Brachial-ankle pulse wave velocity is associated with walking distance in patients referred for peripheral arterial disease evaluation

The Association Between Ankle-Brachial Index and Daily Patterns of Physical Activity: Results From the Hispanic Community Health Study/Study of Latinos

BACKGROUND

Peripheral artery disease (PAD) is associated with lower physical activity but less is known about its association with daily patterns of activity. We examined the cross-sectional association between ankle-brachial index (ABI) and objectively measured patterns of physical activity among Hispanic/Latino adults.

METHODS

We analyzed data from 7 688 participants (aged 45-74 years) in the Hispanic Community Health Study/Study of Latinos. ABI was categorized as low (≤0.90, indicating PAD), borderline low (0.91-0.99), normal (1.00-1.40), and high (>1.40, indicating incompressible ankle arteries). Daily physical activity metrics derived from accelerometer data included: log of total activity counts (LTAC), total log-transformed activity counts (TLAC), and active-to-sedentary transition probability (ASTP). Average differences between ABI categories in physical activity, overall and by 4-hour time-of-day intervals, were assessed using linear regression and mixed-effects models, respectively.

RESULTS

In Hispanic/Latino adults, 5.3% and 2.6% had low and high ABIs, respectively. After adjustment, having a low compared to a normal ABI was associated with lower volume (LTAC = -0.13, p < .01; TLAC = -74.4, p = .04) and more fragmented physical activity (ASTP = 1.22%, p < .01). Having a low ABI was linked with more fragmented physical activity after 12 pm (p < .01). Having a high ABI was associated with lower volumes of activity (TLAC = -132.0, p = .03).

CONCLUSIONS

Having a low or high ABI is associated with lower and more fragmented physical activity in Hispanic/Latino adults. In adults with low ABI, physical activity is more fragmented in the afternoon to evening. Longitudinal research is warranted to expand these findings to guide targeted interventions for PAD or incompressible ankle arteries.

The effects of sedentary behaviour on patients with peripheral arterial Disease: A systematic review

Sedentary behavior has recently emerged as a risk factor for cardiometabolic diseases. The objective of this review was to assess the relationship between sedentary behavior and peripheral arterial disease (PAD). Using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, we performed an electronic search across databases including Cochrane Central Register of Controlled Trials, Embase, MEDLINE (Ovid), CINHAL and PubMed to identify studies focusing on sedentary behavior and PAD. A total of 678 records fulfilled eligibility; 166 duplicates were removed, 487 were excluded at the title and abstract level and 15 studies were excluded at the full article level. Thus, our review comprised 10 studies of 20,064 patients with mean age 67.4 years. The average sedentary time was 544.9 min/day. The current review findings indicate that patients with PAD exhibited prolonged periods of sedentary behavior. Furthermore, sedentary behavior among patients with PAD was associated with lower survival rates. The included studies also reported varied outcomes regarding walking distance with some showing an association between reduced sedentary behavior and increased total walking distance. A randomized controlled trial in this review highlighted that reducing sedentary time among patients with PAD improved walking distance. Therefore, the connection between sedentary behavior and PAD seems to be bidirectional. Sedentary time could contribute to PAD development, and PAD-related symptoms may lead to prolonged sedentary behavior. A call for research investigating the link between PAD and sedentary time. Additionally, intervention studies are needed to target the reduction of sedentary time in patients with PAD.

Relationship between physical fitness and arterial stiffness in Korean older adults

Pulse-wave velocity (PWV) is a widely used clinical marker of arterial stiffness. Associations between several physical fitness measures and arterial stiffness have been examined. However, these results were inconsistent. Therefore, we conducted a cross-sectional study to assess the relationship between various physical fitness parameters and arterial stiffness in older adults. From January 2014 to December 2015, 1500 participants (men, n = 587; mean age, 71.78 ± 5.10 years) in South Korea were enrolled in the study. Koreans aged >65 years who agreed to participate in the study were enrolled. Individuals who were unable to exercise because of underlying conditions were excluded. VO2 max (mL/kg/min), handgrip strength (kg), handgrip strength (kg)/body weight (kg) ratio, one-leg standing time (s), and 10-meter walking speed (m/s) were measured. The brachial-ankle pulse wave velocity (baPWV) was measured using a VP-1000 instrument. VO2 max (mL/kg/min), handgrip (kg)/body weight (kg) ratio, one-leg standing time (s), and 10-meter walking speed (m/s) were significantly inversely associated with baPWV. This association was consistent even after adjusting for confounding factors. Our study revealed a significant association between various aspects of physical fitness and arterial stiffness. This study suggests that physical fitness is a useful predictor of arterial stiffness in older adults.

Cardiac Rehabilitation in Peripheral Artery Disease in a Tertiary Center-Impact on Arterial Stiffness and Functional Status after 6 Months

Background and Objectives: Cardiac rehabilitation (CR) plays an essential role in peripheral artery disease (PAD), leading to improved functional status, increased quality of life, and reduced arterial stiffness. We aimed to assess factors associated with clinical improvement 6 months after enrolment in a rehabilitation program at an academic medical center in north-eastern Europe. Materials and Methods: We conducted a prospective cohort study on 97 patients with PAD admitted to a single tertiary referral center. At the 6-months follow-up, 75 patients (77.3%) showed improved clinical status. We analyzed demographics and clinical and paraclinical parameters in order to explore factors associated with a favorable outcome. Results: Hypertension (p = 0.002), diabetes mellitus (p = 0.002), dyslipidemia (p = 0.045), and obesity (p = 0.564) were associated with no clinical improvement. Smoking cessation (p < 0.001), changing sedentary lifestyle (p = 0.032), and improvement of lipid and carbohydrate profile as well as functional status parameters and ambulatory arterial stiffness index (p = 0.008) were factors associated with clinical improvement at the 6-months follow-up. Conclusions: PAD patients require an integrative, multidisciplinary management to maintain functional status and increase quality of life. Improving carbohydrate and lipid profile, adopting a healthy lifestyle, quitting smoking and increasing exercise capacity are predictors for clinical improvement 6 months after enrolment in a CR program.

Are Vascular Parameters Associated with Walking Impairment in Patients with Claudication?

BACKGROUND

The mechanisms underlying functional impairments in symptomatic PAD patients are controversial and poorly understood. Endothelial dysfunction and arterial stiffness have been proposed as potential mechanisms related to functional impairment in symptomatic PAD patients, however, more studies are needed to confirm these associations.

OBJECTIVE

To analyze the association between vascular function and walking impairment in patients with peripheral arterial disease (PAD) and symptoms of claudication.

METHODS

This was a cross-sectional study that included 68 patients with symptomatic PAD. All patients underwent an objective (Six-minute walk test [6MWT], 4-meter walk test) and a subjective (Walking Impairment Questionnaire [WIQ]) measurement of walking impairment. Vascular parameters measured were pulse-wave velocity (PWV) and flow-mediated dilation (FMD). Multiple linear regression was performed to investigate the association among walking impairment variables with vascular function parameters.

RESULTS

No significant associations between the claudication onset distance (PWV: b=.060, P = 0.842; FMD: b=-.192, P = 0.456), 6MWT (PWV: b=.007, P = 0..975; FMD: b=.090, P = 0.725), WIQ distance (PWV: b=.337, P = 0.117; FMD: b=-.025, P = 0.895) WIQ speed (PWV: b=.320, P = 0.181; FMD: b=-.028, P = 0.497), WIQ stairs (PWV: b=.256, P = 0.204; FMD: b=-.228, P = 0.230), 4-meter usual walk (PWV: b=-.421, P = 0.107; FMD: b=-.338, P = 0.112), 4-meter fast walk (PWV: b=-.496, P = 0.063; FMD: b=-.371, P = 0.086) and vascular function were found.

CONCLUSIONS

In symptomatic PAD patients, vascular function is not associated to walking impairment, even when adjusting for comorbid conditions and diabetes.

Impacts of aquatic walking on arterial stiffness, exercise tolerance, and physical function in patients with peripheral artery disease: a randomized clinical trial

Peripheral artery disease (PAD) is an atherosclerotic disease that is associated with attenuated vascular function, cardiorespiratory capacity, physical function, and muscular strength. It is essential to combat these negative effects on health by incorporating lifestyle interventions to slow disease progression, such as exercise. We sought to examine the effects of aquatic walking exercise on cardiovascular function, cardiorespiratory capacity [maximal volume of oxygen consumption (V̇o_2max)], exercise tolerance [6-min walking distance (6MWD)], physical function, muscular strength, and body composition in patients with PAD. Patients with PAD (n = 72) were recruited and randomly assigned to a 12-wk aquatic walking training group (AQ, n = 35) or a control group (CON, n = 37). The AQ group performed walking and leg exercises in waist-to-chest-deep water. Leg arterial stiffness [femoral-to-ankle pulse wave velocity (legPWV)], heart rate (HR), blood pressure (BP), ankle-to-brachial index (ABI), V̇o_2max, 6MWD, physical function, muscular strength, body composition, resting metabolic rate (RMR), and flexibility were measured before and after 12 wk. There were significant group × time interactions (P < 0.05) after 12 wk for legPWV and HR, which significantly decreased (P < 0.05) in AQ, and V̇o_2max, 6MWD, physical function, and muscular strength, which significantly increased (P < 0.05) in AQ, compared with no changes in CON. There were no significant differences (P > 0.05) for BP, ABI, RMR, or flexibility after 12 wk. Interestingly, there was relatively high adherence (84%) to the aquatic walking exercise program in this population. These results suggest that aquatic walking exercise is an effective therapy to reduce arterial stiffness and resting HR and improve cardiorespiratory capacity, exercise tolerance, physical function, and muscular strength in patients with PAD.NEW & NOTEWORTHY The results of this study reveal for the first time that aquatic walking exercise can decrease arterial stiffness and improve exercise tolerance, cardiorespiratory capacity, and muscular strength in patients with peripheral artery disease (PAD). Aquatic walking exercise training demonstrates relatively high exercise adherence in this population. Aquatic walking exercise training may be a useful therapeutic intervention for improving physical function in patients with PAD.

Factors Associated to Arterial Stiffness in Patients With Symptomatic Peripheral Artery Disease

BACKGROUND

The aim of this study was to identify the clinical factors associated with arterial stiffness in patients with symptomatic peripheral artery disease.

METHODS

In this cross-sectional study, 181 patients (67% men; mean aged 66 ± 9 years) were recruited and had their central arterial stiffness assessed by carotid-femoral pulse wave velocity (cf-PWV). Clinical characteristics are sociodemographic data, body mass index, comorbid conditions, and walking capacity.

RESULTS

Multiple linear regression analysis showed that age (b = 0.182, P = 0.032), body mass index (b = 0.254, P = 0.002), and mean blood pressure (b = 0.249, P = 0.021) were positively associated with cf-PWV.

CONCLUSIONS

Our results showed that the aging, elevated body mass index, and higher blood pressure are clinical factors associated with increased arterial stiffness in patients with peripheral artery disease.

Restless legs syndrome is associated with arterial stiffness and clinical outcome in stroke patients

OBJECTIVE

Restless legs syndrome (RLS) has been associated with vascular diseases, including cerebrovascular and cardiovascular diseases. Among the various mechanisms in RLS, peripheral vascular endothelial dysfunction in patients with RLS has recently been proposed as a vascular pathophysiology of RLS. This study investigated arterial stiffness related to RLS in acute ischemic stroke patients and its influence on stroke outcome.

METHODS

RLS in patients with acute ischemic stroke was assessed based on the four essential criteria of the International Restless Legs Syndrome Study Group described in 2003. The patients' clinical and laboratory characteristics, arterial stiffness, small vessel disease occurrence, and burden on brain MRI were recorded. Stroke severity was determined using the National Institute of Health Stroke Scale (NIHSS), and clinical outcomes were determined using the modified Rankin Scale.

RESULTS

Of 296 patients with acute ischemic stroke, 16 (5.4%) were diagnosed with restless legs syndrome. Logistic regression analysis showed that a 1 m/s increase in brachial arterial pulse wave velocity was associated with the diagnosis of RLS (odds ratio, 1.092; 95% confidence interval, 1.019-1.170, p = 0.012). Diagnosis of RLS in patients with acute ischemic stroke was associated with poor clinical outcome three months after stroke (modified Rankin Scale 3-6) (odds ratio, 4.263; 95% confidence interval, 1.229-14.792, p = 0.022) along with initial NIHSS score.

CONCLUSION

RLS in patients with acute ischemic stroke is associated with increased arterial stiffness and poor clinical outcomes.

The relationship between pulse waveform analysis indices, endothelial function and clinical outcomes in patients with peripheral artery disease treated using percutaneous transluminal angioplasty during a one-year follow-up period

BACKGROUND

Several predictors of clinical outcomes after percutaneous transluminal angioplasty (PTA) interventions in patients with peripheral arterial disease (PAD) have been investigated. Indices of endothelial function, arterial pulse waveform analysis (aPWA) and markers of peripheral artery ischemia were among the most commonly examined. The aim of the current study was to assess the relationship between potential predictors of clinical outcomes after peripheral artery PTA during a 1-year follow-up period.

METHODS

The study included 72 individuals with PAD at a mean age of 66.3 ± 7.2 (79.1% males). All patients underwent PTA of the peripheral arteries. Among them, 42.8% presented critical limb ischemia (CLI). During the first visit and at 1 month and 6 months after PTA, endothelial function and aPWA measurements were taken. Ankle-brachial index (ABI), toe-brachial index (TBI) and physical evalu-ation of the limbs took place during the first visit and at 1, 6 and 12 months after the PTA. The study endpoints included myocardial infarction, amputation, death, stroke and reintervention. All subjects included in the study were observed for 386 days after the PTA.

RESULTS

A significant improvement was noted in walking distance after PTA at the following time points, as well as transient improvement of ABI and flow-mediated dilatation (FMD) and no significant change in aPWA indices and reactive-hyperaemia index (RHI). The mean ABI, TBI, FMD and RHI values did not correlate with each other at baseline. There were 25 study endpoints which occurred in 16 patients during the follow-up period (22.2%). Patients with CLI, hypercholesterolemia, lower dias-tolic blood pressure, higher subendocardial viability ratio, a greater number of pack-years and lower TBI at baseline presented significantly poorer clinical outcomes in terms of endpoint events.

CONCLUSIONS

Endothelial function assessed as FMD and reactive hyperemia-peripheral arterial tonometry (RH-PAT) before PTA in patients with advanced PAD do not predict clinical outcomes during the 1-year follow-up.

Mitochondrial Bioenergetics in the Metabolic Myopathy Accompanying Peripheral Artery Disease

Peripheral artery disease (PAD) is a serious but relatively underdiagnosed and undertreated clinical condition associated with a marked reduction in functional capacity and a heightened risk of morbidity and mortality. The pathophysiology of lower extremity PAD is complex, and extends beyond the atherosclerotic arterial occlusion and subsequent mismatch between oxygen demand and delivery to skeletal muscle mitochondria. In this review, we evaluate and summarize the available evidence implicating mitochondria in the metabolic myopathy that accompanies PAD. Following a short discussion of the available in vivo and in vitro methodologies to quantitate indices of muscle mitochondrial function, we review the current evidence implicating skeletal muscle mitochondrial dysfunction in the pathophysiology of PAD myopathy, while attempting to highlight questions that remain unanswered. Given the rising prevalence of PAD, the detriment in quality of life for patients, and the associated significant healthcare resource utilization, new alternate therapies that ameliorate lower limb symptoms and the functional impairment associated with PAD are needed. A clear understanding of the role of mitochondria in the pathophysiology of PAD may contribute to the development of novel therapeutic interventions.

Ankle-brachial index and physical function in older individuals: The Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND AND AIMS

Most prior studies investigating the association of lower extremity peripheral artery disease (PAD) with physical function were small or analyzed selected populations (e.g., patients at vascular clinics or persons with reduced function), leaving particular uncertainty regarding the association in the general community.

METHODS

Among 5262 ARIC participants (age 71-90 years during 2011-2013), we assessed the cross-sectional association of ankle-brachial index (ABI) with the Short Physical Performance Battery (SPPB) score (0-12), its individual components (chair stands, standing balance, and gait speed) (0-4 points each), and grip strength after accounting for potential confounders, including a history of coronary disease, stroke, or heart failure.

RESULTS

There were 411 participants (7.8%) with low ABI ≤0.90 and 469 (8.9%) participants with borderline low ABI 0.91-1.00. Both ABI ≤0.90 and 0.91-1.00 were independently associated with poor physical function (SPPB score ≤6) compared to ABI 1.11-1.20 (adjusted odds ratio 2.10 [95% CI 1.55-2.84] and 1.86 [1.38-2.51], respectively). The patterns were largely consistent across subgroups by clinical conditions (e.g., leg pain or other cardiovascular diseases), in every SPPB component, and for grip strength. ABI >1.3 (472 participants [9.0%]), indicative of non-compressible pedal arteries, was related to lower physical function as well but did not necessarily reach significance.

CONCLUSIONS

In community-dwelling older adults, low and borderline low ABI suggestive of PAD were independently associated with poorer systemic physical function compared to those with normal ABI. Clinical attention to PAD as a potential contributor to poor physical function is warranted in community-dwelling older adults.

Predictive value of brachial-ankle artery pulse wave velocity to heart failure with preserved ejection fraction in hospitalised patients with acute dyspnoea

Objective:

To explore the predictive value of the brachial-ankle artery pulse wave velocity (baPWV) for heart failure with preserved ejection fraction (HFpEF).

Methods:

Echocardiographic data, B-type natriuretic peptide (BNP) level, and baPWV were assessed in 111 consecutive patients admitted for acute dyspnea. The patients were divided into the HFpEF group (n=71) and the control group (n=40).

Results:

Multivariate logistic regression analyses revealed that the ratio of the early mitral inflow velocity to the tissue Doppler velocity (E/e’) at the lateral mitral annulus, BNP, and baPWV were independently predictive of HFpEF. Adding the baPWV to E/e’ at the lateral annulus and to the BNP resulted in an increase in the area under the curve (AUC) to 0.855 (vs. lateral E/e’ alone, P=0.02) or 0.880 (vs. BNP alone, P=0.02), respectively. The AUC of the three combining indicators including the lateral E/e’, BNP, and baPWV was 0.910 (vs. E/e’ lateral alone, P<0.001; vs. BNP alone, P=0.001). The diagnostic accuracy was improved significantly after adding the baPWV to the diagnostic criteria of the 2007 ESC consensus statement (net reclassification improvement 0.127, P=0.02).

Conclusions:

Adding the baPWV to the current diagnostic indicators of the 2007 ESC consensus statement could increase the accuracy of predicting HFpEF.

Brachial-ankle pulse wave velocity is a predictor of walking distance in community-dwelling adults

Arterial stiffness represents the cumulative effects of cardiovascular risk factors, including aging, on the arterial wall, and has been found to be a surrogate marker of cardiovascular disease. However, it remains unknown whether baseline arterial stiffness is independently associated with improvement in functional abilities after exercise training. The subjects were 72 adults (9 men and 63 women) aged 67 ± 7 years from a rural village. Before and at the end of a 12-week Nordic walking program, 6-min walk distance (6MWD) as functional abilities, metabolic characteristics, and the mean of the right and left brachial-ankle pulse wave velocity (baPWV) as a marker of arterial stiffness were measured. Higher baseline mean baPWV levels correlated significantly with shorter baseline 6MWD (P < 0.001), and also with the follow-up 6MWD (P < 0.001) and change rate (P = 0.019) in 6MWD after the 12-week training program. Multivariate linear regression analysis was employed to evaluate the contribution of baseline mean baPWV for 6MWD parameters showing that baseline mean baPWV values were significantly and independently associated with follow-up 6MWD (β = -0.523, P < 0.001) and change rate in 6MWD (β = -0.399, P < 0.001) as well as baseline 6MWD (β = -0.522, P < 0.001), but was not associated with change after the 12-week training program. Higher baPWV, a measurement of arterial stiffness, might be a predictor of functional abilities after exercise training, independent of confounding factors, in the general population.

Exercise capacity is associated with endothelin-1 release during emotional excitement in coronary artery disease patients

Endothelin-1 (ET-1), a potent vasoconstrictor, IL-6, and catecholamines are increased and heart rate variability [SD of normal to normal R-R intervals (SDNN)] decreased during emotional excitement, but individual responses vary. We tested the hypothesis that exercise capacity is associated with physiological responses caused by real-life emotional excitement. We measured the plasma levels of ET-1, IL-6, catecholamines, heart rate, and SDNN in enthusiastic male ice hockey spectators (n = 51; age, 59 ± 9 years) with stable coronary artery disease (CAD) at baseline and during the Finnish National Ice Hockey League's final play-off matches. Maximal exercise capacity (METs) by bicycle exercise test and left ventricular ejection fraction (LVEF) were measured on a separate day. ET-1 response from baseline to emotional excitement correlated with maximal METs (r = -0.30; P = 0.040). In a linear stepwise regression analysis age, body mass index (BMI), METs, LVEF, basal ET-1, and subjective experience of excitement were entered the model as independent variables to explain ET-1 response. This model explained 27% of ET-1 response (P = 0.003). Maximal METs were most strongly correlated with ET-1 response (β = -0.45; partial correlation r = -0.43; P = 0.002), followed by BMI (β = -0.31; partial correlation r = -0.31; P = 0.033) and LVEF (β = -0.30; partial correlation r = -0.33; P = 0.023). Exercise capacity may protect against further cardiovascular events in CAD patients, because it is associated with reduced ET-1 release during emotional excitement.

Pulse wave velocity in four extremities for assessing cardiovascular risk using a new device

Pulse wave velocity (PWV) is used for evaluating atherosclerosis; however, it is far from routine use. The authors validate a new device measuring PWV independently in each limb and explore its usefulness. Validity was studied in 40 patients. PWV was compared with endovascular measurements and comparisons were made between PWV in the extremities in 220 patients. The correlation between brachial PWV and endovascular catheter was (r=0.83, P<.001). The correlation coefficients for interobserver and intraobserver were r=0.87 and r=0.91, respectively. The sum of PWV in limbs allowed better stratification of patients according to cardiovascular risk. The validity and reproducibility of PWV measured with this device was good. The sum of PWV in extremities was a good index for stratifying patients according to vascular risk. These results suggest that the device is useful in the evaluation of arteriosclerosis and could possibly replace measurement devices available today.

Ankle brachial index values, leg symptoms, and functional performance among community-dwelling older men and women in the lifestyle interventions and independence for elders study

Background

The prevalence and significance of low normal and abnormal ankle brachial index (ABI) values in a community‐dwelling population of sedentary, older individuals is unknown. We describe the prevalence of categories of definite peripheral artery disease (PAD), borderline ABI, low normal ABI, and no PAD and their association with lower‐extremity functional performance in the LIFE Study population.

Methods and Results

Participants age 70 to 89 in the LIFE Study underwent baseline measurement of the ABI, 400‐m walk, and 4‐m walking velocity. Participants were classified as follows: definite PAD (ABI <0.90), borderline PAD (ABI 0.90 to 0.99), low normal ABI (ABI 1.00 to 1.09), and no PAD (ABI 1.10 to 1.40). Of 1566 participants, 220 (14%) had definite PAD, 250 (16%) had borderline PAD, 509 (33%) had low normal ABI, and 587 (37%) had no PAD. Among those with definite PAD, 65% were asymptomatic. Adjusting for age, sex, race, body mass index, smoking, and comorbidities, lower ABI was associated with longer mean 400‐m walk time: (definite PAD=533 seconds; borderline PAD=514 seconds; low normal ABI=503 seconds; and no PAD=498 seconds [P<0.001]). Among asymptomatic participants with and without PAD, lower ABI values were also associated with longer 400‐m walk time (P<0.001) and slower walking velocity (P=0.042).

Conclusion

Among older community‐dwelling men and women, 14% had PAD and 49% had borderline or low normal ABI values. Lower ABI values were associated with greater functional impairment, suggesting that lower extremity atherosclerosis may be a common preventable cause of functional limitations in older people.

Clinical Trial Registration

URL: http://clinicaltrials.gov/ Unique identifier: NCT01072500.

Gait performance in relation to aortic pulse wave velocity, carotid artery elasticity and peripheral perfusion in healthy older adults

Arterial stiffening is a widely known physiological change that occurs with ageing, but the functional consequences of vascular ageing are unclear. The purpose of this study was to determine whether carotid-femoral pulse wave velocity (PWV), mechanical properties of the carotid and femoral arteries and/or peripheral perfusion was associated with gait performance measured using a 400-m walk test. Twenty-one healthy older (68 ± 5 years) adults without cardiovascular disease participated in this study. Applanation tonometry was used to measure PWV, and Doppler ultrasound was used to measure arterial wall properties of the left common carotid and common femoral artery along with femoral blood flow. The median walk distance in the first 2 min of the test was 585 ft, and the overall gait speed was 1·5 m s(-1). Gait performance was inversely correlated with PWV (distance: r = -0·51; speed: r = -0·48; P<0·05) and carotid artery stiffness index β (distance: r = -0·56; speed: r = -0·51; P<0·05) after adjustment for age, body mass index, waist circumference and systolic blood pressure. No significant correlations were found between gait performance and femoral artery stiffness index β or femoral artery blood flow. These results found higher central arterial stiffness, as assessed by segmental arterial stiffness or local arterial wall properties, is associated with lower gait performance in older adults independent of other confounders.

β-blockade: benefits beyond blood pressure reduction?

Hypertension is a major cardiovascular (CV) risk factor, but several other common conditions, including chronic obstructive pulmonary disease (COPD), osteoporosis, and peripheral arterial disease (PAD), have been shown to independently increase the risk of CV events and death. The physiological basis for an increased CV risk in those conditions probably lies in the augmentations of oxidative stress, endothelial dysfunction, systemic inflammation, and arterial stiffness, which all are also hallmarks of hypertension. β-Blockers have been used for the treatment of hypertension for more than 40 years, but a number of meta-analyses have demonstrated that treatment with these agents may be associated with an increased risk of CV events and mortality. However, the majority of primary prevention β-blocker trials employed atenolol, an earlier-generation β(1) -selective blocker whose mechanism of action is based on a reduction of cardiac output. Available evidence suggests that vasodilatory β-blockers may be free of the deleterious effects of atenolol. The purpose of this review is to summarize pathophysiologic mechanisms thought to be responsible for the increased CV risk associated with COPD, osteoporosis, and PAD, and examine the possible benefits of vasodilatory β-blockade in those conditions. Our examination focused on nebivolol, a β(1) -selective agent with vasodilatory effects most likely mediated via β(3) activation.

Serum N-terminal pro-B-type natriuretic peptide levels are associated with functional capacity in patients with peripheral arterial disease

We hypothesized that higher serum levels of N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) are associated with lower functional capacity in patients with peripheral arterial disease ([PAD] n = 481, mean age 67, 68% men). Functional capacity was quantified as distance walked on a treadmill for 5 minutes. Patients were divided into 3 groups according to the distance walked: >144 yards (group 1, n = 254); 60 to 144 yards (group 2, n = 80); <60 yards or did not walk (group 3, n = 147). The association between NT-pro-BNP levels and the ordinal 3-level walking distance was assessed using multivariable ordinal logistic regression analyses that adjusted for several possible confounding variables. Higher levels of NT-pro-BNP were associated with a lower ordinal walking category independent of possible confounders (odds ratio [OR] 1.51, 95% confidence interval [CI] 1.28-1.77; P < .001). In conclusion, higher levels of NT-pro-BNP are independently associated with lower functional capacity in patients with PAD and may be a marker of hemodynamic stress in these patients.

Pulse pressure is associated with walking impairment in multiple sclerosis

Persons with multiple sclerosis (MS) have reduced gait performance and this is associated with disability and disease progression. The current study sought to test the hypothesis that higher central (aortic and carotid) and peripheral (brachial) pulse pressure (PP), manifestations of ventricular-vascular uncoupling related to increased arterial stiffness and pressure from wave reflections, would be associated with reduced gait performance in persons with MS. Participants consisted of 33 individuals with MS and 33 age/sex matched controls. Central blood pressure (BP) was assessed via applanation tonometry. Brachial BP was measured using an automated oscillometric cuff. PP was defined as systolic BP--diastolic BP. Gait performance was measured as 6-minute walk (6 MW) distance. Within the sample with MS, the 6 MW distance was significantly associated with brachial (r = -.49, p<.005), aortic (r = -.52, p<.001), and carotid (r = -.57, p<.001) pulse pressure. There was no association between any PP measure and 6 MW distance in controls (p>0.05 for all). In conclusion, PP is a predictor of gait performance in persons with MS. These findings suggest that vascular senescence and altered ventricular-vascular coupling may contribute, in part, to the deterioration of physical function in persons with MS.

Arterial dysfunction and functional performance in patients with peripheral artery disease: A review

Functional performance influences quality of life in individuals with peripheral artery disease (PAD) and is also a powerful prognostic marker in these patients. The pathophysiology of impaired functional performance in patients with PAD is incompletely understood. The severity of atherosclerotic burden, non-invasively assessed by the ankle—brachial index (ABI), does not reliably predict the degree of functional impairment observed in PAD patients. We review associations of measures of arterial function (arterial stiffness and endothelial dysfunction) with functional performance in PAD patients, and also review potential therapies for arterial stiffness and endothelial dysfunction that could improve functional performance in PAD. Recent studies suggest that measures of arterial function, such as arterial stiffness and endothelial function, are associated with exercise performance in the setting of PAD. These studies have provided new insights into (1) the pathophysiology of functional impairment in PAD, (2) mechanisms of strategies known to be effective such as walking programs, and (3) potential new therapeutic interventions for improving functional performance. Thus, therapies aimed at arterial ‘de-stiffening’ and improving endothelial function (such as aerobic exercise, statins and angiotensin-converting enzyme inhibitors) may improve functional performance in patients with PAD; however, further investigations are needed.

β2-microglobulin, a novel biomarker of peripheral arterial disease, independently predicts aortic stiffness in these patients

Arterial stiffness is a prominent feature of vascular ageing and strongly predicts cardiovascular and total mortality. The β2-microglobulin, (β2M) a newly identified biomarker of peripheral arterial disease (PAD), is related to renal insufficiency, inflammatory and neoplastic diseases, but may also play a role in vascular dysfunction. However, the relationship between arterial stiffness and β2M has not been previously studied in patients with atherosclerosis. In the present study we examined a possible association between β2M and arterial stiffness in patients with PAD and in healthy subjects. Plasma β2M levels and parameters of arterial stiffness such as aortic pulse wave velocity (aPWV) and augmentation index (AIx) were measured in 66 patients with PAD and in 66 apparently healthy subjects. Plasma levels of β2M, aPWV and AIx were significantly increased in patients with PAD compared with controls (1858.1 ± 472.8 vs 1554.5 ± 277.9 μg/L, p < 0.001; 9.9 ± 2.2 m/s vs 7.6 ± 1.6 m/s, p < 0.001; 28 ± 8 vs 14 ± 11%, p < 0.001; respectively). There existed significant correlation between aPWV and β2M for the patient group (R = 0.47; p < 0.001), but not for the controls (R = 0.14; p = 0.26). In multivariate analysis, β2M remained independently associated with aPWV, fetuin-A, age and glomerular filtration rate in patients (R(2) = 0.5, p < 0.001). We found no relationship between β2M and AIx in either group. We demonstrated that among patients with PAD elevated plasma β2M levels were associated with higher aortic stiffness irrespective of cardiovascular disease risk factors. These data suggest that β2M may influence the pathogenesis of aortic stiffness in atherosclerosis.

Arterial stiffness and gait speed in older adults with and without peripheral arterial disease

BACKGROUND

Central arterial stiffness is increasingly recognized as an important predictor of cardiovascular events and mortality in older adults; however, few studies have evaluated the association of arterial stiffness with mobility decline, a common consequence of vascular disease.

METHODS

We analyzed the association of pulse wave velocity (PWV), a measure of aortic stiffness, with longitudinal gait speed over 7 years in 2,172 participants in the Health, Aging and Body Composition (ABC) Study (mean age ± s.d. 73.6 ± 2.9 years, 48% men, 39% black).

RESULTS

In mixed-effects models adjusted for demographics, each s.d. (396 cm/s) higher PWV was associated with 0.015 (s.e. 0.004) m/s slower gait at baseline and throughout the study period in the full cohort (P < 0.001); this relationship was largely explained by hypertension and other vascular risk factors. Among participants with peripheral arterial disease (PAD) (n = 261; 12.7%), each s.d. higher PWV was independently associated with 0.028 (s.e. 0.010) m/s slower gait speed at baseline and throughout the study period (P < 0.01).

CONCLUSIONS

These findings suggest that aortic stiffness may be especially detrimental to mobility in older adults with already compromised arterial function.

Do Novel Risk Biomarkers Reflect the Severity of Peripheral Arterial Disease?

The association between novel atherosclerotic risk biomarkers and severity of peripheral arterial disease (PAD) was assessed. Patients (n = 133) with PAD were recruited. Established risk biomarkers including low- and high-density cholesterol, triglycerides, and blood pressure were measured. Novel risk biomarkers including plasma C-reactive protein, von Willebrand factor (vWF), interleukin 6, red cell folate (RCF), vitamin B12, total homocysteine (tHcy), and Hcy genotypes were also determined. The severity of PAD was evaluated, using ankle—brachial pressure index (ABPI), brachial—knee, and brachial—ankle pulse wave velocity (bk- and ba-PWV). Plasma tHcy and systolic blood pressure had a positive independent correlation with bk-PWV (β = +0.56, P = .02 and β = +0.38, P < .001, respectively). Red cell folate had an independent inverse correlation with bk-PWV (β = —0.01, P = .01). Systolic blood pressure showed an independent positive correlation with ba-PWV only after adjustment for other risk biomarkers (β = +0.1, P = .04). Novel markers, plasma tHcy, and RCF levels correlated with the severity of PAD.

Sex-specific correlates of walking speed in a wide age-ranged population

The goals of this cross-sectional study were to explore correlates of walking speed in a large wide age-ranged population and to identify factors affecting lower walking speed at older ages. Participants were 3,872 community-dwelling adults in the first follow-up of the SardiNIA study who completed a 4-m walking test. Sex-specific correlates of walking speed included marital status, height, waist circumference, pulse wave velocity, comorbidity, subjective health, strength, and personality. Effect modifiers of the age-walking speed association included extraversion (<55 years, p = .019) and education (<55 years, p = .021; > or =55 years, p = .012) in women, and openness (<55 years, p = .005), waist circumference (<55 years, p = .010), and subjective health (<55 years, p = .014) in men. The strong impact of personality suggests that certain personality traits may be associated with behaviors that affect physical performance and condition the reduced mobility mostly at younger ages. If these patterns are confirmed in longitudinal studies, personality may be an important target for prevention.