The Effects of Hormone Replacement Therapy on Blood Pressure in Postmenopausal Women FREE

High blood pressure (hypertension) puts people at risk for such complications as heart attacks and strokes. High blood pressure becomes more common as people age; after menopause, it becomes even more common in women than it does in men of the same age. One theory is that the increase in blood pressure in women after menopause is related to the decrease in levels of estrogen and other hormones that occur during that phase of life. It is not known, however, whether treating women with estrogen and progestin (hormone replacement therapy, or HRT) is associated with changes in blood pressure after menopause.

To find out whether blood pressure increased less over time in postmenopausal women who took HRT than in women who did not take HRT.

The researchers studied 226 women who were already participating in a study called the Baltimore Longitudinal Study of Aging. Seventy-seven women took both estrogen and progestin, and 149 used neither hormone. None of the women had high blood pressure at the start of the study.

At the beginning of the study and then every 2 years, the researchers collected information about the women's blood pressure and factors known to be associated with changes in blood pressure, including exercise, smoking, cholesterol levels, alcohol use, and body size. The study followed women for an average of 5 to 6 years (a minimum of 2 years and a maximum of 18.5 years).

At the start of the study, blood pressure was similar in women who did and those who did not take HRT. Average systolic blood pressure (the first, and higher, number in blood pressure readings) increased less rapidly in women taking HRT than in women who did not take HRT. These differences were found even when the other factors that affect blood pressure were taken into account. Diastolic blood pressure (the second, lower number in blood pressure readings) did not change significantly in either group of women.

Women who take hormones tend to be generally healthier and more health conscious than those who choose not to take hormones. It is possible that some of the benefits in blood pressure in the women taking HRT were related to health factors, other than hormone use, that the researchers could not measure.

Postmenopausal women who take HRT have less of an increase in systolic blood pressure over time than those who do not take HRT.