Endothelial function in a cardiovascular risk population with borderline ankle-brachial index

Long-term cardiovascular consequences of adolescent anorexia nervosa

BACKGROUND

Anorexia nervosa (AN) is associated with maladaptive cardiovascular changes. This study investigated whether individuals who recovered from AN during adolescence experience long-term cardiovascular risk in early adulthood.

METHODS

Former AN patients discharged from the Royal Children's and Monash Children's Hospital Eating Disorder Services in Melbourne, Australia underwent cardiovascular testing. Measurements were performed using an oscillometric device for blood pressure and pulse wave velocity, ultrasound for carotid wall structure/function, resting electrocardiogram for heart-rate variability, and the EndoPat 2000 (Itamar) system for endothelial function. Patient measures were compared to healthy controls and/or normal thresholds.

RESULTS

Ninety-one percent of the former AN patients (N = 22) and controls (N = 66) were female, aged approximately 25 years, with a healthy body mass index. The mean time interval from AN recovery to participation was 7.4 years. Pulse wave velocity was lower in the former AN patients than controls. Carotid intima-media thickness was not different; however, carotid distensibility and compliance were lower, and the elastic modulus higher in the former AN patients. Greater vagal tone was observed and endothelial dysfunction was evident in 46% of the former patients.

CONCLUSIONS

Young adults who recovered from adolescent AN exhibit persistent cardiovascular adaptations. Routine cardiovascular monitoring could manage potential disease risk.

IMPACT

Cardiovascular complications are common in patients with anorexia nervosa (AN) and population studies have revealed that developmental adaptations in response to undernutrition have long-term consequences for cardiovascular health. In this study of young adults treated for AN during adolescence, there was evidence of increased carotid artery stiffness, reduced aortic stiffness, vagal hyperactivity, and endothelial dysfunction in early adulthood when compared to healthy controls. It is important to consider the cardiovascular health of patients with AN beyond achieving medical stability. Interventions that monitor cardiovascular health could minimise the burden of future cardiovascular disease.

Examining changes in vascular function, arterial stiffness and systemic inflammation during hospitalization and recovery from an acute exacerbation of chronic obstructive pulmonary disease

An acute exacerbation of COPD (AECOPD) is associated with increased risk of cardiovascular (CV) events. The elevated risk during an AECOPD may be related to changes in vascular function, arterial stiffness, and systemic inflammation; the time course of these measures and their corresponding recovery are poorly understood. Further, physical activity is reduced during an AECOPD, and physical activity may influence the cardiovascular responses to an AECOPD. The purpose of the study was to examine the acute impact of an AECOPD requiring hospitalization on vascular function, arterial stiffness, and systemic inflammation and examine whether physical activity modulates these variables during recovery. Patients hospitalized for an AECOPD were prospectively recruited and compared to control patients with stable COPD. Vascular function, arterial stiffness, and systemic inflammation (CRP, IL-6) were measured at hospital admission, hospital discharge and within 14 days of discharge. Physical activity was electronically tracked daily while in hospital and for 7 days following discharge using a Fitbit. One hundred and twenty-one patients with an AECOPD requiring hospitalization and 33 control patients with stable COPD were enrolled in the study. Vascular function was significantly lower, and systemic inflammation higher at hospital admission in patients with an AECOPD compared to stable COPD. Significant improvements in vascular function and inflammation were observed within 14 days of hospital discharge; however, vascular function remained lower than stable COPD. Physical activity was low at admission and increased following discharge; however, physical activity was unrelated to measures of vascular function or inflammation at any time point. An AECOPD requiring hospitalization is associated with impaired vascular function that persists during recovery. These findings provide a mechanistic link to help explain the enduring increase in CV risk and mortality following a severe AECOPD event.Clinical trial registration: ClinicalTrials.gov #NCT01949727; Registered: 09/20/2013.

Evaluation of Circulating Platelet Extracellular Vesicles and Hypertension Mediated Organ Damage

Elevated circulating platelet-derived extracellular vesicles (pEVs) have been associated with arterial hypertension. The role of hypertension-mediated organ damage (HMOD) to induce EV release is still unknown. We studied the micro- and macro-vascular changes (retinal vascular density and pulse wave velocity), endothelial function (flow-mediated vasodilation of brachial artery and finger plethysmography), and assessed the psychosocial status (anxiety and depression) in hypertensive patients to determine their relationship with EV release. Pulse wave velocity showed a significant positive correlation with pEVs (r = 0.33; p = 0.01). Systolic blood pressure (SBP) negatively correlated with retinal vascularity. The superficial retinal vascular plexus density in the whole image showed a significant negative correlation with 24 h SBP (r = −0.38, p < 0.01), day-SBP (r = −0.35, p = 0.01), and night-SBP (r = −0.27, p = 0.04). pEVs did not show significant associations with microvascular damage (retinal vascular density), endothelial function (flow-mediated vasodilation of brachial artery and finger plethysmography), or psychosocial status (anxiety and depression). Our results indicate that the pEV levels were associated with macrovascular damage measured by PWV, whereas no significant association between pEVs and microvascular damage, endothelial function, or emotional status could be detected. The potential utility of pEV in clinical practice in the context of HMOD may be limited to macrovascular changes.

Impairment of endothelial function in Parkinson's disease

OBJECTIVE

There are conflicting data regarding the relationship between Parkinson's disease (PD) and the atherosclerotic process. This study aimed to compare endothelial function in patients with PD and matched controls. In PD subjects, we searched for factors contributing to endothelial dysfunction as well. Traditional vascular risk factors, PD characteristics, and PD medication were considered.

RESULTS

We prospectively enrolled 41 patients with PD and 41 controls matched for age, sex, body mass index, and vascular risk factors. Endothelial function (EF) was assessed using peripheral arterial tonometry (EndoPAT 2000 device) and expressed as reperfusion hyperemia index (RHI). Clinical characteristics including PD medication were recorded. RHI was non-significantly lower in the PD group than in controls (1.8 ± 0.5 vs. 1.9 ± 0.5, p = 0.478). In PD patients, in linear regression analysis, smoking (beta = -0.453, p = 0.008) and use of dopamine agonists (beta = -0.365, p = 0.030) were significant contributors in a model predicting RHI. Despite non-significant differences in endothelial dysfunction between PD patients and controls, our results suggest an association between smoking, dopamine agonists, and impaired EF in PD patients. The small sample size, as well as the absence of an extended search for traditional and non-traditional vascular risk factors, are the most important factors limiting the interpretation of the current results.

Transplantation of an obesity-associated human gut microbiota to mice induces vascular dysfunction and glucose intolerance

Recent preclinical data suggest that alterations in the gut microbiota may be an important factor linking obesity to vascular dysfunction, an early sign of cardiovascular disease. The purpose of this study was to begin translation of these preclinical data by examining whether vascular phenotypes in humans are transmissible through the gut microbiota. We hypothesized that germ-free mice colonized with gut microbiota from obese individuals would display diminished vascular function compared to germ-free mice receiving microbiota from lean individuals.We transplanted fecal material from obese and lean age-and sex-matched participants with disparate vascular function to germ-free mice. Using Principle Component Analysis, the microbiota of colonized mice separated by donor group along the first principle component, accounting for between 70-93% of the total variability in the dataset. The microbiota of mice receiving transplants from lean individuals was also characterized by increased alpha diversity, as well as increased relative abundance of potentially beneficial bacteria, including Bifidobacterium, Lactobacillus, and Bacteroides ovatis. Endothelium-dependent dilation, aortic pulse wave velocity and glucose tolerance were significantly altered in mice receiving microbiota from the obese donor relative to those receiving microbiota from the lean donor or those remaining germ-free.These data indicate that the obesity-associated human gut microbiota is sufficient to alter the vascular phenotype in germ-free mice in the absence of differences in body weight or dietary manipulation, and provide justification for future clinical trials to test the efficacy of microbiota-targeted therapies in the prevention or treatment of cardiovascular disease.

High-sodium diet does not worsen endothelial function in female patients with postural tachycardia syndrome

PURPOSE

Postural tachycardia syndrome (POTS), a syndrome characterized by orthostatic symptoms and a heart rate increase of at least 30 beats per minute in the absence of hypotension upon standing, is often accompanied by increased sympathetic activity and low blood volume. A common non-pharmacologic recommendation for patients with POTS is a high-sodium (HS) diet with the goal of bolstering circulating blood volume. The objective of this study is to assess the effects of 6 days of a HS diet on endothelial function in POTS.

METHODS

A total of 14 patients with POTS and 13 age-matched healthy controls, all females, were studied following 6 days on a low-sodium (LS) diet (10 mEq/day) and 6 days on a HS diet (300 mEq/day) in a crossover design. We measured endothelial function following reactive hyperemia in the brachial artery using flow-mediated dilation (FMD), leg blood flow (LBF) using strain gauge plethysmography in the calf, and reactive hyperemic index (RHI) in the microcirculation of the hand using pulsatile arterial tonometry.

RESULTS

On the LS diet, FMD% did not differ between patients with POTS and the healthy controls although peak brachial artery diameter was lower for the patient group. RHI was higher for the patient group than for the controls, but there were no differences in post-ischemic LBF increase. On the HS diet, there were no between-group differences in FMD%, LBF increase, or RHI.

CONCLUSION

In summary, a HS diet for 6 days did not induce endothelial dysfunction. This non-pharmacologic treatment used for patients with POTS does not negatively affect endothelial function when used for a sub-acute duration.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01550315; March 9, 2012.

Low Vitamin D Levels are Associated with Vascular Endothelial Dysfunction in Patients with Poorly Controlled Type 2 Diabetes: A Retrospective Study

AIM

This study aimed to determine the association between serum 25-hydroxyvitamin D (25(OH)D) levels and vascular endothelial function in patients with type 2 diabetes (T2D).

METHODS

This retrospective study included 113 patients with poorly controlled T2D who were admitted for in-hospital diabetes educational program and underwent measurements of serum 25(OH)D levels and reactive hyperemia index (RHI).

RESULTS

Serum 25(OH)D levels significantly correlated with RHI in T2D patients. Receiver operating characteristic (ROC) curve analysis showed that serum 25(OH)D level of 16.5 ng/mL is the optimal cutoff level for predicting vascular endothelial dysfunction (RHI＜1.67), with a sensitivity of 68.5%, specificity of 67.9%, and area under the ROC curve of 0.668 (95% confidence interval [CI]: 0.566-0.770, p=0.002). The mean RHI was significantly lower (1.70±0.54) in patients with low 25(OH)D levels (n=56, 25(OH)D levels ＜16.5 ng/mL) than that (1.99±0.58; p＜0.001) in patients with high 25(OH)D levels (n=57, 25(OH)D level ≥ 16.5 ng/mL). The proportion of patients with RHI＜1.67 was higher in the low 25(OH)D group than in the high 25(OH)D group (38% vs. 18%; p＜0.001). Multivariate logistic regression analysis identified that serum 25(OH)D level ＜16.5 ng/mL was associated with increased odds of RHI ＜1.67 (odds ratio 4.598, 95% CI 1.961-10.783, p＜0.001).

CONCLUSION

The results demonstrated the association of serum 25(OH)D levels with endothelial function in poorly controlled T2D patients and identified serum 25(OH)D level of ＜16.5 ng/mL as a predictor of RHI ＜1.67. Serum 25(OH)D level is a potentially useful marker of vascular endothelial dysfunction in poorly controlled T2D patients.

Effects of external counter-pulsation on endothelial function assessed by peripheral artery tonometry, levels of glycaemia and metabolic markers in individuals with type 2 diabetes mellitus

BACKGROUND AND AIMS

External counter-pulsation (ECP) generates sheer stress thereby improving endothelial function and anginal symptoms in coronary artery disease. Endothelial dysfunction is also involved in the pathogenesis of T2DM. The aim of this pilot study was to investigate the use of ECP at different doses in improving endothelial function and glycaemic markers in T2DM.

METHODS

This prospective study involved 46 subjects with T2DM randomly assigned to receive 35 sessions of ECP at different regimens (0.5 h versus 1 h) and duration (7 versus 12 weeks). Endothelial function was evaluated by reactive hyperaemia index (RHI) via peripheral arterial tonometry at the start, midpoint and end of study. Other secondary outcomes included fasting glucose, HOMA-IR, HbA1c, blood pressure, lipid profile, weight and vibration sense.

RESULTS

There was no change in RHI across all 3 regimens of ECP individually or collectively at the end of the study (ΔRHI +0.01%, p = 0.458). Glycaemic markers also remained unchanged at endpoint. Subgroup analysis showed an improvement in RHI (ΔRHI +20.6%, p = 0.0178) in subjects with more severe endothelial dysfunction at baseline.

CONCLUSION

ECP did not show a beneficial effect on endothelial function or glycemic control in this South-East Asian population with T2DM at any of the three regimens. This may partly be explained by less severe endothelial dysfunction and less insulin resistance in our population at baseline.

Changes in endothelial function during educational hospitalization and the contributor to improvement of endothelial function in type 2 diabetes mellitus

Only a few reports have examined vascular endothelial function before and after educational hospitalization and the factors that affect it in patients with type 2 diabetes mellitus (T2DM). The aim of this study was to assess vascular endothelial function before and after educational hospitalization and identify factors that affect it. In 65 patients with T2DM who underwent peripheral arterial tonometry (EndoPAT) before and after hospitalization, vascular endothelial function (reactive hyperemia index [RHI]), glucose metabolism, lipid metabolism, and blood pressure were assessed before and after hospitalization. The primary endpoint was hospitalization-induced changes in vascular endothelial function. Educational hospitalization significantly improved the natural logarithmically scaled RHI (L_RHI) from 0.555 ± 0.212 to 0.625 ± 0.245 (p = 0.012). Multivariable logistic regression analysis identified hypoglycemia during hospitalization as the single factor that significantly altered vascular endothelial function (p = 0.019). The odds of achieving normal vascular endothelial function were 0.08 times lower (95% confidence interval, 0.01-0.67) for each episode of hypoglycemia. Furthermore, multivariable analysis identified hypoglycemia during hospitalization as the single factor that worsened L_RHI. Our study showed that educational hospitalization of patients with T2DM improved vascular endothelial function, and that the development of hypoglycemic episodes had a significant negative impact on normalization of vascular endothelial function.

Peripheral arterial endothelial dysfunction predicts future cardiovascular events in diabetic patients with albuminuria: a prospective cohort study

Background

Reactive hyperemia-peripheral arterial tonometry (RH-PAT) is a noninvasive and simple test for evaluating the endothelial function. There has been sparse evidence on the usefulness of the RH-PAT index (RHI) in predicting future cardiovascular diseases among diabetic patients.

Methods

Asymptomatic diabetic patients with albuminuria were selected; their medical history and laboratory findings were evaluated every 3 to 4 months, respectively. The primary outcome was a composite of three-point major adverse cardiovascular events (3-point MACE): death from cardiovascular causes, acute coronary events, or nonfatal stroke. On the contrary, secondary outcomes included a composite of 3-point MACE, hospitalization for heart failure, or chronic kidney disease (CKD) progression. RHI was measured using the Endo-PAT2000 at the baseline. RHI < 1.67 was considered to indicate peripheral endothelial dysfunction (PED).

Results

In total, 149 subjects were included (mean age, 61.8 ± 9.2 years; duration of diabetes was 12 years). During the follow-up period (median, 49.7 months), of the 149 subjects, primary outcomes were detected in 12 (1 [2.3%] and 11 [10.5%] of those without and with PED, respectively). The presence of PED in baseline measurements significantly increased both primary and secondary outcomes, following adjustment for age, sex, hypertension, glycated hemoglobin, low-density lipoprotein cholesterol, triglyceride, systolic blood pressure, baseline estimated glomerular filtration rate, overt proteinuria, duration of diabetes, premedical history of ischemic events, anti-platelet agents, and smoking history (hazard ratio [HR]: 10.95; 95% confidence interval CI 1.00–119.91 for the primary outcome; HR, 4.12; 95% CI 1.37–12.41 for secondary outcome). In addition, PED could predict secondary outcomes independent of the risk score according to the American College of Cardiology/American Heart Association (HR: 3.24; 95% CI 1.14–9.17).

Conclusions

PED can independently predict future cardiovascular events among diabetic patients with albuminuria.

Establishing the interchangeability of arterial stiffness but not endothelial function parameters in healthy individuals

Background

Development of instruments capable of detecting early stage vascular disease has increased interest in employing arterial stiffness (e.g. pulse wave velocity (PWV), augmentation index (AIx)) and endothelial dysfunction (e.g. reactive hyperemia index (RHI)) to diagnose atherosclerotic disease before occurrence of a cardiovascular event. However, amongst the equipment designed for this purpose, there is insufficient information regarding each of these parameters to establish appropriate cutoffs to distinguish between healthy and unhealthy blood vessels. To address these limitations, the study was designed to establish the upper arterial stiffness and endothelial function thresholds in a healthy population, by comparing the outputs from different instruments capable of measuring PWV, AIx and RHI.

Methods

A systematic comparison of PWV, AIx and RHI was conducted to determine the inter-relationships between these parameters of vascular functionality. Outputs were obtained non-invasively using three instruments, the VP-1000 (VP), SphygmoCor (SC), and EndoPAT (EP), in 40 apparently healthy males and females.

Results

Correlations were found between the brachial-ankle PWV and radial-ankle PWV (by VP and SC), and PWV (VP) with AIx (SC). The interchangeability of these outputs was demonstrated by the Bland Altman test, making it feasible to extrapolate cut-offs for radial-ankle PWV and AIx equivalent to brachial-ankle PWV that signify healthy vessels. In contrast, RHI showed no association with AIx, suggesting these endothelial and arterial parameters are functionally distinct.

Conclusions

It was concluded that it is possible to compare the vascular function outputs of different instruments and identify healthy from unhealthy vessels, even though the approaches for quantifying the underlying physiological processes may differ. In this way, non-invasive determination of arterial function could be a new paradigm for detecting existing early stage asymptomatic atherosclerotic disease in individuals using techniques that are amenable to the clinical setting.

Electronic supplementary material

The online version of this article (10.1186/s12872-019-1167-3) contains supplementary material, which is available to authorized users.

Endothelial Function is improved by Inducing Microbial Polyamine Production in the Gut: A Randomized Placebo-Controlled Trial

Recently, it was demonstrated that spermidine-induced autophagy reduces the risk of cardiovascular disease in mice. Intestinal bacteria are a major source of polyamines, including spermidine. We previously reported that the intake of both Bifidobacterium animalis subsp. lactis (Bifal) and arginine (Arg) increases the production of putrescine, a spermidine precursor, in the gut. Here, we investigated the effects of Bifal and Arg consumption on endothelial function in healthy subjects. Healthy individuals with body mass index (BMI) near the maximum value in the “healthy” range (BMI: 25) (n = 44) were provided normal yogurt containing Bifal and Arg (Bifal + Arg YG) or placebo (normal yogurt) for 12 weeks in this randomized, double-blinded, placebo-controlled, parallel-group comparative study. The reactive hyperemia index (RHI), the primary outcome, was measured using endo-peripheral arterial tone (EndoPAT). The change in RHI from week 0 to 12 in the Bifal + Arg YG group was significantly higher than that in the placebo group, indicating that Bifal + Arg YG intake improved endothelial function. At week 12, the concentrations of fecal putrescine and serum putrescine and spermidine in the Bifal + Arg YG group were significantly higher than those in the placebo group. This study suggests that consuming Bifal + Arg YG prevents or reduces the risk of atherosclerosis.

Higher Serum Calcium Levels Are Associated with Preclinical Peripheral Arterial Disease among the Apparently Healthy Individuals

Background

Epidemiological studies suggest that serum calcium levels correlate with cardiovascular events. An ankle-brachial index (ABI) between 0.9 and 1.00 is a surrogate estimation of preclinical peripheral arterial disease (PAD). Prior studies have shown that an ABI of 0.9–1.0 is also associated with endothelial dysfunction. Therefore, we sought to investigate the relationship between serum calcium levels and preclinical PAD in apparently healthy Korean individuals.

Methods

We evaluated the association between serum calcium levels and preclinical PAD in 596 participants (334 males, 262 females) in a health examination program. Preclinical PAD was defined by an ABI of 0.9–1.0. Multiple logistic regression analysis was used to determine whether the serum calcium level was an independent determinant of preclinical PAD.

Results

The overall prevalence of preclinical PAD was 14.3%. The mean age was 44.0±12.5 years in the non-PAD group and 48.3±11.4 years in the preclinical PAD group (P=0.001). After adjusting for age, gender, systolic blood pressure, fasting plasma glucose, high-density lipoprotein cholesterol, triglycerides, C-reactive protein, g-glutamyltransferase, uric acid, hypertension medication, diabetes medication, and hyperlipidemia medication, the odds ratio (95% confidence intervals) for preclinical PAD was 2.28 (1.02–5.11) with a 1-mg/dL increase in the serum calcium.

Conclusion

These findings suggest that increased serum calcium is independently and positively associated with preclinical PAD regardless of the presence of classic cardiovascular risk factors.

Association of Peripheral Artery Disease With Incident Atrial Fibrillation: The ARIC (Atherosclerosis Risk in Communities) Study

BACKGROUND

Although peripheral artery disease as defined by ankle-brachial index (ABI) is associated with incident atrial fibrillation (AF), questions remain about the risk of AF in borderline ABI (>0.90 to <1.0) or noncompressible arteries (>1.4). We evaluated the association of borderline ABI and ABI >1.4 in the ARIC (Atherosclerosis Risk in Communities) study, a population-based prospective cohort study.

METHODS AND RESULTS

We included 14 794 participants (age, 54.2±5.8 years, 55% women, 26% blacks) with ABI measured at the baseline (1987-1989) and without AF. AF was identified from hospital records, death certificates, and ECGs. Using Cox proportional hazards, we evaluated the association between ABI and AF. During a median follow-up of 23.3 years, there were 2288 AF cases. After adjustment for cardiovascular risk factors, hazard ratio (HR) (95% confidence interval) for AF among individuals with ABI <1.0 compared with ABI 1.0 to 1.4, was 1.13 (1.01-1.27). ABI >1.4 was not associated with increased AF risk. ABI ≤0.9 and borderline ABI were associated with a higher risk of AF compared with ABI 1.0 to 1.4. Demographics-adjusted HRs (95% confidence interval) were 1.43 (1.17-1.75) and 1.32 (1.16-1.50), respectively. However, the associations of ABI ≤0.9 and borderline ABI with AF were attenuated after adjusting for cardiovascular risk factors (HR [95% confidence interval], 1.10 [0.90-1.34] and 1.14 [1.00-1.30]), respectively.

CONCLUSIONS

Peripheral artery disease indicated by low ABI, including borderline ABI, is a weak risk factor for AF. ABI >1.4 is not associated with an increased AF risk. The relationship between peripheral artery disease and AF appears to be mostly explained by traditional atherosclerotic risk factors.

The Relationship between Endothelial Dysfunction and Endothelial Cell Markers in Peripheral Arterial Disease

INTRODUCTION

The endothelial function plays key roles in both promoting and protecting against atherosclerotic disease. Several methods, including peripheral arterial tonometry (PAT), have been reported to be useful for investigating endothelial dysfunction. Furthermore, the level of thrombomodulin (TM) is assumed to reflect the endothelial dysfunction. In the present study, we investigated endothelial dysfunction in patients with peripheral arterial disease (PAD) by measuring their TM levels, and evaluated the correlation between TM and various parameters.

MATERIALS AND METHODS

We measured the TM levels and performed PAT in 17 patients with PAD. We also recorded the patients' demographic information, including comorbidities, and investigated their hemodynamic status by measuring the ankle brachial pressure index (ABI). The PAT results were used to calculate the reactive hyperemia index (RHI), which reflected the patients' level of endothelial dysfunction.

RESULTS

The RHI and ABI values and the serum level of creatinine were found to be significantly correlated with the TM level (P = 0.040, 0.041 and 0.005, respectively). After setting an RHI value of 1.67 as the cut-off, the patients with RHI values of <1.67 were found to have significantly higher TM levels (median, 20.3 U/mL) than the patients with RHI values of ≥1.67 (median, 13.7 U/mL) (P = 0.023).

CONCLUSIONS

The degree of endothelial dysfunction, as calculated by the TM level, might influence the prognostic value of the RHI, which is determined by PAT. The measurement of the TM level and PAT might both be useful methods of measuring endothelial dysfunction in patients with PAD.

Endothelial Dysfunction of Patients with Peripheral Arterial Disease Measured by Peripheral Arterial Tonometry

Objective. Endothelial dysfunction plays a key role in atherosclerotic disease. Several methods have been reported to be useful for evaluating the endothelial dysfunction, and we investigated the endothelial dysfunction in patients with peripheral arterial disease (PAD) using peripheral arterial tonometry (PAT) test in this study. Furthermore, we examined the factors significantly correlated with PAT test. Methods. We performed PAT tests in 67 patients with PAD. In addition, we recorded the patients' demographics, including comorbidities, and hemodynamical status, such as ankle brachial pressure index (ABI). Results. In a univariate analysis, the ABI value (r = 0.271, P = 0.029) and a history of cerebrovascular disease (r = 0.208, P = 0.143) were found to significantly correlate with PAT test, which calculated the reactive hyperemia index (RHI). In a multivariate analysis, only the ABI value significantly and independently correlated with RHI (β = 0.254, P = 0.041). Conclusion. This study showed a significant correlation between RHI and ABI. The PAT test is a useful tool for evaluating not only endothelial dysfunction but also the hemodynamical state in patients with PAD.

Beyond type 2 diabetes, obesity and hypertension: an axis including sleep apnea, left ventricular hypertrophy, endothelial dysfunction, and aortic stiffness among Mexican Americans in Starr County, Texas

BACKGROUND

There is an increasing appreciation for a series of less traditional risk factors that should not be ignored when considering type 2 diabetes, obesity, hypertension, and cardiovascular disease. These include aortic stiffness, cardiac structure, impaired endothelial function and obstructive sleep apnea. They are associated to varying degrees with each disease categorization and with each other. It is not clear whether they represent additional complications, concomitants or antecedents of disease. Starr County, Texas, with its predominantly Mexican American population has been shown previously to bear a disproportionate burden of the major disease categories, but little is known about the distribution of these less traditional factors.

METHODS

Type 2 diabetes, obesity and hypertension frequencies were determined through a systematic survey of Starr County conducted from 2002 to 2006. Individuals from this examination and an enriched set with type 2 diabetes were re-examined from 2010 to 2014 including assessment of cardiac structure, sleep apnea, endothelial function and aortic stiffness. Individual and combined frequencies of these inter-related (i.e., axis) conditions were estimated and associations evaluated.

RESULTS

Household screening of 5230 individuals aged 20 years and above followed by direct physical assessment of 1610 identified 23.7 % of men and 26.7 % of women with type 2 diabetes, 46.2 and 49.5 % of men and women, respectively with obesity and 32.1 and 32.4 % with hypertension. Evaluation of pulse wave velocity, left ventricular mass, endothelial function and sleep apnea identified 22.3, 12.7, 48.6 and 45.2 % of men as having "at risk" values for each condition, respectively. Corresponding numbers in women were 16.0, 17.9, 23.6 and 28.8 %. Cumulatively, 88 % of the population has one or more of these while 50 % have three or more.

CONCLUSIONS

The full axis of conditions is high among Mexican Americans in Starr County, Texas. Individual and joint patterns suggest a genesis well before overt disease. Whether they are all mediated by common underlying factors or whether there exist multiple mechanisms remains to be seen.

Borderline ankle-brachial index is associated with poor short-term clinical outcome after coronary artery intervention

OBJECTIVE

To evaluate the association between borderline ankle-brachial index (ABI) and clinical outcome in patients who underwent percutaneous coronary intervention (PCI).

METHODS

From August 2009 to August 2012, ABI was measured in 1291 patients who underwent PCI. Patients with borderline ABI were compared with those who had normal ABI. The primary outcome was major adverse cardiac and cerebrovascular event (MACCE), defined as a composite of all-cause death, myocardial infarction, stroke, and repeat revascularization.

RESULTS

Of the 1291 patients, 1154 (82%) had normal ABI and 89 (7%) had borderline ABI. The median overall follow-up duration was 19 (interquartile range 13-26) months. After adjustment with IPTW, the incidence of stroke (HR, 6.28; CI 95%, 1.95-20.19; P < 0.01) and MACCE (HR, 2.54; CI 95%, 1.40-4.62; P < 0.01) were higher in the borderline ABI group. In a propensity score-matched population, the incidence of stroke (HR, 4.68; CI 95%, 1.18-18.52; p = 0.03) and MACCE (HR, 2.12; CI 95%, 1.09-4.11; P = 0.03) were still significantly higher.

CONCLUSION

The presence of borderline ABI was associated with worse clinical outcome and increased stroke rate compared with normal ABI during the short-term follow-up period in patients who underwent coronary intervention.

Association between the ankle-brachial index, intermittent claudication, and physical activity level: what is the influence on the functional capacity of patients with or at high risk of cardiovascular disease?

Background

Patients with or at high risk of cardiovascular disease have a poor functional capacity; however, the influence of association among intermittent claudication (IC), abnormal ankle–brachial index (ABI), and physical activity level on functional capacity of these patients has not been fully studied.

Objective

The primary objective of this study was to investigate the association between the ABI, IC, and physical activity level, and the influence of these variables on the functional capacity of patients with or at high risk of cardiovascular disease seen in a reference cardiology outpatient clinic in Southern Brazil. The secondary objective was to assess the prevalence of peripheral arterial disease (PAD) in this sample of patients.

Patients and methods

This was a prospective cross-sectional study in which 162 consecutive patients were evaluated and classified into three groups according to their ABI: normal ABI (n=104, values between 1.00 and 1.40); borderline PAD (n=23, values between 0.91 and 1.00); and patients with PAD (n=35, ≤0.90). The presence of IC was assessed using the Edinburgh Claudication Questionnaire. The level of physical activity was assessed by the short version of the International Physical Activity Questionnaire (IPAQ) and functional capacity was assessed by the 6-minute walk distance (6MWD).

Results

The prevalence of PAD was 21.6% in the total sample. The 6MWD showed strong correlation with the absence of IC (r=0.785; P<0.001), moderate correlation with age (r=−0.347; P<0.001), and weak correlations with IPAQ scores (r=0.164; P=0.038) and ABI (r=0.216; P=0.006). Age, ABI, and absence of IC were independently associated with the outcome (P=0.001, P=0.001, and P=0.028, respectively).

Conclusion

The current study demonstrates that 6MWD is associated with IPAQ scores, ABI, and absence of IC. Age, ABI and absence of IC were independently associated with functional capacity in patients with or at high risk of cardiovascular disease.

Impedance plethysmography as an alternative method for the diagnosis of peripheral arterial disease

BACKGROUND AND OBJECTIVE

In the diagnosis of peripheral artery disease (PAD), the ankle-brachial index (ABI) is considered as the standard, and other noninvasive methods have received too little attention. Therefore, the aim of the study was to determine the diagnostic accuracy of impedance plethysmography in diagnosing PAD and to compare this method with other methods.

MATERIALS AND METHODS

A total of 66 patients with a mean age of 76.1±9.6 years who had been treated for various cardiovascular diseases at Kaunas Clinical Hospital during 2011-2012 were enrolled into the study. All the patients were screened for PAD. Impedance plethysmography was performed with a new-generation Niccomo™ device. The receiver operating characteristic analysis was employed to determine the diagnostic accuracy of 4 parameters of impedance plethysmography: crest time (CT), crest width (CW), pulse amplitude (Pampl), and alternating blood flow (ABF).

RESULTS

There were a significant correlation between the ABI and the CT (r=-0.699, P<0.001), between the ABI and the ABF (r=0.552; P<0.001), and between the ABI and the Pampl only among men (r=0.652; P<0001). No correlation was found between the ABI and the CW. Among all the parameters, the CT had the highest sensitivity and specificity (73.2% and 96.0%, respectively). Other parameters had the following sensitivities and specificities: ABF, 61.0% and 96.0%; and Pampl, 90.0% and 20.0%, respectively.

CONCLUSIONS

Impedance plethysmography, especially its parameter CT, is an alternative noninvasive method in diagnosing PAD and could be used for the screening of patients with PAD.

Correlates of reactive hyperemic index in men and postmenopausal women

The aim of the present study was to investigate the differences in digital reactive hyperemic index (RHI) in men and postmenopausal women. We investigated the differences in and correlates of RHI, measured by peripheral artery tonometry (PAT), in a group of 82 men (mean age ± SD: 55.6 ± 8.2 years; body mass index: 29.0 ± 4.2 kg/m(2)) and 125 postmenopausal women (58.9 ± 5.2 years; 27.7 ± 4.1 kg/m(2)). We also examined fRHI values (natural log of the PAT ratio of the 90-120 seconds post-occlusion interval) and augmentation index (AIx) as a measure of arterial stiffness. We found that RHI, fRHI and AIx were significantly lower in men compared to postmenopausal women (p<0.0001). We also found that fRHI values were significantly lower in individuals with (MetS+) versus without (MetS-) the metabolic syndrome (MetS). Endothelial inflammation was present in MetS+ subjects as indicated by increased plasma soluble intercellular adhesion molecule-1 (sICAM-1) (p<0.001) and E-selectin (p=0.0519) concentrations compared to MetS- individuals. No significant difference was found in RHI or AIx between MetS+ versus MetS- individuals. In summary, our study reveals that men have an impairment of endothelial function, assessed by digital PAT, compared to postmenopausal women. Furthermore, we show that the presence of the MetS is characterized by endothelial dysfunction, as suggested by lower fRHI, as well as by endothelial inflammation, which likely contributes to the increased cardiovascular disease risk associated with the MetS. ClinicalTrials.gov Identifier: NCT01085019.

Future non-invasive imaging to detect vascular plaque instability and subclinical non-obstructive atherosclerosis

Atherosclerosis underlies the major causes of death in the Western World. Our main goal is to detect early changes of atherosclerosis and to identify subjects at highest cardiovascular risk that may aid in the development of prevention approaches and better management that will decrease cardiovascular morbidity and mortality. The new methods that are of interest include the advanced vascular ultrasound methods, the infra red and near infra red imaging techniques, the EndoPat device that reflects peripheral arterial tone, the electron beam computed tomography, the magnetic resonance imaging, and the molecular imaging techniques. In this review we will focus on the future of advanced imaging techniques that are being developed to detect early (pre-clinical) development of atherosclerosis.

The role of nutrition and body composition in peripheral arterial disease

Peripheral arterial disease (PAD) has not been as extensively investigated as other cardiovascular diseases. However, the available data suggest that nutrition-based treatment strategies have the potential to reduce the cost-economic burden of PAD substantially. Abdominal obesity is associated with PAD and prospective and cross-sectional studies have shown that a low dietary intake of folate and reduced synthesis of vitamin D are associated with an increased risk of PAD and severe walking impairment in patients who have the disease. However, dietary patterns that are associated with decreased cardiovascular risk might protect against PAD. A small number of clinical trials have provided evidence that increased intakes of niacin and insoluble fiber might be associated with decreased levels of LDL cholesterol and thrombogenic biomarkers, as well as increased serum levels of HDL cholesterol in patients with PAD. However, little evidence that antioxidants, vitamins B(6) and B(12), or essential fatty acid supplements improve clinical outcomes in these patients exists. Overall, data on the effects of nutrition, body composition, and nutritional supplementation on the risk, progression, and prognosis of PAD are scarce. Further research into these areas is required to allow the development of evidence-based nutritional guidelines for the prevention and treatment of the disease.

Effect of carvedilol and nebivolol on oxidative stress-related parameters and endothelial function in patients with essential hypertension

Oxidative stress and endothelial dysfunction have been associated with essential hypertension (EH) mechanisms. The purpose of this study was to evaluate the effect of carvedilol and nebivolol on the oxidative stress-related parameters and endothelial function in patients with EH. The studied population included 57 patients, either sex, between 30 and 75 years of age, with mild-to-moderate EH complications. Participants were randomized to receive either carvedilol (12.5 mg) (n = 23) or nebivolol (5 mg) (n = 21) for 12 weeks. Measurements included; 24-hr ambulatory blood pressure (BP), flow-mediated dilatation, levels of nitric oxide estimated as nitrite - a nitric oxide metabolite ( NO₂) - in plasma, and oxidative stress-related parameters in plasma and erythrocyte. EH patients who were treated with nebivolol or carvedilol showed systolic BP reductions of 17.4 and 19.9 mmHg, respectively, compared with baseline values (p < 0.01). Diastolic BP was reduced by 13.7 and 12.8 mmHg after the treatment with ebivolol and carvedilol, respectively (p < 0.01) (fig. 2B). Nebivolol and carvedilol showed 7.3% and 8.1% higher endothelium-dependent dilatation in relation to baseline values (p < 0.05). Ferric-reducing ability of plasma (FRAP) and reduced glutathione/oxidized glutathione (GSSH) ratio showed 31.5% and 29.6% higher levels in the carvedilol group compared with basal values; however, nebivolol-treated patients did not show significant differences after treatment. On the other hand, the NO₂ plasma concentration was not modified by the administration of carvedilol. However, nebivolol enhanced these levels in 62.1% after the treatment. In conclusion, this study demonstrated the antihypertensive effect of both beta-blockers. However, carvedilol could mediate these effects by an increase in antioxidant capacity and nebivolol through the raise in NO₂ concentration. Further studies are needed to determine the molecular mechanism of these effects.

Deterioration of endothelial function and carotid intima-media thickness in Tibetan male adolescents exposed to second-hand smoke

INTRODUCTION

It has been commonly accepted that second-hand smoke (SHS) is associated with atherosclerosis and endothelial dysfunction. There is growing evidence that the changes might begin in childhood. Unfortunately, no study has focused on the early atherosclerosis of Tibetan adolescents exposed to SHS.

AIMS

We aimed to investigate the endothelial function and carotid atherosclerosis in healthy school-aged Tibetan male adolescents.

MATERIALS AND METHODS

All passive smoking participants (SHS) were students were 16 years old and male, and were recruited through middle schools in Lhasa city. In total 624 subjects were accepted after excluding subjects who actively smoked. The adolescents were divided into three groups according to serum cotinine level: high cotinine group (High Group) with 205 boys, intermediate cotinine group (Intermediate Group) with 210 boys, and low cotinine group (Low Group) with 209 boys. Venous blood was sampled for the measurement of cotinine concentration, lipid profile and endothelin-1 (ET-1) quantitation. High-resolution B-mode ultrasonography was performed to evaluate carotid intima-media thickness (cIMT) and intima smoothness. The invasive vascular endothelial function was evaluated through the measurement of flow-mediated dilation (FMD) with B-mode ultrasound and ankle-brachial index (ABI) by using a blood pressure cuff and a Doppler instrument.

RESULTS

No statistical significance was found between groups in total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride, ApoA-I, systolic blood pressure, diastolic blood pressure, and heart rate (p>0.05). In the lipid profile, only apolipoprotein B (ApoB) values were different between groups: ApoB in the High Group was higher than in the Low Group (p=0.0164). Plasma ET-1 concentrations in the High Group were also much higher than in the Intermediate and Low Groups (p=0.0112, p<0.001). The cIMT and intima smoothness had deteriorated in the High Group compared with the Low Group (p<0.001 and p<0.05 respectively). FMD and ABI, which indicate vascular endothelial function, was decreased in the High Group compared with the Intermediate and Low Groups (FMD, p<0.001; ABI, p<0.001).

CONCLUSIONS

SHS was associated with sub-clinical carotid atherosclerosis and endothelial dysfunction in Tibetan school-aged male adolescents. Considering the widespread exposure to SHS and the clinical relevance of early atherosclerosis, this result is of public health importance in Tibet, where health education is not satisfactory. Data from our study emphasize the importance of endorsing smoke-free environments for adolescents.