The effect of physical activity interventions on cognition function in patients with diabetes: A systematic review and meta-analysis

Background In recent years, studies have revealed that cognition may be impaired by glucose metabolism disorder. Meanwhile, physical activity has been demonstrated to maintain blood glucose. This meta-analysis was conducted to assess the effect of physical activity on cognition in patients with diabetes and provide evidence for the treatment of cognition impairment among them. Methods We searched studies published in five databases from 1 January 1984 to 29 August 2020. A random-effect or fixed-effect meta-analysis was used to estimate the pooled effect of physical activity on the change of cognition throughout intervention duration and post-intervention cognition scores by standardized mean difference (SMD) and its 95% confidence interval (CI). We used funnel plots to evaluate the publication bias, I-2 statistic to evaluate the heterogeneity and did subgroup analysis stratified by sample size and follow-up time. Results Five eligible studies involving 2581 patients with diabetes were included. The pooled effect of physical activity on cognition improvement in patients with diabetes was significant (SMD = 0.98, 95% CI: 0.34-1.62), while the effect on post-intervention cognition scores was not significant (SMD = 0.35, 95% CI: -0.04-0.73). In the subgroup analysis, the pooled effect was significantly higher in studies of follow-up time less than 1 year (SMD = 2.14, 95% CI: 1.63-2.64), while observing no significant effect in studies of follow-up time over 1 year (SMD = 0.10, 95% CI: -0.11-0.32). Conclusions Physical activity is beneficial to improving cognition in patients with diabetes. However, the long-term effect needs to be explored in future studies.