| dc.description.abstract | Stroke is a major cause of permanent disability worldwide. In the United States, stroke is the leading cause of disability and the 5th leading cause of death. The cost of care associated with stroke is expected to be $184 billion by 2030. After stroke, people commonly experience cardiovascular disease (metabolic syndrome, coronary artery disease, myocardial infarction, and hypertension), cognitive decline, sensorimotor disability, pulmonary dysfunction, psychological problems, and decreased bone health. The majority of past studies of rehabilitation therapy in stroke survivors have focused on recovery of sensorimotor function. Fewer studies have focused on cardiovascular, cardiopulmonary, and bone health after stroke, particularly in non-ambulatory individuals. The objective of this pilot project was to investigate the feasibility of an aerobic walking exercise program and its effects on the following outcome measures: cardiovascular risk factors, pulmonary function, and bone health in non-ambulatory stroke survivors. In chapter one, we first reviewed the health sequelae after stroke focusing on cardiovascular, pulmonary, and bone health decline. We then reviewed the pharmacological and non-pharmacological (such as aerobic exercise) interventions for stroke survivors in general. We finally stated the significance of this dissertation project and listed aims and hypotheses. In chapter two, a scoping review manuscript, we focused on the health benefits of aerobic walking exercise on cardiovascular, pulmonary, and bone health in non-ambulatory stroke survivors. We first reviewed the current state of clinical research findings of aerobic walking exercise in non-ambulatory stroke survivors. We summarized the health issues in the cardiopulmonary and skeletal systems in non-ambulatory stroke survivors. We reviewed the aerobic exercise guidelines for non-ambulatory stroke survivors. We then reviewed various studies reporting the pros and cons of body posture (standing vs. sitting) during exercise in terms of improvement or maintenance of health of the cardiopulmonary and skeletal systems in non-ambulatory stroke survivors. We finally briefly reviewed the walking assistive device that makes walking exercise feasible for non-ambulatory stroke survivors. In chapter three, we examined the feasibility and the effect of 8-weeks of aerobic walking exercise on lung function in non-ambulatory stroke survivors using a treadmill, body weight support system, and a gait training device. Lung function is compromised in stroke survivors, which may cause fatigue and exercise intolerance. We have completed a low intensity walking exercise program (30 minutes/session; three sessions/week for eight weeks) in 9 non-ambulatory stroke survivors (5 males, mean age 61.8 13.6 years, 8 with ischemic stroke). We showed that 8-week of aerobic walking exercise was feasible, and compliance rate was 100% among the nine participants who completed the intervention. The attrition rate was10%. Before and after the intervention, vital capacity (VC) and forced vital capacity (FVC) using a spirometer were measured in eight of the participants. There were significant differences between pre- and post -intervention assessments in FVC (p= 0.09), percentage of predicted VC (p= 0.08), and percentage of predicted FVC (p= 0.08). The results are promising; however, future studies are needed. In chapter four, we examined the effect of low intensity aerobic walking exercise on cardiovascular risk factors in non-ambulatory stroke survivors using a treadmill, body weight support system, and walking assistive device. Approximately 75% of stroke survivors are prone to having cardiovascular disease, the main cause of death in stroke survivors. However, few efforts have been made to control risks of cardiovascular diseases, especially in non-ambulatory stroke survivors. Nine non-ambulatory stroke survivors (age: 61.8 13.6 years, 5 men, 8 with ischemic stroke) completed the aerobic walking exercise program (three sessions/week for eight weeks). Glycated hemoglobin (HbA1C), resting heart rate (rHR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and serum level of low-density lipoprotein (LDL) were measured pre- and post-intervention. After the intervention, there were significant differences in HbA1c, rHR, SBP, and DBP. The results in this chapter suggest that the aerobic walking exercise may improve cardiovascular risk factors in non-ambulatory stroke survivors. In chapter five, we aimed to examine changes after aerobic walking exercise in bone health in non-ambulatory stroke survivors using a treadmill, body weight support system, and a walking training device. Stroke survivors are at high risk of bone fracture. Compared to healthy people, stroke survivors are less active, and they tend to unload their bones on their affected lower limbs which rapidly increase bone loss. Non-ambulatory stroke survivors are largely losing bone health when compared to stroke survivors who walk independently. We recruited nine non-ambulatory stroke survivors (age: 61.8 13.6 years, 5 men, 8 with ischemic stroke). They completed the aerobic walking exercise program (three sessions/week for eight weeks). Serum concentration of osteocalcin (OC) and carboxy-terminal telopeptide of type I collagen (ICTP) were measured pre- and post-intervention. OC increased significantly from 8.51±2.28 ng/ml to 9.39±2.97 ng/ml (p < 0.1). ICTP increased significantly from 4.45±2.58 ng/ml to 5.31±2.92 ng/ml (p < 0.1). The results suggest that the low intensity aerobic walking exercise may improve bone health by increasing bone formation markers. However, the initial severe disability of the participants and the nature of the aerobic walking exercise may initiate the bone remodeling process slowly. In conclusion, past rehabilitation interventions for stroke survivors have not focused on controlling risks of pulmonary and cardiovascular diseases and bone loss, especially in strokes survivors who could not walk independently. To date, there have been very few clinical trials that attempted to examine the effects of aerobic walking exercise on risks of pulmonary function, cardiovascular disease, and bone health in non-ambulatory stroke survivors. The results of this dissertation project show that the low-intensity, aerobic walking exercise is feasible and might improve pulmonary function, cardiovascular health, and bone health in non-ambulatory stroke survivors. | |
