Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
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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
Exposure to sun radiation (SUR) with ambient temperature may be an influencer on athletes’ sweat loss in different environments, but the results are not currently known. The purpose of this study was to determine the effects of SUR on fluid balance (FB) and hydration status (HS) in athletes exercising indoors and outdoors.
Initial FB and HS were assessed in NCAA-DI female soccer athletes (n=10) of a single team in temperate, dry conditions (55-68°F, 18-48% humidity) who were monitored during 3 practices of equal estimated energy expenditure (EE): two outdoors in direct SUR (cold/moderate temperatures) and one indoors without SUR (moderate temperatures). Humidity, temperature, and wet bulb globe temperature (WBGT – a measurement partly based on SUR, including ambient temperature/relative humidity) were recorded using Heat Stress Meters placed in the direct sun or in the shade. Each athlete’s semi-nude dry body weight was recorded before and after exercise. Urine samples were taken before, after, and the morning after. Urine specific gravity (USG) was tested to assess HS. Athletes wore combined heart rate and activity monitors to estimate EE and were provided ad libitum water and/or a zero-calorie sports drink. Their total intake included weights of consumed food and drink. Sweat rate was calculated using body weight change and intakes of liquids minus urine losses/hour.
Two-way repeated measures ANOVA analyzed group-level differences. No significance was found in total FB (1.01±0.32 L/hr) or EE/hr (444±97.1 kcal/hr) across all days (p>0.05). In analyzing individual athlete results, 40% had consistent USG >1.025 (p=0.001) suggesting potential dehydration. These 4 athletes selected water as their beverage, of which is known that consuming only water does not stimulate drinking behavior as does electrolyte drinks. The remaining 60% were overall not dehydrated (USG <1.025) but must be aware of incidental dehydration in hotter temperatures.
The conclusion is that in low-moderate temperatures, athletes self-regulate drinking habits and achieve fluid balance during exercise with or without sun radiation. However, athletes with average USG >1.025 are likely to remain dehydrated in moderate temperatures. The findings suggest that more education would benefit these athletes by ensuring hydration in any environment.
Initial FB and HS were assessed in NCAA-DI female soccer athletes (n=10) of a single team in temperate, dry conditions (55-68°F, 18-48% humidity) who were monitored during 3 practices of equal estimated energy expenditure (EE): two outdoors in direct SUR (cold/moderate temperatures) and one indoors without SUR (moderate temperatures). Humidity, temperature, and wet bulb globe temperature (WBGT – a measurement partly based on SUR, including ambient temperature/relative humidity) were recorded using Heat Stress Meters placed in the direct sun or in the shade. Each athlete’s semi-nude dry body weight was recorded before and after exercise. Urine samples were taken before, after, and the morning after. Urine specific gravity (USG) was tested to assess HS. Athletes wore combined heart rate and activity monitors to estimate EE and were provided ad libitum water and/or a zero-calorie sports drink. Their total intake included weights of consumed food and drink. Sweat rate was calculated using body weight change and intakes of liquids minus urine losses/hour.
Two-way repeated measures ANOVA analyzed group-level differences. No significance was found in total FB (1.01±0.32 L/hr) or EE/hr (444±97.1 kcal/hr) across all days (p>0.05). In analyzing individual athlete results, 40% had consistent USG >1.025 (p=0.001) suggesting potential dehydration. These 4 athletes selected water as their beverage, of which is known that consuming only water does not stimulate drinking behavior as does electrolyte drinks. The remaining 60% were overall not dehydrated (USG <1.025) but must be aware of incidental dehydration in hotter temperatures.
The conclusion is that in low-moderate temperatures, athletes self-regulate drinking habits and achieve fluid balance during exercise with or without sun radiation. However, athletes with average USG >1.025 are likely to remain dehydrated in moderate temperatures. The findings suggest that more education would benefit these athletes by ensuring hydration in any environment.
ContributorsOlzinski, Stephanie (Author) / Wardenaar, Floris (Thesis advisor) / Johnston, Carol (Committee member) / Yudell, Amber (Committee member) / Arizona State University (Publisher)
Created2019
Description
Water is an essential nutrient that is often overlooked. As a result of this hydration status is often forgotten as well. Becoming hypohydrated puts athletes at risk of decreased performance and potentially life-threatening heat illness. Being able to self-assess hydration status is may be instrumental in helping athletes safely optimize performance. Therefore, this study investigated, 1) the ability of an athletic population vs. trained investigators to self-diagnose underhydration, 2) the diagnostic ability of urine color (Ucol) charts as a method for diagnosing underhydration, and 3) the accuracy of participant and investigator assessments. Members of an athletic population each provided a urine sample and scored samples using both the traditional 8-color and newly developed 7-color Ucol chart. Investigators then scored the samples using the same methods. To determine the diagnostic value of the Ucol charts, Ucol scores were compared to concentration measures of Urine Specific Gravity (USG) and Urine Osmolality (Uosm). Differences in participant and investigator scores were compared using Mann-Whitney U and Spearman’s Correlation. Bland-Altman plots were drawn to assess individual differences in reporting against the mean of the two methods. Receiver Operating Characteristic (ROC) analysis was used to both determine the ability of both charts to diagnose underhydration and to determine how well participants and investigators can determine their level of hydration. Athletes reported Ucol significantly lighter compared to investigators. Investigators showed no difference in reporting between the two charts but, athletes reported less than a color shade difference. The charts performed fair (8-color) to good (7-color) at diagnosing hypohydration. Athletes reported with less accuracy compared to investigators, and Ucol classification was found to be more accurate when compared to USG. Ucol charts are a practical tool to determine hydration status. Ucol scoring is similar regardless of the type of chart used. Trained investigators reported with slightly higher accuracy on both charts compared to untrained athletes. Athletes score Ucol fair to good in comparison to investigators. Ucol scoring is similar regardless of the type of chart used. The diagnostic ability of both Ucol charts is good in relation to USG. With education, athletes may be able to improve scores.
ContributorsPesek, Kathryn Margaret (Author) / Wardenaar, Floris (Thesis advisor) / Johnston, Carol (Committee member) / Yudell, Amber (Committee member) / Arizona State University (Publisher)
Created2022
Description
Tools designed to help match people with behaviors they identify as likely to lead to a successful behavioral outcome remain under-researched. This study assessed the effect of a participant-driven behavior-matching intervention on 1) the adoption of a new behavior related to fruit and vegetable (F&V) consumption, 2) study attrition, and 3) changes in F&V consumption. In this two-arm randomized controlled trial, 64 adults who did not meet standard F&V recommendations were allocated to an intervention (n=33) or control group (n=31). Participants in the intervention group ranked 20 F&V-related behaviors according to their perceived likelihood of engagement in the behavior and their perception of the behavior’s efficacy in increasing F&V consumption. Participants in the intervention group were subsequently shown the list of 20 behaviors in order of their provided rankings, with the highest-ranked behaviors at the top, and were asked to choose a behavior they would like to perform daily for 4 weeks. The control group chose from a random-order list of the same 20 behaviors to adopt daily for 4 weeks. During the study period, text messages were sent to all participants 90 minutes before their reported bedtime to collect Yes/No data reflecting successful behavior engagement each day. The binary repeated-measures data collected from the text messages was analyzed using mixed-effects logistic regression, differences in attrition were assessed using log-rank analysis, and change scores in F&V consumption were compared between the two groups using the Man-Whitney U test. P<0.05 indicated significance. The rate of successful behavior adoption did not differ significantly between the two groups (b=0.09, 95%CI= -0.81, 0.98, p=0.85). The log rank test results indicated that there was no significant difference in attrition between the two groups (χ2=2.68, df=1, p=0.10). F&V consumption increased significantly over the 4 weeks in the total sample (Z=-5.86, p<0.001), but no differences in F&V change scores were identified between the control and intervention groups (Z=-0.21, p=0.84). The behavior-matching tool assessed in this study did not significantly improve behavior adoption, study attrition, or F&V intake over 4 weeks.
ContributorsCosgrove, Kelly Sarah (Author) / Wharton, Christopher (Thesis advisor) / Adams, Marc (Committee member) / DesRoches, Tyler (Committee member) / Grebitus, Carola (Committee member) / Johnston, Carol (Committee member) / Arizona State University (Publisher)
Created2023
Description
A large amount of research associates the lack of fruit and vegetable consumption and the intake of animal-based foods with poor health outcomes. Making shifts towards a plant-focused diet could benefit the health of individuals. Individuals who show the highest long-term adherence to the avoidance of animal-based foods are those who value animal welfare. PURPOSE: The primary purpose of this study is to explore the validity of a novel animal food frequency questionnaire (AFFQ) in relation to dietary animal food intake using 3-day dietary food logs and measuring potential renal acid load (PRAL). PRAL is the amount of acid that is produced by the body after digesting food. Fruits and vegetables produce a lower acid load, which is reflective of positive health outcomes. A secondary aim of this study is to explore the relation between AFFQ scores and measures of empathy. METHODS: Participants complete a 10-minute survey including the AFFQ and the BES-A. The Basic Scale of Empathy for adults will be viewed based on the 2 factor and 3 factor analysis assessing: Affective empathy, Cognitive empathy, Emotional contagion, and Emotional Disconnection. The AFFQ will be scored and correlated with the 3-day food log and PRAL to explore validity of the new AFFQ scale. Secondarily, the AFFQ will be scored and correlated with the BES-A to explore an association. RESULTS: The null hypotheses H01 and H02 were rejected. H01 showed that AFFQ correlates significantly with percentage of dietary protein coming from animal- based products (r=.676, p=.016). H02 showed AFFQ has a significant correlation to PRAL (r=.831, p<.001). PRAL and the percentage of protein in the diet coming from animal-based products have a significant correlation (r=.725, p=.008). The null hypothesis H03 was accepted with AFFQ and BES-A 2 factor and 3 factor’s correlations showing (r= -.412, p=.183) and (r= -.307, p=.332). CONCLUSION: The AFFQ was able to reflect differences in frequency of animal-based food intake among the convenience sample. The AFFQ and individuals’ food choices were not related to their empathy levels.
ContributorsAlpine, Evajean May (Author) / Wharton, Christopher (Thesis advisor) / Lehmann, Jessica (Committee member) / Johnston, Carol (Committee member) / Arizona State University (Publisher)
Created2021
Description
Low water intake and underhydration are public health issues that may increase risk for diseases such as Type 2 Diabetes Mellitus. Studies suggest that high vasopressin (AVP) levels associated with low water intake may contribute to hyperglycemia. This study explored the physiological system by which AVP impairs glucose regulation through a single-blind randomized, counterbalanced, crossover design. This is a pilot and feasibility study of AVP infusion at increasing incremental rates, which was completed to determine the rate of infusion for the cross-over study. Participants completed a control and experimental trial. The experimental trial included a 3-hour AVP infusion and a 2-hour euglycemic-hyper insulinemic clamp at the end of the first hour versus control of 0.9% sodium chloride replacing AVP. In both trials, blood samples were taken every 5 minutes to measure glucose, as well as 7 other time points of insulin infusion. Two participants completed the pilot (47.5±3.5 years, 172.5 ±7.5cm, 82.5±17.7kg, 27.5±3.5 kg/m2, 5.1±0.64% HbA1c), and 3 participants completed the cross-over study (49±1.7 years, 173.7±6.7cm, 80.4±150kg, 26.5±3.2kg/m2, 5.3±0.2% HbA1c), all females. The rate of AVP infusion for the cross-over study was 12.5 mU/min. Compared to the control, the AVP trial blood glucose trended higher towards the end of the experiment, as did glucose metabolism, plasma osmolality, and plasma volume. Blood pressure was slightly higher in the AVP trial versus the saline, while plasma sodium and potassium levels did not differ. Total plasma protein seemed higher in the saline trials than in the AVP trials. This study supports the notion that increased levels of vasopressin over time may increase blood glucose. This could lead to supplementation of type 2 diabetes interventions with increased water intake.
ContributorsAcri, Emily Suzanne (Author) / Kavouras, Stavros (Thesis advisor) / Johnston, Carol (Committee member) / Shepard, Christina (Committee member) / Arizona State University (Publisher)
Created2024