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Lipidomics

Volume 580 of the series Methods in Molecular Biology™ pp 371-381

Date:

The Effect of Lipid Adjustment on the Analysis of Environmental Contaminants and the Outcome of Human Health Risks

  • Audrey J. GaskinsAffiliated withDivision of Epidemiology, Statistics and Prevention Research, Eunice Kennedy Schriver National Institute of Child Health and Human Development, NIH
  • , Enrique F. SchistermanAffiliated withDivision of Epidemiology, Statistics and Preventive Research, Eunice Kennedy Schriver National Institute of Child Health and Human Development, NIH

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Summary

Past literature on exposure to lipophilic agents such as organochlorines (OCs) is conflicting, posing challenges for the interpretation of their potential human health risks. Since blood is often used as a proxy for adipose tissue, it is necessary to model serum lipids when assessing health risks of OCs. Using a simulation study, we evaluated four statistical models (unadjusted, standardized, adjusted, and two-stage) for the analysis of polychlorinated biphenyls (PCBs) exposure, serum lipids, and health outcome risk. Eight candidate true causal scenarios, depicted by directed acyclic graphs, were used to illustrate the ramifications of misspecification of underlying assumptions when interpreting results. Biased results were produced when statistical models that deviated from the underlying causal assumptions were used with the lipid standardization method found to be particularly prone to bias. We concluded that investigators must consider biology, biological medium, laboratory measurement, and other underlying modeling assumptions when devising a statistical model for assessing health outcomes in relation to environmental exposures.

Key words

Causal modeling Directed acyclic graphs Risk estimation Serum lipids Organochlorines Polychlorinated biphenyls