ASU Electronic Theses and Dissertations
This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.
In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.
Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.
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- Creators: Sweazea, Karen
Description
ABSTRACT The hormone leptin is an important regulator of body weight and energy balance, while nitric oxide (NO) produced in the blood vessels is beneficial for preventing disease-induced impaired vasodilation and hypertension. Elevations in the free radical superoxide can result in impaired vasodilation through scavenging of NO. Omega 3 is a polyunsaturated fatty acid that is beneficial at reducing body weight and in lowering many cardiovascular risk factors like atherosclerosis. The present study was designed to examine the change in plasma concentrations of leptin, nitric oxide, and the antioxidant superoxide dismutase in addition to examining the association between leptin and NO in healthy normal weight adult female subjects before and following omega 3 intakes. Participants were randomly assigned to either a fish oil group (600 mg per day) or a control group (1000 mg of coconut oil per day) for 8 weeks. Results showed no significant difference in the percent change of leptin over the 8 week supplementation period for either group (15.3±31.9 for fish oil group, 7.83±27 for control group; p=0.763). The percent change in NO was similarly not significantly altered in either group (-1.97±22 decline in fish oil group, 11.8±53.9 in control group; p=0.960). Likewise, the percent change in superoxide dismutase for each group was not significant following 8 weeks of supplementation (fish oil group: 11.94±20.94; control group: 11.8±53.9; p=0.362). The Pearson correlation co-efficient comparing the percent change of both leptin and NO was r2= -0.251 demonstrating a mildly negative, albeit insignificant, relationship between these factors. Together, these findings suggest that daily supplementation with 600 mg omega 3 in healthy females is not beneficial for improving these cardiovascular risk markers. Future studies in this area should include male subjects as well as overweight subjects with larger doses of fish oil that are equivalent to three or more servings per week. The importance of gender cannot be underestimated since estrogen has protective effects in the vasculature of females that may have masked any further protective effects of the fish oil. In addition, overweight individuals are often leptin-resistant and develop impaired vasodilation resulting from superoxide-mediated scavenging of nitric oxide. Therefore, the reported antioxidant and weight loss properties of omega 3 supplementation may greatly benefit overweight individuals.
ContributorsAlanbagy, Samer (Author) / Sweazea, Karen (Thesis advisor) / Johnston, Carol (Committee member) / Shepard, Christina (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2014
Description
Long term high fat diets (HFD) are correlated with the development of diabetes
and kidney disease. However, the impact of short term high fat intake on the etiology of kidney disease has not been well-studied. Therefore, this study examined the impact of a six week HFD (60% fat) on kidney structure and function in young male Sprague-Dawley rats. Previous studies have shown that these animals develop indices of diabetes compared to rats fed a standard rodent chow (5% fat) for six weeks. The hypothesis of this study is that six weeks of HFD will lead to early stages of kidney disease as evidenced by morphological and functional changes in the kidney. Alterations in morphology were determined by measuring structural changes in the kidneys (changes in mass, fatty acid infiltration, and structural damage). Alterations in kidney function were measured by analyzing urinary biomarkers of oxidative RNA/DNA damage, renal tissue lipid peroxidation, urinary markers of impaired kidney function (urinary protein, creatinine, and hydrogen peroxide (H2O2)), markers of inflammation (tumor necrosis factor alpha (TNFα) and interleukin 6 (IL-6)), as well as cystatin C, a plasma biomarker of kidney function. The results of these studies determined that short term HFD intake is not sufficient to induce early stage kidney disease. Beyond increases in renal mass, there were no significant differences between the markers of renal structure and function in the HFD and standard rodent chow-fed rats.
and kidney disease. However, the impact of short term high fat intake on the etiology of kidney disease has not been well-studied. Therefore, this study examined the impact of a six week HFD (60% fat) on kidney structure and function in young male Sprague-Dawley rats. Previous studies have shown that these animals develop indices of diabetes compared to rats fed a standard rodent chow (5% fat) for six weeks. The hypothesis of this study is that six weeks of HFD will lead to early stages of kidney disease as evidenced by morphological and functional changes in the kidney. Alterations in morphology were determined by measuring structural changes in the kidneys (changes in mass, fatty acid infiltration, and structural damage). Alterations in kidney function were measured by analyzing urinary biomarkers of oxidative RNA/DNA damage, renal tissue lipid peroxidation, urinary markers of impaired kidney function (urinary protein, creatinine, and hydrogen peroxide (H2O2)), markers of inflammation (tumor necrosis factor alpha (TNFα) and interleukin 6 (IL-6)), as well as cystatin C, a plasma biomarker of kidney function. The results of these studies determined that short term HFD intake is not sufficient to induce early stage kidney disease. Beyond increases in renal mass, there were no significant differences between the markers of renal structure and function in the HFD and standard rodent chow-fed rats.
ContributorsCrinigan, Catherine (Author) / Sweazea, Karen (Thesis advisor) / Johnston, Carol (Committee member) / Mayol-Kreiser, Sandra (Committee member) / Arizona State University (Publisher)
Created2015
Description
Birds have shown promise as models of diabetes due to health and longevity despite naturally high plasma glucose concentrations, a condition which in diabetic humans leads to protein glycation and various complications. Research into mechanisms that protect birds from high plasma glucose have shown that some species of birds have naturally low levels of protein glycation. Some hypothesize a diet rich in carotenoids and other antioxidants protects birds from protein glycation and oxidative damage. There is little research, however, into the amount of protein glycation in birds of prey, which consume a high protein, high fat diet. No studies have examined the potential link between the diet of carnivorous birds and protein glycation. The overall purpose of this study was to evaluate whether birds of prey have higher protein glycation given their high protein, high fat diet in comparison to chickens, which consume a diet higher in carbohydrates. This was accomplished through analyses of serum samples from select birds of prey (bald eagle, red-tailed hawk, barred owl, great horned owl). Serum samples were obtained from The Raptor Center at the University of Minnesota where the birds of prey consumed high protein, high fat, non-supplemented diets that consisted of small animals and very little to no carbohydrate. Serum was also obtained from one chicken for a control, which consumed a higher carbohydrate and antioxidant-rich diet. Glucose, native albumin glycation and antioxidant concentrations (uric acid, vitamin E, retinol and several carotenoids) of each sample was measured. Statistical analyses showed significant between group differences in percent protein glycation amongst the birds of prey species. Glycation was significantly higher (p < 0.001) in bald eagles (23.67 ± 1.90%) and barred owls (24.28 ± 1.43%) compared to red-tailed hawks (14.31 ± 0.63%). Percent glycation was higher in all birds of prey compared to the chicken sample and literature values for chicken albumin glycation. Levels of the carotenoid lutein were significantly higher in bald eagles and barred owls compared to great horned owls and red-tailed hawks and the carotenoids beta-cryptoxanthin and beta-carotene were significantly greater in bald eagles compared to red-tailed hawks and great horned owls.
ContributorsIngram, Tana (Author) / Sweazea, Karen (Thesis advisor) / Johnston, Carol (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2017
Description
Background. Despite research aimed at understanding the mechanisms of essential hypertension, instances of this condition continue to rise. Recent findings indicate that the administration of dietary nitrates, in the form of beetroot juice and other nitrate-rich vegetables, may offer anti-hypertensive effects in various study populations.
Objective. This randomized, placebo-controlled, crossover trial sought to compare the effects of high-nitrate vegetable salads to the effects of low-nitrate canned vegetables on plasma nitrate
itrite concentration, peripheral and central-aortic systolic and diastolic blood pressures, pulse wave velocity, and flow-mediated dilation.
Methods. Healthy, post-menopausal women (n=5; 80% Caucasian; 52.6 ± 5.7 years) with mildly elevated blood pressure (mean blood pressure ≥ 115/70 mm Hg and < 140/80 mm Hg) were randomly assigned to ingest a fresh, high-nitrate vegetable salad or a low-nitrate vegetable medley, twice per day, for a total of 10 consecutive days. Given the crossover design of the trial, participants observed a two to three week washout period followed by reassignment to the opposite condition. Findings were considered significant at a p-value < 0.05, and Wilcoxon Signed-Rank tests compared mean differences between conditions.
Results. Plasma nitrate
itrite concentration was significantly higher following consumption of the high-nitrate versus the low-nitrate condition (p = 0.043). Conversely, the differences in peripheral systolic and diastolic blood pressures were not statistically significant (p = 0.345 and p = 0.684 for systolic and diastolic pressures, respectively) nor were the differences in central-aortic systolic and diastolic blood pressures statistically significant (p = 0.225 and p = 0.465 for systolic and diastolic pressures, respectively). Similarly, when comparing the effects of the high-nitrate condition to the low-nitrate condition, the difference in pulse wave velocity was not statistically significant (p = 0.465). Finally, flow-mediated dilation tended to improve following consumption of the high nitrate condition (p = 0.080).
Conclusion. Twice daily consumption of a fresh, high-nitrate vegetable salad significantly increased plasma nitrate
itrite concentration. Although the trial was underpowered, there was a trend for improved flow-mediated dilation. Finally, twice daily consumption of a fresh, high-nitrate vegetable salad did not significantly lower peripheral or central-aortic systolic or diastolic blood pressures or pulse wave velocity.
Objective. This randomized, placebo-controlled, crossover trial sought to compare the effects of high-nitrate vegetable salads to the effects of low-nitrate canned vegetables on plasma nitrate
itrite concentration, peripheral and central-aortic systolic and diastolic blood pressures, pulse wave velocity, and flow-mediated dilation.
Methods. Healthy, post-menopausal women (n=5; 80% Caucasian; 52.6 ± 5.7 years) with mildly elevated blood pressure (mean blood pressure ≥ 115/70 mm Hg and < 140/80 mm Hg) were randomly assigned to ingest a fresh, high-nitrate vegetable salad or a low-nitrate vegetable medley, twice per day, for a total of 10 consecutive days. Given the crossover design of the trial, participants observed a two to three week washout period followed by reassignment to the opposite condition. Findings were considered significant at a p-value < 0.05, and Wilcoxon Signed-Rank tests compared mean differences between conditions.
Results. Plasma nitrate
itrite concentration was significantly higher following consumption of the high-nitrate versus the low-nitrate condition (p = 0.043). Conversely, the differences in peripheral systolic and diastolic blood pressures were not statistically significant (p = 0.345 and p = 0.684 for systolic and diastolic pressures, respectively) nor were the differences in central-aortic systolic and diastolic blood pressures statistically significant (p = 0.225 and p = 0.465 for systolic and diastolic pressures, respectively). Similarly, when comparing the effects of the high-nitrate condition to the low-nitrate condition, the difference in pulse wave velocity was not statistically significant (p = 0.465). Finally, flow-mediated dilation tended to improve following consumption of the high nitrate condition (p = 0.080).
Conclusion. Twice daily consumption of a fresh, high-nitrate vegetable salad significantly increased plasma nitrate
itrite concentration. Although the trial was underpowered, there was a trend for improved flow-mediated dilation. Finally, twice daily consumption of a fresh, high-nitrate vegetable salad did not significantly lower peripheral or central-aortic systolic or diastolic blood pressures or pulse wave velocity.
ContributorsMayra, Selicia (Author) / Sweazea, Karen (Thesis advisor) / Johnston, Carol (Committee member) / Mayol-Kreiser, Sandra (Committee member) / Arizona State University (Publisher)
Created2017
Description
Cardiovascular disease is the leading cause of death in the world, responsible for 17.3 million deaths annually. Aerobic activity and almond ingestion have a cardio-protective effect against cardiovascular disease, however, the synergistic effect of both interventions is not known. This 8-week randomized, parallel, two-arm study examined the combined effect of daily almond ingestion (2.5 ounces) and brisk walking (10,000 steps per day) compared to ingestion of an isocaloric placebo (4 Tbsp cookie butter) and brisk walking (10,000 steps per day) in sedentary adults on various markers of cardiovascular health. The additive effect of the daily walking intervention with almond consumption resulted in significant differences in total cholesterol with a -11.0 ± 10.5 and +3.3 ± 15.8 mg/dL (p=0.043) change in the ALM and CON group respectively and LDL with a -11.5 ± 7.5 and +0.5 ± 13.7 mg/dL (p=0.025) change in the ALM and CON group respectively. There was a trend for TBARS to decrease in the ALM group versus the CON group (-0.2 ± 0.8 and +0.3 ± 0.6 nmol MDA/mL (p=0.099) respectively) with a large effect size of 0.304 but this did not reach statistical significance. There were no significant differences seen in markers of other plasma lipid profile measures, plasma inflammatory cytokines, or blood pressure regulation. Results suggest that the simple, cost-effective, and accessible intervention of daily brisk walking and almond consumption is an effective strategy to reduce cardiovascular disease risk in sedentary adults through improvements in cholesterol. This represents a pilot study due to the small sample size, therefore, additional studies are needed to determine the impact and mechanisms of this synergistic effect.
ContributorsSchwab, Emily (Author) / Sweazea, Karen (Thesis advisor) / Johnston, Carol (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2017
Description
This feasibility study explored the use of an evolutionary mismatch narrative in nutritional education intervention aiming to reduce ultra-processed foods in the diets of veterans with type 2 diabetes and improve diabetic outcomes. Ultra-processed foods are foods that are primarily manufactured through industrial processes. These foods are high in calories but low in nutritional content. Diets high in these foods have been linked to increased health risks. One of the major health risks is type 2 diabetes. Type 2 diabetes is a chronic disease that is developed when cells become unable to properly utilize insulin. Over time this may lead to additional health conditions such as nerve damage, cardiovascular disease, and renal disease. Evolutionary mismatch narrative nutritional intervention offers a different approach to nutritional education to help reduce ultra-processed foods in diets. This study was a randomized controlled feasibility study at the Phoenix VA. Eleven participants were enrolled and randomly selected to be given either an evolutionary mismatch narrative education intervention or general nutritional education about ultra-processed foods. 24-hour diet recalls and blood chemistry were collected and analyzed. Blood chemistry provided diabetes related measurements which included glucose, HbA1c, insulin, HOMA-IR, and C-reactive protein. Statistically significant findings in this study included percentage of ultra-processed foods decreasing for both control and experimental groups from week 0 to week 4 (p=0.014), and C-reactive protein levels between the control and experimental groups (p=0.042). However, baseline C-reactive protein concentrations were lower in the experimental group such that normalizing for group differences at baseline revealed no significant difference in C-reactive protein change between interventions (p = 1.000). There were no other statistically significant values regarding diabetes related measurements. The results from this study suggest that nutritional education in general may help decrease ultra-processed food consumption.
ContributorsLiang, Nathan Adam (Author) / Sweazea, Karen (Thesis advisor) / Basile, Anthony J (Committee member) / Johnston, Carol (Committee member) / Arizona State University (Publisher)
Created2023
Description
The glycation of plasma proteins leading to the production of advanced glycation end products (AGEs) and subsequent damage is a driving factor in the pathophysiology of diabetic complications. The overall research objective was to elucidate the mechanisms by which birds prevent protein glycation in the presence of naturally high plasma glucose concentrations. This was accomplished through the specific purpose of examining the impact of temperature and glucose concentration on the percent glycation of chicken serum albumin (CSA) in comparison to human serum albumin (HSA). Purified CSA and HSA solutions prepared at four different glucose concentrations (0 mM, 5.56 mM, 11.11 mM, and 22.22 mM) were incubated at three different temperatures (37.0°C, 39.8°C, and 41.4°C) on separate occasions for seven days with aliquots extracted on days 0, 3, and 7. Samples were analyzed by LC-ESI-MS for percent glycation of albumin. The statistically significant interaction between glucose concentration, temperature, albumin type, and time as determined by four-way repeated measures ANOVA (p = 0.032) indicated that all independent variables interacted to affect the mean percent glycation of albumin. As glucose concentration increased, the percent glycation of both HSA and CSA increased over time at all temperatures. In addition, HSA was glycated to a greater extent than CSA at the two higher glucose concentrations examined for all temperature conditions. Temperature differentially affected percent glycation of HSA and CSA wherein glycation increased with rising temperatures for HSA but not CSA. The results of this study suggest an inherent difference between the human and chicken albumin that contributes to the observed differences in glycation. Further research is needed to characterize this inherent difference in an effort to elucidate the mechanism by which birds protect plasma proteins from glycation. Future related work has the potential to lead to the development of novel therapies to prevent or reverse protein glycation prior to the formation of AGEs in humans, thus preventing the development and devastating effects of numerous diabetic complications.
ContributorsZuck, Jessica (Author) / Sweazea, Karen (Thesis advisor) / Johnston, Carol (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2016
Description
In the United States, two-thirds of adults are considered hypertensive orprehypertensive. In addition, chronic illness, such as hypertension, cardiovascular disease, and type II diabetes, results in $3.5 trillion in annual healthcare cost and is the primary cause of disability and death. As a result, many individuals seek cheaper and simpler alternatives to combat their conditions. In this exploratory analysis, a study assessing nitrate intake and its effects on vascular function in 39 young adult males was investigated for underlying metabolic variations through a liquid chromatography – mass spectrometry-based large-scale targeted metabolomics approach. A two-way repeated measures ANOVA was used, and 18 significant metabolites were discovered across the time, treatment, and time & treatment groups, including prostaglandin E2 (p<0.001), stearic acid (p=0.002), caprylic acid (p=0.016), pentadecanoic acid (p=0.027), and heptadecanoic acid (p=0.005). In addition, log-transformed principal component analysis and orthogonal partial least squares – discriminant analysis models demonstrated distinct separation among the treatment, control, and time variables. Moreover, pathway and enrichment analyses validated the effect of nitrate intake on the metabolite sets and its possible function in fatty acid oxidation. This better understanding of altered metabolic pathways may help explicate the benefits of nitrate on vascular function and reveal any unknown mechanisms of its supplementation.
ContributorsPatterson, Jeffrey (Author) / Gu, Haiwei (Thesis advisor) / Johnston, Carol (Committee member) / Sweazea, Karen (Committee member) / Arizona State University (Publisher)
Created2020