Association between gait characteristics and endothelial oxidative stress and inflammation in patients with symptomatic peripheral artery disease

Neuromodulation of Cardiovascular Risks Associated With Cardiotoxic Chemotherapy: A First-in-Human Randomized Pilot Study. Neuromodulation in Cancer Study (NCAN)

OBJECTIVES

Cardiotoxic chemotherapy is used to treat malignancies such as breast cancer and lymphoma. These treatments predispose patients to cardiotoxicity that can lead to cancer treatment-related cardiac dysfunction (CTRCD). The use of high doses of anthracyclines or in combination with human epidermal growth factor receptor 2 antagonists is associated with a progressively higher risk of CTRCD. CTRCD is preceded by increased activation of the sympathetic nervous system and abnormal left ventricular mechanical deformation as measured by abnormal global longitudinal strain (GLS). Low-level tragus stimulation (LLTS) is a new, safe, noninvasive technique that offers great potential to reduce increased sympathetic activation and improve GLS. Here, we describe a study method to examine the effects of LLTS on autonomic balance and cardiac function in breast cancer or lymphoma patients treated with anthracyclines.

METHODS

A first-in-human pilot, randomized, double-blind feasibility study will evaluate 104 patients (age >50 y) with breast cancer or lymphoma who receive anthracyclines with one additional CTRCD risk factor. Patients undergo 2 weeks of LLTS daily (1 h/d). Autonomic balance will be measured using heart rate variability metrics. Strain imaging using GLS will be performed pre and post-LLTS. Endothelial inflammation and oxidative stress measures will be performed using in vitro assays at baseline and after 2 weeks.

CONCLUSIONS

We hypothesize that LLTS stabilizes sympathovagal imbalance and improves cardiac performance in anthracycline-treated patients with breast cancer or lymphoma.

The link between impaired oxygen supply and cognitive decline in peripheral artery disease

Although peripheral artery disease (PAD) primarily affects large arteries outside the brain, PAD is also associated with elevated cerebral vulnerabilities, including greater risks for brain injury (such as stroke), cognitive decline and dementia. In the present review, we aim to evaluate recent literature and extract information on potential mechanisms linking PAD and consequences on the brain. Furthermore, we suggest novel therapeutic avenues to mitigate cognitive decline and reduce risk of brain injury in patients with PAD. Various interventions, notably exercise, directly or indirectly improve systemic blood flow and oxygen supply and are effective strategies in patients with PAD or cognitive decline. Moreover, triggering protective cellular and systemic mechanisms by modulating inspired oxygen concentrations are emerging as potential novel treatment strategies. While several genetic and pharmacological approaches to modulate adaptations to hypoxia showed promising results in preclinical models of PAD, no clear benefits have yet been clinically demonstrated. We argue that genetic/pharmacological regulation of the involved adaptive systems remains challenging but that therapeutic variation of inspired oxygen levels (e.g., hypoxia conditioning) are promising future interventions to mitigate associated cognitive decline in patients with PAD.

Noninvasive low-level tragus stimulation attenuates inflammation and oxidative stress in acute heart failure

PURPOSE

Acute decompensated heart failure (ADHF) is associated with inflammation, oxidative stress, and excess sympathetic drive. It is unknown whether neuromodulation would improve inflammation and oxidative stress in acute heart failure. We, therefore, performed this proof-of-concept study to evaluate the effects of neuromodulation using noninvasive low-level tragus stimulation on inflammation and oxidative stress in ADHF.

METHODS

Nineteen patients with ejection fraction < 40% were randomized to neuromodulation 4 h twice daily (6-10 a.m. and 6-10 p.m.) (n = 8) or sham stimulation (n = 11) during hospital admission. All patients received standard-of-care treatment. Blood samples were collected at admission and discharge. Serum cytokines were assayed using standard immunosorbent techniques. Reactive oxygen species inducibility from cultured coronary endothelial cells exposed to patient sera was determined using a dihydrodichlorofluorescein probe test (expressed as fluorescein units).

RESULTS

Compared to sham stimulation, neuromodulation was associated with a significant reduction of circulating serum interleukin-6 levels (-78% vs. -9%; p = 0.012). Similarly, neuromodulation led to a reduction of endothelial cell oxidative stress in the neuromodulation group (1363 units to 978 units, p = 0.003) compared to sham stimulation (1146 units to 1083 units, p = 0.094). No significant differences in heart rate, blood pressure, or renal function were noted between the two groups.

CONCLUSION

In this proof-of-concept pilot study, in acute decompensated heart failure, neuromodulation was feasible and safe and was associated with a reduction in systemic inflammation and attenuation of coronary endothelial cellular oxidative stress.

CLINICAL TRIAL REGISTRATION

NCT02898181.

Effects of Long-Term Home Exercise in Participants With Peripheral Artery Disease

Background This randomized controlled trial compared long-term changes in peak walking time (PWT) and exercise time-to-minimum calf muscle oxygen saturation (StO2) in symptomatic participants with peripheral artery disease following a long-term home exercise program (HEP), a short-term supervised exercise therapy (SET) program that transitioned to a long-term HEP (SET/HEP), and a control intervention. Methods and Results For the first 3 months, HEP and SET/HEP groups performed intermittent walking to mild-to-moderate claudication pain, whereas the control group performed light resistance training. For the subsequent 15 months, the HEP group continued their exercise program, the SET/HEP group transitioned from SET to the HEP program, and the control group transitioned to only receive walking advice. PWT increased significantly from baseline to month 18 in the HEP group (408±279 meters to 814±393 meters, P<0.001) and in the SET/HEP group (457±288 meters to 818±313 meters, P<0.001). Exercise time-to-minimum calf muscle StO2 increased significantly from baseline to month 18 in the HEP group (238±241 seconds to 497±485 seconds, P<0.05) and in the SET/HEP group (296±289 seconds to 620±450 seconds, P<0.001). These changes in PWT and exercise time-to-minimum calf muscle StO2 were greater than in the control group (P<0.001 and P<0.01, respectively). Additionally, the change in exercise time-to-minimum calf muscle StO2 was correlated with the change in PWT in both exercise groups combined (r=0.601, P=0.0015). Conclusions Long-term HEP and SET/HEP were efficacious in improving PWT and exercise time-to-minimum calf muscle StO2 in symptomatic participants with peripheral artery disease, and these changes were correlated with each other. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT00618670.

Noninvasive low-level tragus stimulation attenuates inflammation and oxidative stress in acute heart failure

Purpose

Acute decompensated heart failure is associated with inflammation, oxidative stress, and excess sympathetic drive. It is unknown if neuromodulation would improve inflammation and oxidative stress in acute heart failure. We, therefore, performed this proof-of-concept study to evaluate the effects of neuromodulation using noninvasive low-level Tragus stimulation on inflammation and oxidative stress in ADHF.

Methods

19 patients with ejection fraction < 40% were randomized to neuromodulation- 4 hours twice daily (6 AM-10 AM and 6 PM-10 PM) (n = 8) or sham stimulation (n = 11) during hospital admission. All patients received standard-of-care treatment. Blood samples were collected at admission and discharge. Serum cytokines were assayed using standard immunosorbent techniques. Reactive oxygen species inducibility from cultured coronary endothelial cells exposed to patient sera was determined using dihydrodichlorofluorescein probe test (expressed as fluorescein units).

Results

Compared to sham stimulation, neuromodulation was associated with a significant reduction of circulating serum Interleukin-6 levels (-78% vs -9%; p = 0.012). Similarly, neuromodulation led to reduction of endothelial cell oxidative stress, in the neuromodulation group (1363 units to 978 units, p = 0.003) compared to sham stimulation (1146 units to 1083 units, p = 0.094). No significant difference in heart rate, blood pressure or renal function were noted between the two groups.

Conclusion

In this proof-of-concept pilot study, in acute systolic heart failure, neuromodulation was feasible and safe and was associated with a reduction in systemic inflammation and attenuation of cellular oxidative stress.

Clinical trial

NCT02898181.

Diabetes Is Negatively Associated With Meeting Physical Activity Time-Intensity Guidelines in Patients With Claudication

PURPOSES

We determined the percentage of patients with peripheral artery disease (PAD) and claudication who meet the 2018 physical activity (PA) time-intensity guidelines, and we identified the clinical characteristics associated with the status of meeting the guidelines.

METHODS

Five hundred seventy-two patients were assessed on their daily ambulatory activity for 1 wk with a step activity monitor, and were evaluated on whether or not they achieved 150 min/wk of moderate-intensity PA.

RESULTS

Thirty-one percent (n = 175) of the patients with PAD met the PA time-intensity guidelines and 69% (n = 397) did not. In a final multivariable logistic regression model identifying the independent predictors of meeting the PA time-intensity guidelines from clinical characteristics, diabetes was the only significant variable entered (OR = 0.310: 95% CI, 0.175-0.538; P < .001) and was associated with a 69% lower chance of meeting the guidelines. Patients with diabetes spent less daily time in moderate-intensity ambulatory PA than patients without diabetes (15 ± 13 vs 23 ± 20 min/d; P < .001).

CONCLUSIONS

Thirty-one percent of patients with PAD and claudication met the PA time-intensity guidelines. Furthermore, patients with diabetes were least likely to meet the PA time-intensity guidelines, as they had a 69% lower chance than patients without diabetes. The clinical significance is that PAD patients who have diabetes are particularly susceptible to being physically sedentary, and are therefore prime patients who should be encouraged to increase their daily PA.

Maximal calf conductance is associated with 6-minute walk distance in participants with and without peripheral artery disease

INTRODUCTION

The aims were (a) to compare the maximal calf conductance and 6-minute walk distance of participants with and without peripheral artery disease (PAD) and claudication, (b) to determine whether maximal calf conductance was more strongly associated with 6-minute walk distance in participants with PAD than in the controls, and (c) to determine whether this association was significant in participants with PAD after adjusting for ABI, as well as for demographic, anthropometric, and comorbid variables.

METHODS

Participants with PAD (n = 633) and without PAD (n = 327) were assessed on maximal calf conductance using venous occlusion plethysmography, and on 6-minute walk distance. Participants were further characterized on ABI, and on demographic, anthropometric, and comorbid variables.

RESULTS

The PAD group had lower maximal calf conductance than the control group (0.136 ± 0.071 vs 0.201 ± 0.113 mL/100 mL/min/mmHg, p < 0.001). Additionally, the PAD group had a lower 6-minute walk distance (375 ± 98 m vs 480 ± 107 m, p < 0.001). Maximal calf conductance was positively associated with 6-minute walk distance in both groups (p < 0.001) and was more strongly associated in the PAD group (p < 0.001). In adjusted analyses, maximal calf conductance remained positively associated with 6-minute walk distance in the PAD group (p < 0.001) and in the control group (p < 0.001).

CONCLUSIONS

Participants with PAD and claudication had impaired maximal calf conductance and a lower 6-minute walk distance than those without PAD, and maximal calf conductance was positively and independently associated with 6-minute walk distance within each group before and after adjusting for ABI, and for demographic, anthropometric, and comorbid variables.

Increased pulse wave velocity is related to impaired working memory and executive function in older adults with metabolic syndrome

Age-related vascular alterations promote the pathogenesis of vascular cognitive impairment (VCI). Cardiovascular risk factors that accelerate vascular aging exacerbate VCI. Metabolic syndrome (MetS) constitutes a cluster of critical cardiovascular risk factors (abdominal obesity, hypertension, elevated triglycerides, elevated fasting glucose, reduced HDL cholesterol), which affects nearly 37% of the adult US population. The present study was designed to test the hypotheses that MetS exacerbates cognitive impairment and that arterial stiffening moderates the association between cognitive dysfunction and MetS in older adults. MetS was defined by the NCEP ATP III guidelines. Cognitive function (digit span and trail-making tests) and brachial-ankle pulse wave velocity (baPWV; a non-invasive clinical measurement of arterial stiffness) were assessed in older adults with MetS and age- and sex-matched controls. Multiple linear regression models were applied to test for the main effects of MetS, baPWV, and their interaction on cognitive performance. Fifty-three participants with MetS (age: 68 ± 8 years) and 39 age-matched individuals without MetS (age: 66 ± 9 years) were enrolled into the study. In adjusted multivariable regression analyses of the digit span backward length score, both MetS (ß = 1.97, p = 0.048) and MetS by baPWV interaction (ß =  - 0.001, p = 0.026) were significant predictors. In participants with MetS, higher baPWV was associated with poorer performance on digit span backward length score, a test of working memory (R =  - 0.44, p = 0.0012), but there was no association in those without MetS (R = 0.035, p = 0.83). MetS was negatively associated with performance on the digit span backward length score, baPWV was negatively associated with multiple neuropsychological outcomes, and baPWV moderated the association between digit span backward length score and MetS, as individuals with both MetS and higher baPWV had the most impaired cognitive function. Our findings add to the growing body of evidence that individuals with MetS and higher baPWV may be prone to VCI.

Association Between Meeting Physical Activity Time-Intensity Guidelines With Ambulation, Quality of Life, and Inflammation in Claudication

PURPOSE

The aim of this investigation was to determine if meeting the 2018 physical activity (PA) time-intensity guidelines was associated with better ambulatory function, health-related quality of life (HRQoL), vascular function, and inflammation than failing to meet the guidelines in patients with peripheral artery disease and claudication. Second, we determined the optimal number of total steps/d and steps taken at moderate cadence needed to meet the PA time-intensity guidelines.

METHODS

Five hundred seventy-two patients were assessed on daily ambulatory activity for 1 wk with a step activity monitor, and were grouped according to whether they achieved <150 min/wk of moderate-intensity PA (group 1 = do not meet guidelines; n = 397) or whether they were above this threshold (group 2 = meet guidelines; n = 175).

RESULTS

Treadmill peak walking time (mean ± SD) was higher ( P < .001) in group 2 (709 ± 359 sec) than in group 1 (427 ± 281 sec). The physical function HRQoL score was higher ( P < .001) in group 2 (61 ± 22%) than in group 1 (44 ± 21%). High-sensitivity C-reactive protein was lower ( P < .001) in group 2 (3.6 ± 4.5 mg/L) than in group 1 (5.9 ± 6.1 mg/L). Finally, ≥7675 total steps/d and ≥1660 steps/d at moderate cadence were optimal thresholds associated with meeting PA guidelines.

CONCLUSIONS

Patients with claudication who meet the 2018 PA time-intensity guidelines for US adults had better ambulation, HRQoL, and vascular outcomes than those who failed to meet the PA guidelines. Patients with claudication best achieved the PA time-intensity guidelines by taking ≥7675 total steps/d, and ≥1660 steps/d at a moderate cadence.

Clinical utility of simple subjective gait speed for the risk stratification of heart failure in a primary prevention setting

Little is known regarding the relationship between self-reported gait speed and the subsequent risk of heart failure (HF) and cardiovascular disease (CVD). We sought to clarify the clinical utility of self-reported gait speed in primary CVD prevention settings. This is an observational cohort study using the JMDC Claims Database, which is an administrative health claims database. Data were collected between January 2005 and April 2020. Medical records of 2,655,359 participants without a prior history of CVD were extracted from the JMDC Claims Database. Gait speed was assessed using information from questionnaires provided at health check-ups, and study participants were categorized into fast or slow gait speed groups. The primary outcome was HF. The secondary outcomes included myocardial infarction (MI), angina pectoris (AP), and stroke. The median age was 45.0 years, and 55.3% of participants were men. 46.1% reported a fast gait speed. The mean follow-up period was 1180 ± 906 days. HF, MI, AP, and stroke occurred in 1.9%, 0.2%, 1.9%, and 1.0% of participants, respectively. Multivariable Cox regression analyses showed that, compared with slow gait speed, fast gait speed was associated with a lower incidence of HF, MI, AP, and stroke. The discriminative predictive ability for HF significantly improved by adding self-reported gait speeds to traditional risk factors (net reclassification improvement 0.0347, p < 0.001). In conclusion, our analysis demonstrated that subjective gait speed could be a simple method to stratify the risk of HF and other CVD events in the general population. Further investigations are required to clarify the underlying mechanism of our results and to develop a novel approach for primary CVD prevention.

Microvascular dysfunction and neurovascular uncoupling are exacerbated in peripheral artery disease, increasing the risk of cognitive decline in older adults

Peripheral artery disease (PAD) is a vascular pathology with high prevalence among the aging population. PAD is associated with decreased cognitive performance, but the underlying mechanisms remain obscure. Normal brain function critically depends on an adequate adjustment of cerebral blood supply to match the needs of active brain regions via neurovascular coupling (NVC). NVC responses depend on healthy microvascular endothelial function. PAD is associated with significant endothelial dysfunction in peripheral arteries, but its effect on NVC responses has not been investigated. This study was designed to test the hypothesis that NVC and peripheral microvascular endothelial function are impaired in PAD. We enrolled 11 symptomatic patients with PAD and 11 age- and sex-matched controls. Participants were evaluated for cognitive performance using the Cambridge Neuropsychological Test Automated Battery and functional near-infrared spectroscopy to assess NVC responses during the cognitive n-back task. Peripheral microvascular endothelial function was evaluated using laser speckle contrast imaging. We found that cognitive performance was compromised in patients with PAD, evidenced by reduced visual memory, short-term memory, and sustained attention. We found that NVC responses and peripheral microvascular endothelial function were significantly impaired in patients with PAD. A positive correlation was observed between microvascular endothelial function, NVC responses, and cognitive performance in the study participants. Our findings support the concept that microvascular endothelial dysfunction and neurovascular uncoupling contribute to the genesis of cognitive impairment in older PAD patients with claudication. Longitudinal studies are warranted to test whether the targeted improvement of NVC responses can prevent or delay the onset of PAD-associated cognitive decline.NEW & NOTEWORTHY Peripheral artery disease (PAD) was associated with significantly decreased cognitive performance, impaired neurovascular coupling (NVC) responses in the prefrontal cortex (PFC), left and right dorsolateral prefrontal cortices (LDLPFC and RDLPFC), and impaired peripheral microvascular endothelial function. A positive correlation between microvascular endothelial function, NVC responses, and cognitive performance may suggest that PAD-related cognitive decrement is mechanistically linked, at least in part, to generalized microvascular endothelial dysfunction and subsequent impairment of NVC responses.

Relationship between tooth loss and sarcopenia in suburban community-dwelling older adults in Shanghai and Tianjin of China

Both sarcopenia and loss of teeth are associated with aging. The purpose of this study was to investigate potential relationships between tooth loss and sarcopenia and its components in suburban community-dwelling older adults of Shanghai and Tianjin, China. The subjects were 1494 people over 60 years of age (40.7% men; aged 71.64 ± 5.97 years) from Chongming District of Shanghai and Hangu District of Tianjin. Asian Working Group for Sarcopenia(AWGS) criteria were used to define sarcopenia. Muscle mass, muscle strength, and physical performance were assessed using a bioelectrical impedance analyzer, a grip strength test, and a four-meter walk test, respectively. The subjects were divided into groups depending on self-reported loss of teeth. Our studies found no correlation between tooth loss and sarcopenia or muscle mass. However, the walking speed of female participants with at least 10 teeth lost was 0.059 m/s slower than that of participants with fewer than 10 teeth lost (p < 0.001), and grip strength was 1.577 kg lower among male participants with at least 10 teeth lost than among males with fewer than 10 teeth lost (p = 0.023). These results are consistent with the importance of good oral hygiene in preventing declines of physical performance in older adults.

LIGHT AND MODERATE INTENSITY PHYSICAL ACTIVITY ARE ASSOCIATED WITH BETTER AMBULATION, QUALITY OF LIFE, AND VASCULAR MEASUREMENTS IN PATIENTS WITH CLAUDICATION

OBJECTIVES

To determine whether patients with claudication who reported performing either light-intensity physical activity (LPA) or moderate-to-vigorous intensity physical activity (MVPA) had higher levels of objectively-determined physical activity, and better physical function, health-related quality of life (HRQoL), and vascular measures, consisting of exercise time to minimum calf muscle oxygen saturation (StO₂) and high-sensitivity C-reactive protein, than patients who reported being physically sedentary.

METHODS

Two hundred sixty-nine patients were assessed on the Johnson Space Center physical activity scale. Patients were grouped according to whether they performed no physical activities (n=75), LPA (n=140), or MVPA (n=54). Primary measurements were total daily steps obtained from a step activity monitor worn for one week, peak walking time obtained from a treadmill test, the physical function score on the Medical Outcomes Study Short-Form 36 survey to assess HRQoL, and high-sensitivity C-reactive protein.

RESULTS

Total daily steps (mean±SD) was significantly different among groups, as both the LPA group (7878±2808 steps/day) and the MVPA group (8551±3365 steps/day) took more daily steps (p<0.01) than the sedentary group (3323±986 steps/day). Treadmill peak walking time was significantly different among groups, as both the LPA group (433±296 sec) and the MVPA group (548±300 sec) had greater peak walking time (p<0.01) than the sedentary group (302±210 sec). Physical function score was significantly different among groups, as both the LPA group (44±20%) and the MVPA group (58±19%) had higher scores (p<0.01) than the sedentary group (36±20%). Exercise time to the minimum calf muscle StO₂ was significantly different among groups, as both the LPA group (215±238 sec) and the MVPA group (377±351 sec) had greater values (p<0.05 and p<0.01, respectively) than the sedentary group (147±172 sec). Finally, high-sensitivity C-reactive protein was significantly different among groups, as both the LPA group (4.8±5.5 mg/L) and the MVPA group (3.5±3.6 mg/L) had lower values (p<0.01) than the sedentary group (8.6±8.4 mg/L).

CONCLUSIONS

Patients with claudication who reported performing LPA had greater amounts of objectively-determined physical activity levels and better physical function, HRQoL, and vascular measures than those who reported being physically sedentary. Furthermore, these favorable results associated with LPA were even more pronounced in patients who performed MVPA than in patients who were sedentary. The clinical significance is that engaging in any physical activity, even at relatively light intensity, is associated with favorable health and vascular measures in patients with claudication.

Abnormal vibration perception threshold alters the gait features in type 2 diabetes mellitus patients

OBJECTIVE

It is generally believed that gait characteristics of diabetic neuropathic patients differ from those of non-diabetic ones. However, it is still unclear how the abnormal foot sensation influences the gait during walking in type 2 diabetes mellitus (T2DM). For the purpose of gaining a better insight into the alterations of detailed gait parameters and figuring out important aspects in the gait indexes by peripheral neuropathy in elder T2DM patients, we compared the gait features in participants with normal glucose tolerance (NGT) controls and diabetic individuals complicated by peripheral neuropathy or not.

SUBJECTS AND METHODS

Gait parameters were observed during the 10-m walk on flat land among different conditions of diabetes in 1,741 participants from three clinical centers. Subjects were divided into four groups: persons with NGT were taken as the control group; patients with T2DM included three subgroups: DM control (no chronic complications), DM-DPN (DM complicated by only peripheral neuropathy), and DM-DPN+LEAD (DM complicated by both neuropathy and artery disease). The clinical characteristics and gait parameters were assessed and compared among these four groups. Analyses of variance were employed to verify possible differences of gait parameters between groups and conditions. Stepwise multivariate regression analysis was performed to reveal possible predictors of gait deficits. Receiver operating characteristic (ROC) curve analysis was employed to find any discriminatory power of diabetic peripheral neuropathy (DPN) for the step time.

RESULTS

In participants burdened with DPN, whether complicated by lower extremity arterial disease (LEAD) or not, step time increased sharply (p < 0.05). Stepwise multivariate regression models showed that independent variables of gait abnormality were sex, age, leg length, vibration perception threshold (VPT), and ankle-brachial index (ABI) (p < 0.01). Meanwhile, VPT was a significant independent predictor of step time, spatiotemporal variability (SD_A), and temporal variability (SD_B) (p < 0.05). ROC curve analysis was explored to find the discriminatory power of DPN for the occurrence of increased step time. The area under the curve (AUC) value was 0.608 (95% CI: 0.562-0.654, p < 0.01), and the cutoff point was 538.41 ms accompanied by a higher VPT. A significant positive association was observed between increased step time and the highest VPT group [odds ratio (OR) = 1.83, 95% CI: 1.32-2.55, p< 0.01]. In female patients, this OR value elevated to 2.16 (95% CI: 1.25-3.73, p< 0.01).

CONCLUSIONS

In addition to sex, age, and leg length, VPT was a distinct factor that associated with altered gait parameters. DPN is associated with increased step time, and the step time increases with worsening VPT in type 2 diabetes.

Association Between Daily Steps at Moderate Cadence and Vascular Outcomes in Patients With Claudication

PURPOSE

We determined whether patients with peripheral artery disease (PAD) and claudication grouped according to tertiles of community-based daily steps taken at a moderate cadence had differences in vascular function and biomarkers and whether group differences in vascular function and biomarkers persisted after adjusting for demographic variables, comorbid conditions, and severity of PAD.

METHODS

Two hundred sixty-three patients were evaluated for 1 wk on steps taken at a moderate cadence (exceeding 60 steps/min), and patients were placed into low (group 1), intermediate (group 2), and high (group 3) tertiles.

RESULTS

Ankle/brachial index (ABI) at 1 min after exercise (mean ± SD) was significantly higher in groups 2 and 3 than in group 1 in unadjusted (P < .01) and adjusted (P < .01) analyses (group 1: 0.34 ± 0.25; group 2: 0.38 ± 0.27; and group 3: 0.44 ± 0.28). Exercise time to reach the minimum calf muscle oxygen saturation (StO2) value during treadmill exercise was significantly longer in groups 2 and 3 than in group 1 in unadjusted (P < .01) and adjusted (P < .01) analyses (group 1: 127 ± 127 sec; group 2: 251 ± 266 sec; and group 3: 310 ± 323 sec). Fibrinogen was significantly lower in group 3 than in group 1 in unadjusted (P = .02) and adjusted (P = .05) analyses (group 1: 3.5 ± 1.2 g/L; group 2: 3.6 ± 1.5 g/L; and group 3: 3.0 ± 1.1 g/L).

CONCLUSIONS

Compared with patients with claudication in the lowest tertile of community-based daily steps taken at a moderate cadence, patients in the second and third tertiles had better calf muscle StO2 and ABI values during and immediately after exercise. Second, the most active group had lower fibrinogen levels than the least active group.

Supervised Exercise Training Improves 6 min Walking Distance and Modifies Gait Pattern during Pain-Free Walking Condition in Patients with Symptomatic Lower Extremity Peripheral Artery Disease

This study aimed to investigate the effects of supervised exercise training (SET) on spatiotemporal gait and foot kinematics parameters in patients with symptomatic lower extremity peripheral artery disease (PAD) during a 6 min walk test. Symptomatic patients with chronic PAD (Fontaine stage II) following a 3 month SET program were included. Prior to and following SET, a 6 min walk test was performed to assess the 6 min walking distance (6MWD) of each patient. During this test, spatiotemporal gait and foot kinematics parameters were assessed during pain-free and painful walking conditions. Twenty-nine patients with PAD (65.4 ± 9.9 years.) were included. The 6MWD was significantly increased following SET (+10%; p ≤ 0.001). The walking speed (+8%) and stride frequency (+5%) were significantly increased after SET (p ≤ 0.026). The stride length was only significantly increased during the pain-free walking condition (+4%, p = 0.001), whereas no significant differences were observed during the condition of painful walking. Similarly, following SET, the relative duration of the loading response increased (+12%), the relative duration of the foot-flat phase decreased (−3%), and the toe-off pitch angle significantly increased (+3%) during the pain-free walking condition alone (p ≤ 0.05). A significant positive correlation was found between changes in the stride length (r = 0.497, p = 0.007) and stride frequency (r = 0.786, p ≤ 0.001) during pain-free walking condition and changes in the 6MWD. A significant negative correlation was found between changes in the foot-flat phase during pain-free walking condition and changes in the 6MWD (r = −0.567, p = 0.002). SET was found to modify the gait pattern of patients with symptomatic PAD, and many of these changes were found to occur during pain-free walking. The improvement in individuals’ functional 6 min walk test was related to changes in their gait pattern.

Physical Activity in Polluted Air-Net Benefit or Harm to Cardiovascular Health? A Comprehensive Review

Both exposure to higher levels of polluted air and physical inactivity are crucial risk factors for the development and progression of major noncommunicable diseases and, in particular, of cardiovascular disease. In this context, the World Health Organization estimated 4.2 and 3.2 million global deaths per year in response to ambient air pollution and insufficient physical activity, respectively. While regular physical activity is well known to improve general health, it may also increase the uptake and deposit of air pollutants in the lungs/airways and circulation, due to increased breathing frequency and minute ventilation, thus increasing the risk of cardiovascular disease. Thus, determining the tradeoff between the health benefits of physical activity and the potential harmful effects of increased exposure to air pollution during physical activity has important public health consequences. In the present comprehensive review, we analyzed evidence from human and animal studies on the combined effects of physical activity and air pollution on cardiovascular and other health outcomes. We further report on pathophysiological mechanisms underlying air pollution exposure, as well as the protective effects of physical activity with a focus on oxidative stress and inflammation. Lastly, we provide mitigation strategies and practical recommendations for physical activity in areas with polluted air.

Evaluation of Biosafety, Antiobesity, and Endothelial Cells Proliferation Potential of Basil Seed Extract Loaded Organic Solid Lipid Nanoparticle

The present study aimed to synthesize solid lipid nanoparticles to enhance liposome-assisted intracellular uptake of basil seed active components in adipocytes and vascular smooth muscle cells to attain increased bioavailability. To obtain solid lipid nanoparticle (SLNp), the water phase containing basil seed extract (BSE) was encapsulated with lipid matrix containing chia seed phospholipids using homogenization and cold ultra-sonication method. The physicochemical characterization of BSE loaded solid lipid nanoparticles (BSE-SLNp) has been analyzed using Zetasizer, FT-IR, and TEM. The BSE-SLNp showed an average diameter of 20-110 nm on the day of preparation and it remains the same after 60 days of storage. The cytotoxicity assay confirmed that the BSE-SLNp did not produce toxicity in hMSCs, preadipocytes, or human umbilical vein endothelial cells (HUVECs) until the tested higher dose up to 64 μg/ml. During effective dose determination, 4 μg/ml of BSE-SLNp confirmed non-toxic and enhanced metabolic function in hMSCs, preadipocytes, and HUVECs. Biosafety assay confirmed normal nuclear morphology in PI staining and high mitochondrial membrane potential in JC-1 assay within 48 h in hMSCs. The maturing adipocyte treated with 4 μg/ml of BSE-SLNp significantly increased the mitochondrial efficiency and fatty acid beta-oxidation (PPARγC1α, UCP-1, and PRDM-16) related gene expression levels. Oxidative stress induced HUVECs treated with 4 μg/ml of BSE-SLNp potentially enhanced antioxidant capacity, cell growth, and microtubule development within 48 h H₂O₂ induced oxidative stressed HUVECs have shown 39.8% viable cells, but treatment with BSE-SLNp has shown 99% of viable cells within 48 h confirmed by Annexin-V assay. In addition, mitochondrial membrane potential (Δψ_m) increased to 89.4% confirmed by JC-1 assay. The observed DNA integrity, cell viability was confirmed by increased antioxidant and tumor suppressor-related gene expression levels. VEGF expression has been significantly increased and pro-inflammation-related mRNA levels were decreased in BSE-SLNp treated cells. In conclusion, enhanced adipocyte fatty acid oxidation is directly associated with decreased adipocytokine secretion which arrests obesity-associated comorbidities. In addition, suppressing vascular cell oxidative stress and metabolic inflammation supports vascular cell proliferation and arrests ageing-related vascular diseases.

Cognitive decrement in older adults with symptomatic peripheral artery disease

Peripheral artery disease (PAD) is highly prevalent, affecting up to 20% of people over 70 years of age. To test the hypothesis that PAD promotes the pathogenesis of vascular cognitive impairment (VCI), we compared cognitive function in older adults with symptomatic PAD and in participants without PAD who had a burden of comorbid conditions. Furthermore, we compared the cognitive function of these groups after adjusting for demographic and clinical characteristics, comorbid conditions, and cardiovascular risk factors. Participants with PAD (age: 69 ± 8 years; n = 58) and those without PAD (age: 62 ± 8 years; n = 30) were assessed on a battery of eight neuropsychological tests. The tests assessed attention and working memory, verbal memory, non-verbal memory, perceptuo-motor speed, and executive function. Participants were further characterized on demographic and clinical characteristics, comorbid conditions, cardiovascular risk factors, and ankle-brachial index. The PAD group had significantly lower neuropsychological scores than the non-PAD control group on all eight tests (P < .01). After adjusting for covariates, significantly worse scores in the PAD group persisted for verbal memory, measured by tests on logical memory-immediate recall (P = .022), and logical memory-delayed recall (P < .001), and for attention and working memory, measured by tests on digits forward (P < .001), and digits backward (P = .003). Participants with symptomatic PAD have substantially lower levels of performance on tests of attention, working memory, and verbal memory than participants without PAD independent of demographic characteristics and comorbid health burdens. These findings provide additional evidence in support of the concept that generalized accelerated vascular aging manifesting as symptomatic PAD in the peripheral circulation also affects the brain promoting the pathogenesis of VCI. These cognitive difficulties may also negatively impact symptomatic patient's ability to understand and adhere to behavioral and medical therapies, creating a vicious cycle. We speculate that more intensive follow-up may be needed to promote adherence to therapies and monitor cognitive decline that may affect care.

Neutrophil-lymphocyte ratio as a predictor of slow gait speed in older adults: The Rugao Longitudinal Aging Study

BACKGROUND

Few studies have investigated the association of the neutrophil-to-lymphocyte ratio (NLR) with gait speed, but whether the NLR is predictive of slow gait speed in older adults remains unknown. The aim of this study is to examine the association of NLR levels with risk of slow gait speed development in older adults.

METHODS

Overall, 1753 participants (53.11% male, aged 60-92 years, with a mean age of 77.01 ± 4.27 years) from the second wave of the Rugao Longitudinal Aging Study were included. The second wave was recognized as the baseline in this study. Gait speed was measured using a 5-m walk test at baseline and at the 3.5-year follow-up. A slow gait speed was considered a walking speed less than 0.8 m/s. The NLR was calculated based on absolute blood neutrophil and lymphocyte counts. Logistic regression models were used to investigate the association between NLR levels and slow gait speed.

RESULTS

In the cross-sectional analysis, 394 individuals were identified as having slow gait speed. We found that increased NLR levels were associated with a higher risk of slow gait speed in older adults with and without comorbidities (P-value <0.05). During the 3.5-year follow-up period, 440 individuals had developed new-onset slowness. After confounding factors were controlled, increased NLR levels were significantly and independently associated with an increased risk of slow gait speed among older adults with (odds ratio [OR] 3.82, 95% confidence interval [CI] 1.87-7.89) and without (OR 3.29, 95% CI: 1.54-7.10) comorbidities.

CONCLUSION

The NLR is an inexpensive and easily obtainable inflammatory biomarker that robustly and independently predicts slow gait speed risk in older adults.

Association between Physical Activity and Mortality in Patients with Claudication

PURPOSE

This study aimed to determine the association between light-intensity physical activity and the incidence of all-cause and cardiovascular mortality in patients with peripheral artery disease (PAD) limited by claudication followed for up to 18.7 yr.

METHODS

A total of 528 patients with PAD and claudication were screened in Baltimore between 1994 and 2002, and 386 were deemed eligible for the study. At baseline, patients were classified into three physical activity groups: 1) physically sedentary, 2) light intensity, and 3) moderate to vigorous intensity based on a questionnaire. All-cause and cardiovascular mortality of patients through December 2014 was determined using the National Death Index and the U.S. Department of Veterans Affairs and the U.S. Department of Defense Suicide Data Repository.

RESULTS

Median survival time was 9.9 yr (interquartile range, 4.9-15.7 yr; range, 0.38-18.7 yr). During follow-up, 257 patients (66.6%) died, consisting of 40/48 (83.3%) from the sedentary group, 135/210 (64.3%) from the light-intensity group, and 82/128 (64.0%) from the moderate- to vigorous-intensity group. For all-cause mortality, light-intensity activity status (hazard ratio [HR] = 0.523, P = 0.0007) and moderate- to vigorous-intensity status (HR = 0.425, P < 0.0001) were significant predictors. During follow-up, 125 patients died because of cardiovascular causes (32.4%), in which light-intensity activity status (HR = 0.511, P = 0.0113) and moderate- to vigorous-intensity activity status (HR = 0.341, P = 0.0003) were significant predictors.

CONCLUSIONS

Light-intensity physical activity is associated with nearly 50% lower risk of all-cause and cardiovascular mortality in high-risk patients with PAD and claudication. Furthermore, moderate- to vigorous-intensity physical activity performed regularly is associated with 58% and 66% lower risk of all-cause and cardiovascular mortality, respectively. The survival benefits associated with light-intensity physical activity make it a compelling behavioral intervention that extends beyond improving ambulation.

Association between meeting daily step count goals with ambulatory function and quality of life in patients with claudication

OBJECTIVE

To determine (a) whether patients with peripheral artery disease (PAD) who walked at least 7000 and 10,000 steps/day had better ambulatory function and health-related quality of life (HRQoL) than patients who walked less than 7000 steps/day, and (b) whether differences in ambulatory function and HRQoL in patients grouped according to these daily step count criteria persisted after adjusting for covariates.

METHODS

Two hundred forty-eight patients were assessed on their daily ambulatory activity for 1 week with a step activity monitor, and were grouped according to daily step count targets. Patients who took fewer than 7000 steps/day were included in group 1 (n = 153), those who took 7000 to 9999 steps/day were included in group 2 (n = 57), and patients who took at least 10,000 steps/day were included in group 3 (n = 38). Primary outcomes were the 6-minute walk distance (6MWD) and Walking Impairment Questionnaire (WIQ) distance score, which is a disease-specific measurement of HRQoL. Patients were further characterized on demographic variables, comorbid conditions, and cardiovascular risk factors.

RESULTS

The groups were significantly different on ankle-brachial index (P = .02), and on the prevalence of hypertension (P = .04), diabetes (P < .01), abdominal obesity (P < .01), arthritis (P = .04), and chronic obstructive pulmonary disease (P < .01). Thus, these variables served as covariates in adjusted analyses, along with age, weight, and sex. The 6MWD (mean ± standard deviation) was significantly different among the groups in unadjusted (P < .01) and adjusted (P < .01) analyses (group 1, 313 ± 90 m; group 2, 378 ± 84 m; and group 3, 414 ± 77 m), with groups 2 and 3 having a higher 6MWD than group 1 (P < .01). The WIQ distance score was significantly different among the groups in unadjusted (P < .01) and adjusted (P < .01) analyses (group 1, 30 ± 30%; group 2, 45 ± 35%; and group 3, 47 ± 34%), with groups 2 and 3 having higher WIQ distance scores than group 1 (P < .01).

CONCLUSIONS

Patients with PAD who walked more than 7000 and 10,000 steps/day had greater ambulatory function and HRQoL than patients who walked fewer than 7000 steps/day. Second, the greater ambulatory function and HRQoL associated with walking 7000 and 10,000 steps/day persisted after adjusting for covariates. This study provides preliminary evidence that patients with PAD who walk more than 7000 steps/day have better ambulatory function and HRQoL than patients below this threshold.

Daily Step Counts in Participants With and Without Peripheral Artery Disease

PURPOSE

We compared the prevalence of participants with and without symptomatic peripheral artery disease (PAD) who met the goals of attaining >7000 and 10 000 steps/d, and we determined whether PAD status was significantly associated with meeting the daily step count goals before and after adjusting for demographic variables, comorbid conditions, and cardiovascular risk factors.

METHODS

Participants with PAD (n = 396) and without PAD (n = 396) were assessed on their walking for 7 consecutive days with a step activity monitor.

RESULTS

The PAD group took significantly fewer steps/d than the non-PAD control group (6722 ± 3393 vs. 9475 ± 4110 steps/d; P < .001). Only 37.6% and 15.7% of the PAD group attained the goals of walking >7000 and 10 000 steps/d, respectively, whereas 67.9% and 37.4% of the control group attained these goals (P < .001 for each goal). Having PAD was associated with a 62% lower chance of attaining 7000 steps/d than compared with the control group (OR = 0.383; 95% CI, 0.259-0.565; P < .001), and a 55% lower chance of attaining 10 000 steps/d (OR = 0.449; 95% CI, 0.282-0.709; P < .001). Significant covariates (P < .01) included age, current smoking, diabetes, and body mass index.

CONCLUSIONS

Participants with symptomatic PAD had a 29% lower daily step count compared with age- and sex-matched controls, and were less likely to attain the 7000 and 10 000 steps/d goals. Additionally, participants who were least likely to meet the 7000 and 10 000 daily step count recommendations included those who were older, currently smoked, had diabetes, and had higher body mass index.

Patients With Peripheral Arterial Disease With Exaggerated Pressor Response Have Greater Ambulatory Dysfunction Than Patients With Lower Pressor Response

We determined whether patients with peripheral arterial disease (PAD) who have either an exaggerated or a negative pressor response during treadmill walking have shorter peak walking time (PWT) and claudication onset time (COT) than patients with a normal pressor response, independent of comorbid conditions. A total of 249 patients were categorized to 1 of 3 groups based on systolic blood pressure (SBP) responses at 2 minutes of treadmill walking (speed = 2 mph, grade = 0%): group 1 (negative pressor response, SBP < 0 mm Hg), group 2 (normal pressor response, SBP 18 mm Hg), and group 3 (exaggerated pressor response, SBP > 18 mm Hg). After adjusting for comorbid conditions, group 3 (exaggerated) had significantly reduced COT (P = .011) and PWT (P = .002) compared to group 2 (normal), while group 1 (negative) and group 2 (normal) were not different. Patients with symptomatic PAD with an increase in SBP > 18 mm Hg after 2 minutes of treadmill walking experience claudication earlier and thus have greater ambulatory dysfunction, compared to patients with PAD with a normal pressor response, whereas patients with PAD with negative pressor response had a similar walking performance. The implication is that the magnitude of pressor response to only 2 minutes of treadmill walking can partially explain the degree of ambulatory dysfunction in patients with PAD.

Comparison of hemorrhagic and ischemic stroke after allogeneic hematopoietic stem cell transplantation

Stroke is an important complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT). Nevertheless, few studies have been published to analyzed the occurrence and prognosis of stroke after allo-HSCT. From January 2007 to December 2018 in Peking University People's Hospital, 6449 patients received HSCT and there were 2.3% of patients diagnosed with stroke after allo-HSCT (hemorrhagic: 1.0%, ischemic: 1.3%). The median time to hemorrhagic and ischemic stroke after HSCT was 161 days and 137 days, respectively. In total, 8.4% of patients experienced neurological sequelae. The outcome was much worse in patients with stroke than in control subjects. The comparison of prognosis showed no statistical differences between patients with hemorrhagic stroke and those with ischemic stroke. Significant risk factors for hemorrhagic stroke were pretransplant central nervous system leukemia (CNSL), and delayed platelet engraftment. Risk factors associated with the occurrence of ischemic stroke included high-risk disease, prior venous thromboembolism (VTE), grade III-IV acute graft-versus-host disease (aGVHD), and thrombotic microangiopathy (TMA). Haplo-identical transplantation was not a risk factor for stroke and had no impact on the prognosis compared with HLA-matched HSCT. Altogether, these results show that stroke is a severe complication after allo-HSCT. The prognosis of posttransplant stroke did not differ between hemorrhagic and ischemic stroke.

Diet is associated with ankle-brachial index, inflammation, and ambulation in patients with intermittent claudication

OBJECTIVE

The aims of this investigation were to determine whether the daily dietary intake of nutrients by patients with peripheral artery disease (PAD) and intermittent claudication (IC) met recommended levels for adults older than 50 years and to determine whether meeting recommended levels of nutrients was associated with ankle-brachial index (ABI), inflammation, and ambulation of patients with PAD and IC.

METHODS

A total of 48 patients were assessed on their dietary intake of 20 nutrients during a 3-day period. Patients were further characterized on demographic variables, comorbid conditions, cardiovascular risk factors, ABI, 6-minute walk distance (6MWD), and high-sensitivity C-reactive protein (hsCRP) concentration.

RESULTS

Few patients met the daily recommended intakes for calcium (4%), fiber (6%), vitamin E (6%), trans fatty acids (13%), vitamin A (15%), total sugars (19%), potassium (23%), sodium (29%), saturated fat (29%), and vitamin C (31%), and none of the patients met the daily recommended intake of vitamin D (0%). Overall, patients met few of the 20 dietary recommendations as the median score was seven recommendations. Only 17 of 48 patients met more than seven of the recommendations. For the ABI regression model adjusted for age, sex, race, smoking, hypertension, dyslipidemia, body mass index, and percentage body fat, the only significant predictor was total sugars (P < .001); patients who did not meet the recommendation had lower ABI values. For the hsCRP-adjusted regression model, the strongest significant predictor was omega-3 polyunsaturated fatty acids (P = .001), indicating that those who did not meet the recommendation had higher hsCRP values. Finally, for the 6MWD-adjusted regression model, folate (P = .011) and dietary score index (P = .014) were significant predictors; those who did not meet the recommendation for folate and those who met 5 or fewer of the 20 recommendations had shorter 6MWD.

CONCLUSIONS

Patients with PAD and IC consume a low-nutrient-dense diet that is deficient in many vitamins, calcium, fruits, and vegetables and contains too much added sugar, saturated and trans fats, and processed foods. In addition, more severe PAD, greater inflammation, and ambulatory dysfunction are independently associated with aspects of a low-nutrient-dense diet, such as too much intake of added sugars, low intake of omega-3 polyunsaturated fatty acids and folate, and meeting the recommended intakes of only five or fewer nutrients.

Association between calf muscle oxygen saturation with ambulatory function and quality of life in symptomatic patients with peripheral artery disease

OBJECTIVE

The objective of this study was to determine whether calf muscle hemoglobin oxygen saturation (Sto₂) obtained during a standardized treadmill test is associated with ambulatory function and health-related quality of life (HRQoL) in patients with symptomatic peripheral artery disease (PAD). We hypothesized that a rapid decline in calf muscle Sto₂ during walking is associated with impaired ambulatory function and HRQoL and that these associations are independent of ankle-brachial index (ABI).

METHODS

Calf muscle Sto₂, peak walking time, and claudication onset time were obtained during a treadmill test in 151 symptomatic men and women with PAD. Patients were further characterized by demographic variables, comorbid conditions, cardiovascular risk factors, ABI, 6-minute walk distance, daily ambulatory activity, Walking Impairment Questionnaire (WIQ) score, and Medical Outcomes Study 36-Item Short Form Health Survey physical function score to assess HRQoL.

RESULTS

The median calf muscle Sto₂ value at rest was 52%, which declined to 22% after only 1 minute of walking during the treadmill test and reached a minimum value of 9% after a median time of 87 seconds of walking. Of the various calf muscle Sto₂ measurements obtained during the treadmill test, the exercise time to the minimum calf muscle Sto₂ value (log transformed) had the strongest univariate associations with peak walking time (r = 0.56; P < .001), claudication onset time (r = 0.49; P < .001), 6-minute walk distance (r = 0.31; P < .001), WIQ distance score (r = 0.33; P < .001), WIQ speed score (r = 0.39; P < .001), WIQ stair-climbing score (r = 0.37; P < .001), and Medical Outcomes Study 36-Item Short Form Health Survey physical function score (r = 0.32; P < .001). In adjusted multiple regression models, these associations persisted (P < .001) after adjustment for demographic measures, cardiovascular risk factors, comorbid conditions, and ABI.

CONCLUSIONS

More rapid decline in oxygen saturation of the calf musculature during walking, indicative of impaired microcirculation, is predictive of impaired ambulatory function and HRQoL in patients with symptomatic PAD. Of particular importance, these associations are independent of ABI and other common health burdens, highlighting the clinical relevance that the microcirculation has on ambulatory function and HRQoL in patients with symptomatic PAD.

Oxidative Stress and Inflammation, Key Targets of Atherosclerotic Plaque Progression and Vulnerability: Potential Impact of Physical Activity

Atherosclerosis, a complex cardiovascular disease, is a leading cause of mortality and morbidity worldwide. Oxidative stress and inflammation are both involved in the development of atherosclerotic plaque as they increase the biological processes associated with this pathology, such as endothelial dysfunction and macrophage recruitment and adhesion. Atherosclerotic plaque rupture leading to major ischemic events is the result of vulnerable plaque progression, which is a result of the detrimental effect of oxidative stress and inflammation on risk factors for atherosclerotic plaque rupture, such as intraplaque hemorrhage, neovascularization, and fibrous cap thickness. Thus, both are key targets for primary and secondary interventions. It is well recognized that chronic physical activity attenuates oxidative stress in healthy subjects via the improvement of antioxidant enzyme capacities and inflammation via the enhancement of anti-inflammatory molecules. Moreover, it was recently shown that chronic physical activity could decrease oxidative stress and inflammation in atherosclerotic patients. The aim of this review is to summarize the role of oxidative stress and inflammation in atherosclerosis and the results of therapeutic interventions targeting them in both preclinical and clinical studies. The effects of chronic physical activity on these two key processes are then reviewed in vulnerable atherosclerotic plaques in both coronary and carotid arteries.

Role of endothelial NAD+ deficiency in age-related vascular dysfunction

Age-related alterations in endothelium and the resulting vascular dysfunction critically contribute to a range of pathological conditions associated with old age. To develop therapies rationally that improve vascular health and thereby increase health span and life span in older adults, it will be essential to understand the cellular and molecular mechanisms contributing to vascular aging. Preclinical studies in model organisms demonstrate that NAD+ availability decreases with age in multiple tissues and that supplemental NAD+ precursors can ameliorate many age-related cellular impairments. Here, we provide a comprehensive overview of NAD+-dependent pathways [including the NAD+-using silent information regulator-2-like enzymes and poly(ADP-ribose) polymerase enzymes] and the potential consequences of endothelial NAD+ deficiency in vascular aging. The multifaceted vasoprotective effects of treatments that reverse the age-related decline in cellular NAD+ levels, as well as their potential limitations, are discussed. The preventive and therapeutic potential of NAD+ intermediates as effective, clinically relevant interventions in older adults at risk for ischemic heart disease, vascular cognitive impairment, and other common geriatric conditions and diseases that involve vascular pathologies (e.g., sarcopenia, frailty) are critically discussed. We propose that NAD+ precursors [e.g., nicotinamide (Nam) riboside, Nam mononucleotide, niacin] should be considered as critical components of combination therapies to slow the vascular aging process and increase cardiovascular health span.

Vascular Inflammation, Calf Muscle Oxygen Saturation, and Blood Glucose are Associated With Exercise Pressor Response in Symptomatic Peripheral Artery Disease

We determined whether calf muscle oxygen saturation (StO2) and vascular biomarkers of inflammation and oxidative stress were associated with an exercise pressor response during treadmill walking in 179 patients with symptomatic peripheral artery disease (PAD). The exercise pressor response was measured as the change in blood pressure from rest to the end of the first 2-minute treadmill stage (2 mph, 0% grade). There was a wide range in the change in systolic blood pressure (−46 to 50 mm Hg) and in diastolic blood pressure (−23 to 38 mm Hg), with mean increases of 4.3 and 1.4 mm Hg, respectively. In multiple regression analyses, significant predictors of systolic pressure included glucose ( P < .001) and insulin ( P = .039). Significant predictors of diastolic pressure included cultured endothelial cell apoptosis ( P = .019), the percentage drop in exercise calf muscle (StO2; P = .023), high-sensitivity C-reactive protein ( P = .032), and glucose ( P = .033). Higher levels in pro-inflammatory vascular biomarkers, impaired calf muscle StO2 during exercise, and elevated blood glucose were independently associated with greater exercise pressor response in patients with symptomatic PAD. The clinical implication is that exercise and nutritional interventions designed to improve inflammation, microcirculation, and glucose metabolism may also lower blood pressure during exercise in patients with symptomatic PAD.

Changes in vascular and inflammatory biomarkers after exercise rehabilitation in patients with symptomatic peripheral artery disease

OBJECTIVE

Home-based exercise is an alternative exercise mode to a structured supervised program to improve symptoms in patients with peripheral artery disease (PAD), but little is known about whether the slow-paced and less intense home program also elicits changes in vascular and inflammatory biomarkers. In an exploratory analysis from a randomized controlled trial, we compared changes in vascular and inflammatory biomarkers in patients with symptomatic PAD (typical and atypical of claudication) after home-based exercise and supervised exercise programs and in an attention-control group.

METHODS

A total of 114 patients were randomized into one of the three groups (n = 38 per group). Two groups performed exercise interventions, consisting of home-based and supervised programs of intermittent walking to mild to moderate claudication pain for 12 weeks; a third group performed light resistance training as a nonwalking attention-control group. Before and after intervention, patients were characterized on treadmill performance and endothelial effects of circulating factors present in sera by a cell culture-based bioassay on primary human arterial endothelial cells, and they were further evaluated on circulating vascular and inflammatory biomarkers.

RESULTS

Treadmill peak walking time increased (P = .008) in the two exercise groups but not in the control group (P > .05). Cultured endothelial cell apoptosis decreased after home-based exercise (P < .001) and supervised exercise (P = .007), and the change in the exercise groups combined was different from that in the control group (P = .005). For circulating biomarkers, increases were found in hydroxyl radical antioxidant capacity (P = .003) and vascular endothelial growth factor A (P = .037), and decreases were observed in E-selectin (P = .007) and blood glucose concentration (P = .012) after home-based exercise only. The changes in hydroxyl radical antioxidant capacity (P = .005), vascular endothelial growth factor A (P = .008), and E-selectin (P = .034) in the exercise groups combined were different from those in the control group.

CONCLUSIONS

This exploratory analysis found that both home-based and supervised exercise programs are efficacious to decrease cultured endothelial cell apoptosis in patients with symptomatic PAD. Furthermore, a monitored home-based exercise program elicits additional vascular benefits by improving circulating markers of endogenous antioxidant capacity, angiogenesis, endothelium-derived inflammation, and blood glucose concentration in patients with symptomatic PAD. The novel clinical significance is that important trends were found in this exploratory analysis that a contemporary home-based exercise program and a traditional supervised exercise program may favorably improve vascular and inflammatory biomarkers in addition to the well-described ambulatory improvements in symptomatic patients with PAD.

Predictors of health-related quality of life in patients with symptomatic peripheral artery disease

OBJECTIVE

The aim of this study was to identify predictors of baseline measures of health-related quality of life (HRQoL) in symptomatic patients with peripheral artery disease (PAD) from objective markers of severity of PAD, clinical and demographic characteristics, comorbid conditions, cardiovascular risk factors, objectively measured physical activity, and patient-based measures of physical function.

METHODS

HRQoL measurements of 216 symptomatic men and women with PAD were assessed with the Medical Outcomes Study 36-Item Short Form Health Survey. Patients were further characterized on demographic variables, comorbid conditions, cardiovascular risk factors, ankle-brachial index, peak walking time during a maximal treadmill test, 6-minute walk distance, gait speed, ambulatory activity monitored during 1 week, activities of daily living (ADLs), Mini-Mental State Examination questionnaire, and Walking Impairment Questionnaire (WIQ).

RESULTS

For the physical function HRQoL subscale, the significant predictors included WIQ speed score (P < .001), history of stumbling (P < .001), WIQ stair climbing score (P < .001), ADL associated with bathing (P = .001), 6-minute walk distance (P = .004), and daily walking cadence (P = .043). For the role emotional function HRQoL subscale, the significant predictors included a history of stumbling (P < .001), the ADL associated with transferring from a bed to a chair (P < .001), and the WIQ distance score (P = .022).

CONCLUSIONS

Physical and mental subscales of HRQoL in symptomatic patients with PAD are primarily predicted by patient-based physical function rather than by more specific markers of PAD severity and comorbid conditions. The clinical significance is that interventions designed to improve HRQoL should focus on improving the quality of executing functional tasks, such as walking more steadily without stumbling; completing ADLs that are not specific to walking, such as bathing and transferring; and improving patient-based ability to walk various distances and speeds and to climb stairs.

Greater Exercise Pressor Response Is Associated With Impaired Claudication Outcomes in Symptomatic Peripheral Artery Disease

We determined whether a greater exercise pressor response during a constant-load treadmill test was associated with lower peak walking time (PWT) and claudication onset time (COT) measured during a graded maximal treadmill test in 304 patients with symptomatic peripheral artery disease (PAD). The exercise pressor response was assessed by measuring heart rate and blood pressure (BP) at rest and during a constant-load treadmill test (speed = 2 mph, grade = 0%). After only 2 minutes of walking, mean heart rate increased by 26 beats/min from rest and mean systolic BP increased by 16 mm Hg. In adjusted analyses, increases in systolic BP (P = .021), heart rate (P = .002), mean arterial pressure (P = .034), and rate-pressure product (P < .001) from rest to 2 minutes of constant-load exercise were negatively associated with COT. Similarly, increases in heart rate (P = .012) and rate-pressure product (P = .018) from rest to 2 minutes of constant-load exercise were negatively associated with PWT. A greater exercise pressor response observed after only 2 minutes of walking at no incline was independently associated with impaired claudication outcomes in patients with symptomatic PAD. The implication is that the exercise pressor response is an important and easily obtained clinical measurement that partially explains differences in PWT and COT.

Endothelial Cell Inflammation and Antioxidant Capacity are Associated With 6-Minute Walk Performance in Patients With Symptomatic Peripheral Artery Disease

We determined whether 6-minute walk total distance and pain-free distance were associated with circulating biomarkers of antioxidant capacity and inflammation and with cultured endothelial cell inflammation, oxidative stress, and apoptosis in 251 patients with symptomatic peripheral artery disease (PAD). In multivariate analyses, pain-free distance during the 6-minute walk test was negatively associated with dyslipidemia ( P < .001), chronic kidney disease ( P = .004), and transient transfection, nuclear factor κ-Light-Chain-Enhancer of activated B (NF-κB) cultured endothelial cells ( P = .007) and was positively associated with height ( P = .008). Furthermore, total distance walked during the 6-minute walk test was negatively associated with cultured endothelial cell NF-κB ( P < .001), coronary artery disease ( P = .009), and body mass index ( P = .022) and was positively associated with ankle-brachial index ( P < .001), male sex ( P < .001), and hydroxyl radical antioxidant capacity ( P < .001). The 6-minute walk performance in symptomatic patients with PAD was associated with vascular biomarkers, as walking distances were negatively associated with cultured endothelial cell inflammation and positively associated with circulating antioxidant capacity. The clinical implication is that behavioral interventions designed to alleviate endothelial cell inflammation and increase circulating antioxidant capacity, such as exercise and antioxidant intake, may improve ambulation of patients with PAD during submaximal exercise that is typically performed during daily activities.

Crossroads between peripheral atherosclerosis, western-type diet and skeletal muscle pathophysiology: emphasis on apolipoprotein E deficiency and peripheral arterial disease

Atherosclerosis is a chronic inflammatory process that, in the presence of hyperlipidaemia, promotes the formation of atheromatous plaques in large vessels of the cardiovascular system. It also affects peripheral arteries with major implications for a number of other non-vascular tissues such as the skeletal muscle, the liver and the kidney. The aim of this review is to critically discuss and assimilate current knowledge on the impact of peripheral atherosclerosis and its implications on skeletal muscle homeostasis. Accumulating data suggests that manifestations of peripheral atherosclerosis in skeletal muscle originates in a combination of increased i)-oxidative stress, ii)-inflammation, iii)-mitochondrial deficits, iv)-altered myofibre morphology and fibrosis, v)-chronic ischemia followed by impaired oxygen supply, vi)-reduced capillary density, vii)- proteolysis and viii)-apoptosis. These structural, biochemical and pathophysiological alterations impact on skeletal muscle metabolic and physiologic homeostasis and its capacity to generate force, which further affects the individual's quality of life. Particular emphasis is given on two major areas representing basic and applied science respectively: a)-the abundant evidence from a well-recognised atherogenic model; the Apolipoprotein E deficient mouse and the role of a western-type diet and b)-on skeletal myopathy and oxidative stress-induced myofibre damage from human studies on peripheral arterial disease. A significant source of reactive oxygen species production and oxidative stress in cardiovascular disease is the family of NADPH oxidases that contribute to several pathologies. Finally, strategies targeting NADPH oxidases in skeletal muscle in an attempt to attenuate cellular oxidative stress are highlighted, providing a better understanding of the crossroads between peripheral atherosclerosis and skeletal muscle pathophysiology.

Association between daily walking and antioxidant capacity in patients with symptomatic peripheral artery disease

OBJECTIVE

The primary aim of the study was to assess whether both the amount and pace of daily walking were associated with circulating antioxidant capacity in symptomatic patients with peripheral artery disease (PAD).

METHODS

Community-based walking was measured in 244 men and women who were limited by symptomatic PAD during a 1-week period in which they wore an ankle-mounted step activity monitor. Patients were further characterized by circulating antioxidant capacity with the OxiSelect (Cell Biolabs Inc, San Diego, Calif) hydroxyl radical antioxidant capacity (HORAC) activity assay.

RESULTS

To assess the amount of walking, patients were grouped into low (≤2440 strides/d), middle (2441-3835 strides/d), and high (>3835 strides/d) stride tertiles. HORAC was higher in the middle (P = .03) and high (P = .01) stride tertiles than in the low tertile, but there was no difference between middle and high tertiles (P = .44). To assess the pace of walking, patients were grouped into slow (<25.0 strides/min), middle (25.0-31.6 strides/min), and fast (>31.6 strides/min) cadence tertiles. HORAC was higher in the high cadence tertile than in the low (P < .01) and middle (P < .01) tertiles, but there was no difference between low and middle tertiles (P = .48). Similar findings were obtained on group differences in HORAC after adjusting for age, sex, race, and ankle-brachial index for both the amount and pace of daily walking.

CONCLUSIONS

Walking >2440 strides each day and walking at a cadence faster than 31.6 strides/min for 30 minutes each day are both associated with greater circulating antioxidant capacity in symptomatic patients with PAD. The clinical significance is that a home-based walking program may be one approach to increase endogenous antioxidant capacity.