Safety of home-based exercise for people with intermittent claudication:A systematic review

Intermittent claudication (IC) is a classic symptom of peripheral artery disease, with first line treatment being supervised exercise therapy (SET). Despite this, SET is frequently underutilised, and adherence is often poor. An alternative option are home-based exercise programmes (HBEP). Although HBEPs are well tolerated, to the authors’ knowledge, no research has assessed their safety. The aim of this review was to assess the safety of HBEPs in people living with IC. We performed an electronic search of the MEDLINE, CINHAL and Cochrane Library databases. The main parameter of interest was complication rate, calculated as the number of related adverse events per patient-hours. Sub-analysis was undertaken to determine differences in safety for studies that did and did not include pre-exercise cardiac screening, and for studies with exercise at low, moderate and high levels of claudication pain. Our search strategy identified 8693 results, of which 27 studies were included for full review. Studies included 1642 participants completing 147,810 patient-hours of home-based exercise. Four related adverse events were reported, three of which were cardiac in origin, giving an all cause complication rate of one event per 36,953 patient-hours. Three of these events occurred following exercise to high levels of claudication pain, and one occurred with pain-free exercise. All four events occurred in studies without cardiac screening. Based on the low number of related adverse events, HBEPs appear to be a safe method of exercise prescription for people with IC. Our results strengthen the rationale for providing alternative exercise options for this population. PROSPERO registration: CRD4202125458

A Systematic Review of Exercise Prescription in Patients with Intermittent Claudication: Does Pain Matter?

Background: Current guidelines for intermittent claudication advocate exercise at moderate to maximal claudication pain. However, adherence rates to supervised exercise programmes (SEP) remain poor and claudication pain is a contributing factor. Limited evidence suggests that moderate or pain-free exercise may be just as beneficial and may be better tolerated. However, it remains unclear what ‘level’ of claudication pain is optimal for improving functional outcomes. We therefore conducted a systematic review to synthesise the evidence for exercise prescribed at different levels of claudication pain. Methods: The CENTRAL, MEDLINE, Embase and CINAHL databases were searched up to October 2020. Randomized controlled trials (RCTs) that directly compared at least 2 different intensities of claudication pain were included. Outcome measures included walking performance, adherence, quality of life and vascular function. Results: Of 1,543 search results, 2 studies were included. Maximal walking distance improved by 100–128% in the moderate-pain SEP groups, and by 77–90% in the pain-free SEP groups. Importantly, there were no significant differences between the moderate-pain and pain-free SEP groups in either study for improvements in walking performance, though comparison to a maximal-pain SEP group was not made. Conclusions: The efficacy of SEPs for patients with intermittent claudication is irrefutable, though there is no consensus on the optimal level of pain. Therefore, adequately powered RCTs are required to compare the effect of pain-free SEPs, moderate-pain SEPs and maximal-pain SEPs on functional outcomes. (PROSPERO ID: CRD42020213684)

The Evolution of Primate Short-Term Memory.

Short-term memory is implicated in a range of cognitive abilities and is critical for understanding primate cognitive evolution. To investigate the effects of phylogeny, ecology and sociality on short-term memory, we tested the largest and most diverse primate sample to date (421 non-human primates across 41 species) in an experimental delayed-response task. Our results confirm previous findings that longer delays decrease memory performance across species and taxa. Our analyses demonstrate a considerable contribution of phylogeny over ecological and social factors on the distribution of short-term memory performance in primates; closely related species had more similar short-term memory abilities. Overall, individuals in the branch of Hominoidea performed better compared to Cercopithecoidea, who in turn performed above Platyrrhini and Strepsirrhini. Interdependencies between phylogeny and socioecology of a given species presented an obstacle to disentangling the effects of each of these factors on the evolution of short-term memory capacity. However, this study offers an important step forward in understanding the interspecies and individual variation in short-term memory ability by providing the first phylogenetic reconstruction of this trait’s evolutionary history. The dataset constitutes a unique resource for studying the evolution of primate cognition and the role of short-term memory in other cognitive abilities.info:eu-repo/semantics/publishedVersio

The Evolution of Primate Short-Term Memory

Short-term memory is implicated in a range of cognitive abilities and is critical for understanding primate cognitive evolution. To investigate the effects of phylogeny, ecology and sociality on short-term memory, we tested the largest and most diverse primate sample to date (421 non-human primates across 41 species) in an experimental delayed-response task. Our results confirm previous findings that longer delays decrease memory performance across species and taxa. Our analyses demonstrate a considerable contribution of phylogeny over ecological and social factors on the distribution of short-term memory performance in primates; closely related species had more similar short-term memory abilities. Overall, individuals in the branch of Hominoidea performed better compared to Cercopithecoidea, who in turn performed above Platyrrhini and Strepsirrhini. Interdependencies between phylogeny and socioecology of a given species presented an obstacle to disentangling the effects of each of these factors on the evolution of short-term memory capacity. However, this study offers an important step forward in understanding the interspecies and individual variation in short-term memory ability by providing the first phylogenetic reconstruction of this trait’s evolutionary history. The dataset constitutes a unique resource for studying the evolution of primate cognition and the role of short-term memory in other cognitive abilities

Modelling relationships between lichen bioindicators, air quality and climate on a national scale : results from the UK OPAL air survey

Air pollution has many negative effects on the natural environment, from changes in plant growth patterns to loss of ecosystem function. This study uses citizen science to investigate national-scale patterns in the distribution and abundance of selected lichen species on tree trunks and branches, and to relate these to air pollution and climate. Volunteers collected data for nine lichen indicators on 19,334 deciduous trees. Submitted data provided information on species-level patterns, and were used to derive composite lichen indices. Multiple linear regression and ANCOVA were used to model the relationships between lichen response variables on Quercus spp. and pollution, climate and location. The study demonstrated significant relationships between patterns in indicator lichens and levels of N- and S-containing pollutants on trunks and twigs. The derived lichen indices show great potential as a tool to provide information on local, site-specific levels of air quality

Does the level of encouragement affect 6-minute walk test performance in patients with intermittent claudication? A protocol for a randomised multicentre controlled trial

Plain English Summary Why we are undertaking the research: Peripheral artery disease is a common problem where the blood vessels in the leg are narrowed by fatty build-ups. These fatty deposits may restrict blood flow which causes pain during exercise and limits how far people can walk. To assess a patient’s maximal walking distance, clinicians may use a 6-minute walk test whereby patients are asked to walk as far as possible in six minutes. Currently, encouragement is recommended during the test to ensure the patient walks as far as possible. However, the optimal frequency of this encouragement is still debated and may prove an important factor to guarantee the patient performs to the best of their ability. What we aim to do: We plan to run an investigation to assess whether the frequency of encouragement delivered by an exercise professional affects how far a patient can walk during a 6-minute walk test. People with peripheral artery disease will be asked to enrol in a 6-minute walk test every week for six weeks. During each of their six tests they will receive standardised encouragement at either 1-minute or 2-minute intervals. Following all the tests, the two groups will have their average maximal walking distances compared. At the end of the study we hope to gain an insight into how often standardised encouragement should be delivered during a 6- minute walk test. We also hope to be able to inform future guidelines of the best way to conduct this highly utilised test in people with peripheral artery disease

The Effects of Exercise Prescribed at Different Levels of Claudication Pain on Walking Performance in Patients with Intermittent Claudication: A Protocol for a Randomised Controlled Trial

Peripheral artery disease affects over 236 million people globally and the classic symptom is intermittent claudication (IC) which is associated with reduction in physical activity. The evidence that supervised exercise programmes (SEPs) improve pain-free and maximal walking distance is irrefutable. However, adherence rates are low with exercise-related pain cited as a contributing factor. National and international guidelines recommend exercising at a moderate to maximal level of claudication pain to improve walking ability; however, exercising pain-free or at mild claudication pain has been shown to achieve this outcome. There is limited evidence that compares the relative effects of exercise prescribed at different levels of claudication pain. The objective of this study is to directly compare the effects of exercise prescribed at three different levels of claudication pain on walking performance. This study will be a single-centre randomised controlled trial. Based on an power calculation, 51 patients with IC will be allocated to 24 weeks of twice-weekly pain-free (PF), moderate pain (MOD-P) or maximal pain (MAX-P) exercise. The PF group will cease exercise at the onset of claudication (1 on the 0-4 IC rating scale), the MOD-P group will stop once moderate pain is reached (2 on the rating scale) and the MAX-P group will stop once maximal pain is reached (4 on the rating scale). Outcome measures will be assessed at baseline, 12 and 24 weeks adopting an analysis of covariance (ANCOVA) to compare MWD across three time points. The primary outcome for the trial will be change in maximal treadmill walking distance at 12 and 24 weeks. Trial registration number: NCT04370327