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 European descent or populations in Africa. Within populations of African descent, darker skinned persons have higher blood pressures than lighter skinned persons. Whether examined within or between populations, there is an interaction between skin color and socioeconomic status (SES) in relation to blood pressure, with persons with dark skin color and low SES having the highest blood pressures. This interaction was examined in Brazil using a measure of a cultural dimension of SES called "cultural consonance in lifestyle." This measure was derived using cultural consensus analysis linked with social survey data. It was found that darker skinned Brazilians with lower cultural consonance in lifestyle had adjusted systolic blood pressures 16.2 mm Hg higher than darker skinned Brazilians with higher cultural consonance (P <.01); the corresponding difference in adjusted diastolic blood pressure was 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 results could be due either to an interaction of genetic predisposition and SES, or the result of a socially and culturally-mediated process. Given that cultural consonance in lifestyle measures the ability of the person to live up to cultural norms, and given the existence of racial stratification in Brazil, it is argued that a social and cultural mediation of the relationship is more plausible. Am. J. Hum. Biol. 11:49-59, 1999. Copyright 1999 Wiley-Liss, Inc.