Effect of Circuit Class Training for Eight Weeks on Changes in Ratios of F-Trp/BCAAs and Depression in People with Poststroke Depression

Does Exercise Influence Kynurenine/Tryptophan Metabolism and Psychological Outcomes in Persons With Age-Related Diseases? A Systematic Review

Background:

The kynurenine (KYN) pathway has been implicated in many diseases associated with inflammation and aging (“inflammaging”). Targeting the kynurenine pathway to modify disease outcomes has been trialled pharmacologically, but the evidence of non-pharmacological means (ie, exercise) remains unclear.

Objective:

We aim to assess the evidence of the effects of exercise on the kynurenine pathway and psychological outcomes.

Methods:

Under Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines, a systematic literature search was performed in MEDLINE, EMBASE, EMCARE, and the Cochrane Central Registry of Controlled Trials. The main outcomes were changes in kynurenine pathway metabolite levels and psychological outcomes.

Results:

Six studies were analyzed (total n = 379) with exercise demonstrating significant concomitant effects on kynurenine pathway metabolite levels and associated psychological outcomes in domains of somatization, anxiety, and depression.

Conclusion:

Exercise has significant concomitant effect on kynurenine pathway metabolite levels and psychological outcomes. However, clear limitations exist in determining if the changes in the kynurenine pathway can fully explain the changes in psychological outcomes, or whether different diseases and exercise interventions act as confounding factors.

Exercise as a treatment for depression: A meta-analysis

BACKGROUND

This meta-analysis of randomized controlled trials (RCTs) examines the efficacy of physical exercise as treatment for unipolar depression, both as an independent intervention and as an adjunct intervention to antidepressant medication.

METHODS

We searched PsycINFO, EMBASE, MEDLINE, CENTRAL, and Sports Discus for articles published until November 2014. Effect sizes were computed with random effects models. The main outcome was reduction in depressive symptoms or remission.

RESULTS

A total of 23 RCTs and 977 participants were included. Physical exercise had a moderate to large significant effect on depression compared to control conditions (g=-0.68), but the effect was small and not significant at follow-up (g=-0.22). Exercise compared to no intervention yielded a large and significant effect size (g=-1.24), and exercise had a moderate and significant effect compared to usual care (g=-0.48). The effects of exercise when compared to psychological treatments or antidepressant medication were small and not significant (g=-0.22 and g=-0.08, respectively). Exercise as an adjunct to antidepressant medication yielded a moderate effect (g=-0.50) that trended toward significance.

LIMITATIONS

Use of the arms with the largest clinical effect instead of largest dose may have overestimated the effect of exercise.

CONCLUSIONS

Physical exercise is an effective intervention for depression. It also could be a viable adjunct treatment in combination with antidepressants.

Physical fitness training for stroke patients

BACKGROUND

Levels of physical fitness are low after stroke. It is unknown whether improving physical fitness after stroke reduces disability.

OBJECTIVES

To determine whether fitness training after stroke reduces death, dependence, and disability and to assess the effects of training with regard to adverse events, risk factors, physical fitness, mobility, physical function, quality of life, mood, and cognitive function. Interventions to improve cognitive function have attracted increased attention after being identified as the highest rated research priority for life after stroke. Therefore we have added this class of outcomes to this updated review.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched February 2015), the Cochrane Central Register of Controlled Trials (CENTRAL 2015, Issue 1: searched February 2015), MEDLINE (1966 to February 2015), EMBASE (1980 to February 2015), CINAHL (1982 to February 2015), SPORTDiscus (1949 to February 2015), and five additional databases (February 2015). We also searched ongoing trials registers, handsearched relevant journals and conference proceedings, screened reference lists, and contacted experts in the field.

SELECTION CRITERIA

Randomised trials comparing either cardiorespiratory training or resistance training, or both (mixed training), with usual care, no intervention, or a non-exercise intervention in stroke survivors.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed quality and risk of bias, and extracted data. We analysed data using random-effects meta-analyses. Diverse outcome measures limited the intended analyses.

MAIN RESULTS

We included 58 trials, involving 2797 participants, which comprised cardiorespiratory interventions (28 trials, 1408 participants), resistance interventions (13 trials, 432 participants), and mixed training interventions (17 trials, 957 participants). Thirteen deaths occurred before the end of the intervention and a further nine before the end of follow-up. No dependence data were reported. Diverse outcome measures restricted pooling of data. Global indices of disability show moderate improvement after cardiorespiratory training (standardised mean difference (SMD) 0.52, 95% confidence interval (CI) 0.19 to 0.84; P value = 0.002) and by a small amount after mixed training (SMD 0.26, 95% CI 0.04 to 0.49; P value = 0.02); benefits at follow-up (i.e. after training had stopped) were unclear. There were too few data to assess the effects of resistance training.Cardiorespiratory training involving walking improved maximum walking speed (mean difference (MD) 6.71 metres per minute, 95% CI 2.73 to 10.69), preferred gait speed (MD 4.28 metres per minute, 95% CI 1.71 to 6.84), and walking capacity (MD 30.29 metres in six minutes, 95% CI 16.19 to 44.39) at the end of the intervention. Mixed training, involving walking, increased preferred walking speed (MD 4.54 metres per minute, 95% CI 0.95 to 8.14), and walking capacity (MD 41.60 metres per six minutes, 95% CI 25.25 to 57.95). Balance scores improved slightly after mixed training (SMD 0.27, 95% CI 0.07 to 0.47). Some mobility benefits also persisted at the end of follow-up. The variability, quality of the included trials, and lack of data prevents conclusions about other outcomes and limits generalisability of the observed results.

AUTHORS' CONCLUSIONS

Cardiorespiratory training and, to a lesser extent, mixed training reduce disability during or after usual stroke care; this could be mediated by improved mobility and balance. There is sufficient evidence to incorporate cardiorespiratory and mixed training, involving walking, within post-stroke rehabilitation programmes to improve the speed and tolerance of walking; some improvement in balance could also occur. There is insufficient evidence to support the use of resistance training. The effects of training on death and dependence after stroke are still unclear but these outcomes are rarely observed in physical fitness training trials. Cognitive function is under-investigated despite being a key outcome of interest for patients. Further well-designed randomised trials are needed to determine the optimal exercise prescription and identify long-term benefits.