Dr. Jennifer Dowd, professor at the CUNY Graduate School of Public Health and Health Policy and colleagues examined the relationship between socioeconomic and immune response among elderly Latinos. The findings were published in the journal Social Science and Medicine.
[Photo: Dr. Jennifer Beam Dowd]
The prevalence of persistent infections, such as cytomegalovirus, herpes simplex virus-1 (HSV-1), Helicobacter pylori (H. pylori), and Toxoplasma gondii (T. gondii), varies by socioeconomic status. It is unclear if early or later life socioeconomic position is a more salient driver of disparities in immune control of these common infections.
Using data from the Sacramento Area Latino Study on Aging, the research team examined whether early or later life socioeconomic position was the strongest predictor of immune control later in life by contrasting two life course models, the critical period model and the chain of risk model. The team measured early life socioeconomic position as a latent variable, derived from parental education and occupation, and food availability. Indicators for socioeconomic position in later life included education level and occupation. Individuals were categorized by their immune response to each pathogen (seronegative, low, medium and high) with increasing immune response representing poorer immune control. The cumulative immune response was estimated using a latent profile analysis with higher total immune response representing poorer immune control. Structural equation models were used to examine direct, indirect and total effects of early life socioeconomic position on each infection and cumulative immune response, controlling for age and gender.
The direct effect of early life socioeconomic position on immune response was not statistically significant for the infections or cumulative immune response. There was an association between higher early life socioeconomic position and lower immune response to T. gondii, H. pylori, and cumulative immune response through pathways mediated by later life socioeconomic position. For cytomegalovirus, a higher early life socioeconomic position was both directly associated and partially mediated by later life socioeconomic position. The research team found no association between socioeconomic position and HSV-1.
The research team concluded that their findings support a chain of risk model, whereby early life socioeconomic position acts through later life socioeconomic position to affect the immune response to persistent infections in older age.