Although environmental and occupational lead exposure has decreased over the recent decades, the health outcomes associated with past lead exposure continue to be a significant clinical and public health issue. Lead is a multitargeted toxicant, that effect skeletal, cardiovascular and nervous system. Mounting evidence supports a link between lead at levels previously considered safe, to morbidity and mortality.
The objective of this dissertation was to examine association of lead biomarkers with changes in bone mineral density (BMD), incident fractures and falls, cognition and mortality. We utilized data from two epidemiological studies: a) The Study of Osteoporotic Fractures (SOF) that enrolled a population of elderly women (age 65-87), and b)The Lead Occupational study that followed a cohort of male lead exposed and control workers through middle age (40-76 years,63% exposed, 37% controls).
In the longitudinal SOF analysis, baseline total hip BMD was lower in women with high blood lead levels. The annualized rate of decline in hip BMD was greater among women with the high blood lead level, who also experienced a two-fold increased risk of fracture and falls.
In the longitudinal SOF mortality analysis, women with higher blood lead levels at baseline had increased risk of all cause, and cardiovascular mortality compared to women with lower blood lead levels. No association with cancer mortality was found. These relationships were independent of age and shared risk factors between blood lead levels and BMD, fractures, falls and mortality.
In the Lead Occupational study, compared to controls, lead exposed workers had lower total cognitive scores cross sectionally. In longitudinal analysis, cognitive scores of lead exposed workers declined more in compared to controls. Age and important risk factors of lead exposure and cognitive change did not explain this association.
Overall, our findings provide epidemiological evidence of an association between lead exposure, morbidity, and mortality in community residing elderly women as well as a male occupational cohort. A more stringent control of lead exposure and better understanding of the mechanism of its effects may help reduce the public health burden of disease.
| Identifer | oai:union.ndltd.org:PITT/oai:PITTETD:etd-04132007-160216 |
| Date | 27 June 2007 |
| Creators | Khalil, Naila |
| Contributors | JOHN W. WILSON, JANE A. CAULEY, LISA A. MORROW, EVELYN O. TALBOT, HERBERT NEEDLEMAN |
| 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-04132007-160216/ |
| Rights | restricted, 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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