Belinda J. Parmenter

The Effect of Exercise on Haemodynamics in Intermittent Claudication A Systematic Review of Randomized Controlled Trials

Changes in lower limb haemodynamics such as arterial pressure and/or flow have often been, and continue to be, cited as possible mechanisms for the improvement in walking performance that occurs with exercise training in individuals with peripheral arterial disease (PAD), but data are conflicting in this regard. There are a small number of literature reviews examining the effects of exercise on PAD, however, there has been insufficient analysis synthesizing possible mechanisms of effect, overall benefits and limitations of these trials. Our objective was therefore to systematically review the evidence for the effect of exercise on lower limb haemodynamic measures of resting and post-exercise ankle brachial index (ABI), resting toe pressure, and resting and reactive hyperaemic calf blood flow in PAD. A systematic search of studies published between 1934 and March 2010 was conducted using MEDLINE, EMBASE, AMED, SportDiscus®, CINAHL®, PEDro, Premedline, Google Scholar and Web of Knowledge databases. Eligible studies included randomized controlled trials using an exercise intervention for the treatment of intermittent claudication with haemodynamic measures of disease severity as outcomes. Relative effect sizes (ESs) and 95% confidence intervals were calculated for outcomes. Correlation and regression analyses were performed to establish relationships between symptoms and haemodynamic outcomes. Thirty-three trials including 1237 subjects with mild to moderate claudication met the eligibility criteria. Exercise did not significantly change lower extremity haemodynamics in most trials; nor were clinical improvements related to changes in resting ABI (mean ES 0.09 ± 0.26; r = 0.02; p = 0.94), post-exercise ABI (mean ES 0.18 ± 0.3; r=-0.33; p = 0.52) or reactive hyperaemic calf blood flow (mean ES 0.38±0.67; r = 0.35; p = 0.26).A relationship may exist between a change in symptoms and changes in resting toe pressure (mean ES 0.22±0.22; r = 0.75; p = 0.25) and resting calf blood flow (mean ES 0.09±0.16; r = 0.59; p = 0.22). Changes in resting and post-exercise ABI and reactive hyperaemic calf blood flow do not appear to explain the clinical benefits of exercise in PAD. More study is required in the areas of resting toe pressure and resting calf blood flow.

Exercise training for health-related quality of life in peripheral artery disease: A systematic review and meta-analysis

We sought to quantify whether health-related quality of life (HRQoL) is improved through exercise training in people with peripheral artery disease (PAD) and to clarify which prescriptions were optimal for improving HRQoL when compared to usual care. We conducted a systematic search (PubMed, CINAHL, Cochrane Central Register of Controlled Trials; 1966 – 31 August 2014). We only included randomized controlled trials (RCTs) of exercise training versus usual medical care in persons with PAD that included the Walking Impairment Questionnaire (WIQ) and Short-Form Health Survey component summary scores as outcomes. Of 15 RCTs, 1257 participants were studied: 543 participated in supervised exercise, with only 61 undertaking resistance training and 316 unsupervised exercise. When compared to controls, participants who completed any form of exercise training significantly improved their WIQ speed [mean difference (MD) 9.60 (95% CI 6.98 to 12.23, p<0.00001)]; WIQ distance [MD 7.41 (95% CI 4.49 to 10.33, p<0.00001)] and WIQ stair-climbing [MD 5.07 (95% CI 3.16 to 6.99, p<0.00001)]. Walking also significantly improved the Short-Form Physical Component Summary (SF-PCS) score when compared to controls [MD 1.24 (95% CI 0.48 to 2.01, p=0.001)], but not the Mental Component Summary (SF-MCS) score [MD –0.55 (95% CI –1.27 to 0.18, p=0.14)]. Exercise training improves the SF-PCS dimension, as well as perceived walking distance, speed and stair-climbing as measured by the WIQ, but not the SF-MCS score. Future studies should aim to blind assessors of such subjective measures, and study alternative modes and prescriptions of exercise alternative to walking.

High-Intensity Progressive Resistance Training Improves Flat-Ground Walking in Older Adults with Symptomatic Peripheral Arterial Disease

To assess the efficacy of whole‐body progressive resistance training (PRT) as a treatment for the symptoms of peripheral arterial disease (PAD) in older adults.

Exercise & Sports Science Australia (ESSA) position statement on exercise prescription for patients with peripheral arterial disease and intermittent claudication

OBJECTIVES Peripheral arterial disease (PAD) is characterised by atherosclerotic stenosis or occlusion of the arteries of the lower limbs, resulting in an impairment of blood flow to the legs. Patients with PAD have a significant reduction in their physical capacity and are limited during activities such as walking by intermittent claudication. DESIGN Position stand. METHODS Synthesis of published work within the field of exercise training and peripheral arterial disease. RESULTS Supervised exercise training is considered the most effective treatment for increasing exercise tolerance in patients with PAD, and is also associated with improvements in daily physical activity and quality of life, and a reduction is cardiovascular disease risk. Exercise should be prescribed and progressed for patients individually, taking into consideration their disease severity, exercise tolerance and relevant comorbidities. CONCLUSIONS While walking programs are beneficial and frequently prescribed, other forms of aerobic exercise such as cycling or arm-cranking may also be incorporated as tolerated by patients. Forty minutes of accumulated aerobic activity, three times per week, is recommended for most patients. Patients should be encouraged to commence exercise at a moderate intensity, and should stop and rest if claudication pain becomes severe. Resistance training should also be included on at least two days per week with the goal of improving muscular strength and endurance. Comorbidities such as musculoskeletal complaints, hypertension, diabetes and peripheral neuropathy are common in patients with PAD and may exacerbate their functional limitations. Given the high cardiovascular risk associated with PAD, it is important that patients are appropriately monitored during exercise.

Preliminary evidence that low ankle-brachial index is associated with reduced bilateral hip extensor strength and functional mobility in peripheral arterial disease

OBJECTIVE Peripheral arterial disease (PAD) has been associated with skeletal muscle pathology, including atrophy of the affected muscles. In addition, oxidative metabolism is impaired, muscle function is reduced, and gait and mobility are restricted. We hypothesized that greater severity of symptomatic PAD would be associated with lower levels of muscle mass, strength, and endurance, and that these musculoskeletal abnormalities in turn would impair functional performance and walking ability in patients with PAD. METHODS We assessed 22 persons with intermittent claudication from PAD in this cross-sectional pilot study. Outcome assessments included initial claudication distance and absolute claudication distance via treadmill protocols and outcomes from the 6-minute walk (6MW). Secondary outcomes included one repetition maximum strength/endurance testing of hip extensors, hip abductors, quadriceps, hamstrings, plantar flexors, pectoral, and upper back muscle groups, as well as performance-based tests of function. Univariate and stepwise multiple regression models were constructed to evaluate relationships and are presented. RESULTS Twenty-two participants (63.6% male; mean [standard deviation] age, 73.6 [8.2] years; range, 55-85 years) were studied. Mean (standard deviation) resting ankle-brachial index (ABI) was 0.54 ([0.13]; range, 0.28-0.82), and participants ranged from having mild claudication to rest pain. Lower resting ABI was significantly associated with reduced bilateral hip extensor strength (r = 0.54; P = .007) and reduced whole body strength (r = 0.32; P = .05). In addition, lower ABI was associated with a shorter distance to first stop during the 6MW (r = 0.38; P = .05) and poorer single leg balance (r = 0.44; P = .03). Reduced bilateral hip extensor strength was also significantly associated with functional outcomes, including reduced 6MW distance to first stop (r = 0.74; P = .001), reduced 6MW distance (r = 0.75; P < .001), and reduced total short physical performance battery score (worse function; r = 0.75; P = .003). CONCLUSIONS Our results suggest the existence of a causal pathway from a reduction in ABI to muscle atrophy and weakness, to whole body disability represented by claudication outcomes and performance-based tests of functional mobility in an older cohort with symptomatic PAD. Longitudinal outcomes from this study and future trials are required to investigate the effects of an anabolic intervention targeting the muscles involved in mobility and activities of daily living and whether an increase in muscle strength will improve symptoms of claudication and lead to improvements in other functional outcomes in patients with PAD.

Accuracy of step count measured by physical activity monitors: the effect of gait speed and anatomical placement site.

INTRODUCTION Consumer-based physical activity monitors (PAMs) are becoming increasingly popular, with multiple global organisations recommending physical activity levels that equate to 10,000 steps per day for optimal health. We therefore aimed to compare the step count of five PAMs to a visual step count to identify the most accurate monitors at varying gait speeds, along with the optimal anatomical placement site. METHODS Participants completed 3min on a treadmill for five speeds (5.0km/h, 6.5km/h, 8.0km/h, 10km/h, 12km/h). An Actigraph wGT3XBT-BT was placed on the waist and wrist, a FitBit One on the waist, and a Fitbit Flex, Fitbit Charge HR and Jawbone UP24 on both wrists. A video of participants lower limbs was recorded for visual count. Analyses of variance (ANOVAs) were conducted to examine the effects of gait speed and device placement site on step count accuracy. RESULTS Thirty-one participants (mean age 24.3±5.2yrs) took part. Step count error ranged from 41.3±13.8% for the wrist-worn Actigraph to only 0.04±4.3% and -0.3±4.0% for the waist-worn Fitbit One and Actigraph, respectively. Across all gait speeds, waist-worn devices achieved better accuracy than those on the wrist (p<0.001). The Jawbone was the most accurate wrist-worn consumer-based device at slower speeds (p=0.026), with the Fitbit Flex, and Fitbit Charge HR increasing in accuracy to match the Jawbone at higher speeds. CONCLUSION The accuracy and reliability of consumer-based PAMs and the Actigraph is affected by anatomical placement site and walking speed. The Fitbit One and Actigraph on the waist were the strongest performers across all speeds.

Interventions to improve fundamental motor skills in pre-school aged children: A systematic review and meta-analysis

OBJECTIVES Mastery in -fundamental motor skills (FMS) is associated with increased physical activity (PA) in school-aged children; however, there is limited research on pre-schoolers (3-5 years). We aimed to evaluate interventions for improving FMS as well as PA. DESIGN/METHODS A search of electronic databases was conducted for controlled trials using PA interventions with FMS as outcomes in healthy pre-schoolers. Standardised mean difference (SMD), 95% confidence intervals and publication bias were calculated for each outcome using Revman 5.3. RESULTS Twenty trials met inclusion criteria. In total, 4255 pre-schoolers were analysed with 854 completing a FMS intervention. Studies were categorised into three groups (i) Teacher-Led (TL)(n=13); (ii) Child-Centred (CC)(n=6) and (iii) Parent-Led (PL)(n=1). Mean age was 4.3±0.4 years, with equal gender distribution. Interventions ran for 21±17 weeks, 3±1 times per week for 35±17 minutes. TL interventions significantly improved overall FMS (SMD=0.14[0.06, 0.21]; p=0.0003), object control (SMD=0.47[0.15, 0.80]; p= 0.004), and locomotor skills (SMD=0.44[0.16, 0.73]; p=0.002), whereas CC interventions were not significant. There was a small, non-significant reduction in sedentary time (SMD=-0.35[-0.80, 0.10]; p= 0.12), and a large non-significant increase in PA (SMD=0.79[-0.83, 2.41]; p=0.34). CONCLUSION PA interventions improve FMS in pre-schoolers; however, due to limited research, more study is needed on CC interventions. Targeting FMS development in pre-schoolers may promote higher PA levels and reduce sedentary time, however more study is needed.

Cardiac Rehabilitation for Patients With Coronary Artery Disease: A Practical Guide to Enhance Patient Outcomes Through Continuity of Care

Coronary artery disease (CAD) is a leading cause of disease burden worldwide. Referral to cardiac rehabilitation (CR) is a class I recommendation for all patients with CAD based on findings that participation can reduce cardiovascular and all-cause mortality, as well as improve functional capacity and quality of life. However, programme uptake remains low, systematic progression through the traditional CR phases is often lacking, and communication between health care providers is frequently suboptimal, resulting in fragmented care. Only 30% to 50% of eligible patients are typically referred to outpatient CR and fewer still complete the programme. In contemporary models of CR, patients are no longer treated by a single practitioner, but rather by an array of health professionals, across multiples specialities and health care settings. The risk of fragmented care in CR may be great, and a concerted approach is required to achieve continuity and optimise patient outcomes. ‘Continuity of care’ has been described as the delivery of services in a coherent, logical, and timely fashion and which entails 3 specific domains: informational, management, and relational continuity. This is examined in the context of CR.

Study Protocol: The Effect of a Fundamental Motor Skills Intervention in a Preschool Setting on Fundamental Motor Skills and Physical Activity: A Cluster Randomised Controlled Trial

Fundamental motor skills (FMS) are the building blocks to specialist movements that are used throughout one’s life in all forms of physical activity (PA) and sports involvement. FMS are acquired through a combination of active play and structured exercise programs. The preschool years have been identified as the critical time to develop FMS Active children experience health benefits such as decreased systolic blood pressure, depressive symptoms, weight gain, and improved concentration, academic performance and bone mineral density. Links have been identified between FMS proficiency and increased PA levels. This study aims to develop and deliver a structured FMS program for preschool aged children (age 3-5 years) in a childcare setting and determine whether it is associated with a change in PA levels and anthropometric measures. A randomized cluster control design will be employed. PLAYFun is a 12-week, games based FMS program aimed to provide children with the chance to learn, practice and develop their FMS within a preschool setting. Participants will be recruited from 4 childcare centres and will be eligible if they are aged 3-5 years and do not have developmental delay/chronic conditions that inhibit participation in PA. Centres will be randomized using concealed allocation. The control group will continue to receive usual childcare play activities while the intervention group will receive a supervised FMS intervention 2-5 sessions/week for 30 minutes duration in addition to usual childcare activities. Outcome measures will be measured pre-, post and 12-weeks post intervention. Intention to treat analysis will be used and effects on the primary outcomes will be calculated by difference between mean group scores accounting for baseline scores. The authors believe the childcare setting may provide the ideal environment to emphasize the development of movement patterns that will be used throughout life and potentially enhance participation in physical activity.

Authors' Reply to Li et al.: "Alternative Statistical Analysis Shows Exercise Training-Induced Improvements in Peak VO2 are Clinically Significant".

We thank Dr. Li et al. [1] for their commentary on our recently published meta-analysis in Sports Medicine [2]. While there is no doubt that there is an argument for the use of a random-effects model in the presence of significant heterogeneity [3], such a model can introduce inherent problems of its own. Our fixed-effects model for our primary peak VO2 analysis yielded a mean difference (MD) of 0.62 mL kg min and a 95 % confidence interval (CI) of 0.47–0.77. One can observe how narrow the 95 % CI is. While the random-effects analysis of Li et al. [1] produced a larger MD of 1.31 mL kg min, the 95 % CI of 0.94–1.69 was much wider—almost triple the width of our 95 % CI. This 95 % CI width suggests much larger variation in how patients responded to exercise training. While we acknowledge the CIs do not overlap in these two analyses, one should note that in the analysis of Li et al. [1] at least 5 %, and more likely 10 %, of patients still do not achieve a clinically significant benefit of [1 mL kg min improvement. One needs to be mindful of this and we therefore chose to take a more conservative approach, which we believe was supported by the Sports Medicine reviewers’ request for us to state the absolute improvements in peak VO2 in L min. While we agree the misuse of fixed-effects models can lead to devastating impacts on clinical practice, noting the rosiglitazone example given by Li et al. [1], in our case the approach taken was conservative. Point estimates, in this case MD, do not convey the complete message and CIs reveal more about the response in all participants, not just those close to the mean or median. In turn, we argue that narrow CIs give us exactly that, more confidence in predicting responses in the whole group, while wide CIs render the point estimates less meaningful. In addition, an improvement in peak VO2 of 0.62 mL kg min, rather than an improvement of 1.31 mL kg min, is not going to change one’s risk of death from cardiovascular causes, nor is it going to reduce the use of exercise as a potential prescription for this cohort. In fact, any improvement in peak VO2 is associated with a reduction in cardiovascular mortality in this particular cohort [4]. With regard to the sensitivity analyses, we could argue that removing the study by Crowther et al. [5] from the subanalysis by Li et. al. [1] appears a rather arbitrary choice. The work by Crowther et al. [5] is one of the longest duration studies (52 weeks) and scores 6 for study quality. We would argue this is one of the more robust interventions and perhaps indirectly reflects the 60 % analysis weighting given to this work. Several other studies scored less than 6 for study quality, and are therefore more deserving of removal during sensitivity analyses. For example, we removed Hiatt et al. [6], Hodges et al. [7], and Savage et al. [8] (all scored 5 on quality), with a negligible reduction in effect size for peak VO2. Regarding the vigorous subanalysis, the MD of 1.64 mL kg min (95 % CI 1.11–2.16; p\ 0.00001) reported by Li et al. [1] is not different from our metaanalysis results [MD 1.42 mL kg min (95 % CI 1.04–1.80; p\ 0.00001)] because the 95 % CIs do overlap. Again, we note that the 95 % CIs of Li et al. [1] are wider than ours. Regarding the program length subanalyses, we again note the results for the 12 weeks or fewer group are not B. J. Parmenter Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia