CM. We measured flow-mediated vasodilation (FMD) as an index of endothelial function and nitroglycerine-induced vasodilation (NID) as an index of vascular smooth muscle function and brachial artery intima-media thickness (bIMT) and brachial-ankle pulse wave velocity (baPWV) as indices of arterial stiffness in 22 patients with ATTRwt-CM and in 22 one-by-one matched control patients using vascular function confounding factors. FMD was significantly greater in patients with ATTRwt-CM than in the controls (5.4 ± 3.4% versus 3.5 ± 2.4%, p = 0.038) and the N-terminal pro-brain natriuretic peptide (NT-proBNP) level was significantly greater in patients with ATTRwt-CM than in the controls (2202 ± 1478 versus 470 ± 677 pg/mL, p < 0.001). There were no significant differences in NID, bIMT or baPWV between the two groups. There was a significant relationship between NT-proBNP and FMD in patients with ATTRwt-CM (r = 0.485, p = 0.022). NT-proBNP showed no significant relationships with NID, bIMT or baPWV. Conclusions: Endothelial function was preserved in patients with ATTRwt-CM. Patients with ATTRwt-CM may have compensatory effects with respect to endothelial function through elevation of BNP.

Effect of exposure to radiation caused by an atomic bomb on endothelial function in atomic bomb survivors.

Background: The purpose of this study was to evaluate the effects of exposure to radiation caused by an atomic bomb in atomic bomb survivors on vascular function and vascular structure and to evaluate the relationships of radiation dose from the atomic bomb with vascular function and vascular structure in atomic bomb survivors. Methods: Flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation (NID) as indices of vascular function, brachial-ankle pulse wave velocity (baPWV) as an index of vascular function and vascular structure, and brachial artery intima-media thickness (IMT) as an index of vascular structure were measured in 131 atomic bomb survivors and 1,153 control subjects who were not exposed to the atomic bomb. Ten of the 131 atomic bomb survivors with estimated radiation dose in a cohort study of Atomic Bomb Survivors in Hiroshima were enrolled in the study to evaluate the relationships of radiation dose from the atomic bomb with vascular function and vascular structure. Results: There was no significant difference in FMD, NID, baPWV, or brachial artery IMT between control subjects and atomic bomb survivors. After adjustment of confounding factors, there was still no significant difference in FMD, NID, baPWV, or brachial artery IMT between control subjects and atomic bomb survivors. Radiation dose from the atomic bomb was negatively correlated with FMD (ρ = -0.73, P = 0.02), whereas radiation dose was not correlated with NID, baPWV or brachial artery IMT. Conclusion: There were no significant differences in vascular function and vascular structure between control subjects and atomic bomb survivors. Radiation dose from the atomic bomb might be negatively correlated with endothelial function.

White blood cell count is not associated with flow-mediated vasodilation or nitroglycerine-induced vasodilation.

It is well known that white blood cell (WBC) count is an independent predictor of cardiovascular events. However, associations of WBC count and WBC subtypes with endothelial function assessed by flow-mediated vasodilation (FMD) and vascular smooth muscle function assessed by nitroglycerine-induced vasodilation (NID) are unclear. The aim of this study was to determine the relationships of WBC count and WBC subtypes with vascular function assessed by FMD and NID. A total of 1351 subjects in whom FMD and NID had been measured were recruited from Hiroshima University Vascular Registry. Mean values were 3.7 ± 2.8% for FMD and 11.8 ± 5.9% for NID. WBC was not correlated with FMD or NID. NID was significantly correlated with lymphocytes in univariate analysis but not with other hematologic parameters. In multiple linear regression analyses, NID was not correlated with lymphocytes. In all subgroups including subgroups of age, gender, body mass index, hypertension, dyslipidemia, diabetes mellitus, smoking and tertile of WBC count, WBC count was not correlated with FMD or NID. WBC count and WBC subtypes were not associated with endothelial function assessed by FMD or vascular smooth muscle function assessed by NID. WBC count and vascular function assessed by FMD and NID may reflect different aspects of atherosclerosis.Clinical Trial Registration Information: URL for Clinical Trial: http://www.umin.ac.jp Registration Number for Clinical Trial: UMIN000039512.

Short stature is associated with low flow-mediated vasodilation in Japanese men.

An inverse association between height and the risk of cardiovascular disease has been reported. The objective of this study was to examine the association between height and endothelial function assessed by flow-mediated vasodilation (FMD). We evaluated cross-sectional associations of height with FMD in 7682 Japanese men. All participants were divided into four groups based on height: <155.0 cm, 155.0-164.9 cm, 165.0-174.9 cm, and ≥175.0 cm. Subjects in a lower quartile of FMD were defined as subjects having low FMD values. Univariate regression analysis revealed that height was significantly correlated with FMD (r = 0.14, p < 0.001). FMD values were 4.6 ± 3.1% in the <155.0 cm group, 5.2 ± 3.1% in the 155.0-164.9 cm group, 5.7 ± 3.1% in the 165.0-174.9 cm group and 6.1 ± 3.2% in the ≥175.0 cm group. FMD significantly increased in relation to an increase in height. Multiple logistic regression analysis revealed that higher height groups were significantly associated with a decreased risk of low FMD value compared with the <155.0 cm group after adjustments for age, presence of hypertension, dyslipidemia, diabetes, current smoking, and brachial artery diameter. FMD was low in subjects with a short stature compared with that in subjects with tall stature. Individuals with a short stature may require intensive interventions to reduce the risk of cardiovascular events.Clinical Trial Registration Information: URL for Clinical Trials: http://www.umin.ac.jp Registration Number for Clinical Trials: UMIN000012952.

Smoking status and endothelial function in Japanese men.

It is established that smoking is a major risk factor of atherosclerosis. Endothelial dysfunction occurs in the initial step in the pathogenesis of atherosclerosis and plays a critical role in the development of atherosclerosis. The purpose of this study was to evaluate the association between smoking status and endothelial function in detail in men. We measured flow-mediated vasodilation (FMD) in 2209 Japanese men including 1181 men who had never smoked and 1028 current smokers. All of the participants were divided into five groups by smoking pack-years: never smoker group (= 0), light smoker group (> 0 to 10), moderate smoker group (> 10 to 20), heavy smoker group (> 20 to 30) and excessive smoker group (> 30). FMD significantly decreased in relation to pack-years (6.6 ± 3.4% in the never smoker group, 6.8 ± 3.0% in the light smoker group, 6.5 ± 2.9% in the moderate smoker group, 5.9 ± 2.9% in the heavy smoker group, and 4.9 ± 2.7% in the excessive smoker group; P < 0.001). After adjustment for age (≥ 65 years), body mass index, systolic blood pressure, low-density lipoprotein cholesterol, glucose, and year of recruitment, FMD was significantly smaller in the excessive smoker group than in the never smoker group as a reference group (OR 1.95, 95% CI 1.42 to 2.67; P < 0.001). These findings suggest that FMD decreases with an increase in the number of cigarettes smoked and that excessive smoking is associated with endothelial dysfunction. Cigarette smoking is harmful to vascular function in men who are heavy smokers.

A Comparison of Adrenalectomy and Eplerenone on Vascular Function in Patients with Aldosterone-producing Adenoma.

CONTEXT: It remains unclear whether adrenalectomy has more beneficial effects than treatment with a mineralocorticoid receptor antagonist on vascular function in patients with aldosterone-producing adenoma (APA). OBJECTIVE: The aim of this study was to compare the effects of adrenalectomy and treatment with eplerenone on vascular function in patients with APA. DESIGN, SETTING, AND PATIENTS: Flow-mediated vasodilation (FMD), as an index of endothelium-dependent vasodilation, and nitroglycerine-induced vasodilation (NID), as an index of endothelium-independent vasodilation, were measured to assess vascular function before and after a 3-month treatment with eplerenone and at 3 months after adrenalectomy in 23 patients with APA. RESULTS: Flow-mediated vasodilation and NID after adrenalectomy were significantly higher than those before treatment with eplerenone (5.4 ± 2.6% vs 2.7 ± 1.9% and 14.8 ± 4.7% vs 9.6 ± 4.6%, P < 0.01, respectively) and those after treatment with eplerenone (5.4 ± 2.6% vs 3.1 ± 2.3% and 14.8 ± 4.7% vs 11.0 ± 5.3%, P < 0.01 and P = 0.03, respectively), while treatment with eplerenone did not alter FMD and NID compared with those before treatment with eplerenone. After adrenalectomy, the increase in FMD and NID were significantly correlated with a decrease in plasma aldosterone concentration and a decrease in the aldosterone-renin ratio. There were no significant relationships between FMD and changes in other parameters or between NID and changes in other parameters. CONCLUSIONS: Adrenalectomy, but not treatment with eplerenone, improved vascular function in patients with APA. Adrenalectomy may be more effective than treatment with eplerenone for reducing the incidence of future cardiovascular events in patients with APA. Clinical Trial Information: URL for the clinical trial: http://UMIN; Registration Number for the clinical trial: UMIN000003409.

Eplerenone improves endothelial function and arterial stiffness and inhibits Rho-associated kinase activity in patients with idiopathic hyperaldosteronism: a pilot study.

OBJECTIVE: Primary aldosteronism is one of the most common cause of secondary hypertension. It is well known that the incidence of cardiovascular events is higher in patients with primary aldosteronism than in patients with essential hypertension. In a previous study, we showed that aldosterone-producing adenoma is associated with vascular function and structure. The aim of this study was to evaluate the effects of eplerenone on vascular function in the macrovasculature and microvasculature, arterial stiffness and Rho-associated kinase (ROCK) activity in patients with idiopathic hyperaldosteronism (IHA). METHODS: Vascular function, including reactive hyperemia index (RHI), flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation (NID), arterial stiffness including brachial-ankle pulse wave velocity (baPWV) and brachial intima-media thickness (IMT) and ROCK activity in peripheral leukocytes were measured before and after 12 weeks of treatment with eplerenone in 50 patients with IHA. RESULTS: After 12 weeks, eplerenone decreased the aldosterone renin ratio but did not alter SBP and DBP. Eplerenone treatment increased log RHI from 0.56 ±â€Š0.25 to 0.69 ±â€Š0.25 (P < 0.01) and NID from 12.8 ±â€Š5.8 to 14.9 ±â€Š6.9% (P = 0.02) and it decreased baPWV from 1540 ±â€Š263 to 1505 ±â€Š281 (P = 0.04) and ROCK activity from 1.20 ±â€Š0.54 to 0.89 ±â€Š0.42 (P < 0.01), whereas there was no significant change in FMD (increase from 4.6 ±â€Š3.4 to 4.6 ±â€Š3.6%, P = 0.99) or brachial IMT (decrease from 0.28 ±â€Š0.07 to 0.28 ±â€Š0.04 mm, P = 0.14). CONCLUSION: Eplerenone improves microvascular endothelial function, vascular smooth muscle function, arterial stiffness and ROCK activity in patients with IHA. CLINICAL TRIAL REGISTRATION INFORMATION: URL for Clinical Trial: http://UMIN; Registration Number for Clinical Trial: UMIN000003409.

Endothelial Function Assessed by Automatic Measurement of Enclosed Zone Flow-Mediated Vasodilation Using an Oscillometric Method Is an Independent Predictor of Cardiovascular Events.

BACKGROUND: A new device for automatic measurement of flow-mediated vasodilation (FMD) using an oscillometric method has been developed to solve technical problems of conventional FMD measurement. This device measures enclosed zone FMD (ezFMD). The purpose of this study was to evaluate the prognostic value of endothelial function assessed by ezFMD for future cardiovascular events. METHODS AND RESULTS: We measured ezFMD in 272 participants who underwent health-screening examinations. First, we investigated cross-sectional associations between ezFMD and cardiovascular risk factors, and then we assessed the associations between ezFMD and first major cardiovascular events (death from cardiovascular causes, stroke, and coronary revascularization). Univariate regression analysis revealed that ezFMD was significantly correlated with age, triglycerides, glucose, smoking pack-years, estimated glomerular filtration rate, high-sensitivity C-reactive protein, and Framingham risk score. During a median follow-up period of 36.1 months (interquartile range 18.8-40.1 months), 12 participants died (6 from cardiovascular causes), 3 had stroke, 8 had coronary revascularization, and 10 were hospitalized for heart failure. There was no episode of acute coronary syndrome during the study period. Participants were divided into tertiles (low, intermediate, and high) based on ezFMD. Kaplan-Meier curves for first major cardiovascular events among the 3 groups were significantly different (P=0.004). After adjustment for cardiovascular risk factors, the low group was significantly associated with an increased risk of first major cardiovascular events compared with the high group (hazard ratio 6.47; 95% CI 1.09-125.55; P=0.038). CONCLUSIONS: These findings suggest that endothelial function assessed by ezFMD may be useful as a surrogate marker of future cardiovascular events. CLINICAL TRIAL REGISTRATION: URL: https://upload.umin.ac.jp. Unique identifier: UMIN000004902.

Effect of aldosterone-producing adenoma on endothelial function and Rho-associated kinase activity in patients with primary aldosteronism.

The purpose of this study was to evaluate vascular function and activity of Rho-associated kinases (ROCKs) in patients with primary aldosteronism. Vascular function, including flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation, and ROCK activity in peripheral leukocytes were evaluated in 21 patients with aldosterone-producing adenoma (APA), 23 patients with idiopathic hyperaldosteronism (IHA), and 40 age-, sex-, and blood pressure-matched patients with essential hypertension (EHT). FMD was significantly lower in the APA group than in the IHA and EHT groups (3.2±2.0% versus 4.6±2.3% and 4.4±2.2%; P<0.05, respectively), whereas there was no significant difference in FMD between the IHA and EHT groups. There was no significant difference in nitroglycerine-induced vasodilation in the 3 groups. ROCK activity was higher in the APA group than in the IHA and EHT groups (1.29±0.57 versus 1.00±0.46 and 0.81±0.36l; P<0.05, respectively), whereas there was no significant difference in ROCK activity between the IHA and EHT groups. FMD correlated with age (r=-0.31; P<0.01), plasma aldosterone concentration (r=-0.35; P<0.01), and aldosterone:renin ratio (r=-0.34; P<0.01). ROCK activity correlated with age (r=-0.24; P=0.04), plasma aldosterone concentration (r=0.33; P<0.01), and aldosterone:renin ratio (r=0.46; P<0.01). After adrenalectomy, FMD and ROCK activity were restored in patients with APA. APA was associated with both endothelial dysfunction and increased ROCK activity compared with those in IHA and EHT. APA may have a higher risk of future cardiovascular events.

Ratio of serum levels of AGEs to soluble form of RAGE is a predictor of endothelial function.

OBJECTIVE: Advanced glycation end products (AGEs) and their specific receptor, the receptor for AGEs (RAGE), play an important role in atherosclerosis. Recently, a soluble form of RAGE (sRAGE) has been identified in human serum. However, the role of sRAGE in cardiovascular disease is still controversial. There is no information on the association between simultaneous measurements of AGEs and sRAGE and vascular function. In this study, we evaluated the associations between serum levels of AGEs and sRAGE, ratio of AGEs to sRAGE, and vascular function. RESEARCH DESIGN AND METHODS: We measured serum levels of AGEs and sRAGE and assessed vascular function by measurement of flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation in 110 subjects who underwent health examinations. Multivariate regression analyses were performed to identify factors associated with vascular function. RESULTS: Univariate regression analysis revealed that FMD correlated with age, BMI, systolic blood pressure, diastolic blood pressure, heart rate, triglycerides, HDL cholesterol, glucose, smoking pack-years, nitroglycerine-induced vasodilation, serum levels of AGEs and sRAGE, and ratio of AGEs to sRAGE. Multivariate analysis revealed that the ratio of AGEs to sRAGE remained an independent predictor of FMD, while serum level of AGEs alone or sRAGE alone was not associated with FMD. CONCLUSIONS: These findings suggest that sRAGE may have a counterregulatory mechanism that is activated to counteract the vasotoxic effect of the AGE-RAGE axis. The ratio of AGEs to sRAGE may be a new chemical biomarker of endothelial function.

Relationship between flow-mediated vasodilation and cardiovascular risk factors in a large community-based study.

OBJECTIVE: To determine the relationships between flow-mediated vasodilation (FMD) and cardiovascular risk factors, and to evaluate confounding factors for measurement of FMD in a large general population in Japan. METHODS: This was a cross-sectional study. A total of 5314 Japanese adults recruited from people who underwent health screening from 1 April 2010 to 31 August 2012 at 3 general hospitals in Japan. Patients' risk factors (age, Body Mass Index, blood pressure, cholesterol parameters, glucose level and HbA1c level) and prevalence of cardiovascular disease (coronary heart disease and cerebrovascular disease) were investigated. RESULTS: Univariate regression analysis revealed that FMD correlated with age (r=-0.27, p<0.001), Body Mass Index (r=-0.14, p<0.001), systolic blood pressure (r=-0.18, p<0.001), diastolic blood pressure (r=-0.13, p<0.001), total cholesterol (r=-0.07, p<0.001), triglycerides (r=-0.10, p<0.001), high-density lipoprotein cholesterol (r=0.06, p<0.001), low-density lipoprotein cholesterol (r=-0.04, p=0.01), glucose level (r=-0.14, p<0.001), HbA1c (r=-0.14, p<0.001), and baseline brachial artery diameter (r=-0.43, p<0.001) as well as Framingham Risk score (r=-0.29, p<0.001). Multivariate analysis revealed that age (t value=-9.17, p<0.001), sex (t value=9.29, p<0.001), Body Mass Index (t value=4.27, p<0.001), systolic blood pressure (t value=-2.86, p=0.004), diabetes mellitus (t value=-4.19, p<0.001), smoking (t value=-2.56, p=0.01), and baseline brachial artery diameter (t value=-29.4, p<0.001) were independent predictors of FMD. CONCLUSIONS: FMD may be a marker of the grade of atherosclerosis and may be used as a surrogate marker of cardiovascular outcomes. Age, sex, Body Mass Index, systolic blood pressure, diabetes mellitus, smoking and, particularly, baseline brachial artery diameter are potential confounding factors in the measurement of FMD.

Autologous bone-marrow mesenchymal stem cell implantation and endothelial function in a rabbit ischemic limb model.

BACKGROUND: The purpose of this study was to determine whether autologous mesenchymal stem cells (MSCs) implantation improves endothelial dysfunction in a rabbit ischemic limb model. METHODS: We evaluated the effect of MSC implantation on limb blood flow (LBF) responses to acetylcholine (ACh), an endothelium-dependent vasodilator, and sodium nitroprusside (SNP), an endothelium-independent vasodilator, in rabbits with limb ischemia in which cultured MSCs were implanted (n = 20) or saline was injected as a control group (n = 20). LBF was measured using an electromagnetic flowmeter. A total of 10(6) MSCs were implanted into each ischemic limb. RESULTS: Histological sections of ischemic muscle showed that capillary index (capillary/muscle fiber) was greater in the MSC implantation group than in the control group. Laser Doppler blood perfusion index was significantly increased in the MSC implantation group compared with that in the control group. LBF response to ACh was greater in the MSC group than in the control group. After administration of N(G)-nitro-L-arginine, a nitric oxide synthase inhibitor, LBF response to ACh was similar in the MSC implantation group and control group. Vasodilatory effects of SNP in the two groups were similar. CONCLUSIONS: These findings suggest that MSC implantation induces angiogenesis and augments endothelium-dependent vasodilation in a rabbit ischemic model through an increase in nitric oxide production.

Nitroglycerine-induced vasodilation for assessment of vascular function: a comparison with flow-mediated vasodilation.

OBJECTIVE: Nitroglycerine-induced vasodilation has been used as a control test for flow-mediated vasodilation (FMD) to differentiate endothelium-dependent from endothelium-independent response when evaluating endothelial function in humans. Recently, nitroglycerine-induced vasodilation has also been reported to be impaired in patients with atherosclerosis. The purpose of this study was to determine the relationships between nitroglycerine-induced vasodilation and cardiovascular risk factors. APPROACH AND RESULTS: We measured nitroglycerine-induced vasodilation and FMD in 436 subjects who underwent health examinations (mean age, 53 ± 19 years; age range, 19-86 years), including patients with cardiovascular diseases. There was a significant relationship between nitroglycerine-induced vasodilation and FMD (r=0.42; P<0.001). Univariate regression analysis revealed that nitroglycerine-induced vasodilation correlated with age (r=-0.34; P<0.001), systolic blood pressure (r=-0.32; P<0.001), diastolic blood pressure (r=-0.24; P<0.001), heart rate (r=-0.21; P<0.001), glucose (r=-0.23; P<0.001), and smoking pack-year (r=-0.12; P=0.01), as well as Framingham risk score (r=-0.30; P<0.001). Nitroglycerine-induced vasodilation was significantly smaller in patients with cardiovascular disease than in both subjects with and without cardiovascular risk factors (10.5 ± 5.6% versus 13.7 ± 5.4% and 15.3 ± 4.3%; P<0.001, respectively), whereas there was no significant difference in nitroglycerine-induced vasodilation between subjects with and without cardiovascular risk factors. Multivariate analysis revealed that male sex, body mass index, hypertension, diabetes mellitus, baseline brachial artery diameter, and FMD were independent predictors of nitroglycerine-induced vasodilation. CONCLUSIONS: These findings suggest that nitroglycerine-induced vasodilation may be a marker of the grade of atherosclerosis. FMD should be interpreted as an index of vascular function reflecting both endothelium-dependent vasodilation and endothelium-independent vasodilation in subjects with impaired nitroglycerine-induced vasodilation.

Geranylgeranylacetone, heat shock protein 90/AMP-activated protein kinase/endothelial nitric oxide synthase/nitric oxide pathway, and endothelial function in humans.

OBJECTIVE: Geranylgeranylacetone (GGA) induces expression of heat shock protein 90 (Hsp90), an adaptor molecule for assembly of endothelial nitric oxide synthase (eNOS) phosphorylation complex. The purpose of this study was to determine whether GGA enhances Hsp90 expression and augments endothelium-dependent vasodilation via upregulation of eNOS in humans. METHODS AND RESULTS: We evaluated the effects of GGA on human umbilical vein endothelial cells (HUVECs) and on forearm blood flow (FBF) responses to acetylcholine and sodium nitroprusside in 40 healthy young men. Hsp90, eNOS, AMP-activated protein kinase (AMPK), and Akt expression in HUVECs and peripheral blood mononuclear cells was detected by Western blot analysis. GGA increased Hsp90 expression and phosphorylation of eNOS and AMPK but not Akt in HUVECs and increased Hsp90 expression in peripheral blood mononuclear cells. Oral administration of GGA (600 mg) augmented the FBF response to acetylcholine. Infusion of N(G)-monomethyl-l-arginine, an NO synthase inhibitor, completely abolished GGA-induced augmentation of the FBF response to acetylcholine. GGA also augmented the acetylcholine-stimulated NO release in smokers. CONCLUSIONS: These findings suggest that GGA-induced activation of Hsp90/AMPK significantly increased NO-mediated vasodilation in healthy subjects, as well as in smokers. The use of GGA may be a new therapeutic approach for improving endothelial dysfunction.

Measurement of Rho-associated kinase (ROCK) activity in humans: validity of leukocyte p-MBS/t-MBS in comparison with vascular response to fasudil.

BACKGROUND: Rho-associated kinases (ROCKs) have been shown to be involved in the pathogenesis of atherosclerosis. It is clinically important to estimate the degree of ROCK activity in humans. The purpose of this study was to confirm the validity of a leukocyte ROCK parameter as an index of ROCK activity in comparison with vascular response to a ROCK inhibitor. METHODS AND RESULTS: We evaluated the ratio of phospho myosin-binding subunit (p-MBS) on myosin light-chain phosphatase to total MBS in peripheral leukocytes by Western blot analysis and forearm blood flow (FBF) response to the ROCK inhibitor fasudil using strain-gauge plethysmography in 36 healthy subjects and 39 patients with cardiovascular diseases. Fasudil (3, 10, 30µg/min) was infused intra-arterially for 5min at each dose. Leukocyte p-MBS/total-MBS was higher in cardiovascular diseases than in healthy subjects (0.97±0.37 vs. 0.51±0.14; P=0.002). Fasudil increased FBF from 4.9±1.2 to 14.5±5.7mL/min/100mL tissue (P<0.0001) in patients with cardiovascular diseases, while fasudil did not alter FBF in healthy subjects. There was a significant relationship between leukocyte p-MBS/total-MBS and maximal FBF response to fasudil in all subjects (r=0.72, P<0.0001). There was also a significant correlation between p-MBS/total-MBS and maximal FBF response to fasudil in patients with cardiovascular diseases (r=0.59, P<0.0001). In healthy subjects, there was no significant correlation between the two parameters. CONCLUSIONS: These findings suggest that assessment of leukocyte ROCK activity is minimally invasive and does not require pharmacologic intervention using ROCK inhibitors. Leukocyte p-MBS/total-MBS may be useful for evaluating ROCK activity in a clinical setting.

Sarpogrelate hydrochloride, a selective 5-hydroxytryptamine(2A) antagonist, augments autologous bone marrow mononuclear cell implantation-induced improvement in endothelium-dependent vasodilation in patients with critical limb ischemia.

BACKGROUND: The purpose of this study was to determine the effect of a combination of bone marrow mononuclear cell (BM-MNC) implantation and sarpogrelate, a selective 5-HT(2A) antagonist, on endothelial function in patients with critical limb ischemia (CLI). METHODS: We evaluated the leg blood flow (LBF) responses to acetylcholine (ACh) and sodium nitroprusside before and after BM-MNC implantation in 16 patients with CLI. We divided patients with CLI into 2 groups: those cotreated with sarpogrelate orally for 12 weeks (sarpogrelate group, n = 8) and those who remained on conventional therapy (control group, n = 8). LBF was measured by strain gauge plethysmography. RESULTS: BM-MNC implantation improved ankle brachial pressure index, transcutaneous oxygen pressure, and pain-free walking time. There was no significant difference in these parameters between the 2 groups. Before BM-MNC implantation, LBF responses to ACh were similar in the sarpogrelate group and control group. Twelve weeks of BM-MNC implantation enhanced LBF responses to ACh in the sarpogrelate and control groups. After 12 weeks of BM-MNC implantation, LBF response to ACh was significantly greater in the sarpogrelate group than in the control group. BM-MNC implantation did not alter the LBF responses to sodium nitroprusside in either group. CONCLUSIONS: These findings suggest that BM-MNC implantation improved not only limb ischemic symptoms but also endothelium-dependent vasodilation in patients with CLI. A combination of BM-MNC implantation and sarpogrelate had a more beneficial effect on vascular function in these patients.

Oral infection-inflammatory pathway, periodontitis, is a risk factor for endothelial dysfunction in patients with coronary artery disease.

OBJECTIVE: Several studies have shown that periodontitis is a risk factor for cardiovascular diseases. There is an association between inflammation and endothelial dysfunction. The purpose of this study was to evaluate endothelial function in patients with coronary artery disease (CAD) who had periodontitis. METHODS AND RESULTS: We evaluated forearm blood flow (FBF) responses to acetylcholine (ACh), an endothelium-dependent vasodilator, and to sodium nitroprusside (SNP), an endothelium-independent vasodilator, in 101 CAD patients with periodontitis (37 men and 11 women, 63+/-12 yr) and without periodontitis (36 men and 17 women, 62+/-13 yr). FBF was measured by using strain-gauge plethysmography. Circulating levels of C-reactive protein and interleukin-6 were significantly higher in the periodontitis group than in the non-periodontitis group. FBF response to ACh was significantly smaller in the periodontitis group than in the non-periodontitis group. SNP-stimulated vasodilation was similar in the two groups. Periodontal therapy reduced serum concentrations of C-reactive protein from 2.7+/-1.9 to 1.8+/-0.9mg/L (P<0.05) and interleukin-6 from 2.6+/-3.4 to 1.6+/-2.6ng/L (P<0.05) and augmented ACh-induced vasodilation from 14.7+/-5.2 to 20.1+/-6.1mL/(min100mL) tissue (P<0.05) in patients with periodontitis. The SNP-stimulated vasodilation was similar before and after treatment. After administration of N(G)-monomethyl-l-arginine, a nitric oxide synthase inhibitor, FBF response to ACh was similar before and after treatment. CONCLUSION: These findings suggest that periodontitis is associated with endothelial dysfunction in patients with CAD through a decrease in nitric oxide bioavailability. Systemic inflammation may be, at least in part, a cause and predictor of progression of endothelial dysfunction.

Cigarette smoking abolishes ischemic preconditioning-induced augmentation of endothelium-dependent vasodilation.

We have shown recently that repetition of ischemic preconditioning stimulus augments endothelium-dependent vasodilation in forearm circulation of healthy subjects through increases in NO production and the number of circulating progenitor cells under a local condition. The purpose of this study was to evaluate the "late" effect of ischemic preconditioning on endothelial function in smokers. Ischemic preconditioning was induced by upper-limb ischemia 6 times a day for 1 month. We evaluated forearm blood flow responses to acetylcholine and sodium nitroprusside before and after ischemic preconditioning stimulus in 15 male smokers (27+/-7 years) and 15 male nonsmokers (26+/-5 years). Forearm blood flow was measured by using a strain-gauge plethysmography. The ischemic preconditioning stimulus resulted in significant increases in the circulating level of circulating progenitor cells from 1029+/-261 to 1232+/-341 mL (P=0.02), cell migration response to vascular endothelial growth factor from 38+/-16 to 52+/-17 per high-power field (P=0.02), and forearm blood flow response to acetylcholine from 25.1+/-5.2 to 32.4+/-6.6 mL/min per 100 mL of tissue (P=0.002) in nonsmokers, but these did not change in the smoker group. The forearm blood flow responses to sodium nitroprusside before and after the ischemic preconditioning stimulus were similar. Intra-arterial infusion of N(G)-monomethyl-l-arginine, an NO synthase inhibitor, completely eliminated the ischemic preconditioning stimulus-induced augmentation of forearm blood flow responses to acetylcholine in nonsmokers. These findings suggest that repetition of ischemic preconditioning stimulus may be a simple, safe, and feasible therapeutic technique for endothelial protection of peripheral vessels. However, smoking abolishes ischemic preconditioning stimulus-induced augmentation of endothelium-dependent vasodilation.