Matching Items (85)
Description
Background: Evidence about the purported hypoglycemic and hypolipidemic effects of nopales (prickly pear cactus pads) is limited. Objective: To evaluate the efficacy of nopales for improving cardiometabolic risk factors and oxidative stress, compared to control, in adults with hypercholesterolemia. Design: In a randomized crossover trial, participants were assigned to a 2-wk intervention with 2 cups/day of nopales or cucumbers (control), with a 2 to 3-wk washout period. The study included 16 adults (5 male; 46±14 y; BMI = 31.4±5.7 kg/m2) with moderate hypercholesterolemia (low density lipoprotein cholesterol [LDL-c] = 137±21 mg/dL), but otherwise healthy. Main outcomes measured included: dietary intake (energy, macronutrients and micronutrients), cardiometabolic risk markers (total cholesterol, LDL-c, high density lipoprotein cholesterol [HDL-c], triglycerides, cholesterol distribution in LDL and HDL subfractions, glucose, insulin, homeostasis model assessment, and C-reactive protein), and oxidative stress markers (vitamin C, total antioxidant capacity, oxidized LDL, and LDL susceptibility to oxidation). Effects of treatment, time, or interactions were assessed using repeated measures ANOVA. Results: There was no significant treatment-by-time effect for any dietary composition data, lipid profile, cardiometabolic outcomes, or oxidative stress markers. A significant time effect was observed for energy, which was decreased in both treatments (cucumber, -8.3%; nopales, -10.1%; pTime=0.026) mostly due to lower mono and polyunsaturated fatty acids intake (pTime=0.023 and pTime=0.003, respectively). Both treatments significantly increased triglyceride concentrations (cucumber, 14.8%; nopales, 15.2%; pTime=0.020). Despite the lack of significant treatment-by-time effects, great individual response variability was observed for all outcomes. After the cucumber and nopales phases, a decrease in LDL-c was observed in 44% and 63% of the participants respectively. On average LDL-c was decreased by 2.0 mg/dL (-1.4%) after the cucumber phase and 3.9 mg/dL (-2.9%) after the nopales phase (pTime=0.176). Pro-atherogenic changes in HDL subfractions were observed in both interventions over time, by decreasing the proportion of HDL-c in large HDL (cucumber, -5.1%; nopales, -5.9%; pTime=0.021) and increasing the proportion in small HDL (cucumber, 4.1%; nopales, 7.9%; pTime=0.002). Conclusions: These data do not support the purported benefits of nopales at doses of 2 cups/day for 2-wk on markers of lipoprotein profile, cardiometabolic risk, and oxidative stress in hypercholesterolemic adults.
ContributorsPereira Pignotti, Giselle Adriana (Author) / Vega-Lopez, Sonia (Thesis advisor) / Gaesser, Glenn (Committee member) / Keller, Colleen (Committee member) / Shaibi, Gabriel (Committee member) / Sweazea, Karen (Committee member) / Arizona State University (Publisher)
Created2013
Effect of a Wii Fit® intervention on balance, muscular fitness, and bone health in middle-aged women
Description
Sustaining a fall can be hazardous for those with low bone mass. Interventions exist to reduce fall-risk, but may not retain long-term interest. "Exergaming" has become popular in older adults as a therapy, but no research has been done on its preventative ability in non-clinical populations. The purpose was to determine the impact of 12-weeks of interactive play with the Wii Fit® on balance, muscular fitness, and bone health in peri- menopausal women. METHODS: 24 peri-menopausal-women were randomized into study groups. Balance was assessed using the Berg/FICSIT-4 and a force plate. Muscular strength was measured using the isokinetic dynamometer at 60°/180°/240°/sec and endurance was assessed using 50 repetitions at 240°/sec. Bone health was tracked using dual-energy x-ray absorptiometry (DXA) for the hip/lumbar spine and qualitative ultrasound (QUS) of the heel. Serum osteocalcin was assessed by enzyme immunoassay. Physical activity was quantified using the Women's Health Initiative Physical Activity Questionnaire and dietary patterns were measured using the Nurses' Health Food Frequency Questionnaire. All measures were repeated at weeks 6 and 12, except for the DXA, which was completed pre-post. RESULTS: There were no significant differences in diet and PA between groups. Wii Fit® training did not improve scores on the Berg/FICSIT-4, but improved center of pressure on the force plate for Tandem Step, Eyes Closed (p-values: 0.001-0.051). There were no significant improvements for muscular fitness at any of the angular velocities. DXA BMD of the left femoral neck improved in the intervention group (+1.15%) and decreased in the control (-1.13%), but no other sites had significant changes. Osteocalcin indicated no differences in bone turnover between groups at baseline, but the intervention group showed increased bone turnover between weeks 6 and 12. CONCLUSIONS: Findings indicate that WiiFit® training may improve balance by preserving center of pressure. QUS, DXA and osteocalcin data confirm that those in the intervention group were experiencing more bone turnover and bone formation than the control group. In summary, twelve weeks of strength /balance training with the Wii Fit® shows promise as a preventative intervention to reduce fall and fracture risk in non-clinical middle aged women who are at risk.
ContributorsWherry, Sarah Jo (Author) / Swan, Pamela D (Thesis advisor) / Adams, Marc (Committee member) / Der Ananian, Cheryl (Committee member) / Sweazea, Karen (Committee member) / Vaughan, Linda (Committee member) / Arizona State University (Publisher)
Created2014
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
ABSTRACT
Asthma is a high-stress, chronic medical condition; 1 in 12 adults in the United States combat the bronchoconstriction from asthma. However, there are very few strong studies indicating any alternative therapy for asthmatics, particularly following a cold incidence. Vitamin C has been proven to be effective for other high-stress populations, but the asthmatic population has not yet been trialed. This study examined the effectiveness of vitamin C supplementation during the cold season on cold incidence and asthmatic symptoms. Asthmatics, otherwise-healthy, who were non-smokers and non-athletes between the ages of 18 and 55 with low plasma vitamin C concentrations were separated by anthropometrics and vitamin C status into two groups: either vitamin C (500 mg vitamin C capsule consumed twice per day) or control (placebo capsule consumed twice per day). Subjects were instructed to complete the Wisconsin Upper Respiratory Symptom Survey-21 and a short asthma symptoms questionnaire daily along with a shortened vitamin C Food Frequency Questionnaire and physical activity questionnaire weekly for eight weeks. Blood samples were drawn at Week 0 (baseline), Week 4, and Week 8. Compliance was monitored through a calendar check sheet. The vitamin C levels of both groups increased from Week 0 to Week 4, but decreased in the vitamin C group at Week 8. The vitamin C group had a 19% decrease in plasma histamine while the control group had a 53% increase in plasma histamine at the end of the trial, but this was not statistically significant (p>0.05). Total symptoms recorded from WURSS-21 were 129.3±120.7 for the vitamin C and 271.0±293.9, but the difference was not statistically significant (p=0.724). Total asthma symptoms also slightly varied between the groups, but again was not statistically significant (p=0.154). These results were hindered by the low number of subjects recruited. Continued research in this study approach is necessary to definitively reject or accept the potential role of vitamin C in asthma and cold care.
Asthma is a high-stress, chronic medical condition; 1 in 12 adults in the United States combat the bronchoconstriction from asthma. However, there are very few strong studies indicating any alternative therapy for asthmatics, particularly following a cold incidence. Vitamin C has been proven to be effective for other high-stress populations, but the asthmatic population has not yet been trialed. This study examined the effectiveness of vitamin C supplementation during the cold season on cold incidence and asthmatic symptoms. Asthmatics, otherwise-healthy, who were non-smokers and non-athletes between the ages of 18 and 55 with low plasma vitamin C concentrations were separated by anthropometrics and vitamin C status into two groups: either vitamin C (500 mg vitamin C capsule consumed twice per day) or control (placebo capsule consumed twice per day). Subjects were instructed to complete the Wisconsin Upper Respiratory Symptom Survey-21 and a short asthma symptoms questionnaire daily along with a shortened vitamin C Food Frequency Questionnaire and physical activity questionnaire weekly for eight weeks. Blood samples were drawn at Week 0 (baseline), Week 4, and Week 8. Compliance was monitored through a calendar check sheet. The vitamin C levels of both groups increased from Week 0 to Week 4, but decreased in the vitamin C group at Week 8. The vitamin C group had a 19% decrease in plasma histamine while the control group had a 53% increase in plasma histamine at the end of the trial, but this was not statistically significant (p>0.05). Total symptoms recorded from WURSS-21 were 129.3±120.7 for the vitamin C and 271.0±293.9, but the difference was not statistically significant (p=0.724). Total asthma symptoms also slightly varied between the groups, but again was not statistically significant (p=0.154). These results were hindered by the low number of subjects recruited. Continued research in this study approach is necessary to definitively reject or accept the potential role of vitamin C in asthma and cold care.
ContributorsEarhart, Kathryn Michelle (Author) / Johnston, Carol (Thesis advisor) / Sweazea, Karen (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2015
Description
For animals that experience annual cycles of gonad development, the seasonal timing (phenology) of gonad growth is a major adaptation to local environmental conditions. To optimally time seasonal gonad growth, animals use environmental cues that forecast future conditions. The availability of food is one such environmental cue. Although the importance of food availability has been appreciated for decades, the physiological mechanisms underlying the modulation of seasonal gonad growth by this environmental factor remain poorly understood.
Urbanization is characterized by profound environmental changes, and urban animals must adjust to an environment vastly different from that of their non-urban conspecifics. Evidence suggests that birds adjust to urban areas by advancing the timing of seasonal breeding and gonad development, compared to their non-urban conspecifics. A leading hypothesis to account for this phenomenon is that food availability is elevated in urban areas, which improves the energetic status of urban birds and enables them to initiate gonad development earlier than their non-urban conspecifics. However, this hypothesis remains largely untested.
My dissertation dovetailed comparative studies and experimental approaches conducted in field and captive settings to examine the physiological mechanisms by which food availability modulates gonad growth and to investigate whether elevated food availability in urban areas advances the phenology of gonad growth in urban birds. My captive study demonstrated that energetic status modulates reproductive hormone secretion, but not gonad growth. By contrast, free-ranging urban and non-urban birds did not differ in energetic status or plasma levels of reproductive hormones either in years in which urban birds had advanced phenology of gonad growth or in a year that had no habitat-related disparity in seasonal gonad growth. Therefore, my dissertation provides no support for the hypothesis that urban birds begin seasonal gonad growth because they are in better energetic status and increase the secretion of reproductive hormones earlier than non-urban birds. My studies do suggest, however, that the phenology of key food items and the endocrine responsiveness of the reproductive system may contribute to habitat-related disparities in the phenology of gonad growth.
Urbanization is characterized by profound environmental changes, and urban animals must adjust to an environment vastly different from that of their non-urban conspecifics. Evidence suggests that birds adjust to urban areas by advancing the timing of seasonal breeding and gonad development, compared to their non-urban conspecifics. A leading hypothesis to account for this phenomenon is that food availability is elevated in urban areas, which improves the energetic status of urban birds and enables them to initiate gonad development earlier than their non-urban conspecifics. However, this hypothesis remains largely untested.
My dissertation dovetailed comparative studies and experimental approaches conducted in field and captive settings to examine the physiological mechanisms by which food availability modulates gonad growth and to investigate whether elevated food availability in urban areas advances the phenology of gonad growth in urban birds. My captive study demonstrated that energetic status modulates reproductive hormone secretion, but not gonad growth. By contrast, free-ranging urban and non-urban birds did not differ in energetic status or plasma levels of reproductive hormones either in years in which urban birds had advanced phenology of gonad growth or in a year that had no habitat-related disparity in seasonal gonad growth. Therefore, my dissertation provides no support for the hypothesis that urban birds begin seasonal gonad growth because they are in better energetic status and increase the secretion of reproductive hormones earlier than non-urban birds. My studies do suggest, however, that the phenology of key food items and the endocrine responsiveness of the reproductive system may contribute to habitat-related disparities in the phenology of gonad growth.
ContributorsDavies, Scott (Author) / Deviche, Pierre (Thesis advisor) / Sweazea, Karen (Committee member) / McGraw, Kevin (Committee member) / Orchinik, Miles (Committee member) / Warren, Paige (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
The common cold is a significant cause of morbidity world-wide, with human rhinovirus infections accounting for a majority colds suffered each year. While the symptoms of the common cold are generally mild and self-limiting, vulnerable populations such as individuals with asthma can experience severe secondary complications including acute asthma exacerbation which can result in severe morbidity. Most human rhinovirus types utilize Intercellular Adhesion Molecule-1 (ICAM-1) as a receptor to enter cells and initiate infection. Expression of this cell-surface protein is elevated in the respiratory tract of asthma patients. The theoretical basis for this research is the observation that plasma measures of the soluble form of Intercellular Adhesion Molecule-1 (sICAM-1) decrease in response to vitamin C supplementation. As rhinovirus infection occurs in the upper respiratory tract, the primary aim of this study was to evaluate change in sICAM-1 concentration in nasal lavage of asthmatic individuals in response to vitamin C supplementation. Otherwise healthy asthmatic adults between the ages of 18-65 years who were not currently using steroidal nasal sprays, smoking, or actively training for competitive sports were recruited from a university community and surrounding area to participate in an 18-day double-blind randomized placebo-controlled supplement study with a parallel arm design. 13 subjects were stratified based on age, gender, BMI and baseline plasma vitamin C level to receive either 500 mg vitamin C twice daily (VTC, n=7) or placebo (PLC, n=6). Biochemical measures included nasal lavage sICAM-1, plasma sICAM-1, plasma histamine, and plasma vitamin C. Survey measures included Wisconsin Upper Respiratory Symptom Survey-21 to assess colds, Daytime Symptom Diary Scale to assess asthma symptoms, and measures of diet quality including a vitamin C food frequency questionnaire and Rapid Eating Assessment for Participants. No between group comparison of means reached significance (Mann-Whitney U test, p>0.05). Nasal lavage sICAM-1 levels were decreased in VTC group by 37% at study day 4, although this finding did not reach significance. Findings in this study can be used to develop future investigations into the response of nasal lavage sICAM-1 to vitamin C supplementation.
ContributorsGnant, Lindsay (Author) / Johnston, Carol (Thesis advisor) / Sweazea, Karen (Committee member) / Chang, Yung (Committee member) / Arizona State University (Publisher)
Created2014
Description
ABSTRACT Fruit and vegetable intake is not uniform across levels of socioeconomic status (SES) and researchers have identified low SES as a risk factor for poor intake of fruits and vegetables. In an effort to eliminate public health disparities and increase fruit and vegetable intake, the Women, Infant, and Children (WIC) program implemented additional food assistance programs, with a specific emphasis on fresh fruits and vegetables. The Farmers' Market Nutrition Program (FMNP) provides pre-existing WIC clients with coupons to purchase fresh, locally grown produce at farmers' markets. In addition, Congress also approved the WIC Cash Value Voucher (CVV) program, which provides WIC participants with vouchers to purchase fresh fruits and vegetables at farmers' markets or grocery stores. The purpose of this thesis was to investigate the relation of FMNP coupon use with accessibility and WIC CVV redemption rates at farmers' markets. Furthermore, this thesis addressed whether WIC shoppers redeemed a higher percentage of their WIC CVV value at farmers' markets or grocery stores. WIC CVV and FMNP issuance and redemption data were analyzed to establish overall redemption rates and total perecent of WIC CVV value redeemed. Accessibility was assessed using the Geographic Information System, which allowed me to calculate the distance that WIC participants would have to travel to redeem their FMNP coupons at FMNP-approved farmers' markets. The results showed that less than 1% of WIC shoppers redeem their WIC CVVs at farmers'markets in Arizona. However, the redemption of WIC CVV was significantly higher during the months when shoppers had the option of using both WIC CVV and FMNP coupons at farmers' markets. Furthermore, the percent of total CVV value redeemed at farmers' markets was 99%, significantly higher than grocery stores (93.5%). Average FMNP coupon redemption rates for 2008-2010 was 43.3%, well below the national average of 59%. However, my spatial analysis revealed that there was no significant association between the distance traveled to farmers' markets and FMNP redemption rates. This indicates that the distance traveled to farmers' markets is not a major barrier to redemption of FMNP coupons in Arizona.
ContributorsTucker, Wesley Jack (Author) / Wharton, Christopher (Christopher Mack), 1977- (Thesis advisor) / Vaughan, Linda (Committee member) / Johnston, Carol S (Committee member) / Arizona State University (Publisher)
Created2012
Description
Mexican Americans have an increased risk for type 2 diabetes and premature cardiovascular disease (CVD). The association of hyperglycemia with traditional CVD risk factors in this population has been established, but there is limited data regarding other non-traditional CVD risk factors. Thus, this cross-sectional study was conducted to evaluate CVD risk among Mexican Americans by measuring concentrations of lipids, high-sensitivity C-reactive protein (hsCRP), and cholesterol in low-density-lipoprotein (LDL) and high-density-lipoprotein (HDL) subfractions. Eighty overweight/obese Mexican-American adults participating in the Maricopa Insulin Resistance Initiative were randomly selected from each of the following four groups (n = 20 per group): nomolipidemic
ormoglycemic controls (NC), dyslipidemic
ormoglycemic (DN), dyslipidemic/prediabetic (DPD) and dyslipidemic/diabetic (DD). Total cholesterol (TC) was 30% higher among DD than in NC participants (p<0.0001). The DPD group had 27% and 12% higher LDL-C concentrations than the NC and DN groups, respectively. Similarly, LDL-C was 29% and 13% higher in DD than in NC and DN participants (p=0.013). An increasing trend was observed in %10-year CVD risk with increasing degree of hyperglycemia (p<0.0001). The NC group had less cholesterol in sdLDL particles than dyslipidemic groups, regardless of glycemic status (p<0.0001). When hyperglycemia was part of the phenotype (DPD and DD), there was a greater proportion of total and HDL-C in sHDL particles in dyslipidemic individuals than in NC (p=0.023; p<0.0001; respectively). Percent 10-year CVD risk was positively correlated with triglyceride (TG) (r=0.384, p<0.0001), TC (r=0.340, p<0.05), cholesterol in sdLDL(r=0.247; p<0.05), and TC to HDL-C ratio (r=0.404, p<0.0001), and negatively correlated with HDL-C in intermediate and large HDL(r=-0.38, p=0.001; r=0.34, p=0.002, respectively). The TC/HDL-C was positively correlated with cholesterol in sdLDL particles (r=0.698, p<0.0001) and HDL-C in sHDL particles (r=0.602, p<0.0001), and negatively correlated with cholesterol in small (r=-0.35, p=0.002), intermediate (r=-0.91, p<0.0001) and large (r=-0.84, p<0.0001) HDL particles, and HDL-C in the large HDL particles (r=-0.562, p<0.0001). No significant association was found between %10-year CVD risk and hsCRP. Collectively, these results corroborate that dyslipidemic Mexican-American adults have higher CVD risk than normolipidemic individuals. Hyperglycemia may further affect CVD risk by modulating cholesterol in LDL and HDL subfractions.
ormoglycemic controls (NC), dyslipidemic
ormoglycemic (DN), dyslipidemic/prediabetic (DPD) and dyslipidemic/diabetic (DD). Total cholesterol (TC) was 30% higher among DD than in NC participants (p<0.0001). The DPD group had 27% and 12% higher LDL-C concentrations than the NC and DN groups, respectively. Similarly, LDL-C was 29% and 13% higher in DD than in NC and DN participants (p=0.013). An increasing trend was observed in %10-year CVD risk with increasing degree of hyperglycemia (p<0.0001). The NC group had less cholesterol in sdLDL particles than dyslipidemic groups, regardless of glycemic status (p<0.0001). When hyperglycemia was part of the phenotype (DPD and DD), there was a greater proportion of total and HDL-C in sHDL particles in dyslipidemic individuals than in NC (p=0.023; p<0.0001; respectively). Percent 10-year CVD risk was positively correlated with triglyceride (TG) (r=0.384, p<0.0001), TC (r=0.340, p<0.05), cholesterol in sdLDL(r=0.247; p<0.05), and TC to HDL-C ratio (r=0.404, p<0.0001), and negatively correlated with HDL-C in intermediate and large HDL(r=-0.38, p=0.001; r=0.34, p=0.002, respectively). The TC/HDL-C was positively correlated with cholesterol in sdLDL particles (r=0.698, p<0.0001) and HDL-C in sHDL particles (r=0.602, p<0.0001), and negatively correlated with cholesterol in small (r=-0.35, p=0.002), intermediate (r=-0.91, p<0.0001) and large (r=-0.84, p<0.0001) HDL particles, and HDL-C in the large HDL particles (r=-0.562, p<0.0001). No significant association was found between %10-year CVD risk and hsCRP. Collectively, these results corroborate that dyslipidemic Mexican-American adults have higher CVD risk than normolipidemic individuals. Hyperglycemia may further affect CVD risk by modulating cholesterol in LDL and HDL subfractions.
ContributorsNeupane, Srijana (Author) / Vega-Lopez, Sonia (Thesis advisor) / Shaibi, Gabriel Q (Committee member) / Johnston, Carol S (Committee member) / Arizona State University (Publisher)
Created2011
Description
While exercising mammalian muscle increasingly relies on carbohydrates for fuel as aerobic exercise intensity rises above the moderate range, flying birds are extraordinary endurance athletes and fuel flight, a moderate-high intensity exercise, almost exclusively with lipid. In addition, Aves have long lifespans compared to weight-matched mammals. As skeletal muscle mitochondria account for the majority of oxygen consumption during aerobic exercise, the primary goal was to investigate differences in isolated muscle mitochondria between these species and to examine to what extent factors intrinsic to mitochondria may account for the behavior observed in the intact tissue and whole organism. First, maximal enzyme activities were assessed in sparrow and rat mitochondria. Citrate synthase and aspartate aminotransferase activity were higher in sparrow compared to rat mitochondria, while glutamate dehydrogenase activity was lower. Sparrow mitochondrial NAD-linked isocitrate dehydrogenase activity was dependent on phosphate, unlike the mammalian enzyme. Next, the rate of oxygen consumption (JO), electron transport chain (ETC) activity, and reactive oxygen species (ROS) production were assessed in intact mitochondria. Maximal rates of fat oxidation were lower than for carbohydrate in rat but not sparrow mitochondria. ETC activity was higher in sparrows, but no differences were found in ROS production between species. Finally, fuel selection and control of respiration at three rates between rest and maximum were assessed. Mitochondrial fuel oxidation and selection mirrored that of the whole body; in rat mitochondria the reliance on carbohydrate increased as the rate of oxygen consumption increased, whereas fat dominated under all conditions in the sparrow. These data indicate fuel selection, at least in part, can be modulated at the level of the mitochondrial matrix when multiple substrates are present at saturating levels. As an increase in matrix oxidation-reduction potential has been linked to a suppression of fat oxidation and high ROS production, the high ETC activity relative to dehydrogenase activity in avian compared to mammalian mitochondria may result in lower matrix oxidation-reduction potential, allowing fatty acid oxidation to proceed while also resulting in low ROS production in vivo.
ContributorsKuzmiak, Sarah (Author) / Willis, Wayne T (Thesis advisor) / Mandarino, Lawrence (Committee member) / Sweazea, Karen (Committee member) / Harrison, Jon (Committee member) / Gadau, Juergen (Committee member) / Arizona State University (Publisher)
Created2012