Differences in the relationship between social capital and hypertension in emerging vs. established economies in Sub-Saharan Africa

BACKGROUND: The global burden of hypertension is growing, particularly in low- and middle-income countries. This study aimed to investigate differences in the relationship between social capital and hypertension between regions in Sub-Saharan Africa (West vs. South Africa) and within regions (rural vs. urban residence within each country). METHODS: Data for 9,800 adults were analyzed from the Study on Global Ageing and Adult Health (SAGE) 2007-2010 for Ghana (West African emerging economy) and South Africa (South African established economy). Outcomes were self-reported and measured hypertension. The primary independent variable was social capital, dichotomized into low vs. medium/high. Interaction terms were tested between social capital and rural/urban residence status for each outcome by country. Linear and logistic regression models were run separately for both countries and each outcome. RESULTS: Those with low social capital in the emerging economy of Ghana were more likely to have hypertension based on measurement (OR=1.35, 95% CI=1.18,1.55), but the relationship with self-reported hypertension lost significance after adjustment. There was no significant relationship in the relationship between social capital and hypertension in the established economy of South Africa after adjustment. No significant interactions existed by rural/urban residence status in either country. CONCLUSION: Low social capital was associated with worse hypertension outcomes, however, the relationship differed between South Africa and Ghana. Further investigation is needed to understand differences between and within countries to guide development of programs targeted at leveraging and promoting social capital as a positive component of overall health.