Burnier 2004 ). Interestingly, as women transition through menopause, their RAAS
becomes more active in sodium andfluid volume regulation, their blood pressure
becomes more sensitive to dietary sodium, and they also become more susceptible
to and experience more cardiovascular pathology (Pechere-Bertschi and Burnier
2004 ).
Blood Pressure Adaptability Through Adult Life Stages
As people age, the qualitative nature of the environments they have to adapt to
changes. For example, people may begin their adult lives living single, but then
they may marry and have children. The question arises as to how blood pressure
adapts to this type of role change over the lifespan. Is it possible to see differences
in circadian patterns of blood pressure variation based upon the changes or dif-
ferences in family structure and sociological role? We conducted studies to examine
this question in pre-menopausal women, aged 18–50 who were employed outside
the home. All the women studied were employed in the same occupations (secre-
taries and technicians) at the same work place (a hospital in New York City).
Figure8.7illustrates the difference in the circadian variation of systolic pressure
between pre-menopausal women who were single and childless and those who were
married with children (from Pickering et al. 1990 ). Thisfigure graphically illus-
trates the effect of having a family on the circadian adaptive responses of blood
pressure. The single women had their higher waking pressures at work while the
lowest were at home, with an additional increase during their commute from work
to home (around 6 p.m.). Conversely, the married women with children actually
had slightly lower pressures at work than at home and had a commuting peak an
hour earlier as they left work earlier (5 p.m.). From the perspective of a comparison
of circadian blood pressure patterns, there was a crossover in the level of pressure
that occurred as the women began their evenings at home (around 7 p.m.). Thus, the
single women had higher pressures than married women with children while they
were on the job, but the married women with children had higher pressures than the
single women at home in the evening. This difference is likely related to differences
in how the women perceived their sociological role (as worker, mother, or both)
(Schlussel et al. 1992 ; James et al. 1996 ). The data, however, also suggest that as
single womenfirst enter the workforce and then get married and have children, their
circadian blood pressure pattern changes with their sociological roles (a single
worker to a working mother assuming they stay in the workforce). What impact this
pattern change might have on long-term cardiovascular health is unknown.
In a second study, we examined the work–home difference in blood pressure in
20 age- and occupation-matched (all clerks) pre-menopausal women and men (total
of 40 subjects) who either had or did not have children (see Fig.8.8) (Schlussel
et al. 1992 ; Pickering et al. 1995 ; James et al. 1996 ). The results of this study
showed that the pattern among men with children was exactly opposite of that of
women with children. Specifically, the men’s systolic pressure at work increased
160 G.D. James