Sex differences in factors affecting the daily variation of blood pressure

The purpose of this study was to examine whether the life experiences described by postural, situational, and emotional changes during the day have similar effects on the blood pressure of men and women. The subjects of the study were 137 men and 67 women from the clinical population of the Hypertension Center at The New York Hospital-Cornell Medical Center. There were 3023 individual pressure measurements available for study, 2072 from the men, and 951 from the women, which were taken using noninvasive ambulatory blood pressure monitoring techniques. Pressures were transformed to z-scores using the subject's daily mean pressure and standard deviation to assess the relative elevation during the various effects. Separate but identical ANOVA models were run for each sex. The results show that there were differences between men and women in the parameters associated with the level of systolic and diastolic pressure. Men's systolic pressure varied by situation of measurement (P <0.0001) and emotional state (P <0.0001), while that of women varied by posture (P <0.0005) and situation of measurement (P <0.0001). The diastolic pressure of men varied by emotional state as did that of women, except that men's diastolic pressure tended to be highest during reported anger while that of women tended to be highest during reported anxiety. Differences in occupation or environment, hormones, or in behavioral patterns related to the socialization process may all contribute to the differences between the sexes. While there are limitations with regard to the interpretation of the data, the findings are consistent with the concept that both the factors which influence blood pressure variation and the degree of variation associated with these factors are different between the sexes.