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dc.contributor.authorGuignel, Nadine Joëlleen_US
dc.date.accessioned2014-03-14T20:40:28Z
dc.date.available2014-03-14T20:40:28Z
dc.date.issued2005-06-06en_US
dc.identifier.otheretd-06242005-103302en_US
dc.identifier.urihttp://hdl.handle.net/10919/33725
dc.description.abstractObesity is a worldwide epidemic increasing at an alarming rate among youth who are facing similar health problems as adults. Sleep Apnea Syndrome (SAS) is an underdiagnosed comorbidity of obesity, characterized by repetitive nocturnal interruptions in breathing. Obesity is associated with delayed skeletal maturation in overweight youth, but mechanisms contributing to this problem are unclear. Obesity and SAS both have been shown to disrupt regulatory hormones and cytokines that influence bone accretion during adolescence. PURPOSE: The purpose of this study was to assess the combined effects of excess body weight and SAS on bone mineral density (BMD) and content (BMC), bone turnover, and on the regulatory hormones leptin and IGF-1 known to potentially influence bone accretion during adolescence. METHODS: Men aged 18-28 years were assigned to groups as follows: normal weight controls (CON: AHI <3, n=8); overweight without SAS (OWT: BMI < 26 kg/m2 and AHI <3, n=9); and overweight with SAS (SAS: BMI >26 kg/m2 and AHI >5, n=8). The apnea/hypopnea index (AHI) expresses the score for disrupted nighttime breathing events/hr and was obtained in this study with results from a home sleep screening test. Health history and Epworth Sleepiness Scale (ESS) questionnaires also were administered. Bone mineral parameters and body composition variables were measured with dual-energy X-ray absorptiometry. Serum osteocalcin, leptin, IGF-1, and NTx-1 were measured, respectively, by radioimmunoassay and enzyme-linked immunoabsorbent assay. RESULTS: Fat-free mass, intra-abdominal fat, and fat mass were higher in the SAS and OWT groups (p<0.03). ESS scores revealed that SAS individuals were sleepier than CON and OWT groups (p<0.009). Total body and site-specific BMD and BMC values (lumbar spine, hip, and forearm) were similar between groups and did not relate to the estimated AHI score. Serum OC and NTx-1 did not differ between groups. Leptin levels were 30% higher in OWT and SAS than in the CON group (p<0.02), but did not correlate with the AHI score. Across all subjects (n=25), only lumbar spine BMC (p<0.005) was correlated to AHI (r=-.52; p<0.01). The preponderance of this relationship between AHI and lumbar spine BMC was attributable to the close inverse association of these two variables within the SAS group (r = -.81; p<0.001). CONCLUSION: The effects of SAS were not influenced by the amount of whole-body, intra-abdominal adiposity or lean body mass. Neither leptin nor IGF-1 predicted bone status across all groups. Daytime fatigue and sleepiness, a cardinal symptom of SAS, combined with overweight may contribute to lower lumbar BMC by chronically reducing weight-bearing physical activity and thereby reduce exposure time for mechanical loading of the spine in affected individuals. Further research is needed to explore the biochemical, physiological, and apparently the physical activity implications of SAS on skeletal status and turnover.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartNadine_Guignel_thesis.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectSleep apnea syndromeen_US
dc.subjectInsulin-like growth factor-1en_US
dc.subjectBone mineral contenten_US
dc.subjectLeptinen_US
dc.subjectN-telopeptide of type I collagen cross-linken_US
dc.subjectOsteocalcinen_US
dc.titleSkeletal Status and Bone Turnover in Overweight Young Men with and without Sleep Apnea Syndromeen_US
dc.typeThesisen_US
dc.contributor.departmentHuman Nutrition, Foods, and Exerciseen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineHuman Nutrition, Foods, and Exerciseen_US
dc.contributor.committeechairHerbert, William G.en_US
dc.contributor.committeememberRamp, Warren K.en_US
dc.contributor.committeememberGwazdauskas, Francis C.en_US
dc.contributor.committeememberNickols-Richardson, Sharon M.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-06242005-103302/en_US
dc.date.sdate2005-06-24en_US
dc.date.rdate2007-07-07
dc.date.adate2005-07-07en_US


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