a PSC Research Project
Progress in eliminating population health disparities requires interdisciplinary efforts among social and biological scientists, and new or improved data sets through which complex hypotheses linking social and biological processes can be tested. Researchers studying health disparities are increasingly interested in using telomere length (TL), a biomeasure of aging, as a marker of cumulative wear and tear on the body. Current research on racial/ethnic or socioeconomic differences in TL tends to be rudimentary, often based on highly select, racially homogeneous, or convenience samples and lacking controls for socioeconomic variables. Leukocyte derived DNA from fresh venous blood samples, the state-of-the-art for TL measurement, is labor intensive and very expensive to collect. Likewise, it is expensive to mount studies using large, representative or community-based samples to collect data on the broad range of socioeconomic, psychosocial, and environmental factors needed to advance interdisciplinary health disparities research.
However, several ongoing national data collections that include a broad range of social measures also isolate blood DNA and bank it in repositories after the cells have been transformed and immortalized using Epstein-Barr virus (EBV). Others collect, store and extract DNA from saliva. Neither of these types of samples is ideal for gauging individual TL measurement. EBV-immortalization activates processes that affect TL, and saliva-based TL is longer than blood leukocyte-derived DNA. The critical unanswered question for population research is whether the error introduced in these methods is random or systematic with respect to original telomere length or to populations of interest.
This project analyzes the validity of using EBV-immortalized or saliva cells to estimate population differences in TL. We draw and analyze blood and saliva from 150 adult black, white, or Mexican-origin women and measure each woman's TL multiple times: using DNA directly isolated from fresh blood cells, DNA isolated from cells that are EBV-immortalized, and DNA extracted from saliva. By stratifying the sample along key axes of comparison – race/ethnicity, socioeconomic status, and neighborhood – and within-woman results by immortalized and fresh blood samples, and by fresh blood samples and saliva, we will directly gauge the effect that immortalization or tissue type has on the validity and reliability of using these biomeasures. Given that biosamples of these materials are currently available in large, representative data sets, our findings have implications for the pace of health disparities research.
|Funding:||National Institute on Aging (1 R01 AG 047167)|
Funding Period: 04/15/2014 to 03/31/2017