Blood pressure and interpersonal discrimination: systematic review of epidemiologic studies

The relationship between blood pressure and discrimination has been recently investigated, and there are conflicting debates in literature devoted to the topic. The objective of this study was to update previous literature reviews on discrimination and blood pressure. A bibliographic search was conducted in PubMed between January/2000 and December/2010, including epidemiological studies, assessing the relationship between interpersonal discrimination and blood pressure/hypertension. The 22 studies included originated from the United States; 96% of them used the cross-sectional design with convenience sample, comprising, in 59% of the studies, exclusively Black participants. The Everyday Discrimination Scale and the Perceived Racism Scale were the most frequently used instruments, emphasizing lifetime or chronic/everyday racial/ethnic discrimination. In the 22 studies assessed, the association between discrimination and blood pressure/hypertension was assessed 50 times. Twenty results (40%) showed no association between them, and only 15 (30%) revealed global positive associations, of which 67% were statistically significant. Eight negative associations were also observed, suggesting that higher exposure to discrimination would be associated with lower blood pressure/hypertension. The studies did not consistently support the hypothesis that discrimination is associated with higher blood pressure. These findings can be partially attributed to the limitations of the studies, especially those related to the measurement of discrimination and of factors that might modify its association with outcomes. To establish discrimination as an epidemiological risk factor, more rigorous methodological strategies should be used, and the theoretical frameworks that postulate causal relationships between discrimination and blood pressure should be reviewed.