Skin color, ethnicity, and blood pressure. II. Detroit whites

Census areas in Detroit were ranked for their stress scores based on instability (e.g., crime, marital break up) and socioeconomic status. Four areas were selected for detailed study: 1) high stress, population predominantly black and 2) white, and 3) low stress, population predominantly black and white. A sample was drawn from each of persons of the predominant race, 25-60 years old, married and living with spouse, and having relatives in the Detroit Area. Nurses interviewed such persons; three blood pressure readings were taken during the first half-hour of medical history, and skin color was rated. While lighter skin color showed a negligible relation to higher blood pressure, a four-category division of European national background based on a skin color cline in Europe from Northern areas to the Mediterranean was significantly associated with a nurse-rating of skin color. The rank order of this four category variable, white ethnicity, was related linearly to both systolic and diastolic blood pressure means. Respondents with parents from Mediterranean countries had the lowest pressures and those from Northern Europe had the highest. The relationship is stronger for women than men. The relationship was independent of nine other control variables including age, overweight, smoking, etc., and high and low stress areas, although of greater magnitude for the high than low stress groups. In this article, findings in whites are compared with prior results in blacks. Findings suggest that physiological and biological correlates exist that can be explored profitably by future research.