Browsing by Author "Butner, Katrina Lindauer"
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- An Evaluation of 1) Bone Changes Following Bariatric Surgery and 2) Fat and Muscle Indices Assessed by pQCT: Implications for Osteoporosis and Type-2 Diabetes RiskButner, Katrina Lindauer (Virginia Tech, 2010-10-29)STUDY 1 Aim: To compare the effects of Roux-en-Y gastric bypass (RYGB) and laparoscopic adjustable gastric banding (LAGB) on changes in bone mineral density (BMD), weight loss and blood biomarkers related to bone turnover, hormonal, and nutrient status. Subjects: Nine bariatric surgery patients. Methods: Patients had a DXA bone scan and fasting blood draw at baseline, three, and six months following surgery. Results: RYGB patients had greater weight loss vs. LAGB at both three (mean loss: 19 vs. 9%) and six months (26 vs. 11%), p<0.01. RYGB patients lost an average of 7% hip BMD at six months. Hip BMD loss at six months was correlated to decreased leptin (r=0.88) and increased adiponectin (r=-0.82), p<0.05. Bone turnover was indicated by elevated serum bone biomarkers after surgery. Conclusions: Research with larger sample sizes is warranted to better evaluate potential implications for late-life osteoporosis risk following bariatric surgery. STUDY 2 Aim: To determine repeatability for IMAT and muscle density, to evaluate the distribution of foreleg muscle and fat indices measured by pQCT and to determine predictors of muscle density and type-2 diabetes risk. Subjects: 82 women with varying BMI and physical activity levels. Methods: Subjects had DXA and pQCT bone scans, a fasting blood draw, and completed a 4-day physical activity record. Results: Fat and muscle distribution in the foreleg was highly correlated to total and central body adiposity. The pQCT device reliably measured muscle density (CV=0.8%), thus justifying use as surrogates for IMAT. Muscle density was positively related to physical activity (r=0.29; p<0.05) and negatively associated with markers of fat distribution and risk for type-2 diabetes [HOMA-IR (r=-0.44, p<0.01)]. Conclusions: Further research is necessary to determine whether specific fat or muscle depots can be targeted through exercise training to help with the prevention and treatment of obesity or type-2 diabetes.
- The Roles of Yoga and Cooperative Extension in Meeting and Promoting the Physical Activity Guidelines for AmericansDysart, Susanna Frances (Virginia Tech, 2022-04-11)Cooperative Extension (CE) is a nationwide system that addresses leading concerns for United States residents from agricultural production to healthy youth development. As 80% of Americans are not meeting the Physical Activity Guidelines (PAG), promoting physical activity is a recent addition to CE priority areas. To build capacity of CE to offer physical activity, training on physical activity within the system is needed. Since yoga is a public health intervention growing in popularity due to its link to flourishing and mental well-being, this is a holistic practice that may target physical and mental health in the United States. Due to the variety of yoga practices one could engage with it is important to clarify the link between physical activity and yoga. This dissertation included four studies to promote physical activity and yoga within CE. Study one established the efficacy of a virtual micro-credentialing program for CE professionals (N = 64) that increased their knowledge about physical activity programming and increased their own physical activity levels. The second study was an iterative and pragmatic investigation of wellness initiatives for CE professionals to increase flourishing and physical activity within themselves. The third study explored the degree to which temperature and tempo of yoga classes impacted measured heart rate and rate of perceived exertion. Preliminary evidence suggests that ~30% of the yoga class contributed to moderate-vigorous physical activity, regardless of the temperature and speed. The fourth study was a systematic appraisal of urban and rural yoga studio offerings. The results included that most studios offer 60-minute classes, focused on asana (movement) rather than the other limbs (components) of yoga. This work also resulted in a studio audit form for CE professionals to assess yoga studios for appropriateness to recommend to their participants. Future work includes scaling out the micro-credentialing program and determining the degree to which knowledge of physical activity leads to physical activity program adoption (study 1); ensuring CE professionals have access to wellness initiatives to avoid burn out (study 2); ongoing investigation of the physiological benefits of yoga (study 3); and testing the utility of the studio audit form (study 4).