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Cardiovascular mortality has been shown to vary seasonally. However, it has not been determined whether vascular function is affected by the season. The purpose of this study was to investigate the associations of vascular function with season and outdoor temperature. Between April 2007 and March 2022, measurements of flow-mediated vasodilation (FMD) of the brachial artery as an index of endothelial function and nitroglycerine-induced vasodilation (NID) as an index of endothelium-independent vasodilation were performed in 2190 subjects. There was no significant seasonal difference in FMD (spring, 3.9 ± 3.1%; summer, 3.5 ± 3.0%; fall, 3.7 ± 3.0%; winter, 3.6 ± 3.2%; P = 0.14). There was no significant correlation between FMD and daily mean outdoor temperature (r = -0.02, P = 0.25). Multivariate analyses revealed that neither season (β = -0.020, P = 0.31) nor outdoor temperature (β = 0.005, P = 0.81) was significantly associated with FMD after adjustment for other confounding factors. There were significant seasonal differences in NID (spring, 12.8 ± 6.3%; summer, 12.0 ± 6.1%; fall, 11.7 ± 6.1%; winter, 12.3 ± 5.9%; P = 0.02). However, multivariate analysis revealed that there was no significant association between season and NID after adjustment for other confounding factors (β = -0.012, P = 0.56). There was no significant correlation between NID and daily outdoor mean temperature (r = -0.03, P = 0.17). Multivariate analysis revealed that outdoor temperature was not significantly associated with NID (β = -0.006, P = 0.78). There was no significant association of FMD or NID with season or outdoor temperature, suggesting that it is not necessary to take into account the effects of season and outdoor temperature on vascular function when interpreting the results of FMD and NID measurements. Public trials registry number: UMIN000039512., (© 2023. The Author(s), under exclusive licence to The Japanese Society of Hypertension.)

Aim: An experimental study showed that potassium inhibits the formation of reactive oxygen species by vascular cells. The purpose of this study was to investigate the association between serum potassium levels and vascular function., Methods: We measured flow-mediated vasodilation (FMD) as an index of endothelial function in 3045 subjects (1964 men; mean age, 62.3±13.8 years) and nitroglycerine-induced vasodilation (NID) as an index of vascular smooth muscle function in 1578 subjects (1001 men; mean age, 61.8±16.3 years)., Results: In the 3045 subjects, there was a significant positive correlation between FMD and serum potassium levels (r=0.09, P＜0.001). Multivariate analysis revealed that serum potassium levels were significantly associated with FMD (β=0.109, P＜0.001). When subjects were divided into two groups based on treatment with drugs that could alter serum potassium levels, the association between serum potassium levels and FMD was significant both in subjects with (β=0.096, P＜0.001) and subjects without (β=0.123, P＜0.001) treatment with drugs that could alter serum potassium levels. In the 1578 subjects, there was a significant positive correlation between NID and serum potassium levels (r=0.11, P＜0.001). Multivariate analysis revealed that serum potassium levels were significantly associated with NID (β=0.098, P＜0.001). The association between serum potassium levels and NID was significant both in subjects with (β=0.121, P=0.001) and subjects without (β=0.083, P=0.03) treatment with drugs that could alter serum potassium levels., Conclusions: Serum potassium levels of 4.5-＜5.0 mmol/L are associated with better vascular function regardless of the presence or absence of treatment with drugs that could alter serum potassium levels.

Background: Increased serum triglyceride levels are independently associated with endothelial dysfunction. However, there is little evidence to define normal levels of triglycerides and there is little information on endothelial function in subjects with extremely low levels of triglycerides., Objective: The purpose of this study was to determine the relationship between triglycerides, especially low levels of triglycerides, and vascular function., Methods: We measured flow-mediated vasodilation (FMD) in 7047 subjects and nitroglycerine-induced vasodilation (NID) in 1017 subjects. We divided the subjects into eight groups by triglyceride levels: <50 mg/dL, 50-69 mg/dL, 70-89 mg/dL, 90-109 mg/dL, 110-129 mg/dL, 130-149 mg/dL, 150-199 mg/dL, and ≥200 mg/dL., Results: FMD was significantly higher in subjects with triglyceride levels of <50 mg/dL than in subjects with triglyceride levels of 50-69 mg/dL, 70-89 mg/dL, 90-109 mg/dL, 110-129 mg/dL, 130-149 mg/dL, 150-199 mg/dL, and ≥200 mg/dL (p=0.002, p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, and p<0.001, respectively). Using triglyceride levels of >200 mg/dL as a reference, the odds ratios for a lower quartile of FMD were significantly lower in the <50 mg/dL group, 50-69 mg/dL group, 70-89 mg/dL group, and 90-109 mg/dL group after adjustment for age, gender and other cardiovascular risk factors. There was a slight negative correlation between NID and triglycerides (r=-0.074; p=0.019). However, there was no significant differences in NID among the eight groups., Conclusions: FMD values were highest in subjects with extremely low levels of triglycerides (<50 mg/dL). Lower triglyceride levels were associated with better endothelial function., Clinical Trial Registration Information: http://www.umin.ac.jp (University Hospital Medical Information Network Clinical Trials Registry) (UMIN000012950)., (Copyright © 2021. Published by Elsevier Inc.)

Light to moderate alcohol consumption has protective effects on all-cause death and coronary artery disease in women. It is thought that light to moderate alcohol consumption has a beneficial effect on vascular function in women. We measured flow-mediated vasodilation (FMD) in 702 women aged 17-86 years who provided information on alcohol consumption. We divided the subjects into four groups: non-drinkers (0 g/week), light drinkers (>0 to 140 g/week), moderate drinkers (>140 to 280 g/week) and heavy drinkers (>280 g/week). There was no significant difference in FMD among the four groups. Multivariate regression analysis revealed that alcohol consumption in non-drinkers and light drinkers was not an independent predictor of FMD (β = -0.001, P = 0.98). We compared 50 moderate drinkers and 50 non-drinkers matched for age and medical histories and 22 heavy drinkers and 22 non-drinkers in matched pair analysis. There was no significant difference in FMD between moderate drinkers and non-drinkers (8.2±4.3% vs. 8.1±3.5, P = 0.91), while FMD in heavy drinkers was significantly lower than that in non-drinkers (5.9±2.5% vs. 8.9±3.5%, P = 0.002). These findings suggest that heavy alcohol consumption is associated with endothelial dysfunction but that light to moderate alcohol consumption is not associated with endothelial dysfunction in women. Clinical trial registration information This study was approved by principal authorities and ethical issues in Japan (University Hospital Medical Information Network UMIN000012952, 01/12/2009). www.umin.ac.jp/., Competing Interests: The authors have declared that no competing interests exist.

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., (© Endocrine Society 2020. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Diabetes mellitus is associated with endothelial dysfunction. However, there is little information on the relationships of fasting blood glucose (FBG), including high normal blood glucose and impaired fasting glucose (IFG) with endothelial function. The purpose of this study was to evaluate the relationship between FBG level and flow-mediated vasodilation (FMD) using a large sample size., Research Design and Methods: This study was a cross-sectional study. We measured FMD in 7265 subjects at 31 general hospitals. The subjects were divided into four groups based on FBG levels: <100, 100-109, 110-125, and ≥126 mg/dL or known diabetes. The subjects were also divided into six groups based on FBG levels: <90, 90-94, 95-99, 100-109, 110-125, and ≥126 mg/dL or known diabetes., Results: FMD decreased in relation to increase in FBG level. There was a significant difference in FMD between the FBG of <100 mg/dL group and the other three groups (6.7±3.1% vs 5.9±2.8%, 5.7±3.1%, and 5.1±2.6%, respectively; p<0.001). After adjustment for confounding factors, the odds of having the lowest quartile of FMD were significantly higher in the FBG of 95-99, 100-104, 105-109, 110-125, and ≥126 mg/dL or known diabetes groups than in the FBG of the <90 mg/dL group., Conclusions: These findings suggest that FBG of 100-109 mg/dL and FBG of 110-125 mg/dL are similarly associated with endothelial dysfunction and that a pre-IFG state (FBG of 95-99 mg/dL) is also a risk for endothelial dysfunction compared with FBG of <90 mg/dL., Trial Registration Number: UMIN000012950, UMIN000012951, UMIN000012952, and UMIN000003409., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

High and low hematocrit (Hct) and hemoglobin (Hb) levels are associated with the risk of cardiovascular disease. The purpose of this study was to determine the relationships of Hct, Hb and red blood cells (RBCs) with vascular function and structure. We measured flow-mediated vasodilation (FMD), nitroglycerin-induced vasodilation (NID), brachial intima media thickness (IMT), and brachial-ankle pulse wave velocity (baPWV) in 807 men. The subjects were divided into six groups according to the levels of Hct, Hb and RBCs. NID was highest in the 46.0-48.9% Hct group among the six groups according to Hct levels. Brachial IMT was lowest in the 46.0-48.9% Hct group among the six groups. There were no significant differences in FMD and baPWV among the six groups. We used 46.0-48.9% Hct as a reference to define the lower tertile. The adjusted odds ratio of being in the low tertile of NID was significantly higher in the < 42.9% and ≥ 49.0% Hct groups. Adjusted odds ratio of being in the low tertile of brachial IMT was significantly lower in the < 39.9% Hct groups. Similar results were obtained for Hb and RBCs. Low and high levels of Hct, Hb and RBCs were associated with vascular smooth muscle dysfunction, and low Hct levels were associated with abnormal vascular structure. Increases in the levels of Hct, Hb and RBCs within normal ranges may have beneficial effects on the vasculature.

Background Diagnostic criteria of flow-mediated vasodilation (FMD), an index of endothelial function, and nitroglycerin-induced vasodilation (NID), an index of vascular smooth muscle function, of the brachial artery have not been established. The purpose of this study was to propose diagnostic criteria of FMD and NID for normal endothelial function and normal vascular smooth muscle function. Methods and Results We investigated the cutoff values of FMD and NID in subjects with (risk group) and those without cardiovascular risk factors or cardiovascular diseases (no-risk group) in 7277 Japanese subjects (mean age 51.4±10.8 years) from the Flow-Mediated Dilation Japan study and the Flow-Mediated Dilatation Japan Registry study for analysis of the cutoff value of FMD and in 1764 Japanese subjects (62.2±16.1 years) from the registry of Hiroshima University Hospital for analysis of the cutoff value of NID. Receiver-operator characteristic curve analysis of FMD to discriminate subjects in the no-risk group from patients in the risk group showed that the optimal cutoff value of FMD to diagnose subjects in the no-risk group was 7.1%. Receiver-operator characteristic curve analysis of NID to discriminate subjects in the no-risk group from patients in the risk group showed that the optimal cutoff value of NID to diagnose subjects in the no-risk group was 15.6%. Conclusions We propose that the cutoff value for normal endothelial function assessed by FMD of the brachial artery is 7.1% and that the cutoff value for normal vascular smooth muscle function assessed by NID of the brachial artery is 15.6% in Japanese subjects. Clinical Trial Registration www.umin.ac.jp Unique identifiers: UMIN000012950, UMIN000012951, UMIN000012952, and UMIN000003409.

Hypertension is associated with vascular failure, such as increased arterial stiffness, endothelial dysfunction, and vascular smooth muscle dysfunction. The purpose of this study was to investigate the relationship between out-of-office blood pressure and vascular function in patients receiving antihypertensive drugs. We assessed out-of-office blood pressure, including daytime and night-time blood pressure, by home blood pressure monitoring and performed vascular function tests, including brachial-ankle pulse wave velocity (baPWV), flow-mediated vasodilation (FMD), and nitroglycerine-induced vasodilation (NID), in 169 patients receiving antihypertensive drugs, of whom 86 (50.9%) had normotension, 23 (13.6%) had isolated nocturnal hypertension (night-time systolic blood pressure ≥120 mm Hg), 26 (15.4%) had isolated daytime hypertension (daytime systolic blood pressure ≥135 mm Hg), and 34 (20.1%) had sustained hypertension (daytime and nocturnal hypertension). baPWV was significantly higher in patients with sustained hypertension than in those without sustained hypertension (1585 ± 257 cm/s in normotension; 1687 ± 267 cm/s in isolated nocturnal hypertension; 1688 ± 313 cm/s in isolated daytime hypertension; and 1923 ± 399 cm/s in sustained hypertension; P < 0.001). baPWV above the cutoff value of 1858 cm/s, derived from receiver operating characteristic curve analysis to diagnose patients with sustained hypertension, was significantly associated with sustained hypertension after adjustment of other confounding factors (odds ratio, 5.01; 95% confidence interval, 1.94-13.41; P < 0.001). In contrast, there was no significant association of home blood pressure status with FMD or NID in these patients. In patients receiving antihypertensive drugs, baPWV was significantly associated with sustained hypertension, whereas FMD and NID were impaired regardless of the home blood pressure status.

Background: Inflammation is associated with endothelial dysfunction and plays an important role in the pathogenesis and development of cardiovascular diseases. It has been shown that colchicine, an anti-inflammatory drug, improves the cardiovascular outcome in patients with cardiovascular disease. The purpose of this study was to evaluate the short-term effect of low-dose colchicine on endothelial function in patients with coronary artery disease (CAD)., Methods: This was a double-blind, randomized, placebo-controlled, crossover-within-subject clinical trial. A total of 28 patients with CAD received low-dose colchicine (0.5 mg/day) or a placebo for 7 days with a washout period of at least 14 days. Flow-mediated vasodilation (FMD) and serum concentrations of high-sensitivity C-reactive protein (hs-CRP) were measured after the 7-day treatment with colchicine or the placebo., Results: The serum concentration of hs-CRP was significantly decreased after administration of colchicine compared with that after administration of the placebo [median (interquartile range): 0.04 (0.02-0.08) mg/dL vs. 0.07 (0.04-0.11) mg/dL, P = 0.003], while there was no significant difference in FMD between the treatments [median (interquartile range): 3.1% (1.5-5.3%) vs. 3.3% (1.9-5.2%), P = 0.384]. Colchicine, however, significantly improved FMD in coronary artery disease patients with white blood cell (WBC) counts of ≥7500 WBC/mm 3 [median (interquartile range): 3.3% (2.1-6.6%) vs. 2.0% (1.4-3.8%), P = 0.043]., Conclusions: Administration of low-dose colchicine did not improve endothelial function in patients with CAD, but exploratory analysis suggested that endothelial function is significantly improved in patients with leukocyte activation., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Purpose: The purpose of this study was to evaluate acute effects of coffee with a high content of chlorogenic acids and different hydroxyhydroquinone contents on postprandial endothelial dysfunction., Methods: This was a single-blind, randomized, placebo-controlled, crossover-within-subject clinical trial. A total of 37 patients with borderline or stage 1 hypertension were randomized to two study groups. The participants consumed a test meal with a single intake of the test coffee. Subjects in the Study 1 group were randomized to single intake of coffee with a high content of chlorogenic acids and low content of hydroxyhydroquinone or coffee with a high content of chlorogenic acids and a high content of hydroxyhydroquinone with crossover. Subjects in the Study 2 group were randomized to single intake of coffee with a high content of chlorogenic acids and low content of hydroxyhydroquinone or placebo coffee with crossover. Endothelial function assessed by flow-mediated vasodilation and plasma concentration of 8-isoprostanes were measured at baseline and at 1 and 2 h after coffee intake., Results: Compared with baseline values, single intake of coffee with a high content of chlorogenic acids and low content of hydroxyhydroquinone, but not coffee with a high content of chlorogenic acids and high content of hydroxyhydroquinone or placebo coffee, significantly improved postprandial flow-mediated vasodilation and decreased circulating 8-isoprostane levels., Conclusions: These findings suggest that a single intake of coffee with a high content of chlorogenic acids and low content of hydroxyhydroquinone is effective for improving postprandial endothelial dysfunction., Clinical Trial Registration: URL for Clinical Trial: https://upload.umin.ac.jp ; Registration Number for Clinical Trial: UMIN000013283.

The aims were to evaluate the relationship between idiopathic hyperaldosteronism (IHA) and grade of vascular function in the macrovasculature and microvasculature. Vascular function, including reactive hyperemia index (RIH), flow-mediated vasodilation (FMD), and nitroglycerine-induced vasodilation (NID) were evaluated in 52 patients with IHA, 53 patients with aldosterone-producing adenoma (APA), and 52 age-, sex-, and blood pressure-matched patients with essential hypertension (EHT). Log RHI was lower in the IHA and APA groups than in the EHT group (0.54 ± 0.25 and 0.55 ± 0.23 versus 0.79 ± 0.28; P < 0.01, respectively). FMD was lower in the APA group than in the EHT group (3.4 ± 2.1% versus 4.8 ± 2.8%; P = 0.02), whereas there was no significant difference in FMD between the IHA and the APA and EHT groups. NID was lower in the APA group than in the EHT group (10.0 ± 4.5% versus 12.5 ± 5.7%; P = 0.03), whereas there was no significant difference in NID between the IHA, APA, and EHT groups. Multiple regression analysis revealed an association of log RHI with plasma aldosterone concentration (t = -2.24; P = 0.03) and an association of FMD with plasma aldosterone concentration (t = -3.07; P < 0.01). Microvascular endothelial function was impaired in patients with IHA compared with that in patients with EHT.

Background: Measurement of flow-mediated vasodilation (FMD) is an established method for assessing endothelial function. Measurement of FMD is useful for showing the relationship between atherosclerosis and endothelial function, mechanisms of endothelial dysfunction, and clinical implications including effects of interventions and cardiovascular events. To shorten and simplify the measurement of FMD, we have developed a novel technique named short time FMD (stFMD). We investigated the validity of stFMD for assessment of endothelial function compared with conventional FMD., Methods and Results: We evaluated stFMD and conventional FMD in 82 subjects including patients with atherosclerotic risk factors and cardiovascular disease (66 men and 16 women, 57 ± 16 years). Both stFMD and conventional FMD were significantly correlated with age, systolic blood pressure, diastolic blood pressure and baseline brachial artery diameter. In addition, stFMD was significantly correlated with conventional FMD (r = 0.76, P < 0.001). Bland-Altman plot analysis showed good agreement b etween stFMD and conventional FMD. Moreover, stFMD in the at risk group and that in the cardiovascular disease group were significantly lower than that in the no risk group (4.6 ± 2.3% and 4.4 ± 2.2% vs. 7.3 ± 1.9%, P < 0.001, respectively). Optimal cutoff value of stFMD for diagnosing atherosclerosis was 7.0% (sensitivity of 71.0% and specificity of 85.0%)., Conclusions: These findings suggest that measurement of stFMD, a novel and simple method, is useful for assessing endothelial function. Measurement of stFMD may be suitable for screening of atherosclerosis when repeated measurements of vascular function are required and when performing a clinical trial using a large population., Clinical Trial Registration Information: URL for Clinical Trial: http://UMIN; Registration Number for Clinical Trial: UMIN000025458., (Copyright © 2018 Elsevier B.V. All rights reserved.)

This paper proposes a novel non-invasive method for assessing the vascular endothelial function of lower-limb arteries based on the dilation rate of air-cuff plethysmograms measured using the oscillometric approach. The principle of evaluating vascular endothelial function involves flow-mediated dilation. In the study conducted, blood flow in the dorsal pedis artery was first monitored while lower-limb cuff pressure was applied using the proposed system. The results showed blood flow was interrupted when the level of pressure was at least 50 mmHg higher than the subject's lower-limb systolic arterial pressure and that blood flow velocity increased after cuff release. Next, values of the proposed index, %ezFMD L , for assessing the vascular endothelial function of lower-limb arteries were determined from 327 adult subjects: 87 healthy subjects, 150 subjects at high risk of arteriosclerosis and 90 patients with cardiovascular disease (CAD). The mean values and standard deviations calculated using %ezFMD L were 30.5 ± 12.0% for the healthy subjects, 23.6 ± 12.7% for subjects at high risk of arteriosclerosis and 14.5 ± 15.4% for patients with CAD. The %ezFMD L values for the subjects at high risk of arteriosclerosis and the patients with CAD were significantly lower than those for the healthy subjects (p < 0.01). The proposed method may have potential for clinical application.

Background: Lower urinary tract symptoms (LUTS) is not only common symptoms in elderly men and women but also risk of future cardiovascular events. The purpose of this study was to evaluate the relationships of vascular function and structure with LUTS in men and women., Methods: We investigated flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation (NID) as vascular function, brachial-ankle pulse wave velocity (baPWV) as vascular structure, and LUTS assessed by International Prostate Symptom Score (IPSS) in 287 men and 147 women., Results: IPSS was significantly correlated with traditional cardiovascular risk factors, Framingham risk score, FMD, NID and baPWV. Moderate to severe LUTS was associated with the prevalence of coronary heart disease in men but not in women. In men, FMD and NID were significantly lower in the moderate to severe LUTS group than in the none to mild LUTS group (2.1 ± 2.0% vs. 4.0 ± 3.0% and 9.3 ± 6.1% vs. 12.8 ± 6.6%, P < 0.001, respectively). baPWV was significantly higher in the moderate to severe LUTS group than in the none to mild LUTS group (1722 ± 386 cm/s vs. 1509 ± 309 cm/s, P < 0.001). In multivariate analysis, FMD was independently associated with a decrease in the odds ratio of moderate to severe LUTS in men (OR: 0.83, 95% CI, 0.72-0.95; P = 0.008) but not in women. NID and baPWV were not independently associated with moderate to severe LUTS either in men or women., Conclusions: These findings suggest that endothelial dysfunction is associated with LUTS in men. LUTS in men may be useful for a predictor of cardiovascular events., Clinical Trial Registration Information: URL for Clinical Trial: http://UMIN; Registration Number for Clinical Trial: UMIN000003409., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Although reactive hyperemia-peripheral arterial tonometry (RH-PAT) is widely used for assessment of endothelial function, RH index (RHI) cannot be measured in some cases when pulse wave amplitude (PWA) is very low. Decrease in PWA is mainly caused by proper palmar digital artery (PPDA) stenosis. The purpose of this study was to evaluate the relationship between PWA measured by RH-PAT and stenosis of the PPDA measured by digital subtraction angiography and to evaluate the limitation of assessment of endothelial function measured by RHI in patients with PPDA stenosis., Methods: We measured baseline PWA in 51 fingers including the first to third fingers of both hands in 10 patients who had PPDA stenosis and in 66 fingers that were the first fingers of both hands in 33 subjects who had no PPDA stenosis. Severe stenosis was defined as over 75% by lower percent diameter stenosis between two PPDAs in a finger., Results: PWA was significantly correlated with stenosis of the digital artery (r=-0.55; P<0.0001). A PWV value of 300mV was the optimal cut-off value for severe stenosis (sensitivity, 84.0%; specificity, 88.5%). Log RHI was significantly lower in patients with PPDA stenosis than in subjects without PPDA stenosis (0.33±0.27 versus 0.73±0.27, P=0.007)., Conclusions: RH-PAT may be useful for assessment of not only endothelial function but also PPDA stenosis. RHI may be underestimated in patients with PPDA stenosis. We should pay attention to low baseline PWA when measuring RHI., Clinical Trial Registration Information: URL for clinical trial: http://UMIN; registration number for clinical trial: UMIN000003409., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Backgrounds: Nitroglycerine-induced vasodilation (NID) is usually assessed as a control test for flow-mediated vasodilation (FMD). However, NID per se is impaired in patients with high cardiovascular risk. The purpose of this study was to investigate the associations of chronic kidney disease (CKD) with NID and FMD., Methods: We measured NID and FMD in a total of 1567 adult subjects without end-stage renal disease (ESRD), 28% of whom had CKD as judged by measurements of estimated glomerular filtration rate (995 men and 572 women; mean age, 59.0±16.9years; age range, 18 to 92years)., Results: NID was significantly smaller in patients with CKD than in those without CKD (10.8±6.0% vs. 12.7±5.7%, P<0.001). The prevalence of vascular smooth muscle dysfunction, defined as NID of less than the division point for the lowest quartile, was significantly higher in patients with CKD than in those without CKD (37.5% vs. 21.5%, P<0.001). Multivariate analysis revealed that CKD was independently associated with vascular smooth muscle dysfunction (OR: 1.36, 95% CI: 1.02 to 1.81, P=0.04). FMD was significantly smaller in patients with CKD than in those without CKD (3.1±2.8% vs. 4.0±3.0%, P<0.001). The prevalence of endothelial dysfunction, defined as FMD of less than the division point for the lowest quartile, was significantly higher in patients with CKD than in those without CKD (31.7% vs. 23.1%, P=0.002). However, CKD was not independently associated with endothelial dysfunction in an age- and sex-adjusted model (OR: 0.95, 95% CI: 0.71 to 1.26, P=0.72)., Conclusions: Non-ESRD CKD is independently associated with vascular smooth muscle dysfunction but not with endothelial dysfunction., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Hypertension is associated with endothelial dysfunction. Blood pressure significantly correlates with endothelial function in antihypertensive drug-naive subjects. The purpose of this study was to determine whether treatment status affects the relationship between blood pressure and endothelial function. We measured flow-mediated vasodilation (FMD) in 2297 subjects, including 1822 antihypertensive drug-naive subjects and 475 treated hypertensive patients. FMD significantly decreased in relation to increase in systolic blood pressure (8.2±3.1% in subjects with systolic blood pressure of <120 mm Hg, 7.5±2.8% for 120-129 mm Hg, 7.1±2.8% for 130-139 mm Hg, and 6.7±2.6% for ≥140 mm Hg; P <0.001). Systolic blood pressure was independently associated with FMD in untreated subjects. In contrast, there was no significant relationship between systolic blood pressure and FMD in treated hypertensive patients (4.6±3.1% in treated hypertensives with systolic blood pressure of <120 mm Hg, 4.8±2.7% for 120-129 mm Hg, 4.9±2.8% for 130-139 mm Hg, and 4.5±2.3% for ≥140 mm Hg; P =0.77). Propensity score matching analysis revealed that the prevalence of endothelial dysfunction defined as FMD of less than the division point for the lowest tertile, and the middle tertile of FMD was significantly higher in treated hypertensive patients than in untreated subjects in all systolic blood pressure categories. Endothelial function assessed by FMD was impaired regardless of the level of blood pressure achieved by antihypertensive drug treatment in hypertensive patients., (© 2017 American Heart Association, Inc.)

Background: Periodontal disease is associated with endothelial dysfunction, leading to cardiovascular disease. The effect of detailed tooth brushing behavior, not only frequency but also duration of tooth brushing, on endothelial function is unclear. The purpose of this study was to evaluate the relationships of detailed methods of tooth brushing with vascular function., Methods: We evaluated flow-mediated vasodilation (FMD), nitroglycerine-induced vasodilation, and frequency and duration of tooth brushing in 896 subjects. We divided the subjects into three groups according to the frequency and duration of tooth brushing: low frequency and short duration group (

The presence of an earlobe crease (ELC) may be a simple sign to predict atherosclerosis. We evaluated the relation between ELC and vascular function. We measured flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation (NID) and observed bilateral earlobes in 400 consecutive subjects. At first, the subjects were divided into 3 groups: non-ELC group, unilateral ELC group, and bilateral ELC group. FMD and NID were significantly lower in the unilateral and bilateral ELC groups than those in the non-ELC group. After adjustment of cardiovascular risk factors, bilateral ELC, but not unilateral ELC, was associated with lower FMD and lower NID. We also investigated whether an increase in the number of ELCs worsens endothelial function, whether the difference in ELC structure (cross stripes and/or ramification) affects endothelial function, and whether endothelial function is impaired in subjects with superficial wrinkles depending on age. The number of ELCs, shape of the ELC, and superficial wrinkles were not associated with endothelial dysfunction. In conclusion, these findings suggest that the presence of bilateral ELCs is associated with vascular dysfunction., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Endothelial dysfunction and abnormal vascular structure may be involved in the pathogenesis of chronic heart failure (HF). The purpose of this study was to evaluate simultaneously vascular function and vascular structure in patients with heart failure with preserved ejection fraction (HFpEF)., Methods: We measured flow-mediated vasodilatation (FMD) and nitroglycerine-induced vasodilation as indices of vascular function and intima-media thickness (IMT) as an index of vascular structure of the brachial artery in 41 patients with HFpEF (23 men and 18 women; mean age, 66±12yr) and 165 patients without HF (95 men and 70 women; mean age, 54±16yr)., Results: FMD was significantly smaller in patients with HFpEF than in patients without HF (2.9±2.1% versus 4.6±2.7%, P=0.0002). Nitroglycerine-induced vasodilation was significantly smaller in patients with HFpEF than in patients without HF (9.3±4.1% versus 12.9±4.9%, P<0.0001). Brachial artery IMT was significantly larger in patients with HFpEF than in patients without HF (0.35±0.06mm versus 0.31±0.07mm, P=0.0002). After adjustment for age, sex, hypertension, dyslipidemia, and diabetes mellitus, the associations remained significant between HFpEF and FMD (odds ratio, 0.79; 95% confidence interval, 0.66-0.92; P=0.0032), nitroglycerine-induced vasodilation (odds ratio, 0.88; 95% confidence interval, 0.80-0.96; P=0.0039), and brachial artery IMT (odds ratio, 1.08; 95% confidence interval, 1.01-1.17; P=0.033)., Conclusions: These findings suggest that both endothelial dysfunction and abnormal vascular structure may contribute to the pathogenesis and maintenance of HFpEF. Endothelial function and vascular structure may be potential therapeutic targets for HFpEF., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Heavy drinking should be a predictor of endothelial dysfunction. However, there is little information on the effects of light to moderate alcohol consumption on endothelial function. The purpose of this study was to estimate the effects of dose-dependent alcohol consumption on endothelial function., Methods: We measured flow-mediated vasodilation (FMD) in 2734 men aged 21-81years who provided information on alcohol intake at 3 general hospitals. The subjects were divided into 5 groups; non-drinkers (0g/week), light drinkers (>0 to 140g/week), moderate drinkers (>140 to 280g/week), heavy drinkers (>280 to 420g/week), and excessive heavy drinkers (>420g/week)., Results: FMD showed a gradual decrease in accordance with alcohol consumption in the entire study population (non-drinkers, 6.6±3.4%; light drinkers, 6.2±3.0%; moderate drinkers, 6.0±3.0%; heavy drinkers, 5.5±2.9%; excessive heavy drinkers, 5.3±3.0%; P<0.001). There was a significant difference in FMD between the light alcohol drinker group and the non-drinker group (P=0.015). After adjustment for other risk factors, the odds of having FMD in the lowest quartile was found to be significantly increased in the 4 drinker groups than in the non-drinker group: light (OR, 1.38; 95% CI, 1.10 to 1.75), moderate (OR, 1.36; 95% CI, 1.01 to 1.82), heavy (OR, 2.05; 95% CI, 1.46 to 2.87), excessive (OR, 2.04; 95% CI, 1.43 to 2.89)., Conclusion: These findings suggest that FMD is impaired in relation to alcohol consumption and that FMD is significantly smaller even in light alcohol drinkers than in non-drinkers. Alcohol intake per se may be harmful for vascular function., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

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., (© 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)

Background: Pigment epithelium-derived factor (PEDF) is a glycoprotein that belongs to the superfamily of serine protease inhibitors. It is thought that PEDF plays a protective role against atherosclerosis. Clinical studies have shown that serum levels of PEDF are increased in subjects with cardiovascular risk factors. The role of PEDF in cardiovascular disease is still controversial. The purpose of this study was to evaluate the associations between serum levels of PEDF and vascular function and structure., Methods: We measured serum levels of PEDF, assessed vascular function by measurements of flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation in the brachial artery, and measured brachial artery intima-media thickness (IMT) in 150 subjects who underwent health examinations., Results and Conclusions: Univariate regression analysis revealed that serum level of PEDF was significantly correlated with body mass index, high-density lipoprotein cholesterol, glucose, FMD, nitroglycerine-induced vasodilation, and brachial artery IMT. Multivariate analysis revealed that serum levels of PEDF remained an independent predictor of nitroglycerine-induced vasodilation (β=-0.20, P=0.02) and brachial artery IMT (β=0.14, P=0.03) after adjustment of cardiovascular risk factors, while serum level of PEDF was not associated with FMD (β=-0.02, P=0.79). These findings suggest that PEDF may be a factor directly associated with atherosclerosis. The serum level of PEDF may be a new biochemical marker of atherosclerosis., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Background and Aims: It is established that low-density lipoprotein cholesterol is an independent risk factor for cardiovascular events. Recently, circulating triglycerides level has been focused on as a risk factor for cardiovascular events. In this study, we evaluated the associations between triglycerides and endothelial function in a general population., Methods: We analyzed data for 4887 subjects who were enrolled in the FMD-Japan registry. We investigated cross-sectional associations between serum triglyceride levels and endothelial function assessed by measurement of flow-mediated vasodilation (FMD)., Results: Serum triglyceride levels were correlated with FMD (r = -0.12, p < 0.001). Subjects were divided into six groups based on serum triglyceride levels. FMD was significantly decreased with an increase in serum triglyceride levels (≤0.71 mmol/L, 7.0 ± 3.5%; 0.72-0.94 mmol/L, 6.3 ± 3.5%; 0.95-1.19 mmol/L, 6.0 ± 3.1%; 1.20-1.48 mmol/L, 5.8 ± 3.2%; 1.49-2.02 mmol/L, 5.7 ± 3.1%; ≥2.03 mmol/L, 5.5 ± 3.0%; p for trend <0.001). After adjustment for age, sex, and cardiovascular risk factors, including high-density lipoprotein cholesterol, serum triglyceride levels of more than 1.20 mmol/L were independently associated with the low quartile of FMD (1.20-1.48 mmol/L, odds ratio (OR) 1.41, 95% confidence interval (CI) 1.09 to 1.82; 1.49-2.02 mmol/L, OR 1.31, 95% CI 1.00 to 1.70; ≥2.03 mmol/L, OR 1.48, 95% CI 1.13 to 1.95) using serum triglyceride levels of less than 0.71 mmol/L group as the reference., Conclusions: These findings suggest that triglycerides are an independent predictor of endothelial function. Lowering circulating triglyceride levels may improve endothelial function, leading to a decrease in cardiovascular events., Clinical Trial Registration Information: URL for Clinical Trial: http://UMIN; Registration Number for Clinical Trial: UMIN000003409., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Unlabelled: Measurement of nitroglycerine-induced vasodilation has been performed to differentiate endothelium-dependent vasodilation from endothelium-independent vasodilation as a control test for flow-mediated vasodilation (FMD). Recently, nitroglycerine-induced vasodilation per se has been reported to be a useful marker of the grade of atherosclerosis. The present study aimed to evaluate the prognostic value of FMD combined with nitroglycerine-induced vasodilation for future cardiovascular events. We measured FMD and nitroglycerine-induced vasodilation in 402 subjects, including patients with cardiovascular diseases. During a median follow-up period of 32.3 months, 38 first major cardiovascular events (death from cardiovascular causes, acute myocardial infarction, stroke, and coronary revascularization) occurred. Receiver-operator characteristic curve analysis revealed that FMD alone and nitroglycerine-induced vasodilation alone can predict cardiovascular events with areas under the curve of 0.671 (cutoff 3.3%) and 0.692 (cutoff 11.6%), respectively. FMD combined with nitroglycerine-induced vasodilation predicts cardiovascular events with an area under the curve of 0.701. After adjustment for age, sex, and cardiovascular risk factors, above cutoff FMD (≥3.3%) and below cutoff nitroglycerine-induced vasodilation (<11.6%; hazard ratio, 5.55; 95% confidence interval, 1.61-25.46;P=0.006) and below cutoff FMD (<3.3%) and below cutoff nitroglycerine-induced vasodilation (<11.6%; hazard ratio, 7.20; 95% confidence interval, 2.37-31.36;P<0.001) remained strong independent indicator of cardiovascular events. These findings suggest that the combination of FMD and nitroglycerine-induced vasodilation measurements can more accurately predict cardiovascular events compared with FMD alone., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: UMIN000001167., (© 2016 American Heart Association, Inc.)

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., (© 2015 American Heart Association, Inc.)

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., (© 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.)

Background:  Poor oral health is an independent predictor of cardiovascular outcome. Endothelial dysfunction is the initial step of atherosclerosis, resulting in cardiovascular outcomes; but there is no information on the association between oral health and endothelial function. The purpose of this study was to determine the relationships between oral health and endothelial function., Methods and Results:  A total of 190 subjects who underwent health examinations (mean age, 57±18 years), including patients with cardiovascular disease, completed a questionnaire on oral health and frequency of tooth brushing, and underwent measurement of vascular function, flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation. The subjects were divided into 2 groups according to frequency of tooth brushing (≥twice/day and

Background: It is clinically important to estimate the degree of endothelial dysfunction. Several methods have been used to assess endothelial function in humans. Recently, we developed a new noninvasive method for measurement of vascular response to reactive hyperemia in the brachial artery, named enclosed zone flow-mediated vasodilation (ezFMD). The purpose of this study was to determine the validity of ezFMD for assessment of endothelial function., Methods and Results: We measured ezFMD by a new device using an oscillometric method and conventional FMD using ultrasonography in 306 subjects, including patients with hypertension, dyslipidemia, and diabetes mellitus (218 men and 88 women, 30 ± 16 yr). Univariate regression analysis revealed that ezFMD significantly correlated with age (r = -0.42, P < 0.0001), body mass index (r = -0.13, P = 0.028), systolic blood pressure (r = -0.15, P = 0.009), diastolic blood pressure (r = -0.14, P = 0.011), fasting glucose level (r = -0.27, P = 0.006), smoking (r = -0.21, P = 0.007) and baseline pulse wave amplitude (r = -0.51, P < 0.0001). ezFMD significantly correlated with conventional FMD (r = 0.34, P < 0.0001). Multiple regression analysis revealed that age (P = 0.002), body mass index (P = 0.013), systolic blood pressure (P = 0.009), smoking (P = 0.004) and baseline pulse wave amplitude (P < 0.001) were independent predictors of ezFMD., Conclusions: These findings suggest that measurement of ezFMD, a novel noninvasive and simple method, may be useful for determination of vascular diameter response to reactive hyperemia. Since ezFMD is automatically measured by a device with an oscillometric method, measurement of ezFMD is easier and less biased than that of conventional FMD., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

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.

Background: Patients with Gilbert syndrome have mild unconjugated hyperbilirubinemia. It has been shown that bilirubin is an endogenous antioxidant. We evaluated the role of oxidative stress in endothelial function in patients with Gilbert syndrome under normal conditions without cardiovascular risk factors., Methods and Results: A total of 108 young men with Gilbert syndrome without cardiovascular risk factors and 108 age-matched healthy men (normal controls) were enrolled in this study. Serum concentrations of bilirubin were higher in patients with Gilbert syndrome than in control subjects (29.2±11.6 versus 9.4±2.7 μmol/L; P<0.001). Serum concentrations of malondialdehyde-modified low-density lipoprotein and urinary excretion of 8-hydroxy-2'-deoxyguanosine (8-OHdG), as indices of oxidative stress, were lower in patients with Gilbert syndrome than in control subjects (61.8±24.5 versus 72.5±21.8 U/L, P=0.034; 7.8±2.4 versus 10.4±3.2 ng/mg creatinine, P=0.001, respectively). Flow-mediated vasodilation was greater in patients with Gilbert syndrome than in normal control subjects (7.2±2.2% versus 5.9±1.7%; P<0.001). Vascular responses to nitroglycerine were not significantly different between the 2 groups. Flow-mediated vasodilation correlated with serum concentration of bilirubin (r=0.44, P<0.001), malondialdehyde-modified low-density lipoprotein (r=-0.25, P=0.01), and urinary excretion of 8-OHdG (r=-0.27, P=0.004) in patients with Gilbert syndrome but not in control subjects. In addition, serum concentration of bilirubin correlated with malondialdehyde-modified low-density lipoprotein (r=-0.20, P=0.04) and 8-OHdG (r=-0.21, P=0.02) in patients with Gilbert syndrome but not in control subjects., Conclusions: Patients with Gilbert syndrome had low levels of oxidative stress associated with hyperbilirubinemia and enhancement of endothelium-dependent vasodilation., Clinical Trial Registration: URL: http://www.umin.ac.jp. Unique identifier: UMIN000003409.

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.