Objective To evaluate the effect of aerobic exercise on cognitive function in people with mild cognitive impairment (MCI). Design Systematic review and meta-analysis of aerobic exercise intervention for cognitive function in older adults with MCI. Data sources PubMed, EMBASE, SinoMed, China National Knowledge Infrastructure (CNKI), Wanfang and Chinese Science and Technology Periodical (VIP) databases from their inception to 31 January 2015, the Cochrane Central Register of Controlled Trials (Cochrane Library, 2015, Issue 3) and the reference lists of all retrieved articles. Eligibility criteria Randomised controlled trials, older adults with MCI, aerobic exercises compared with no specific exercise intervention for global cognitive ability and any specific domains of cognition. Data synthesis Meta-analysis was conducted with RevMan V.5.3 software using the fixed-effect model for the available data without significant heterogeneity, or the random-effect model was used if appropriate. Results 11 studies were identified involving 1497 participants. Meta-analysis showed that aerobic exercise significantly improved global cognitive ability (Mini-Mental State Examination (MMSE) scores: MD=0.98, 95% CI 0.5 to 1.45, p<0.0001; Montreal Cognitive Assessment (MoCA) scores: MD=2.7, 95% CI 1.11 to 4.29, p=0.0009); weakly, positively improve memory (immediately recall: SMD=0.29, 95% CI 0.13 to 0.46, p=0.0005; delay recall: SMD=0.22, 95% CI 0.09 to 0.34, p=0.0005). No significant improvement was found in other domains of cognition. Conclusions Aerobic exercise led to an improvement in global cognitive ability and had a positive effect with a small effect size on memory in people with MCI. However, owing to the limitations of the included studies, these findings should be interpreted cautiously.

Background: Chronic inflammation plays a significant role in accelerating the aging process and is closely associated with the initiation and progression of a broad range of age-related diseases. Physical exercise is considered beneficial in alleviating these conditions, but the effects of aerobic exercise on inflammatory markers in a healthy population should be furtherly clarified. Objective: The purpose of this systematic review and meta-analysis was to evaluate the effect of aerobic exercise on inflammatory markers in middle-aged and older adults. Methods: The literature search was conducted utilizing PubMed, Web of Science, Embase, and the Cochrane Library from their inception through April 2018, and the reference lists were screened to identify appropriate studies. Only randomized controlled trials that investigated the effect of aerobic exercise on inflammatory markers in middle-aged and older adults were eligible for this review. Results: Eleven studies involving 1,250 participants were retrieved from the databases for analysis. The pooled results showed that aerobic exercise significantly reduced inflammatory markers (C-reactive protein (CRP): SMD = 0.53, 95% CI 0.26–0.11, p = 0.0002; tumor necrosis factor-alpha (TNF-α): SMD = 0.75, 95% CI 0.31–1.19, p = 0.0007; interleukin 6 (IL-6): SMD = 0.75, 95% CI 0.31–1.19, p = 0.0007). No significant improvement was found in relation to interleukin 4 (IL-4). Conclusions: Aerobic exercise may have a positive effect on reduction of CRP, TNF-α, and IL-6 in middle-aged and older adults. Further randomized controlled trials (RCTs) need to be conducted to determine the effect of aerobic exercise on additional inflammatory markers in the population of middle-aged and older adults.

Mild cognitive impairment (MCI) is a common neurological disorder. This study aims to investigate the modulation effect of Baduanjin (a popular mind-body exercise) on MCI. 69 patients were randomized to Baduanjin, brisk walking, or an education control group for 24 weeks. The Montreal Cognitive Assessment (MoCA) and Magnetic Resonance Imaging scans were applied at baseline and at the end of the experiment. Compared to the brisk walking and control groups, the Baduanjin group experienced significantly increased MoCA scores. Amplitude of low-frequency fluctuations (ALFF) analysis showed significantly decreased ALFF values in the right hippocampus (classic low-freqency band, 0.01-0.08 Hz) in the Baduanjin group compared to the brisk walking group and increased ALFF values in the bilateral anterior cingulate cortex (ACC, slow-5 band, 0.01-0.027 Hz) in the Baduanjin group compared to the control group. Further, ALFF value changes in the right hippocampus and bilateral ACC were significantly associated with corresponding MoCA score changes across all groups. We also found increased gray matter volume in the Baduanjin group in the right hippocampus compared to the brisk walking group and in the bilateral ACC compared to the control group. In addition, there was an increased resting state functional connectivity between the hippocampus and right angular gyrus in the Baduanjin group compared to the control group. Our results demonstrate the potential of Baduanjin for the treatment of MCI.

A growing number of studies have shown that mind-body exercise is beneficial to cognitive function, especially memory, in elderly MCI patients. However, few studies have explored the effect of mind-body exercise on the attention of MCI population. We recruited 69 participants and divided them equally into Baduanjin, brisk walking (BWK) exercise or usual physical activity (UAP) control groups. The two exercise groups performed 60 min of exercise three times per week for 24 weeks. All subjects underwent whole-brain functional MRI and assessment of attentional abilities, including selective, divided, and sustained attention, and processing speed at baseline and after 24 weeks. The results show that: Baduanjin exercise significantly increased the selective attention of MCI patients, and Dorsal attention network (DAN) of Baduanjin exercise group exhibited functional connectivity decreased in right rolandic operculum (ROL. R), right middle temporal gyrus (MTG. R), right supramarginal inferior parietal, angular gyri (IPL. R), right precuneus (PCUN. R), and right fusiform gyrus (FFG. R) regions compared with the other two groups. The BWK exercise group had obviously functional connectivity increased in IPL. R and decreased in the MTG. R region compared to that in the UAP group. But no significant association between the changes of functional connectivity of DAN and the change of attentional ability test was observed. Thus, our data indicated Baduanjin exercise may be a potential beneficial intervention to improve the attention of the elderly with MCI. Further study with more samples is necessary to elucidate its imaging mechanism.

Numerous previous studies have suggested that physical activity or exercise may play an important role in both structural integrity of the brain and cognitive function. However, it is unclear what effect exercise has on cognitive related brain structure. The present study comprehensively reviews the effect of exercise on cognitive related brain regions of the healthy elderly by using activation likelihood estimation (ALE). Seven electronic databases were searched for randomized controlled trials published up to September 2017. The quality of the selected studies was evaluated using the Cochrane Collaboration's tool for assessing the risk of bias. GingerALE version 2.3.6 was used to perform the coordinate-based ALE meta-analysis. Nine randomized controlled trials (RCTs) with 50 distinct foci were analyzed for structural changes, containing 412 healthy older subjects. ALE showed significant regional increases in regions including the left superior temporal gyrus, left medial temporal gyrus, left inferior frontal gyrus, right medial frontal gyrus, right and left superior frontal gyrus, left cingulate gyrus, right anterior cingulate and left lentiform nucleus in subjects with the exercise intervention compared to controls. However, considering the quantity and limitations of the included studies, the conclusion could not yet be drawn. Additional randomized controlled trials with rigorous designs and longer intervention periods are needed in the future.