Effect of upper- and lower-limb exercise training on circulating soluble adhesion molecules, hs-CRP and stress proteins in patients with intermittent claudication

The effect of age and sex on peak oxygen uptake during upper and lower body exercise: A systematic review

BACKGROUND

Large scale population norms for peak oxygen uptake (VO2peak) during cycle ergometry (CE) have been published for men and women across a wide range of ages. Although upper body functional capacity has an important role in activities of daily living far less is known regarding the effect of age and sex on upper body functional capacity (i.e. arm crank ergometry; ACE). The aim of this review was to determine the effect of age and sex on VO2peak obtained during ACE and CE in the same participants.

METHOD

The review was pre-registered with PROSEPERO (Ref: CRD42022349566). A database search using Academic Search Complete including CINAHL complete, CINHAL Ultimate, Medline, PubMed, SPORTDiscus was undertaken.

RESULTS

The initial search yielded 460 articles which was reduced to 243 articles following removal of duplicates. Twenty-five articles were subsequently excluded based on title resulting in 218 articles considered for retrieval. Following review of the abstracts, 78 further articles were excluded leaving 140 to be assessed for eligibility. Eighty-five articles were subsequently excluded, resulting in 55 articles being included. The decrease in VO2peak with age during CE was consistent with previous studies. Decreases in VO2peak during ACE with age, although paralleling those of CE, appeared to be of greater functional importance. When changes in VO2peak were considered below the age of 50 years little change was observed for absolute VO2peak during ACE and CE. In contrast, relative VO2peak demonstrated decreases in VO2peak for both ACE and CE likely reflecting increases in body mass and body fat percentage with age. After 50 years of age absolute and relative VO2peak demonstrated more similar and subtle responses. Heterogeneity across studies for both absolute and relative VO2peak between ACE and CE was large. Although strict inclusion criteria were applied, the inter-individual variation in sample populations was likely the main source of heterogeneity. There was a considerable lack data sets available for ages above 40 years of age.

CONCLUSIONS

These responses suggest that upper body VO2peak decreases in line with that of the lower body but, due to the lower peak values achieved during ACE, decreases in VO2peak may have more profound functional impact compared to that for the lower body. Using absolute and relative measures of VO2peak results in different age-related profiles when considered below 50 years of age. To further our understanding of whole body ageing more data is required for participants in mid and later life. The association between VO2peak and underlying physiological factors with age needs to be studied further, particularly in conjunction with activities of daily living and independent living.

Modes of exercise training for intermittent claudication

BACKGROUND

According to international guidelines and literature, all patients with intermittent claudication should receive an initial treatment of cardiovascular risk modification, lifestyle coaching, and supervised exercise therapy. In the literature, supervised exercise therapy often consists of treadmill or track walking. However, alternative modes of exercise therapy have been described and yielded similar results to walking. This raises the following question: which exercise mode produces the most favourable results? This is the first update of the original review published in 2014.

OBJECTIVES

To assess the effects of alternative modes of supervised exercise therapy compared to traditional walking exercise in patients with intermittent claudication.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 4 March 2019. We also undertook reference checking, citation searching and contact with study authors to identify additional studies. No language restriction was applied.

SELECTION CRITERIA

We included parallel-group randomised controlled trials comparing alternative modes of exercise training or combinations of exercise modes with a control group of supervised walking exercise in patients with clinically determined intermittent claudication. The supervised walking programme needed to be supervised at least twice a week for a consecutive six weeks of training.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, extracted data, and assessed the risk of bias for each study. As we included studies with different treadmill test protocols and different measuring units (metres, minutes, or seconds), the standardised mean difference (SMD) approach was used for summary statistics of mean walking distance (MWD) and pain-free walking distance (PFWD). Summary estimates were obtained for all outcome measures using a random-effects model. We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

For this update, five additional studies were included, making a total of 10 studies that randomised a total of 527 participants with intermittent claudication (IC). The alternative modes of exercise therapy included cycling, lower-extremity resistance training, upper-arm ergometry, Nordic walking, and combinations of exercise modes. Besides randomised controlled trials, two quasi-randomised trials were included. Overall risk of bias in included studies varied from high to low. According to GRADE criteria, the certainty of the evidence was downgraded to low, due to the relatively small sample sizes, clinical inconsistency, and inclusion of three studies with risk of bias concerns. Overall, comparing alternative exercise modes versus walking showed no clear differences for MWD at 12 weeks (standardised mean difference (SMD) -0.01, 95% confidence interval (CI) -0.29 to 0.27; P = 0.95; 6 studies; 274 participants; low-certainty evidence); or at the end of training (SMD -0.11, 95% CI -0.33 to 0.11; P = 0.32; 9 studies; 412 participants; low-certainty evidence). Similarly, no clear differences were detected in PFWD at 12 weeks (SMD -0.01, 95% CI -0.26 to 0.25; P = 0.97; 5 studies; 249 participants; low-certainty evidence); or at the end of training (SMD -0.06, 95% CI -0.30 to 0.17; P = 0.59; 8 studies, 382 participants; low-certainty evidence). Four studies reported on health-related quality of life (HR-QoL) and three studies reported on functional impairment. As the studies used different measurements, meta-analysis was only possible for the walking impairment questionnaire (WIQ) distance score, which demonstrated little or no difference between groups (MD -5.52, 95% CI -17.41 to 6.36; P = 0.36; 2 studies; 96 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

This review found no clear difference between alternative exercise modes and supervised walking exercise in improving the maximum and pain-free walking distance in patients with intermittent claudication. The certainty of this evidence was judged to be low, due to clinical inconsistency, small sample size and risk of bias concerns. The findings of this review indicate that alternative exercise modes may be useful when supervised walking exercise is not an option. More RCTs with adequate methodological quality and sufficient power are needed to provide solid evidence for comparisons between each alternative exercise mode and the current standard of supervised treadmill walking. Future RCTs should investigate outcome measures on walking behaviour, physical activity, cardiovascular risk, and HR-QoL, using standardised testing methods and reporting of outcomes to allow meaningful comparison across studies.

The effects of resistance and endurance training on risk factors of vascular inflammation and atherogenesis in non-athlete men

Background

Studies show that different types of training have a significant role in reducing both new and traditional risk factors of cardiovascular diseases, and the new risk factors are more sensitive and accurate in predicting such diseases.

Objective

The aim of this study was to determine the effects of resistance and endurance exercises on risk factors of vascular inflammation and atherogenesis in non-athlete men.

Methods

Thirty-six non-athlete male students (mean age: 20.45 ± 1.20 years; mean body mass index: 23.66 ± 3.65 kg/m²) were randomly assigned into either three groups: control group, resistance training (RT), and endurance training (ET). The training groups exercised for 3 days/week for 8 weeks. ET group performed treadmill-running at 65%–80% of maximum heart rate and with a 16–30 min duration; the task of RT group consisted of three repetition sets, 8–10 per set, at 60%–80% of one repetition maximum, with 2-min recesses. Blood samples were taken before and after the training program. Data were analyzed by Shapiro–Wilk test, one-way ANOVA, LSD test, and dependent t-test (α ≤ 0.05).

Results

The results indicated a significant reduction in total cholesterol levels in both RT and ET groups. Also high-density lipoprotein cholesterol significantly increased in both training groups. In addition, following 8 weeks, low-density lipoprotein cholesterol in ET group was significantly decreased, whereas these training methods have had no significant effects on the new cardiovascular biomarkers (hs-CRP, IL-6, and sICAM-1).

Conclusion

It seems that both ET and RT with improvement in lipid profiles could be effective in prevention and treatment of the cardiovascular disease.

Exercise for intermittent claudication

BACKGROUND

Exercise programmes are a relatively inexpensive, low-risk option compared with other, more invasive therapies for treatment of leg pain on walking (intermittent claudication (IC)). This is the fourth update of a review first published in 1998.

OBJECTIVES

Our goal was to determine whether an exercise programme was effective in alleviating symptoms and increasing walking treadmill distances and walking times in people with intermittent claudication. Secondary objectives were to determine whether exercise was effective in preventing deterioration of underlying disease, reducing cardiovascular events, and improving quality of life.

SEARCH METHODS

For this update, the Cochrane Vascular Information Specialist searched the Specialised Register (last searched 15 November 2016) and the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 10) via the Cochrane Register of Studies Online, along with trials registries.

SELECTION CRITERIA

Randomised controlled trials of an exercise regimen versus control or versus medical therapy for people with IC due to peripheral arterial disease (PAD). We included any exercise programme or regimen used for treatment of IC, such as walking, skipping, and running. Inclusion of trials was not affected by duration, frequency, or intensity of the exercise programme. Outcome measures collected included treadmill walking distance (time to onset of pain or pain-free walking distance and maximum walking time or maximum walking distance), ankle brachial index (ABI), quality of life, morbidity, or amputation; if none of these was reported, we did not include the trial in this review.

DATA COLLECTION AND ANALYSIS

For this update (2017), RAL and AH selected trials and extracted data independently. We assessed study quality by using the Cochrane 'Risk of bias' tool. We analysed continuous data by determining mean differences (MDs) and 95% confidence intervals (CIs), and dichotomous data by determining risk ratios (RRs) and 95% CIs. We pooled data using a fixed-effect model unless we identified significant heterogeneity, in which case we used a random-effects model. We used the GRADE approach to assess the overall quality of evidence supporting the outcomes assessed in this review.

MAIN RESULTS

We included two new studies in this update and identified additional publications for previously included studies, bringing the total number of studies meeting the inclusion criteria to 32, and involving a total of 1835 participants with stable leg pain. The follow-up period ranged from two weeks to two years. Types of exercise varied from strength training to polestriding and upper or lower limb exercises; supervised sessions were generally held at least twice a week. Most trials used a treadmill walking test for one of the primary outcome measures. The methodological quality of included trials was moderate, mainly owing to absence of relevant information. Most trials were small and included 20 to 49 participants. Twenty-seven trials compared exercise versus usual care or placebo, and the five remaining trials compared exercise versus medication (pentoxifylline, iloprost, antiplatelet agents, and vitamin E) or pneumatic calf compression; we generally excluded people with various medical conditions or other pre-existing limitations to their exercise capacity.Meta-analysis from nine studies with 391 participants showed overall improvement in pain-free walking distance in the exercise group compared with the no exercise group (MD 82.11 m, 95% CI 71.73 to 92.48, P < 0.00001, high-quality evidence). Data also showed benefit from exercise in improved maximum walking distance (MD 120.36 m, 95% CI 50.79 to 189.92, P < 0.0007, high-quality evidence), as revealed by pooling data from 10 studies with 500 participants. Improvements were seen for up to two years.Exercise did not improve the ABI (MD 0.04, 95% CI 0.00 to 0.08, 13 trials, 570 participants, moderate-quality evidence). Limited data were available for the outcomes of mortality and amputation; trials provided no evidence of an effect of exercise, when compared with placebo or usual care, on mortality (RR 0.92, 95% CI 0.39 to 2.17, 5 trials, 540 participants, moderate-quality evidence) or amputation (RR 0.20, 95% CI 0.01 to 4.15, 1 trial, 177 participants, low-quality evidence).Researchers measured quality of life using Short Form (SF)-36 at three and six months. At three months, the domains 'physical function', 'vitality', and 'role physical' improved with exercise; however this was a limited finding, as it was reported by only two trials. At six months, meta-analysis showed improvement in 'physical summary score' (MD 2.15, 95% CI 1.26 to 3.04, P = 0.02, 5 trials, 429 participants, moderate-quality evidence) and in 'mental summary score' (MD 3.76, 95% CI 2.70 to 4.82, P < 0.01, 4 trials, 343 participants, moderate-quality evidence) secondary to exercise. Two trials reported the remaining domains of the SF-36. Data showed improvements secondary to exercise in 'physical function' and 'general health'. The other domains - 'role physical', 'bodily pain', 'vitality', 'social', 'role emotional', and 'mental health' - did not show improvement at six months.Evidence was generally limited in trials comparing exercise versus antiplatelet therapy, pentoxifylline, iloprost, vitamin E, and pneumatic foot and calf compression owing to small numbers of trials and participants.Review authors used GRADE to assess the evidence presented in this review and determined that quality was moderate to high. Although results showed significant heterogeneity between trials, populations and outcomes were comparable overall, with findings relevant to the claudicant population. Results were pooled for large sample sizes - over 300 participants for most outcomes - using reproducible methods.

AUTHORS' CONCLUSIONS

High-quality evidence shows that exercise programmes provided important benefit compared with placebo or usual care in improving both pain-free and maximum walking distance in people with leg pain from IC who were considered to be fit for exercise intervention. Exercise did not improve ABI, and we found no evidence of an effect of exercise on amputation or mortality. Exercise may improve quality of life when compared with placebo or usual care. As time has progressed, the trials undertaken have begun to include exercise versus exercise or other modalities; therefore we can include fewer of the new trials in this update.

Effect of exercise training on C reactive protein: a systematic review and meta-analysis of randomised and non-randomised controlled trials

PURPOSE

C-reactive protein (CRP) is a marker of chronic systemic inflammation frequently used in cardiovascular disease risk assessment. The purpose of this meta-analysis was to provide a quantitative estimate of the magnitude of change in CRP following participation in physical exercise interventions.

METHODS

All studies included in the meta-analysis were peer reviewed and published in English. Human participants were assigned to a non-exercise comparison group or exercise training group, with the intervention lasting ≥2 weeks. CRP levels were measured at baseline, during and/or after completion of the exercise training programme. Random-effects models were used to aggregate a mean effect size (ES), 95% CIs and potential moderators.

RESULTS

83 randomised and non-randomised controlled trials met the inclusion criteria and resulted in 143 effects (n=3769). The mean ES of 0.26 (95% CI 0.18 to 0.34, p<0.001) indicated a decrease in CRP following exercise training. A decrease in body mass index (BMI; β=1.20, SE=0.25, p<0.0001) and %Fat (β=0.76, SE=0.21, p=0.0002) were associated with a decrease in CRP, independently accounting for 11.1% and 6.6% of the variation in response, respectively. Exercise training led to a greater reduction in CRP when accompanied by a decrease in BMI (ES=0.38, 95% CI 0.26 to 0.50); however, a significant improvement in CRP occurred in the absence of weight loss (ES=0.19, 95% CI 0.10 to 0.28; both p<0.001).

CONCLUSIONS

These results suggest that engaging in exercise training is associated with a decrease in CRP levels regardless of the age or sex of the individual; however, greater improvements in CRP level occur with a decrease in BMI or %Fat.

Effect of Nigella sativa supplementation to exercise training in a novel model of physiological cardiac hypertrophy

Exercise training is employed as supplementary therapy to patients with heart failure due to its multiple beneficial cardiac effects including physiological remodeling of the heart. However, precautions might be taken for the concomitant high oxidant release. Nigella sativa (NS) has been found to induce cardiac hypertrophy and enhance cardiac function. Combination of NS supplementation and exercise training might induce a safer model of cardiac hypertrophy. Our aim was to study biomarkers associated with cardiac hypertrophy induced by NS supplementation of exercise-trained rats. Forty-five adult male Wistar rats (body weight 150-220 g) were divided equally into three groups: control, exercise-trained (ET) and NS-treated-exercise-trained (NSET) groups. Daily 800 mg/kg NS was administered orally to NSET group for 8 weeks. Rats of the ET and NSET groups were subjected to treadmill running sessions for 2 h/day for 8 weeks. By the end of the experiment, the following were recorded: body, heart and left ventricular weights (BW, HW, LVW), cardiomyocyte diameter, serum growth hormone, insulin growth factor-I (IGF-I), thyroid hormones, catecholamines, total nitrate, ICAM and antioxidant capacity. A homogenous cardiac hypertrophy was evidenced by increased HW/BW, LVW/BW ratios and cardiomyocyte diameter in the two groups of exercise-trained compared with control rats. Rats of ET group had higher growth hormone. Those of NSET group developed higher IGF-I and total antioxidant capacity, as well as lower serum thyroxin level. Simultaneous NS supplementation to an exercise training program preserves and augments exercise-induced physiological cardiac hypertrophy with step-forward adaptive signs of increased IGF-I and reduced thyroxin level, and with an added advantage of elevation of total serum antioxidant capacity. Thus, the novel model of NSET-induced cardiac hypertrophy might be introduced as a new therapeutic strategy for the treatment of heart failure with superior advantages to exercise training alone.

Plasma cytokine and exertional responses in relation to exercise intensity and volume of exercising muscle mass during arm-crank ergometry

This original study investigated the effect of submaximal exercise intensity and volume of contracting muscle mass on plasma inflammation-mediating cytokine and perceived exertional responses to acute arm-crank ergometry (ACE). Twelve recreationally active but upper limb untrained males performed 30 min of (i) low-intensity (40% peak oxygen uptake) ACE (LOW); (ii) moderate-intensity (60% peak oxygen uptake) ACE (MOD); and (iii) concurrent low-intensity (40% peak oxygen uptake) ACE plus lower limb cycle ergometry to match total power output in MOD (HYB). Plasma concentrations of interleukin (IL)-6, IL-10, IL-1ra, adrenaline, and cortisol were determined at rest, immediately postexercise, and 1 h and 2 h postexercise. Heart rate (HR) and differentiated ratings of perceived exertion (RPE) were also recorded. Plasma IL-6 concentrations were elevated (p < 0.05) immediately postexercise and 1 h postexercise (∼ 2.5-fold) in all trials and 2 h postexercise in MOD (3-fold). Plasma IL-1ra concentrations were elevated (p < 0.05) 2 h postexercise in MOD only (2-fold). No plasma IL-10, cortisol, and adrenaline responses were observed. HR and differentiated RPE were significantly higher during MOD than HYB and LOW. Peripheral RPE were significantly higher than central and overall RPE in each trial. Thirty minutes of moderate intensity ACE initiated a plasma cytokine response associated with the protective effect of regular exercise against cardiovascular and metabolic disease risk. Further work is required to establish an optimal intensity and duration of upper limb exercise to maximise the anti-inflammatory potential whilst managing the risk of over-use injury.

[Reduction of exercise-mediated endothelial dysfunction markers in sedentary adults with chronic spinal cord injury]

BACKGROUND AND OBJECTIVE

Recent studies have found increased markers of endothelial activation in men with chronic spinal cord injury. This study was conducted to determine the effects of arm-cranking exercise on endothelial dysfunction in male adults with chronic SCI.

METHOD

A prospective randomized study of 17 sedentary adult males with chronic SCI at or under T5 level. Nine performed a supervised exercise program at a moderate intensity (arm-cranking: 12 weeks, 3 sessions/week). Plasma levels of endothelin-1, soluble intercellular adhesion molecule type 1 (sICAM-1), and soluble vascular adhesion molecule type 1 (sVCAM-1) were assessed by ELISA. Outcome measurements also included physical fitness and total body fat mass percentage.

RESULTS

We observed both in the randomized and in the before-after studies a significant reduction of the levels of endothelin-1 and sICAM-1. Furthermore, significant improvements of both physical fitness and body composition were also found.

CONCLUSION

Arm-cranking exercise improved endothelial dysfunction in adult males with chronic SCI. Long-term studies are still required to determine whether the correction of endothelial dysfunction improves the clinical outcomes of adults with chronic SCI.

Exercise for intermittent claudication

BACKGROUND

Exercise programmes are a relatively inexpensive, low-risk option compared with other more invasive therapies for leg pain on walking (intermittent claudication (IC)). This is an update of a review first published in 1998.

OBJECTIVES

The prime objective of this review was to determine whether an exercise programme in people with intermittent claudication was effective in alleviating symptoms and increasing walking treadmill distances and walking times. Secondary objectives were to determine whether exercise was effective in preventing deterioration of underlying disease, reducing cardiovascular events and improving quality of life.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched September 2013) and CENTRAL (2013, Issue 8).

SELECTION CRITERIA

Randomised controlled trials of an exercise regimen versus control or versus medical therapy in people with IC due to peripheral arterial disease. Any exercise programme or regimen used in the treatment of intermittent claudication was included, such as walking, skipping and running. Inclusion of trials was not affected by the duration, frequency or intensity of the exercise programme. Outcome measures collected included treadmill walking distance (time to onset of pain or pain-free walking distance and maximum walking time or maximal walking distance), ankle brachial index (ABI), quality of life, morbidity or amputation; if none of these were reported the trial was not included in this review.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality.

MAIN RESULTS

Eleven additional studies were included in this update making a total of 30 trials which met the inclusion criteria, involving a total of 1816 participants with stable leg pain. The follow-up period ranged from two weeks to two years. The types of exercise varied from strength training to polestriding and upper or lower limb exercises; generally supervised sessions were at least twice a week. Most trials used a treadmill walking test for one of the outcome measures. Quality of the included trials was moderate, mainly due to an absence of relevant information. The majority of trials were small with 20 to 49 participants. Twenty trials compared exercise with usual care or placebo, the remainder of the trials compared exercise to medication (pentoxifylline, iloprost, antiplatelet agents and vitamin E) or pneumatic calf compression; people with various medical conditions or other pre-existing limitations to their exercise capacity were generally excluded.Overall, when taking the first time point reported in each of the studies, exercise significantly improved maximal walking time when compared with usual care or placebo: mean difference (MD) 4.51 minutes (95% confidence interval (CI) 3.11 to 5.92) with an overall improvement in walking ability of approximately 50% to 200%. Walking distances were also significantly improved: pain-free walking distance MD 82.29 metres (95% CI 71.86 to 92.72) and maximum walking distance MD 108.99 metres (95% CI 38.20 to 179.78). Improvements were seen for up to two years, and subgroup analyses were performed at three, six and 12 months where possible. Exercise did not improve the ABI (MD 0.05, 95% CI 0.00 to 0.09). The effect of exercise, when compared with placebo or usual care, was inconclusive on mortality, amputation and peak exercise calf blood flow due to limited data. No data were given on non-fatal cardiovascular events.Quality of life measured using the Short Form (SF)-36 was reported at three and six months. At three months, physical function, vitality and role physical all significantly improved with exercise, however this was a limited finding as this measure was only reported in two trials. At six months five trials reported outcomes of a significantly improved physical summary score and mental summary score secondary to exercise. Only two trials reported improvements in other domains, physical function and general health.Evidence was generally limited for exercise compared with antiplatelet therapy, pentoxifylline, iloprost, vitamin E and pneumatic foot and calf compression due to small numbers of trials and participants.

AUTHORS' CONCLUSIONS

Exercise programmes are of significant benefit compared with placebo or usual care in improving walking time and distance in people with leg pain from IC who were considered to be fit for exercise intervention.

Modes of exercise training for intermittent claudication

BACKGROUND

According to international guidelines and literature, all patients with intermittent claudication should receive an initial treatment of cardiovascular risk modification, lifestyle coaching, and supervised exercise therapy. In most studies, supervised exercise therapy consists of treadmill or track walking. However, alternative modes of exercise therapy have been described and yielded similar results to walking. Therefore, the following question remains: Which exercise mode gives the most beneficial results?

PRIMARY OBJECTIVE

To assess the effects of different modes of supervised exercise therapy on the maximum walking distance (MWD) of patients with intermittent claudication.

SECONDARY OBJECTIVES

To assess the effects of different modes of supervised exercise therapy on pain-free walking distance (PFWD) and health-related quality of life scores (HR-QoL) of patients with intermittent claudication.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Cochrane Peripheral Vascular Diseases Group Specialised Register (July 2013); CENTRAL (2013, Issue 6), in The Cochrane Lib rary; and clinical trials databases. The authors searched the MEDLINE (1946 to July 2013) and Embase (1973 to July 2013) databases and reviewed the reference lists of identified articles to detect other relevant citations.

SELECTION CRITERIA

Randomised controlled trials of studies comparing alternative modes of exercise training or combinations of exercise modes with a control group of supervised walking exercise in patients with clinically determined intermittent claudication. The supervised walking programme needed to be supervised at least twice a week for a consecutive six weeks of training.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies, extracted data, and assessed the risk of bias for each study. Because of different treadmill test protocols to assess the maximum or pain-free walking distance, we converted all distances or walking times to total metabolic equivalents (METs) using the American College of Sports Medicine (ACSM) walking equation.

MAIN RESULTS

In this review, we included a total of five studies comparing supervised walking exercise and alternative modes of exercise. The alternative modes of exercise therapy included cycling, strength training, and upper-arm ergometry. The studies represented a sample size of 135 participants with a low risk of bias. Overall, there was no clear evidence of a difference between supervised walking exercise and alternative modes of exercise in maximum walking distance (8.15 METs, 95% confidence interval (CI) -2.63 to 18.94, P = 0.14, equivalent of an increase of 173 metres, 95% CI -56 to 401) on a treadmill with no incline and an average speed of 3.2 km/h, which is comparable with walking in daily life.Similarly, there was no clear evidence of a difference between supervised walking exercise and alternative modes of exercise in pain-free walking distance (6.42 METs, 95% CI -1.52 to 14.36, P = 0.11, equivalent of an increase of 136 metres, 95% CI -32 to 304). Sensitivity analysis did not alter the results significantly. Quality of life measures showed significant improvements in both groups; however, because of skewed data and the very small sample size of the studies, we did not perform a meta-analysis for health-related quality of life and functional impairment.

AUTHORS' CONCLUSIONS

There was no clear evidence of differences between supervised walking exercise and alternative exercise modes in improving the maximum and pain-free walking distance of patients with intermittent claudication. More studies with larger sample sizes are needed to make meaningful comparisons between each alternative exercise mode and the current standard of supervised treadmill walking. The results indicate that alternative exercise modes may be useful when supervised walking exercise is not an option for the patient.

The effect of physical activity or exercise on key biomarkers in atherosclerosis--a systematic review

OBJECTIVE

This systematic review aimed to summarize published papers on the effect of physical activity (PA)/exercise on key atherosclerotic factors in patients with risk factors for or established cardiovascular disease (CVD).

METHODS

Studies involving PA and cytokines, chemokines, adhesion molecules, CRP and angiogenic factors were searched for in Medline and Cochrane library. Original human studies of more than 2 weeks of PA intervention were included. Study quality was assessed according to the GRADE system of evidence.

RESULTS

Twenty-eight papers fulfilled the inclusion criteria. PA decreases the cytokines, tumor necrosis factor-a (TNF-a), interleukin-6 (IL-6), and interferon-y IFN-y (high, moderate and low evidence, respectively). The effect of PA on chemokines; stromal derived factor-1 (SDF-1), interleukin-8 (IL-8) (insufficient evidence) and monocyte chemoattractant protein-1 (MCP-1) (low evidence) was inconclusive. Aerobic exercise decreased the adhesion molecules, vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) (moderate and high evidence, respectively), while effects of PA on E- and P-selectin were inconclusive. PA decreases C-reactive protein (CRP) (high evidence). The angiogenic actors, endothelial progenitor cells (EPCs) are increased (high evidence) and VEGF is decreased (moderate evidence) by PA. The effect of PA on these factors seems to depend on the type and duration of exercise intervention and patient factors, such as presence of ischemia.

CONCLUSION

As presented in this review, there is a high level of evidence that physical activity positively affects key players in atherosclerosis development. These effects could partly explain the scientifically proven anti-atherogenic effects of PA, and do have important clinical implications.

Carotid inflammation is unaltered by exercise in hypercholesterolemic Swine

INTRODUCTION

Reduction of vascular inflammation might contribute to the beneficial effects of exercise. We hypothesized that 1) exercise would reduce carotid endothelial vascular cell adhesion molecule-1 (VCAM-1) and that 2) in vivo detection of carotid inflammation can be achieved in a large animal model using contrast-enhanced ultrasound (CEU) with VCAM-1-targeted microbubbles (MBs).

METHODS

Familial hypercholesterolemic (FH) swine were divided into sedentary (Sed) and exercise-trained (Ex) groups. Ex pigs underwent 16-20 wk of treadmill aerobic exercise. At the end of the study, in vivo CEU with VCAM-1-targeted MBs and assessment of endothelial-dependent dilation (EDD) were performed in carotid arteries. VCAM-1 mRNA and protein expression were compared with markers of atherosclerotic disease and health, and in vitro EDD was assessed in carotid arteries.

RESULTS

Exercise training neither reduced inflammation nor improved EDD in carotid arteries of FH swine. Markers of atherosclerosis including VCAM-1 were prominent in the bifurcation compared with the proximal or distal common carotid artery and inversely associated with phosphorylated and total endothelial nitric oxide synthase. Signal intensity from VCAM-1-to-control MBs positively correlated with carotid VCAM-1 protein expression, validating our technique.

CONCLUSION

These results first demonstrate that aerobic exercise has no effect on carotid endothelial inflammatory markers and EDD in FH swine. Second, our findings indicate that CEU using VCAM-1-targeted MBs can detect inflammation in vivo, providing strong foundations for longitudinal studies examining the effect of therapeutic interventions on the inflammatory status of the endothelium.

Exercise interventions for patients with peripheral arterial disease: a review of the literature

Peripheral arterial disease (PAD) is a common chronic cardiovascular condition that affects the lower extremities and can substantially limit daily activities and quality of life. Lifestyle interventions, including smoking cessation, diet modification, regular physical activity, and pharmacotherapy, are often prescribed to treat patients with PAD. Exercise interventions can be effective in increasing claudication onset time and maximal walking distance. Of the various types of exercise interventions available for patients with PAD, little is known about the differences that may exist between men and women in patient response to such interventions. The purpose of this literature review is to examine the current knowledge of exercise interventions for individuals with mild (Fontaine stages I-II) PAD and to consider any differences that may exist between men and women. Women with PAD present with a different clinical profile compared with men, but respond similarly to an acute bout of exercise and a training program. Patients with PAD should be encouraged to walk regularly; however, more research is needed to determine differences between men and women in their response to various exercise interventions.

Supervised Exercise Training Reduces Plasma Levels of the Endothelial Inflammatory Markers E-Selectin and ICAM-1 in Patients With Peripheral Arterial Disease

Elevated plasma levels of vascular inflammatory markers have been reported in patients with peripheral arterial disease (PAD). We assessed the effect of supervised exercise training (ET) on vascular inflammation, hypothesizing that ET reduces plasma levels of the endothelial adhesion molecules E-selectin, intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1). Twenty-nine patients with PAD underwent a supervised ET program for 8 weeks. Before and after ET, walking distances (pain-free, PWD; maximal, MWD) were determined by a standard treadmill test. Plasma levels of E-selectin and ICAM-1 were significantly reduced (E-selectin: 45.5-40.4 ng/mL, P = .013); ICAM-1: 342.0-298.0 ng/mL, P = .016). VCAM-1 levels were unchanged. Walking distances increased significantly (PWD: median 77-150 m, P < .001; MWD: median 306-535 m, P < .001). In conclusion, 8 weeks of ET in patients with PAD reduces plasma levels of the specific endothelium-derived inflammatory markers E-selectin and ICAM-1.

Resistance exercise training-induced muscle hypertrophy was associated with reduction of inflammatory markers in elderly women

Aging is associated with low-grade inflammation. The benefits of regular exercise for the elderly are well established, whereas less is known about the impact of low-intensity resistance exercise on low-grade inflammation in the elderly. Twenty-one elderly women (mean age ± SD, 85.0 ± 4.5 years) participated in 12 weeks of resistance exercise training. Muscle thickness and circulating levels of C-reactive protein (CRP), serum amyloid A (SAA), heat shock protein (HSP)70, tumor necrosis factor (TNF)-α, interleukin (IL)-1, IL-6, monocyte chemotactic protein (MCP-1), insulin, insulin-like growth factor (IGF)-I, and vascular endothelial growth factor (VEGF) were measured before and after the exercise training. Training reduced the circulating levels of CRP, SAA (P < .05), HSP70, IGF-I, and insulin (P < .01). The training-induced reductions in CRP and TNF-α were significantly (P < .01, P < .05) associated with increased muscle thickness (r = −0.61, r = −0.54), respectively. None of the results were significant after applying a Bonferroni correction. Resistance training may assist in maintaining or improving muscle volume and reducing low-grade inflammation.

Limb-specific and cross-transfer effects of arm-crank exercise training in patients with symptomatic peripheral arterial disease

Arm cranking is a useful alternative exercise modality for improving walking performance in patients with intermittent claudication; however, the mechanisms of such an improvement are poorly understood. The main aim of the present study was to investigate the effects of arm-crank exercise training on lower-limb O2 delivery in patients with intermittent claudication. A total of 57 patients with intermittent claudication (age, 70±8 years; mean±S.D.) were randomized to an arm-crank exercise group or a non-exercise control group. The exercise group trained twice weekly for 12 weeks. At baseline and 12 weeks, patients completed incremental tests to maximum exercise tolerance on both an arm-crank ergometer and a treadmill. Respiratory variables were measured breath-by-breath to determine peak V̇O2 (O2 uptake) and ventilatory threshold. Near-IR spectroscopy was used in the treadmill test to determine changes in calf muscle StO2 (tissue O2 saturation). Patients also completed a square-wave treadmill-walking protocol to determine V̇O2 kinetics. A total of 51 patients completed the study. In the exercise group, higher maximum walking distances (from 496±250 to 661±324 m) and peak V̇O2 values (from 17.2±2.7 to 18.2±3.4 ml·kg−1 of body mass·min−1) were recorded in the incremental treadmill test (P<0.05). After training, there was also an increase in time to minimum StO2 (from 268±305 s to 410±366 s), a speeding of V̇O2 kinetics (from 44.7±10.4 to 41.3±14.4 s) and an increase in submaximal StO2 during treadmill walking (P<0.05). There were no significant changes in the control group. The results suggest that the improvement in walking performance after arm-crank exercise training in patients with intermittent claudication is attributable, at least in part, to improved lower-limb O2 delivery.