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Walking interventions focused on increasing step counts are typically associated with salutary effects on glycemia, fasting insulin, insulin resistance and blood lipids which may be in turn associated with improvements in cardiorespiratory fitness (peak oxygen uptake – VO2peak) and vascular stiffness. We hypothesized that a novel 4-month, behavioral economics-based walking intervention would have favorable effects on glucose homeostasis and blood lipids and that these in turn would be related to VO2peak and vascular stiffness (carotid femoral pulse wave velocity – cfPWV).
We carried out secondary analyses on a subsample of sedentary, overweight/obese adults who participated in a 4-month, 2x2, randomized-controlled walking intervention examining the effects of goal setting (static v. adaptive goals) and rewards (immediate v. delayed) on steps/day (N=96). Fasting blood samples (n=58) were collected from participants before and after the intervention. Premenopausal females were in the follicular phase of their menstrual cycles. Lipid and glucose levels were measured using an automated chemistry analyzer, while insulin was measured using radio-immunoassay. Homeostatic model of insulin resistance (HOMA-IR) was calculated using the following formula (HOMA-IR=glucose x insulin / 405). We examined associations [partial correlations (adjusted for age)] between changes in blood biomarkers and VO2peak and cfPWV, irrespective of group, and we used linear mixed models to examine between-group differences in levels of and change in biomarker outcomes.
Groups did not differ in overall levels of, or degree of change in, biomarker outcomes (all p>0.05). Mean changes, irrespective of group, in biomarkers were as follows: glucose Δ= 0.74± 4.5mg/dl; insulin Δ= 0.09 ± 4.1 µU/ml; total cholesterol Δ= 0.24 ± 20.6 mg/dl; HDL-C Δ= 0.27 ± 5.1 mg/dl; LDL-C Δ= 1.3 ± 19.9 mg/dl; triglycerides Δ= 1.7 ± 27.2 mg/dl; HOMA-IR Δ = -.0548 ± 1.05). We found no significant associations between change in biomarker levels and change in VO2peak or change in cfPWV (all correlation coefficients < 0.15; p > 0.05).
A 4-month, behavioral economics-based mHealth intervention focused on increasing steps/day did not bring about favorable changes on markers of glycemia, insulin resistance and blood lipids.
We carried out secondary analyses on a subsample of sedentary, overweight/obese adults who participated in a 4-month, 2x2, randomized-controlled walking intervention examining the effects of goal setting (static v. adaptive goals) and rewards (immediate v. delayed) on steps/day (N=96). Fasting blood samples (n=58) were collected from participants before and after the intervention. Premenopausal females were in the follicular phase of their menstrual cycles. Lipid and glucose levels were measured using an automated chemistry analyzer, while insulin was measured using radio-immunoassay. Homeostatic model of insulin resistance (HOMA-IR) was calculated using the following formula (HOMA-IR=glucose x insulin / 405). We examined associations [partial correlations (adjusted for age)] between changes in blood biomarkers and VO2peak and cfPWV, irrespective of group, and we used linear mixed models to examine between-group differences in levels of and change in biomarker outcomes.
Groups did not differ in overall levels of, or degree of change in, biomarker outcomes (all p>0.05). Mean changes, irrespective of group, in biomarkers were as follows: glucose Δ= 0.74± 4.5mg/dl; insulin Δ= 0.09 ± 4.1 µU/ml; total cholesterol Δ= 0.24 ± 20.6 mg/dl; HDL-C Δ= 0.27 ± 5.1 mg/dl; LDL-C Δ= 1.3 ± 19.9 mg/dl; triglycerides Δ= 1.7 ± 27.2 mg/dl; HOMA-IR Δ = -.0548 ± 1.05). We found no significant associations between change in biomarker levels and change in VO2peak or change in cfPWV (all correlation coefficients < 0.15; p > 0.05).
A 4-month, behavioral economics-based mHealth intervention focused on increasing steps/day did not bring about favorable changes on markers of glycemia, insulin resistance and blood lipids.
ContributorsHook, Benjamin E. (Author) / Angadi, Siddhartha (Thesis director) / Gaesser, Glenn (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
With an excessive amount of resources in the United States healthcare system being spent on the treatment of diseases that are largely preventable through lifestyle change, the need for successful physical activity interventions is apparent. Unfortunately an individual's physical activity and health goals are often not supported by the social context of their daily lives. This single-case design study, Walking Intervention through Text messaging for CoHabiting individuals (WalkIT CoHab), looks at the efficacy of a text based adaptive physical activity intervention to promote walking over a three month period and the effects of social support in intervention performance in three pairs of cohabiting pairs of individuals (n=6). Mean step increase from baseline to intervention ranged from 1300 to 3000 steps per day for all individuals, an average 45.87% increase in physical activity. Goal attainment during the intervention ranged from 43.96% to 71.43%, meaning all participants exceeded the 40% success rate predicted by 60th percentile goals. Social support scores for study partners, unlike social support scores for family and friends, were often in the high social support range and had a moderate increase from pre to post visits for most participants. Although there was variation amongst participants, there was a high correlation in physical activity trends and successful goal attainment in each pair of participants. Less ambitious percentile goals and more personalized motivational text messages might be beneficial to some participants. An extended intervention, something the majority of participants expressed interest in, would further support the efficacy of this behavioral intervention and allow for possible long term benefits of social support in the intervention to be investigated.
ContributorsFernandez, Jacqueline Alyssa (Author) / Adams, Marc (Thesis director) / Angadi, Siddhartha (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Background: Cardiovascular disease (CVD) is the leading cause of mortality in the United States and remains a great public health challenge. Unhealthy lifestyle behaviors (e.g., unhealthy diet, sedentary behavior, cigarette smoking, and obesity) are associated with a greater risk of incident CVD and all-cause mortality. From the prevention strategy, maintaining a healthy lifestyle throughout a lifetime is a key to CVD prevention. Nonetheless, the prevalence of healthy lifestyle behaviors in US communities is low as 3 to 5%. Moreover, the prevalence of a healthy population among college students remains unknown. Objective: We investigated the prevalence of healthy lifestyle behaviors among college students. Methods: We recruited 747 undergraduate students from Arizona State University using a survey questionnaire. The survey questionnaire investigated demographic characteristics, body mass index, dietary habits, physical activity habits, and smoking habits. The chi-square test was used to investigate the frequency of ideal lifestyle behaviors in college students. Results: Prevalence of students who met all 4 ideal health behaviors (ideal cardiovascular health) is very low at 7.6%. Approximately 55.7% of students had only 2 or less ideal lifestyle behaviors (poor cardiovascular health). In addition, there were no statistical differences in combined ideal lifestyle behaviors across gender and different years of undergraduate studies. Conclusion: College students had a very low prevalence of healthy lifestyle behaviors. Increasing healthy low-risk students throughout college education is an important strategy to prevent chronic disease morbidity and mortality at individual and population level.
ContributorsConway, Jason Michael (Author) / Lee, Chong (Thesis director) / Angadi, Siddhartha (Committee member) / Barrett, The Honors College (Contributor) / Department of Supply Chain Management (Contributor) / Economics Program in CLAS (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor)
Created2015-05
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
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
Description
The purpose of this study was to investigate the effects of high intensity interval exercise (HIIE) on postprandial fat and carbohydrate oxidation after a high carbohydrate and fat meal in healthy adults. It was hypothesized that the HIIE would result in greater postprandial fat oxidation than the control condition. Three subjects, all non-obese (BMI<30) from the ages of 21-24, underwent a 3 visit protocol. The first visit was to establish a VO2 max (on a cycle ergometer) and the following two were randomized between a control and exercise condition. The exercise condition was comprised of one hour rest to provide baseline data, followed by a 1 minute on (90-95% HR max), one minute off high intensity interval protocol on a cycle ergometer. This was conducted until the same amount of kcal as the standard meal (490 kcal. 250 kcal snickers and 240 kcal sprite) was expended. After the exercise, the participant waited for one hour to minimize the effects of the excess post-exercise oxygen consumption (EPOC) period, and then consumed the meal. Once this was completed, VO2 was measured for the last 10 minutes of every 30 minutes for a full 5 hours postprandial. The same methodology was employed in the control condition except for the exercise protocol. Results showed a significantly greater fat oxidation in the HIIE condition, oxidizing 28 grams, 32 grams, and 27 grams of fat in each of the 3 subjects compared to 14, 16, and 17 grams in the control condition respectively. This supports the notion that HIIE results in greater postprandial fat oxidation compared to seated rest.
ContributorsSeroka, Zachary Steven (Author) / Gaesser, Glenn (Thesis director) / Angadi, Siddhartha (Committee member) / School of Nutrition and Health Promotion (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The anthracycline drug Doxorubicin (DOX) is a highly effective treatment for breast cancer, but its clinical utility is limited by dose-dependent cardiovascular toxicity. The toxic effects are partly attributed to DOX-induced generation of reactive oxygen species, which may impair nitric oxide-mediated vasodilation. Exercise training activates antioxidant defense mechanisms and is thus hypothesized to counteract oxidative stress when initiated prior to DOX administration. Adult 8-week old, ovariectomized female Sprague-Dawley rats were divided into 4 groups: sedentary + vehicle (Sed+Veh); Sed+DOX; exercise + veh (Ex+Veh); and Ex+DOX. Rats in the exercise groups were preconditioned with high intensity interval training consisting of 4x4 minute bouts of exercise at 85-95% of VO2peak separated by 2 minutes of active recovery performed 5 days per week. Exercise was implemented one week prior to the first injection and continued throughout the study. Animals received either DOX (4mg/kg) or veh (saline) intraperitoneal injections bi-weekly for a cumulative dose of 12 mg/kg per animal. Five days following the final injection, animals were anesthetized with isoflurane, decapitated and aortas and perivascular adipose tissue (PVAT) were removed for western blot analyses. No significant differences in aortic protein expression were detected for inducible nitric oxide synthase (iNOS) or the upstream activator of endothelial nitric oxide synthase (eNOS), Akt, across groups (p>0.05), whereas eNOS protein expression was significantly downregulated in Sed+DOX (p=0.003). In contrast, eNOS expression was not altered in Ex+DOX treated animals. Protein expression of iNOS in PVAT was upregulated with exercise in the DOX-treated groups (p=0.039). These findings suggest that exercise preconditioning may help mitigate vascular effects of DOX by preventing downregulation of eNOS in the aorta.
ContributorsO'Neill, Liam Martin (Author) / Sweazea, Karen (Thesis director) / Angadi, Siddhartha (Committee member) / Dickinson, Jared (Committee member) / School of Human Evolution and Social Change (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Estimates indicate that in the United States 1 in 8 women will develop breast cancer in their lifetime. Improved cancer screenings, early detection, and targeted treatments have increased breast cancer survival rates. However, breast cancer patients treated with chemotherapy are at an increased risk for cardiovascular disease, functional impairments, and loss of cardiorespiratory fitness. These negative outcomes have implications for early morbidity and mortality. The purpose of this thesis was to test the hypothesis that high-intensity exercise preconditioning (exercise commenced prior to initiating chemotherapy and continued throughout treatment cycles) preserves health-related outcomes in breast cancer patients treated with anthracycline-containing chemotherapy. Here, we present a subset of preliminary data from an ongoing trial (NCT02842658) that is focused on VO2peak and skeletal muscle outcomes from the first 10 participants that have enrolled in the trial. Breast cancer patients (N=10; 50 ± 11 y; 168 ± 4 cm; 92 ± 37 kg; 32.3 ± 12.3 kg/m2) scheduled to receive anthracycline-containing chemotherapy were randomly assigned to one of two interventions: 1) exercise preconditioning, (3 days per week of supervised exercise throughout treatment) or 2) standard of care (attention-control). Pre-testing occurred 1-2 week prior to chemotherapy. The interventions were initiated 1 week prior to chemotherapy and continued throughout anthracycline treatment. Post-testing occurred 3-7 days following the last anthracycline treatment. VO2peak (L/min) was reduced by 16% in the control group (P < 0.05), whereas VO2peak was preserved in the exercise preconditioning group. Trends for greater preservation and/or improvement in the exercise preconditioning group were also observed for lean body mass and peak heart rate. Hand grip strength was not changed in either group (P > 0.05). Both groups demonstrated an increase in ultrasound-derived echogenicity measures of the vastus lateralis (P < 0.05), indicating changes in the composition of the skeletal muscle during treatment. These preliminary data highlight that exercise preconditioning may serve as a strategy to preserve cardiorespiratory fitness and perhaps lean mass during anthracycline treatment of breast cancer. There remains a need for larger, definitive clinical trials to identify strategies to prevent the array of chemotherapy-induced toxicities that are observed in breast cancer patients treated with anthracyclines.
ContributorsCasey, Kathleen (Author) / Angadi, Siddhartha (Thesis director) / Gaesser, Glenn (Committee member) / Dickinson, Jared (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05