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. / Ph. D.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/73000 |
| Date | 03 December 2010 |
| Creators | Butner, Katrina Lindauer |
| Contributors | Human Nutrition, Foods, and Exercise, Herbert, William G., Clark, Susan F., Nickols-Richardson, Sharon M., Ramp, Warren K. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | en_US |
| Detected Language | English |
| Type | Dissertation, Text |
| Format | application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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