The effects of different types of exercises on cognition in older persons with mild cognitive impairment: A systematic review and meta-analysis.

ABSTRACT

PURPOSE: This systematic review with meta-analysis aims to analyze the effects of different types of exercise on cognition, neuroprotective and neuroinflammatory blood markers in older adults with mild cognitive impairment (MCI). METHODS: Relevant studies were identified using PubMED, SPORTDiscuss, Web of Science, Scopus, and PsycInfo databases. Methodological quality assessment of the studies was done with modified Downs and Black checklist. Data obtained from the included studies was analyzed using Comprehensive Meta-Analysis 4.0 software and results were reported using the random effects method. RESULTS: A total of twenty-three studies were identified. The findings were summarized as change in cognitive function after the exercise interventions in general and after each type of exercise. On average, the exercise intervention revealed an effect size (ES) 1.165; 0.741 to 1.589 (95% Confidence Interval (CI); p < 0.001); aerobic exercise ES 1.442; 0.624 to 2.260 (95 %CI); p = 0.001; Multimodal ES 0,856; 0.366 to 1.346 (95 % CI); p = 0.001 and resistance exercise ES 1.229; 0.339 to 2.120 (95 % CI); p = 0.007. In addition, we observed significant small ES -0.475; -0.817 to -0.134 (95 %CI); p = 0.006, I2= 0 %; τ2 = 0 of exercise effects on Tumor Necrosis Factor-α (TNF-α) and non-significant large ES0.952; -0.238 to 2.142 (95 %CI); p = 0.117 on Brain Derived Neurotrophic Factor (BDNF) in persons with MCI. CONCLUSION: The present study revealed the existence of a large positive effect of overall exercise intervention on cognitive function and a small effect on TNF-α in old people with MCI. Additionally, this study demonstrates that aerobic and resistance exercises had similar larger positive effects and were better than multimodal exercise on increasing cognition in older persons with MCI.