ObjectiveThe levels of health enjoyed by individuals vary according to socio-economic status, and inflammation has been proposed as one pathway through which socio-economic status influences health in high-income countries. However, little is known regarding the social determinants of inflammation in low- and middle-income countries. This study investigated the association between socio-economic status and C-reactive protein (CRP) in England and Indonesia.MethodsThis study used data from 4923 respondents aged 50+ in the English Longitudinal Study of Ageing and from 1812 respondents from the Indonesian Family Life Survey at baseline. The sources of information on individuals’ education attainment, wealth, CRP and other covariates were ELSA Waves 2, 4 and 6, and IFLS Waves 4 and 5. Linear mixed models were performed to identify the longitudinal relationships between socio-economic status and CRP, and joint models were used to deal with bias in longitudinal ageing surveys due to attrition.ResultsRespondents with high school education (β = −0.036, p < 0.01) or college degree or higher (β = −0.127, p < 0.01) in England had lower CRP levels. Being wealthy is correlated with lower CRP levels in England (middle: β = −0.073, p < 0.01; wealthiest: β = −0.133, p < 0.01). Being wealthy and having higher education were related with higher level of CRP in Indonesia. However, those significant relationships vanished when health behaviour and health status were included in the analysis.ConclusionsThe relationships between socio-economic status and CRP proved to be different in England and Indonesia. Encouraging healthy lifestyles among older adults with low socio-economic status may be the main focus of efforts toward healthy ageing in England and other developed countries. However, in Indonesia and other developing countries, attention is also required to older adults in wealthier socio-economic groups.
- C-reactive proteinHealth inequalitiesDeveloping countryLongitudinal analysis