Personality, Socio-Economic Status and Inflammation: Cross-Sectional, Population-Based Study

Keith Millar,Agnes Mcginty,Paul G Shiels,Suzanne M Lloyd,G David Batty,Alex Mcconnachie,Jonathan Cavanagh,Yoga N Velupillai,Kevin A Deans,Naveed Sattar,Harry Burns,Ian Ford,Jennifer S Mclean,Carol Tannahill,Réne Mõttus,Chris J Packard

doi:10.1371/journal.pone.0058256

Abstract

BackgroundAssociations between socio-economic status (SES), personality and inflammation were examined to determine whether low SES subjects scoring high on neuroticism or hostility might suffer relatively higher levels of inflammation than affluent subjects.MethodsIn a cross-sectional design, 666 subjects were recruited from areas of high (most deprived – “MD”) and low (least deprived – “LD”) deprivation. IL-6, ICAM-1, CRP and fibrinogen were measured along with demographic and health-behaviour variables, and personality traits of neuroticism, extraversion and psychoticism (hostility). Regression models assessed the prediction of inflammation as a function of personality, deprivation and their interaction.ResultsLevels of CRP and IL-6 were an increasing function of neuroticism and extraversion only in LD subjects opposite trends were seen in MD subjects. The result was ascribed parsimoniously to an inflammatory ceiling effect or, more speculatively, to SES-related health-behaviour differences. Psychoticism was strongly associated with ICAM-1 in both MD and LD subjects.ConclusionsThe association between neuroticism, CRP and IL-6 may be reduced in MD subjects confirming speculation that the association differs across population sub-groups. The association between psychoticism and ICAM-1 supports evidence that hostility has adverse effects upon the endothelium, with consequences for cardiovascular health. Health interventions may be more effective by accounting for personality-related effects upon biological processes.

Highlights

Individuals who display certain personality characteristics are more likely to indulge in harmful health behaviours [1,2,3,4,5,6,7,8] and to have increased risk of morbidity and mortality [7,9,10,11]
We have previously extended such findings to examine the association between personality, mental well-being and health behaviours as a function of socio-economic status (SES) [12]
One of our groups [17] has confirmed the negative relationship between C and C-reactive protein (CRP), and that the association was mediated by body mass index (BMI) but not by common health behaviours of smoking, physical activity and alcohol consumption

Summary

Introduction

Individuals who display certain personality characteristics are more likely to indulge in harmful health behaviours [1,2,3,4,5,6,7,8] and to have increased risk of morbidity and mortality [7,9,10,11]. Higher levels of inflammation are often consequences of harmful health behaviours such as smoking, poor diet and lack of exercise, and it is significant that the latter behaviours are characteristic of high N, low C and psychoticism (P) [1,2,3,4,5,6,8]. The fact that the relationship between high N and mortality has been shown in one study to be independent of smoking and exercise [16] might imply the role of factors other than health behaviours. Associations between socio-economic status (SES), personality and inflammation were examined to determine whether low SES subjects scoring high on neuroticism or hostility might suffer relatively higher levels of inflammation than affluent subjects

Methods

Results

Discussion

Conclusion