Race and perceived stress independently affect the diurnal variation of blood pressure in women.

The purpose of this study was to determine whether race (black v white) and perceived stress were independent factors affecting the diurnal blood pressure variation of normal women. The 110 women studied (age = 29.7 +/- 7.2 years, range 20 to 50) were all employed in technical and clerical occupations from the same worksite. They were divided into four groups based on race and how they perceived work stress on the day of study. The results showed that there were no daytime differences in blood pressure levels in blacks or whites, but women who perceived greater stress at work on the day of study had higher pressures during work (123/78 v 115/74; p less than .01). Blacks, however, had higher pressures during sleep than whites, independent of the perception of work stress (109/65 v 104/60; P less than .01). These results suggest that the smaller drop in pressure during sleep in blacks is not related to perceived work stress, but that the effects of perceived stress on daytime pressures is independent of race.