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- Genre: Doctoral Dissertation
Description
Heart failure is a major worldwide health concern and is the leading cause of hospitalization among elderly Americans. Approximately 50% of those diagnosed with heart failure have heart failure with preserved ejection fraction (HFPEF). HFPEF presents a therapeutic dilemma because pharmacological strategies that are effective for the treatment of heart failure and reduced ejection fraction have failed to show benefit in HFPEF. Long term moderate intensity exercise programs have been shown to improve diastolic function in patients HFPEF. High intensity interval training (HIIT) has been shown to improve diastolic function in patients with heart failure and reduced ejection fraction. However, the effects of high intensity interval training in patients with HFPEF are unknown. Fourteen patients with HFPEF were randomized to either: (1) a novel program of high-intensity aerobic interval training (n = 8), or (2) a commonly prescribed program of moderate-intensity (MOD) aerobic exercise training (n = 6). Before and after four weeks of exercise training, patients underwent a treadmill graded exercise test for the determination of peak oxygen uptake (VO2peak), a brachial artery reactivity test for assessment of endothelium-dependent flow-mediated dilation (BAFMD), aortic pulse wave velocity assessment as an index of vascular stiffness and two-dimensional echocardiography for assessment of left ventricular diastolic and systolic function. I hypothesized that (1) high-intensity aerobic interval training would result in superior improvements in FMD, aortic pulse wave velocity, VO2peak, diastolic function and, (2) changes in these parameters would be correlated with changes in VO2peak. The principal findings of the study were that a one month long high intensity interval training program resulted in significant improvements in diastolic function as measured by two-dimensional echocardiography [pre diastolic dysfunction (DD) grade - 2.13 + 0.4 vs. post DD grade - 1.25 + 0.7, p = 0.03]. The left atrial volume index was reduced in the HIIT group compared to MOD ( - 4.4 + 6.2 ml/m2 vs. 5.8 + 10.7 ml/m2, p = 0.02). Early mitral flow (E) improved in the HIIT group (pre - 0.93 + 0.2 m/s vs. post - 0.78 + 0.3 m/s, p = 0.03). A significant inverse correlation was observed between change in BAFMD and change in diastolic dysfunction grade (r = - 0.585, p = 0.028) when all the data were pooled. HIIT appears to be a time-efficient and safe strategy for improving diastolic function in patients with heart failure and preserved ejection fraction. These data may have implications for cardiovascular risk reduction in this population.
ContributorsAngadi, Siddhartha (Author) / Gaesser, Glenn A (Thesis advisor) / Mookadam, Farouk (Committee member) / Swan, Pamela (Committee member) / Vega-Lopez, Sonia (Committee member) / Lee, Chong (Committee member) / Arizona State University (Publisher)
Created2012
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
PURPOSE: Lean hypertension (HTN) is characterized by a mechanistically different HTN when compared to obese HTN. The purpose of this study is to assess whether body phenotype influences blood pressure (BP) responses following both acute and chronic exercise. METHODS: Obese (body mass index (BMI) > 30 kg/m2) and lean (BMI < 25 kg/m2) men with pre-hypertension (PHTN) (systolic BP (SBP) 120 - 139 or diastolic BP (DBP) 80 - 89 mm Hg) were asked to participate in a two-phase trial. Phase 1 assessed differences in post-exercise hypotension between groups in response to an acute exercise bout. Phase 2 consisted of a two-week aerobic exercise intervention at 65-70% of heart rate (HR) max on a cycle ergometer. Primary outcome measures were: brachial BP, central (aortic) BP, cardiac output (CO), and systemic vascular resistance (SVR) measured acutely after one exercise session and following two weeks of training. RESULTS: There were no differences between groups for baseline resting brachial BP, central BP, age, or VO2 peak (all P > 0.05). At rest, obese PHTN had greater CO compared to lean PHTN (6.3 ± 1 vs 4.7 ± 1 L/min-1, P = 0.005) and decreased SVR compared to lean PHTN (1218 ± 263 vs 1606 ± 444 Dyn.s/cm5, P = 0.003). Average 60-minute post-exercise brachial and central SBP reduced by 3 mm Hg in Lean PHTN in response to acute exercise (P < 0.005), while significantly increasing 4 mm Hg for brachial and 3 mm Hg for central SBP (P < 0.05). SVR had a significantly greater reduction following acute exercise in lean PHTN (-223 Dyn·s/cm5) compared to obese PHTN (-75 Dyn·s/cm5, P < 0.001). In lean subjects chronic training reduced brachial BP by 4 mm Hg and central BP by 3 mm Hg but training had no effect on the BP’s in obese subjects. Resting BP reduction in response to training was accompanied by reductions in SVR within lean (-169 Dyn·s/cm5, P < 0.001), while obese experienced increased SVR following training (47 Dyn·s/cm5, P < 0.001). CONCLUSION: Hemodynamic response to both acute and chronic exercise training differ between obese and lean individuals.
ContributorsZeigler, Zachary (Author) / Swan, Pamela (Thesis advisor) / Gaesser, Glenn (Committee member) / Buman, Matthew (Committee member) / Angadi, Siddhartha (Committee member) / Farouk, Mookadam (Committee member) / Arizona State University (Publisher)
Created2016
Description
Sustainability, as it relates to nutrition, affects all aspects of food from systems-level production to consumption. Viability of local food systems in the southwest of the United States has been largely understudied. In order to address this gap in the literature, semi-structured interviews were conducted with 20 farmers in Arizona and New Mexico to determine best practices, challenges and barriers to farming. Interviews were recorded, transcribed, and coded for themes. Many trends were consistent with those reported elsewhere in the US, but the importance of water emerged, a unique need not explicitly noted in other regional studies.
Vegetarian diets are typically more sustainable than omnivorous ones due to using less environmental resources in the production of food. An important consideration with plant protein and vegetarian diets, however, is whether this would affect athletic performance. To examine this, 70 male and female endurance athletes were compared for maximal oxygen uptake (VO2 max), peak torque when doing leg extensions, and body composition. Vegetarians had higher VO2 max, but peak torque was not significantly different by diet. Omnivores had higher total body mass, lean body mass, and there was a trend for peak torque to be higher.
To investigate whether plant-protein can comparably support development of lean body mass and strength development in conjunction with strength training, 61 healthy young males and females began a 12-week training and protein supplementation study. While previous training studies have shown no differences for lean body mass or strength development when consuming either soy (plant) or whey (animal) protein supplements in very large amounts (>48 grams), when consuming around 15-20 grams, whey has contributed to greater lean body mass accrual, although strength increases remain similar. The present study matched supplements by leucine content instead of by total protein amount since leucine has been shown to be a key stimulator of muscle protein synthesis and is more concentrated in animal protein. There were no significant differences between the whey or soy group for lean body mass or strength development, as assessed using isokinetic dynamometry doing leg extensions and flexions.
Vegetarian diets are typically more sustainable than omnivorous ones due to using less environmental resources in the production of food. An important consideration with plant protein and vegetarian diets, however, is whether this would affect athletic performance. To examine this, 70 male and female endurance athletes were compared for maximal oxygen uptake (VO2 max), peak torque when doing leg extensions, and body composition. Vegetarians had higher VO2 max, but peak torque was not significantly different by diet. Omnivores had higher total body mass, lean body mass, and there was a trend for peak torque to be higher.
To investigate whether plant-protein can comparably support development of lean body mass and strength development in conjunction with strength training, 61 healthy young males and females began a 12-week training and protein supplementation study. While previous training studies have shown no differences for lean body mass or strength development when consuming either soy (plant) or whey (animal) protein supplements in very large amounts (>48 grams), when consuming around 15-20 grams, whey has contributed to greater lean body mass accrual, although strength increases remain similar. The present study matched supplements by leucine content instead of by total protein amount since leucine has been shown to be a key stimulator of muscle protein synthesis and is more concentrated in animal protein. There were no significant differences between the whey or soy group for lean body mass or strength development, as assessed using isokinetic dynamometry doing leg extensions and flexions.
ContributorsLynch, Heidi (Author) / Wharton, Christopher M (Thesis advisor) / Johnston, Carol (Committee member) / Dickinson, Jared (Committee member) / Buman, Matthew (Committee member) / Swan, Pamela (Committee member) / Ransdell, Lynda (Committee member) / Arizona State University (Publisher)
Created2017
Description
Physical activity is critical for optimal health and has emerged as a viable option to improve sleep. Moderate- and vigorous-intensity physical activity comparisons to improve sleep in non-exercising adults with sleep problems is limited. The purpose was to determine the effects of moderate- or vigorous-intensity exercise on sleep outcomes and peripheral skin temperature compared to a no-exercise control. The exercise intensity preference also was determined.
Eleven women (46.9±7.0 years) not participating in regular exercise and self-reporting insomnia completed a graded maximal exercise test followed by a crossover trial of three randomly assigned conditions separated by a 1-week washout. Participants performed moderate-intensity [MIC, 30 minutes, 65-70% maximum heart rate (HRmax)] or high-intensity (HIT, 20 minutes, 1-minute bouts at 90-95% HRmax alternating with 1-minute active recovery) treadmill walking or a no-exercise control (NEC) on two consecutive weekdays 4-6 hours prior to typical bed time. A dual-function wrist-worn accelerometer/temperature monitor recorded movement and skin temperature from which sleep-onset latency (SOL), sleep maintenance, sleep efficiency, total sleep time (TST), and peripheral skin temperature changes were calculated. Participants self-reported sleep outcomes weekly, enjoyment of exercise the morning after HIT and MIC, and exercise intensity preference upon completing all conditions. Mixed models analysis of variance examined differences between and within conditions controlling for demographic characteristics and habitual physical activity.
HIT resulted in up to a 90-minute TST increase on night four (448 minutes, 95% CI 422.4-474.2) compared to nights one-three. MIC nights three (43.5 minutes, 95% CI 30.4-56.6) and four (42.1 minutes 95% CI 29.0-55.2) showed nearly a 30-minute SOL worsening compared to nights one-two. No other actigraphy-measured sleep parameters differenced within or between conditions. Self-reported sleep outcomes, peripheral skin temperature change, and exercise enjoyment between conditions were similar (p>0.05). More participants preferred lower (n=3) to higher (n=1) intensity activities.
Early evening high-intensity and moderate-intensity exercise had no effect on sleep outcomes compared to a control in non-exercising adults reporting sleep complaints. Sleep benefits from HIT may require exercise on successive days. Participants indicated partiality for lower intensity exercise. More information on timing and mode of physical activity to improve sleep in this population is warranted.
Eleven women (46.9±7.0 years) not participating in regular exercise and self-reporting insomnia completed a graded maximal exercise test followed by a crossover trial of three randomly assigned conditions separated by a 1-week washout. Participants performed moderate-intensity [MIC, 30 minutes, 65-70% maximum heart rate (HRmax)] or high-intensity (HIT, 20 minutes, 1-minute bouts at 90-95% HRmax alternating with 1-minute active recovery) treadmill walking or a no-exercise control (NEC) on two consecutive weekdays 4-6 hours prior to typical bed time. A dual-function wrist-worn accelerometer/temperature monitor recorded movement and skin temperature from which sleep-onset latency (SOL), sleep maintenance, sleep efficiency, total sleep time (TST), and peripheral skin temperature changes were calculated. Participants self-reported sleep outcomes weekly, enjoyment of exercise the morning after HIT and MIC, and exercise intensity preference upon completing all conditions. Mixed models analysis of variance examined differences between and within conditions controlling for demographic characteristics and habitual physical activity.
HIT resulted in up to a 90-minute TST increase on night four (448 minutes, 95% CI 422.4-474.2) compared to nights one-three. MIC nights three (43.5 minutes, 95% CI 30.4-56.6) and four (42.1 minutes 95% CI 29.0-55.2) showed nearly a 30-minute SOL worsening compared to nights one-two. No other actigraphy-measured sleep parameters differenced within or between conditions. Self-reported sleep outcomes, peripheral skin temperature change, and exercise enjoyment between conditions were similar (p>0.05). More participants preferred lower (n=3) to higher (n=1) intensity activities.
Early evening high-intensity and moderate-intensity exercise had no effect on sleep outcomes compared to a control in non-exercising adults reporting sleep complaints. Sleep benefits from HIT may require exercise on successive days. Participants indicated partiality for lower intensity exercise. More information on timing and mode of physical activity to improve sleep in this population is warranted.
ContributorsKurka, Jonathan M (Author) / Ainsworth, Barbara E (Thesis advisor) / Adams, Marc A (Committee member) / Angadi, Siddhartha (Committee member) / Buman, Matthew P (Committee member) / Youngstedt, Shawn D (Committee member) / Arizona State University (Publisher)
Created2016
Description
High fiber diets have been associated with improved cardiometabolic health with specific efforts to lower circulating levels of low-density lipoprotein (LDL cholesterol). Whole grain and grain-based foods are major contributors of dietary fiber in the American diet, of which wheat has been extensively studied. Corn, however, has not been well studied for its cholesterol-lowering properties. Further, the mechanisms by which grains improve cardiometabolic health require further exploration with regard to the human microbiome. The objective of this single-blind randomized controlled, crossover trial was to assess the impact of three different corn flours (whole grain, refined, and bran-enhanced refined flour mixture) on serum LDL cholesterol and the gut microbiota diversity and composition. Twenty-three participants were recruited, between the ages of 18-70 with hypercholesterolemia (Male = 10, Female = 13, LDL >120 mg/dL) who were not taking any cholesterol-lowering medications. Participants consumed each flour mixture for 4 weeks prepared as muffins and pita breads. At the beginning and end of each 4-week period serum for cholesterol assessment, anthropometrics, and stool samples were obtained. Serum cholesterol was assessed using a clinical analyzer. Stool samples were processed, and microbial DNA extracted and sequenced based on the 16S rRNA gene. A generalized linear model demonstrated a significant treatment effect (p=0.016) on LDL cholesterol and explained a majority of the variance (R-squared= 0.89). Post hoc tests revealed bran-enhanced refined flour had a significant effect on cholesterol in comparison to whole grain flour (p=0.001). No statistically significant differences were observed for gut microbial community composition (Jaccard and weighted Unifrac) after corn consumption. However, relative abundance analysis (LEfSE) identified Mycobacterium celatum (p=0.048 FDR=0.975) as a potential marker of post-corn consumption with this microbe being differentially less abundant following bran-enhanced flour treatment. These data suggest that corn flour consumption may be beneficial for individuals with hypercholesterolemia but the role of gut microbiota in this relationship requires further exploration, especially given the small sample size. Further research and analysis of a fully powered cohort is needed to more accurately describe the associations and potential mechanisms of corn-derived dietary fiber on circulating LDL cholesterol and the gut microbiota.
ContributorsWilson, Shannon L (Author) / Whisner, Corrie M (Thesis advisor) / Sears, Dorothy (Committee member) / Buman, Matthew (Committee member) / Dickinson, Jared (Committee member) / Zhu, Qiyun (Committee member) / Arizona State University (Publisher)
Created2022
Description
Wearable technology has brought in a rapid shift in the areas of healthcare and lifestyle management. The recent development and usage of wearable devices like smart watches has created significant impact in areas like fitness management, exercise tracking, sleep quality assessment and early diagnosis of diseases like asthma, sleep apnea etc. This thesis is dedicated to the development of wearable systems and algorithms to fulfill unmet needs in the area of cardiorespiratory monitoring.
First, a pneumotach based flow sensing technique has been developed and integrated into a face mask for respiratory profile tracking. Algorithms have been developed to convert the pressure profile into respiratory flow rate profile. Gyroscope-based correction is used to remove motion artifacts that arise from daily activities. By using Principal Component Analysis, the follow-up work established a unique respiratory signature for each subject based on the flow profile and lung parameters computed using the wearable mask system.
Next, wristwatch devices to track transcutaneous gases like oxygen (TcO2) and carbon dioxide (TcCO2), and oximetry (SpO2) have been developed. Two chemical sensing approaches have been explored. In the first approach, miniaturized low-cost commercial sensors have been integrated into the wristwatch for transcutaneous gas sensing. In the second approach, CMOS camera-based colorimetric sensors are integrated into the wristwatch, where a part of camera frame is used for photoplethysmography while the remaining part tracks the optical signal from colorimetric sensors.
Finally, the wireless connectivity using Bluetooth Low Energy (BLE) in wearable systems has been explored and a data transmission protocol between wearables and host for reliable transfer has been developed. To improve the transmission reliability, the host is designed to use queue-based re-request routine to notify the wearable device of the missing packets that should be re-transmitted. This approach avoids the issue of host dependent packet losses and ensures that all the necessary information is received.
The works in this thesis have provided technical solutions to address challenges in wearable technologies, ranging from chemical sensing, flow sensing, data analysis, to wireless data transmission. These works have demonstrated transformation of traditional bench-top medical equipment into non-invasive, unobtrusive, ergonomic & stand-alone healthcare devices.
First, a pneumotach based flow sensing technique has been developed and integrated into a face mask for respiratory profile tracking. Algorithms have been developed to convert the pressure profile into respiratory flow rate profile. Gyroscope-based correction is used to remove motion artifacts that arise from daily activities. By using Principal Component Analysis, the follow-up work established a unique respiratory signature for each subject based on the flow profile and lung parameters computed using the wearable mask system.
Next, wristwatch devices to track transcutaneous gases like oxygen (TcO2) and carbon dioxide (TcCO2), and oximetry (SpO2) have been developed. Two chemical sensing approaches have been explored. In the first approach, miniaturized low-cost commercial sensors have been integrated into the wristwatch for transcutaneous gas sensing. In the second approach, CMOS camera-based colorimetric sensors are integrated into the wristwatch, where a part of camera frame is used for photoplethysmography while the remaining part tracks the optical signal from colorimetric sensors.
Finally, the wireless connectivity using Bluetooth Low Energy (BLE) in wearable systems has been explored and a data transmission protocol between wearables and host for reliable transfer has been developed. To improve the transmission reliability, the host is designed to use queue-based re-request routine to notify the wearable device of the missing packets that should be re-transmitted. This approach avoids the issue of host dependent packet losses and ensures that all the necessary information is received.
The works in this thesis have provided technical solutions to address challenges in wearable technologies, ranging from chemical sensing, flow sensing, data analysis, to wireless data transmission. These works have demonstrated transformation of traditional bench-top medical equipment into non-invasive, unobtrusive, ergonomic & stand-alone healthcare devices.
ContributorsTipparaju, Vishal Varun (Author) / Xian, Xiaojun (Thesis advisor) / Forzani, Erica (Thesis advisor) / Blain Christen, Jennifer (Committee member) / Angadi, Siddhartha (Committee member) / Arizona State University (Publisher)
Created2020