Osteoporosis is commonly considered a womens health problem, but is also a significant health concern for older men. Less is known about the predictors of osteoporosis and bone mineral density (BMD) in men. The aging of the population and expected increase in osteoporosis prevalence makes understanding the determinants of BMD of great public health importance.
Genetics is an important determinant of BMD, but little is known about specific loci associated with BMD in men and even less is known about the genetic influences on volumetric BMD (vBMD). With this in mind, we investigated 4108 single nucleotide polymorphisms (SNPs) in 383 candidate genes for their association within a population of older Caucasian men. In addition, we investigated 148 of these SNPs in 28 WNT pathway genes for gene-gene interactions and gene-environment interactions with physical activity and body weight.
We identified several SNPs that were associated with lumbar spine and femoral neck integral vBMD and explained 3.5% and 1.7% of the phenotypic variation in these traits, respectively. SNPs in two genes, adenomatous polyposis coli (APC) and the homeo box A gene cluster (HOXA) were associated with integral vBMD at both the femoral neck and lumbar spine. Analysis of cortical and trabecular vBMD at the femoral neck identified SNPs that explained 1.8% and 4.0% of the phenotypic variance, respectively. None of the SNPs for cortical vBMD were associated with trabecular vBMD. Statistically significant gene-gene and gene-environment interactions were also identified. Of note, statistically significant interaction effects of SNPs in the low density lipoprotein receptor-related protein 5 and physical activity level on integral vBMD at the femoral neck and lumbar spine were identified.
Although additional work is needed to confirm and extend these findings we identified a number of novel associations for vBMD in older Caucasian men. Our results suggest the presence of genetic loci that are skeletal-site specific and specific to either cortical or trabecular bone. Additionally, these findings underscore the importance of evaluating genetic variation in the context of other genes and environmental factors.
| Identifer | oai:union.ndltd.org:PITT/oai:PITTETD:etd-11102008-211135 |
| Date | 29 January 2009 |
| Creators | Yerges, Laura Maria |
| Contributors | Joseph M. Zmuda, Candace M. Kammerer, Jane A. Cauley, Robert E. Ferrell |
| Publisher | University of Pittsburgh |
| Source Sets | University of Pittsburgh |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.pitt.edu/ETD/available/etd-11102008-211135/ |
| Rights | unrestricted, I 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 University of Pittsburgh 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. |
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