Culture, skin color, and arterial blood pressure in Brazil

Populations of African descent in North and South America have higher mean blood pressures and higher rates of hypertension than populations of Europe an descent or populations in A ti ica. Within populations of African descen t, darker skinned persons have higher blood pressures than lighter skinned persons. Whether examined within or between populations, there is an intera ction between skin color and socioeconomic status (SES) in relation to bloo d pressure, with persons with dark skin color and low SES having the highes t blood pressures. This interaction was examined in Brazil using a measure of a cultural dimension of SES called "cultural consonance in lifestyle." T his measure was derived using cultural consensus analysis linked with socia l survey data. It was found that darker skinned Brazilians with lower cultu ral consonance in lifestyle had adjusted systolic blood pressures 16.2 mm H g higher than darker skinned Brazilians with higher cultural consonance (P < .01); the corresponding difference in adjusted diastolic blood pressure w as 9.7 mm Hg (P < .04). The differences for lighter skinned Brazilians were 6.4 mm Hg (P < .02) and 1.0 mm Hg (not significant), respectively. These r esults could be due either to an interaction of genetic predisposition and SES, or the result of a socially and culturally-mediated process. Given tha t cultural consonance in lifestyle measures the ability of the person to li ve up to cultural norms, and given the existence of racial stratification i n Brazil, it is argued that a social and cultural mediation of the relation ship is more plausible. (C) 1999 Wiley-Liss, Inc.