The Effects of Socioeconomic Status, Race, and Immigration on Inflammatory Levels in the United States: An Analysis Using Quantile Regressions

Neil Mehta, University of Pennsylvania

High levels of inflammatory activity are thought be to be a risk factor in the development of many chronic conditions of old age. We use quantile regression techniques to examine the effect of socioeconomic status, race, and immigration on levels of C-reactive protein, a marker of inflammation. Data from the National Health and Nutrition Examination Survey 1999-2002 were utilized. Previous evidence suggests that inflammatory activity may be most sensitive to social factors in individuals who have high levels of C-reactive protein. We argue here that the use of quantile regressions will enhance our understanding of this interrelationship. Our results indicate that socioeconomic status, race, and immigration do have effects on C-reactive levels, however the effects are inconsistent. Importantly, quantile regression analyses showed that inflammatory levels tend to be more sensitive to social factors at the upper tails of the C-reactive protein distribution versus other parts of the distribution.