The benefits of physical exercise to reduce low-grade inflammation and improve Brain-Derived Neurotrophic Factor (BDNF) levels and cognitive function became a growing field of interest. Low-grade inflammation is common during aging and seems to be linked to neurodegenerative process. Regular physical exercises can help to reduce pro-inflammatory cytokines levels and to improve BDNF peripheral concentrations. The main goal of this research was to analyze the effects of a 16-week multimodal physical exercise program on peripheral BDNF levels and on Tumor Necrosis-α (TNF-α) and Interleukin- 6 (IL-6) as pro-inflammatory markers in cognitive healthy elderly individuals and in elderly with mild cognitive impairment (MCI). Cognitive functions were assessed by the Montreal Cognitive Assessment (MoCA) prior to and after the intervention. Thirty cognitively healthy participants and thirty-seven MCI participants were assigned to the control (CG) and trained (TG) groups. The TG participated in a multimodal physical training program for a 16-week period. The results showed a significant between-subjects interaction, which indicates the beneficial contribution of training on the reduction of TNF-α (p=0.001) and IL-6 (p<0.001) and on the improvement of BDNF (p<0.001) peripheral concentrations. Cognitive functions also presented significant improvements for MCI trained group (p=0.03). In conclusion, physical exercise was effective to reduce pro-inflammatory cytokines and to improve BDNF peripheral levels, with positive reflexes on cognition. To the best of our knowledge, this is the first study that evaluated longitudinally the effects of a multimodal physical exercises protocol on peripheral concentrations of pro-inflammatory cytokines and cognition performance in elderly MCI individuals.

The benefits of physical exercise on improvements in brain-derived neurotrophic factor (BDNF) levels and cognitive functioning have been reported in the literature. However, the variability of individual responses may be linked to genetic differences. BDNF is considered one of the most plausible factors involved in the cognitive benefits associated with physical activity practice. A single nucleotide polymorphism localized in the gene that codes BDNF results in a missense mutation that promotes an amino acid substitution (Val66Met) in the protein. This process has been associated with decreased levels of BDNF secretion, with corresponding impairments in specific cognitive functions. Therefore, the objective of this study was to analyze the effects of a multimodal physical exercise program on peripheral BDNF levels and cognitive functions in elderly individuals with mild cognitive impairment (MCI). The participants were genotyped for the BDNF Val66Met polymorphism. Cognitive functions were assessed by the Montreal Cognitive Assessment (MoCA) prior to and after the intervention. Forty-five participants were assigned to the control and trained groups. The trained group participated in a multimodal physical training for a 16-week period. The results showed a significant between-subjects interaction (p < 0.05), which indicates the beneficial contribution of training on cognitive functions independent of the BDNF genotype. However, only participants with BDNF-Met genotypes exhibited significant improvements in peripheral BDNF levels. The BDNF genotype appears to modulate the effects of physical exercise on BDNF secretion, but it does not influence cognition. This is the first study that evaluated the influence of a BDNF polymorphism on physical activity and cognition performance in elderly MCI individuals.

The decline in frontal cognitive functions contributes to alterations of gait and increases the risk of falls in patients with dementia, a category which included Alzheimer's disease (AD). The objective of the present study was to compare the gait parameters and the risk of falls among patients at different stages of AD, and to relate these variables with cognitive functions. This is a cross-sectional study with 23 patients with mild and moderate AD. The Clinical Dementia Rating was used to classify the dementia severity. The kinematic parameters of gait (cadence, stride length, and stride speed) were analyzed under two conditions: (a) single task (free gait) and (b) dual task (walking and counting down). The risk of falls was evaluated using the Timed Up-and-Go test. The frontal cognitive functions were evaluated using the Frontal Assessment Battery (FAB), the Clock Drawing Test (CDT) and the Symbol Search Subtest. The patients who were at the moderate stage suffered reduced performance in their stride length and stride speed in the single task and had made more counting errors in the dual task and still had a higher fall risk. Both the mild and the moderate patients exhibited significant decreases in stride length, stride speed and cadence in the dual task. Was detected a significant correlation between CDT, FAB, and stride speed in the dual task condition. We also found a significant correlation between subtest Similarities, FAB and cadence in the dual task condition. The dual task produced changes in the kinematic parameters of gait for the mild and moderate AD patients and the gait alterations are related to frontal cognitive functions, particularly executive functions.

Background and Purpose: Understanding fall risk factors in people with mild cognitive impairment (MCI) and Alzheimer disease (AD) can help to establish specific plans for prevention of falls. The purpose of this study was to identify fall risk factors in older adults with MCI and mild AD. Methods: A prospective study was conducted with community-dwelling older adults (40 MCI; 38 mild AD). The assessments consisted of sociodemographic and health variables, caloric expenditure, functional status, functional mobility (10-m walk test, dual-task test, and transition Timed Up and Go phases), cognitive domains, and depressive symptoms. Falls were recorded for 6 months by a falls calendar and monthly telephone calls. Results: Falls were reported in 52.6% and 51.4% of people with MCI and mild AD, respectively. Among people with MCI, lower functional status, higher time spent on walk and dual task tests, and higher depressive symptom scores were associated with falls. Higher time spent on the dual-task test was independently associated with falls. Among people with mild AD, falls were associated with lower time spent on the walk test and turn-to-sit phase, and a higher visuospatial domain score. Lower time spent on the turn-to-sit phase was identified as an independent predictor of falls. Conclusions: Careful attention should be given to dual-task and turn-to-sit activities when detecting risk of falls among older people with MCI and mild AD.