Cognitive function and exercise training for chronic renal disease patients: A literature review

Objective Cognitive impairment is very often noted in patients with Chronic Kidney Disease (CKD). Even though, exercise is considered to be a quantifiable activity that improves cognition in animals and humans, it seems that few studies have examined the relationship between cognitive function and CKD from the perspective of physical activity and cognitive performance. Thus, this evidence based review summarizes the present level of knowledge regarding the effects of exercise training on cognitive function in CKD patients. Data sources A comprehensive literature search was conducted in PubMed and Scopus from May 2014 through June 2014, by using the Cochrane and PRISMA guidelines. Review methods Eligibility of the studies based on titles, abstracts and full-text articles was determined by two reviewers. Studies were selected using inclusion and exclusion criteria. We included only those studies that: assessed cognitive function in humans and animals using validated neuropsychological methods in chronic renal diseases patients; used exercise training protocols; addressed randomized control trials or controlled trials or clinical trials designed to evaluate cognitive impairment; and articles that were written in English. Studies were excluded when they concerned behavioral approaches and underpowered studies. Results According to the current review only a few studies have examined the issue of cognitive function in CKD patients. These studies indicate that these patients often exhibit cognitive impairment, which is highly associated with poor outcomes. It has been supported that exercise training can induce positive changes in brain metabolism favoring better scores in cognitive function in Chronic Kidney Disease patients although the physiological mechanisms, which explain the influence of physical activity on cognition, have focused on changes in neurotransmitters, neurotrophins and vasculature. Conclusion Systematic exercise training seems to improve cognitive function in Chronic Kidney Disease patients but further research is warranted to further clarify the mechanisms involved