Immune system and quality of life following aerobic exercise versus resistance exercise training among Alzheimer’s

Alzheimer’s disease (AD) characterized with deteriorated both function, cognition and neuronal loss [1]. Currently, there is about 24 million AD, which expected to reach about 100 million subjects by 2050 around the world [2,3]. The cost of management of the current AD population is greater than 220 billion US dollars, which is expected to reach greater than one trillion by 2050 [4]. Both patient and family are adversely affected by AD as the disease badly deteriorate behavior, cognitive and physical aspects [5].


Introduction
Alzheimer's disease (AD) characterized with deteriorated both function, cognition and neuronal loss [1]. Currently, there is about 24 million AD, which expected to reach about 100 million subjects by 2050 around the world [2,3]. The cost of management of the current AD population is greater than 220 billion US dollars, which is expected to reach greater than one trillion by 2050 [4]. Both patient and family are adversely affected by AD as the disease badly deteriorate behavior, cognitive and physical aspects [5].
Evidences proved an association between in lammation of brain tissue and aging changes that drive the pathological changes in AD [6]. The in lammatory changes induces immunological changes promotes AD development [7,8].
Moreover, the majority of AD individuals suffer from many psychiatric disturbances and depression [9][10][11]. Therefore there is a need to develop novel therapeutic modalities for AD individual care [12].
Evidences reported positive in luence of exercise training on immune system [13]. Therefore, it is usually recommended to apply exercise training to positively in luence immune system through modulation of systemic in lammatory status and cognitive dysfunction among AD individuals [14][15][16][17][18][19][20]. Limited evidences available regarding differences of in luence of aerobic and resisted exercises on elderly with AD. The objective of the this trial was to detect immune system and quality of life(QOL) response following aerobic versus resisted exercise training among AD subjects.

Subjects
Fifty older with AD disease the range of age ranged was 61 to 73 years enrolled in the current study. However, smoking, liver, chest, renal, metabolic and cardiac dysfunction considered as exclusion criteria. Participants were randomly enrolled into group (A) who applied aerobic exercise intervention, while group (B) applied resisted exercise intervention for period of six months. A consent form was signed by legal guardian of all participants before sharing in our study which was ethically approved by FAMS Ethical Research Committee, King Abdulaziz University.

Measurements
A. Flow cytometry analysis: Leukocyte differentiation antigens CD3, CD4 and CD8 were measured using Beckman Coulter, Marseille, France. However, low cytometry (Cytomics FC 500 and CXP software was used for analysis of samples.

B. Health-related quality of life (SF-36 HRQL):
Assessment of quality of life (QOL) was detected using the standard reliable test SF-36 that includes eight subscales: Vitality, Bodily Pain, General Health, Physical Functioning, Social Functioning, Physical Role Functioning, Emotional Role Functioning, and Mental Health [21].

1-Group (A):
Twenty-ive AD elderly subjects received treadmill aerobic exercise training for six months, the training program started with ive minutes warming up, thirty minutes of training on the treadmill with an intensity 60% -80% of individual maximal heart rate and end with ive minutes cooling down [22].

2-Group (B):
Twenty-ive AD elderly subjects received resisted exercise training for six months, the training program started with ten minutes of mobility exercises followed by resisted exercise training on 9 machines of resistance training in order to do resisted training for the main skeletal muscles of the lower limbs, upper limbs and trunk muscles. Training session included 3 sets each set which consisted of 8-12 repetitions with a moment rest in between each 2 set. Training intensity was 60% -80% of one maximum repetition (1-RM) [23].

Results
Baseline variables of all participants proved that both groups were homogeneous as comparing the both groups regarding baseline and demographic parameters revealed no signi icant differences ( Table 1).
The main indings in the current study showed signi icant increase in the mean values of SF-36 which measure QOL along with signi icant improvement in the immunological parameters (CD3 count, CD4 count, CD8 count and CD4/CD8 ratio) following aerobic and resisted exercise training (Tables  2-5). However, comparing between both groups showed signi icant differences with greater signi icant improvement in all measured parameters following aerobic exercise training (Tables 6,7).

Discussion
Globally, millions of elderly individuals are affected with AD who suffer from decline in cognitive ability. However, immune system dysfunction play a principal role in AD pathogenesis [24,25]. Recently, there is no available pharmacological therapeutic intervention for caring of AD. However, exercise training is of positive effects on physical and cognitive function of AD individuals [26,27].
Results of current study proved that after six months, immunological parameters (CD3, CD4 and CD8) signi icantly increased and CD4/CD8 ratio signi icantly decreased in group (A) applied aerobic exercises greater than group (B) applied resisted exercises. Cell numbers are expected to decrease due to aging process. This inding is consistent with other studies, while other contradicting studies have made different observations. As our results agreed with many researches proved that aerobic exercise training improved immune system of elderly subjects [28][29][30][31]. However, Peeri and colleagues, stated that number of CD4 & CD8 cells and physical itness signi icantly increased following aerobic exercise for six months in healthy elderly males [32]. While, Kapasi, et al. reported that two months of combined aerobic and resisted exercises improved CD8+ cells among elderly individuals [33]. On the other hand, limited evidences that measure in luence of immunological response to resisted exercise are available, the majority of these studies reported that 2-3 months of resisted exercise programs had minimal in luence of immune system and in lammatory cytokines [34][35][36][37][38]. While, many studies did not show signi icant immune function improvement following progressive resistance training [39][40][41][42][43].
Concerning QOL, aerobic exercise associated with greater signi icant increase in the SF-36 subscale mean values than resisted exercise. Many previous studies approved these indings that indicate that subjects psychological wellbeing and QOL associated with physical exercises [44][45][46][47]. Mahendra, reported that aerobic exercise training for 3 months improved SF-36 score of in patients with Alzheimer's disease [48]. However, Bowen et al. proved that postmenopausal women experienced improved QOL following twelve months of exercise intervention [49].In addition, Sørensen, et al. mentioned that 12-month exercise trial improved HRQOL of elderly individuals [50]. Similarly, Imayama, et al. stated that twelve months of moderate to vigorous strength training improved HRQOL improved among overweight men following [51]. In addition, there are evidences reported that exercise training with higher intensity improved mental https://doi.org/10.29328/journal.aaai.1001018      health greater than lower intensity exercise training [52,53]. While, Hoffmann, et al. found that AD subjects gained great improvement in QOL and physical itness following aerobic of moderate intensity [54]. The speci ic mechanism for improved QOL following exercise training is not well known. However, improved self-perceptions, self-ef icacy, activity of neurotransmitters [55][56][57], neuronal survival [58], synaptic plasticity [61], brain plasticity and vascularization [62][63][64], along with reduced emotional strain associated with social contact [65].

Conclusion
Aerobic exercise is more appropriately improve quality of life and immune system among elderly Alzheimer's.