Examining the relationships between socio-economic status and hypertension: an application of structural equation modelling

Abstract

Over the years, epidemiological research has seen differing levels of the prevalence of hypertension across socio-economic strata. However in Sub-Saharan Africa, the patterns of association and underlying risk factors have often been poorly understood. In this study, we examined the extent to which socio-economic factors affect systolic and diastolic blood pressure across gender. Furthermore we explored whether certain risk factors associated with hypertension mediate this relationship. We used data from the third phase of the National Income Dynamic Study conducted in South Africa in 2012 on more than 18,000 adult individuals. Structural equation modelling and multiple linear regression were used to estimate the relationship between blood pressure and various behavioural, demographic and socio-economic variables. These results were then compared to determine which technique provides more meaningful results. A higher socio-economic status was associated with a higher systolic and diastolic blood pressure in both males and females. Furthermore, body mass index was a mediator of the indirect effect of socio-economic status on blood pressure. Smoker status, alcohol consumption, physical exercise, emotional well-being and resting heart rate were also mediators; however their role was modest in comparison to BMI. One of the findings of this study is that a reduction in the BMI of an individual will have an impact on lowering hypertension. Furthermore, the promotion of healthy behaviours that target higher income groups need to be established so that these groups can make rational decisions in choosing their behaviours.