Matching Items (551)
Description
Background: Heart failure is the leading cause of hospitalization in older adults and has the highest 30-day readmission rate of all diagnoses. An estimated 30 to 60 percent of older adults lose some degree of physical function in the course of an acute hospital stay. Few studies have addressed the role of posture and mobility in contributing to, or improving, physical function in older hospitalized adults. No study to date that we are aware of has addressed this in the older heart failure population.
Purpose: To investigate the predictive value of mobility during a hospital stay and patterns of mobility during the month following discharge on hospital readmission and 30-day changes in functional status in older heart failure patients.
Methods: This was a prospective observational study of 21 older (ages 60+) patients admitted with a primary diagnosis of heart failure. Patients wore two inclinometric accelerometers (rib area and thigh) to record posture and an accelerometer placed at the ankle to record ambulatory activity. Patients wore all sensors continuously during hospitalization and the ankle accelerometer for 30 days after hospital discharge. Function was assessed in all patients the day after hospital discharge and again at 30 days post-discharge.
Results: Five patients (23.8%) were readmitted within the 30 day post-discharge period. None of the hospital or post-discharge mobility measures were associated with readmission after adjustment for covariates. Higher percent lying time in the hospital was associated with slower Timed Up and Go (TUG) time (b = .08, p = .01) and poorer hand grip strength (b = -13.94, p = .02) at 30 days post-discharge. Higher daily stepping activity during the 30 day post-discharge period was marginally associated with improvements in SPPB scores at 30 days (b = <.001, p = .06).
Conclusion: For older heart failure patients, increased time lying while hospitalized is associated with slower walking time and poor hand grip strength 30 days after discharge. Higher daily stepping after discharge may be associated with improvements in physical function at 30 days.
Purpose: To investigate the predictive value of mobility during a hospital stay and patterns of mobility during the month following discharge on hospital readmission and 30-day changes in functional status in older heart failure patients.
Methods: This was a prospective observational study of 21 older (ages 60+) patients admitted with a primary diagnosis of heart failure. Patients wore two inclinometric accelerometers (rib area and thigh) to record posture and an accelerometer placed at the ankle to record ambulatory activity. Patients wore all sensors continuously during hospitalization and the ankle accelerometer for 30 days after hospital discharge. Function was assessed in all patients the day after hospital discharge and again at 30 days post-discharge.
Results: Five patients (23.8%) were readmitted within the 30 day post-discharge period. None of the hospital or post-discharge mobility measures were associated with readmission after adjustment for covariates. Higher percent lying time in the hospital was associated with slower Timed Up and Go (TUG) time (b = .08, p = .01) and poorer hand grip strength (b = -13.94, p = .02) at 30 days post-discharge. Higher daily stepping activity during the 30 day post-discharge period was marginally associated with improvements in SPPB scores at 30 days (b = <.001, p = .06).
Conclusion: For older heart failure patients, increased time lying while hospitalized is associated with slower walking time and poor hand grip strength 30 days after discharge. Higher daily stepping after discharge may be associated with improvements in physical function at 30 days.
ContributorsFloegel, Theresa A (Author) / Buman, Matthew P (Thesis advisor) / Hooker, Steven (Committee member) / Dickinson, Jared (Committee member) / DerAnanian, Cheryl (Committee member) / McCarthy, Marianne (Committee member) / Arizona State University (Publisher)
Created2015
Description
Obesity impairs skeletal muscle maintenance and regeneration, a condition that can progressively lead to muscle loss, but the mechanisms behind it are unknown. Muscle is primarily composed of multinucleated cells called myotubes which are derived by the fusion of mononucleated myocytes. A key mediator in this process is the cellular fusion protein syncytin-1. This led to the hypothesis that syncytin-1 could be decreased in the muscle of obese/insulin resistant individuals. In contrast, it was found that obese/insulin resistant subjects had higher syncytin-1 expression in the muscle compared to that of the lean subjects. Across the subjects, syncytin-1 correlated significantly with body mass index, percent body fat, blood glucose and HbA1c levels, insulin sensitivity and muscle protein fractional synthesis rate. The concentrations of specific plasma fatty acids, such as the saturated fatty acid (palmitate) and monounsaturated fatty acid (oleate) are known to be altered in obese/insulin resistant humans, and also to influence the protein synthesis in muscle. Therefore, it was evaluated that the effects of palmitate and oleate on syncytin-1 expression, as well as 4E-BP1 phosphorylation, a key mechanism regulating muscle protein synthesis in insulin stimulated C2C12 myotubes. The results showed that treatment with 20 nM insulin, 300 µM oleate, 300 µM oleate +20 nM insulin and 300 µM palmitate + 300 µM oleate elevated 4E-BP1 phosphorylation. At the same time, 20 nM insulin, 300 µM palmitate, 300 µM oleate + 20 nM insulin and 300 µM palmitate + 300 µM oleate elevated syncytin-1 expression. Insulin stimulated muscle syncytin-1 expression and 4E-BP1 phosphorylation, and this effect was comparable to that observed in the presence of oleate alone. However, the presence of palmitate + oleate diminished the stimulatory effect of insulin on muscle syncytin-1 expression and 4E-BP1 phosphorylation. These findings indicate oleate but not palmitate increased total 4E-BP1 phosphorylation regardless of insulin and the presence of palmitate in insulin mediated C2C12 cells. The presence of palmitate inhibited the upregulation of total 4EB-P1 phosphorylation. Palmitate but not oleate increased syncytin-1 expression in insulin mediated C2C12 myotubes. It is possible that chronic hyperinsulinemia in obesity and/or elevated levels of fatty acids such as palmitate in plasma could have contributed to syncytin-1 overexpression and decreased muscle protein fractional synthesis rate in obese/insulin resistant human muscle.
ContributorsRavichandran, Jayachandran (Author) / Katsanos, Christos (Thesis advisor) / Coletta, Dawn (Committee member) / Dickinson, Jared (Committee member) / Arizona State University (Publisher)
Created2017
Description
High childhood obesity rates have resulted in many interventions to attempt to lower these rates. Interventions such as day camps, residential camps, therapy-based interventions and family-based interventions lead to changes in weight and self-esteem but family-based intervention leads to the longest-term success for children ages nine to 17. Analysis of the interventions was measured using tools such as BMI, BMI-percentiles, and weight. Psychological measures such as self-esteem, happiness, and quality of life analysis was preferred, however were not measured in all studies. While most interventions resulted in weight loss and increased self-esteem, results were often not long-term. Studies provided evidence that family-based therapy has potential to last long-term, however there is a lack of research. To determine the most effective childhood nutrition intervention research must conduct follow-ups for many years after the initial intervention to ensure they provide long-term results.
ContributorsAnderson, Megan Lee (Author) / McCoy, Maureen (Thesis director) / Kniskern, Megan (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
ABSTRACT
Background: Although aerobic exercise has been shown to improve the glycemic control of individuals with type 2 diabetes, a simple and effective approach to manage post-meal glycemic control remains less clear.
Purpose: This study examined the effect of 15-minute of post-meal aerobic exercise on the glycemic control and anxiety scores as compared with control trials in participants with and without type 2 diabetes.
Methods: Six adults volunteered to participate in the study (3 adults with type 2 diabetes, age = 44.33 ± 7.71; and 3 adults without type 2 diabetes, age = 31.67 ± 15.76). All participants received aerobic exercise intervention and control treatments. The aerobic exercise treatment was listening to upbeat music and dancing for 15-minutes, whereas the control participants ingested 1 gram of vitamin C 30-minutes post-meal. Glucose levels were measured at baseline, and the 10, and 15-minute mark in both exercise intervention and control conditions 30-minutes post-meal.
Results: There was a significant interaction between treatment and time on the change in glucose levels (P<0.001). There was a significant mean difference in change in glucose levels between exercise intervention and control conditions (P = 0.002). Change in glucose levels in exercise intervention was significantly decreased at 10-minute (-18 ± 4.35 vs. 1.67 ± 4.34, P = 0.009) and 15-minute (-24 ± 4.88 vs. 5.67 ± 4.88, P = 0.001) compared with control condition. Although there were no statistical differences in state anxiety scores between pre- and post-exercise intervention (p=0.42), there was a significant trend in the reduction of state anxiety scores in diabetic participants, as compared with healthy participants, after 15-minute exercise intervention (-8 vs. -1).
Conclusion: Aerobic exercise for 15-minute by dancing to music after a meal is an effective approach to controlling the blood glucose levels in type 2 diabetic and healthy persons.
Background: Although aerobic exercise has been shown to improve the glycemic control of individuals with type 2 diabetes, a simple and effective approach to manage post-meal glycemic control remains less clear.
Purpose: This study examined the effect of 15-minute of post-meal aerobic exercise on the glycemic control and anxiety scores as compared with control trials in participants with and without type 2 diabetes.
Methods: Six adults volunteered to participate in the study (3 adults with type 2 diabetes, age = 44.33 ± 7.71; and 3 adults without type 2 diabetes, age = 31.67 ± 15.76). All participants received aerobic exercise intervention and control treatments. The aerobic exercise treatment was listening to upbeat music and dancing for 15-minutes, whereas the control participants ingested 1 gram of vitamin C 30-minutes post-meal. Glucose levels were measured at baseline, and the 10, and 15-minute mark in both exercise intervention and control conditions 30-minutes post-meal.
Results: There was a significant interaction between treatment and time on the change in glucose levels (P<0.001). There was a significant mean difference in change in glucose levels between exercise intervention and control conditions (P = 0.002). Change in glucose levels in exercise intervention was significantly decreased at 10-minute (-18 ± 4.35 vs. 1.67 ± 4.34, P = 0.009) and 15-minute (-24 ± 4.88 vs. 5.67 ± 4.88, P = 0.001) compared with control condition. Although there were no statistical differences in state anxiety scores between pre- and post-exercise intervention (p=0.42), there was a significant trend in the reduction of state anxiety scores in diabetic participants, as compared with healthy participants, after 15-minute exercise intervention (-8 vs. -1).
Conclusion: Aerobic exercise for 15-minute by dancing to music after a meal is an effective approach to controlling the blood glucose levels in type 2 diabetic and healthy persons.
ContributorsSymons, Nicholas Payne (Author) / Lee, Chong (Thesis director) / Dickinson, Jared (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / W. P. Carey School of Business (Contributor)
Created2015-05
Description
The purpose of this study was to develop proposal lesson plans for 4th-6th graders based on active learning to integrate movement physical activity into the curriculum. The 4th-6th graders were chosen, as this is the age where teaching typically transitions from active learning to sedentary/lecture style teaching. Research compiled indicated positive effects of active based learning on children such as increased attention span, retention, and general focus. A survey was created to not only assess the perception of active versus didactic learners, but to also assess the effects of movement-based learning on the variables that research claimed to change. The lesson plans developed here should be transferable to a classroom lesson to evaluate the hypothesized results.
ContributorsTanna, Nimisha (Author) / Hyatt, JP (Thesis director) / Ainsworth, Barbara (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
About 75% of men and 66.58% of women are considered overweight or obese (BMI ≥25). $117 billion dollars is spent each year in medical costs due to physical inactivity. Aerobic exercise has been well defined in its’ benefits to cardiovascular health; however, the effects of resistance training are still not well defined. The purpose of this preliminary analysis was to evaluate the vascular health effects (central and peripheral blood pressure and VO2 max) of two different types of resistance training programs: high load, low repetitions resistance training and low load, high repetitions resistance training. Fourteen participants aged 18-55 years (6 males, 8 females) were involved in this preliminary analysis. Data were collected before and after the 12-week long exercise program (36 training sessions) via pulse wave analysis and VO2peak testing. Multivariate regression analysis of training program effects, while adjusting for body mass index and time, did not result in significant training effects on central and peripheral diastolic blood pressure, nor VO2peak. A statistical trend was observed between the different training programs for systolic blood pressure, suggesting that subjects partaking in the high load, low repetitions program exhibited higher systolic blood pressures than the low load, high repetitions group. With a larger sample size, the difference in systolic blood pressure may increase between training program groups and indicate that greater loads with minimal repetitions may increase lead to clinically significant elevations in blood pressure. Further work is needed to uncover the relationship between different types of resistance training and blood pressure, especially if these lifting regimens are continued for longer lengths of time.
ContributorsHill, Cody Alan (Co-author) / Hill, Cody (Co-author) / Whisner, Corrie (Thesis director) / Angadi, Siddhartha (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Introduction: Individuals with rotator cuff tears have been found to compensate in their movement patterns by using lower thoracohumeral elevation angles during certain tasks, as well as increased internal rotation of the shoulder (Vidt et al., 2016). Leading joint hypothesis suggests there is one leading joint that creates the foundation for the entire limb motion, and there are other subordinate joints which monitor the passive interaction torque and create a net torque aiding to limb motions required for the task. This experiment seeks to establish a better understanding of joint control strategies during a wide range of arm movements. Based on the leading joint hypothesis, we hypothesize that when a subject has a rotator cuff tear, their performance of planar and three-dimensional motions should be altered not only at the shoulder, which is often the leading joint, but also at other joints on the arm, such as the elbow and wrist. This paper will focus on the effect of normal aging on the control of the joints of the arm.
Methods: There were 4 groups of participants: healthy younger adults (n=14)(21.74 ± 1.97), healthy older adults (n=12)(55-75), older adults (n=4)(55-75) with a partial-thickness rotator cuff tear, and older adults (n=4)(55-75) with a full-thickness rotator cuff tear (RCT). All four groups completed strength testing, horizontal drawing and pointing tasks, and three dimensional (3D) activities of daily living. Kinematic and kinetic variables of the arm were obtained during horizontal and 3D tasks using data from 12 reflective markers placed on the arm, 8 motion capture cameras, and Cortex motion capture software (Motion Analysis Corp., Santa Rosa, CA). Strength testing tasks were measured using a dynamometer. All strength testing and 3D tasks were completed for three trials and horizontal tasks were completed for two trials.
Results: Results of the younger adult participants showed that during the forward portion of seven 3D tasks, there were four phases of different joint control mechanics seen in a majority of the movements. These phases included active rotation of both the shoulder and the elbow joint, active rotation of the shoulder with passive rotation of the elbow, passive rotation of the shoulder with active rotation of the elbow, and passive rotation of both the shoulder and the elbow. Passive rotation during movements was a result of gravitational torque on the different segments of the arm and interaction torque caused as a result of the multi-joint structure of human limbs. The number of tested participants for the minor RCT, and RCT older adults groups is not yet high enough to produce significant results and because of this their results are not reported in this article. Between the older adult control group and the young adult control group in the tasks upward reach to eye height and hair comb there were significant differences found between the groups. The differences were found in shorter overall time and distance between the two groups in the upward eye task.
Discussion: Through the available results, multiple phases were found where one or both of the joints of the arm moved passively which further supports the LJH and extends it to include 3D movements. With available data, it can be concluded that healthy older adults use movement control strategies, such as shortening distance covered, decreasing time percentage in active joint phases, and increasing time percentage in passive joint phases, to account for atrophy along with other age-related declines in performance, such as a decrease in range of motion. This article is a part of a bigger project which aims to better understand how older adults with RCTs compensate for the decreased strength, the decreased range of motion, and the pain that accompany this type of injury. It is anticipated that the results of this experiment will lead to more research toward better understanding how to treat patients with RCTs.
Methods: There were 4 groups of participants: healthy younger adults (n=14)(21.74 ± 1.97), healthy older adults (n=12)(55-75), older adults (n=4)(55-75) with a partial-thickness rotator cuff tear, and older adults (n=4)(55-75) with a full-thickness rotator cuff tear (RCT). All four groups completed strength testing, horizontal drawing and pointing tasks, and three dimensional (3D) activities of daily living. Kinematic and kinetic variables of the arm were obtained during horizontal and 3D tasks using data from 12 reflective markers placed on the arm, 8 motion capture cameras, and Cortex motion capture software (Motion Analysis Corp., Santa Rosa, CA). Strength testing tasks were measured using a dynamometer. All strength testing and 3D tasks were completed for three trials and horizontal tasks were completed for two trials.
Results: Results of the younger adult participants showed that during the forward portion of seven 3D tasks, there were four phases of different joint control mechanics seen in a majority of the movements. These phases included active rotation of both the shoulder and the elbow joint, active rotation of the shoulder with passive rotation of the elbow, passive rotation of the shoulder with active rotation of the elbow, and passive rotation of both the shoulder and the elbow. Passive rotation during movements was a result of gravitational torque on the different segments of the arm and interaction torque caused as a result of the multi-joint structure of human limbs. The number of tested participants for the minor RCT, and RCT older adults groups is not yet high enough to produce significant results and because of this their results are not reported in this article. Between the older adult control group and the young adult control group in the tasks upward reach to eye height and hair comb there were significant differences found between the groups. The differences were found in shorter overall time and distance between the two groups in the upward eye task.
Discussion: Through the available results, multiple phases were found where one or both of the joints of the arm moved passively which further supports the LJH and extends it to include 3D movements. With available data, it can be concluded that healthy older adults use movement control strategies, such as shortening distance covered, decreasing time percentage in active joint phases, and increasing time percentage in passive joint phases, to account for atrophy along with other age-related declines in performance, such as a decrease in range of motion. This article is a part of a bigger project which aims to better understand how older adults with RCTs compensate for the decreased strength, the decreased range of motion, and the pain that accompany this type of injury. It is anticipated that the results of this experiment will lead to more research toward better understanding how to treat patients with RCTs.
ContributorsFlores, Noah Mateo (Author) / Dounskaia, Natalia (Thesis director) / Vidt, Meghan (Committee member) / College of Health Solutions (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
After volunteering at a clinic in Guatemala and seeing the sexism that is so engrained into their culture, I decided to take a look at the U.S. healthcare system. I wanted to uncover the stereotypes, statistics and gender and societal norms that are present in our culture. I first started with the application process and the acceptance rates to medical school. I discovered that men are accepted to medical school at higher rates than women unless that man is deemed dangerous or foreign. I then moved on to the environment in medical school. Many women are subjected to snide comments or “bro talk” made to make them feel inferior. Men always graduate at higher rates than women, which could be because of the unwelcoming environment in medical school or the lack of female faculty chairs or mentors. After medical school, a new doctor must choose a specialty. Men gravitate towards specialties that focus on surgical work and large sums of money. Women tend to choose specialties that require a more soothing and caring environment. Women are more likely to pick specialties where there is a higher proportion of female residents. After specialties, I then explored the life of a doctor. Slightly over half of all doctors in the workforce are men and they make an average of $78,288 more per year than female physicians. Women are discriminated against if they become pregnant on the job and they are more likely to develop mental health issues. Female physicians are overall, more compassionate, rule abiding and patient-focused than their male counterparts but are not receiving the acknowledgments that they deserve. After delving into the U.S. healthcare system, I have realized that sexism in the workforce is blatantly apparent and is one of the outcomes of our patriarchal society. The only way we can make a change is to acknowledge the problem and come together as a society to combat the issue.
ContributorsPurkey, Caroline Rose (Author) / Collins, Michael (Thesis director) / Barry, Anne (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
There has been a rise in the prevalence of mental health disorders among western industrialized populations.1 By 2020, depression will be second to heart disease in its contribution to the global burden of disease as measured by disability-adjusted life years.2 Anxiety disorders are the most common mental illness in the U.S., affecting 40 million adults in the United States ages 18 and older, or 18.1% of the U.S population every year.3
Mental disorders are prevalent in young adults and frequently present between 12-24 years of age.4 The top five sources of stress reported by college students were changes in sleeping routines, changes in eating habits, increased amount of work, new responsibilities, and breaks/vacations.5 Overall, a total of 73% of college students report occasional difficulties sleeping, and 48% of students suffer from sleep deprivation, as self-reported.6,7
Lifestyle factors such as diet, exercise and sleep may influence symptoms related to stress and depression.8 Symptoms of depression include but are not limited to, persistent anxious or sad moods, feeling guilty or helpless, loss of interest in hobbies, irritability, and other behaviors that may interrupt daily living.9 Inadequate intake of folic acid from fruits and vegetables, and essential fatty acids in fish, may increase symptoms of depression.10 Unhealthy eating habits may be associated with increases in depression-like symptoms in women, supporting the notion that healthier eating habits may decrease major depression.11 Diet is only one component of how lifestyle may influence depression and stress in adults. Exercise may be another important component in decreasing depression-related symptoms due to the release of endorphins.12 It has been found that participating in regular physical activity may decrease tension levels, increase and stabilize mood, improve self-esteem, and lead to better sleeping patterns.13 It has been concluded that individuals who consume a healthy diet are less likely to experience depression whereas people eating unhealthy and processed diets are more likely to be depressed.14
Poor sleep quality as well as unstable sleeping patterns may lead to poor psychological and physical health.15 Poor sleep includes longer duration of sleep onset latency, which is defined as the amount of time it takes to fall asleep, waking up multiple times throughout the night, and not getting a restful sleep because of tossing and turning.16 In healthy adults, the short-term consequences of sleep disruption consist of somatic pain, emotional destress and mood disorders, reduced quality of life, and increased stress responsivity.17 Irregular sleep-wake patterns, defined as taking numerous naps within a 24 hour span and not having a main nighttime sleep experience, are present at alarming levels (more than a quarter) among college students.18 A study done with 2,000 college students concluded that more than a quarter of the students were at risk of a sleeping disorder.19 Therefore, college students who were classified as poor-quality sleepers, reported experiencing more psychological and physical health problems compared to their healthy counterparts. Perceived stress was also found to be a factor in lower sleep quality of young adults.20
The link between depression-like symptoms and sleep remains poorly understood. It is mentioned that there are risk factors of poor sleep, depression and anxiety among college students but this topic has not yet been heavily studied within this population.
Mental disorders are prevalent in young adults and frequently present between 12-24 years of age.4 The top five sources of stress reported by college students were changes in sleeping routines, changes in eating habits, increased amount of work, new responsibilities, and breaks/vacations.5 Overall, a total of 73% of college students report occasional difficulties sleeping, and 48% of students suffer from sleep deprivation, as self-reported.6,7
Lifestyle factors such as diet, exercise and sleep may influence symptoms related to stress and depression.8 Symptoms of depression include but are not limited to, persistent anxious or sad moods, feeling guilty or helpless, loss of interest in hobbies, irritability, and other behaviors that may interrupt daily living.9 Inadequate intake of folic acid from fruits and vegetables, and essential fatty acids in fish, may increase symptoms of depression.10 Unhealthy eating habits may be associated with increases in depression-like symptoms in women, supporting the notion that healthier eating habits may decrease major depression.11 Diet is only one component of how lifestyle may influence depression and stress in adults. Exercise may be another important component in decreasing depression-related symptoms due to the release of endorphins.12 It has been found that participating in regular physical activity may decrease tension levels, increase and stabilize mood, improve self-esteem, and lead to better sleeping patterns.13 It has been concluded that individuals who consume a healthy diet are less likely to experience depression whereas people eating unhealthy and processed diets are more likely to be depressed.14
Poor sleep quality as well as unstable sleeping patterns may lead to poor psychological and physical health.15 Poor sleep includes longer duration of sleep onset latency, which is defined as the amount of time it takes to fall asleep, waking up multiple times throughout the night, and not getting a restful sleep because of tossing and turning.16 In healthy adults, the short-term consequences of sleep disruption consist of somatic pain, emotional destress and mood disorders, reduced quality of life, and increased stress responsivity.17 Irregular sleep-wake patterns, defined as taking numerous naps within a 24 hour span and not having a main nighttime sleep experience, are present at alarming levels (more than a quarter) among college students.18 A study done with 2,000 college students concluded that more than a quarter of the students were at risk of a sleeping disorder.19 Therefore, college students who were classified as poor-quality sleepers, reported experiencing more psychological and physical health problems compared to their healthy counterparts. Perceived stress was also found to be a factor in lower sleep quality of young adults.20
The link between depression-like symptoms and sleep remains poorly understood. It is mentioned that there are risk factors of poor sleep, depression and anxiety among college students but this topic has not yet been heavily studied within this population.
ContributorsBosnino, Jasmine (Co-author, Co-author) / Whisner, Corrie (Thesis director) / Petrov, Megan (Committee member) / Mahmood, Tara (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Doxorubicin (DOX) is a cardiotoxic, anthracycline-based, anti-neoplastic agent that causes pathological cardiac remodeling due to altered protein expression associated with cardiotoxicity. DOX cardiotoxicity causes increased Akt phosphorylation, blunted AMPK phosphorylation and upregulated mTOR phosphorylation. Akt is activated by cellular stress and damage. AMPK is activated by increases in AMP and ADP concentrations and decreased ATP concentration. mTOR is active in cellular growth and remodeling. These proteins are cellular kinases with cascades that are influenced by one another. Exercise preconditioning may diminish the cardiotoxic effects on these proteins. Female, Ovariectomized Sprague-Dawley rats (N=33) were randomized to: Exercise+DOX (EX+DOX, n=9); Exercise+Vehicle (EX+VEH, n=8); Sedentary+DOX (SED+DOX, n=8); and Sedentary+Vehicle (SED+VEH, n=8) groups. DOX (4mg/kg) or VEH (saline) intraperitoneal injections were administered bi-weekly (cumulative dose of 12mg/kg). VEH animals received body weight matched volumes of saline based on dosing in animals receiving DOX. Exercise (EX) animals underwent high intensity (85-95% VO2 peak) interval training (HIIT) (4x4 min bouts) separated by low intensity (50-60% VO2max) intervals (2 min bouts) 5 days per week. Exercise began 1 week prior to the first injection and was continued throughout the study. Rats were euthanized 5 days after the last injection. Left ventricular tissue was isolated, processed into lysate and used for western blot analyses [2x2 ANOVA; (α=0.05)]. DOX induced significant phosphorylation of Akt and mTOR (p=0.035; p=0.032) only in SED+DOX rats, but unchanged in EX+DOX rats. No significant differences (p=0.374) in AMPK phosphorylation were observed between groups. Exercise Preconditioning prevents some DOX-induced changes in the cardiac mTOR signaling pathway implicated in pathological remodeling.
ContributorsPanknin, Timothy M (Author) / Angadi, Siddhartha (Thesis director) / Sweazea, Karen (Committee member) / Dickinson, Jared (Committee member) / School of Nutrition and Health Promotion (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05