Blood pressure changes over 20 years in nuns in a secluded order

Blood pressure was recorded for 20 years in 138 nuns in a secluded order and in 126 lay women taken as controls. During the study period none of the nuns or control women smoked, took oral contraceptives or changed residence. Diet was unrestricted and comparable in the two groups. Subjects of both groups were consecutively enrolled without any selection parameters. During the 20 years of observation, systolic and diastolic blood pressure rose with age in the control women but remained almost unchanged in the nuns. The mean of the regression slope of systolic and diastolic blood pressure versus age, which was calculated for each subject, was 0.089 and 0.054 respectively in the nuns, as opposed to 2.171 and 0.742 in the lay women (both P < 0.001). Secluded nuns, who spend almost all their time in silence and prayer in the virtual absence of company apart from when attending religious celebrations, thus showed almost no change in blood pressure with age over a 20-year period. The results support the hypothesis that, at least in women, everyday stress may be a determinant of the progressive increase in blood pressure with ageing.